WO2010091244A2 - Method and apparatus for determining a corrected monitoring voltage - Google Patents
Method and apparatus for determining a corrected monitoring voltage Download PDFInfo
- Publication number
- WO2010091244A2 WO2010091244A2 PCT/US2010/023307 US2010023307W WO2010091244A2 WO 2010091244 A2 WO2010091244 A2 WO 2010091244A2 US 2010023307 W US2010023307 W US 2010023307W WO 2010091244 A2 WO2010091244 A2 WO 2010091244A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- voltage
- power
- correction coefficient
- measurement
- determining
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/22—The renewable source being solar energy
- H02J2300/24—The renewable source being solar energy of photovoltaic origin
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/28—The renewable source being wind energy
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/76—Power conversion electric or electronic aspects
Definitions
- Embodiments of the present disclosure generally relate to power systems and, more particularly, to a method and apparatus for determining a corrected monitoring voltage.
- PV photovoltaic
- AC alternating current
- DG distributed generation
- a DG coupled to a commercial power grid must be operated in accordance with relevant regulatory requirements, such as IEEE-1547.
- IEEE-1547 relevant regulatory requirements
- an inverter within a DG must be deactivated under certain circumstances, including line frequency or line voltage operating outside of pre-defined limits.
- the IEEE- 1547 standard specifies that such voltage requirements must be met at a Point of Common Coupling (PCC) between the commercial power system and the DG (i.e., a point of demarcation between the public utility service and the DG).
- PCC Point of Common Coupling
- an output voltage measured at the inverter may be higher than a voltage measured at the PCC due a voltage drop along the line from the inverter to the PCC.
- the measured voltage at the inverter may exceed the required voltage range although the voltage at the PCC remains within the required range, resulting in the inverter unnecessarily shutting down and thereby reducing energy production.
- the inverter once again activates and begins producing power, resulting in a continued oscillation that negatively impacts power production.
- Embodiments of the present invention generally relate to a method and apparatus for determining a corrected monitoring voltage, at least a portion of the method being performed by a computing system comprising at least one processor.
- the method comprises generating power at a first location; monitoring the generated power by measuring a first voltage proximate the first location; measuring a second voltage proximate a second location, the first and the second locations electrically coupled; and determining, based on the measured second voltage, a corrected monitoring voltage to compensate the measured first voltage for a distance between the first and the second locations.
- FIG. 1 is a block diagram of a system for distributed generation (DG) in accordance with one or more embodiments of the present invention
- FIG. 2 is a block diagram of a control module in accordance with one or more embodiments of the present invention.
- Figure 3 is a block diagram of an inverter in accordance with one or more embodiments of the present invention.
- Figure 4 is a flow diagram of a method for determining a corrected monitoring voltage in accordance with one or more embodiments of the present invention.
- FIG. 1 is a block diagram of a system 100 for distributed generation (DG) in accordance with one or more embodiments of the present invention. This diagram only portrays one variation of the myriad of possible system configurations. The present invention can function in a variety of distributed power generation environments and systems.
- DG distributed generation
- the system 100 comprises a plurality of inverters 102i, 102 2 . . . 102 n , collectively referred to as inverters 102, a plurality of PV modules 104i, 104 2 . . . 104 n , collectively referred to as PV modules 104, an AC bus 106, and a load center 108.
- Each inverter 1 O2 15 102 2 . . . 102 n is coupled to a PV module 104-,, 104 2 . . . 104 n , respectively.
- a DC-DC converter may be coupled between each PV module 104 and each inverter 102 (e.g., one converter per PV module 104).
- multiple PV modules 104 may be coupled to a single inverter 102 (i.e., a centralized inverter); in some such embodiments, a DC-DC converter may be coupled between the PV modules 104 and the centralized inverter.
- the inverters 102 are coupled to the AC bus 106, which in turn is coupled to the load center 108.
- the load center 108 houses connections between incoming power lines from a commercial power grid distribution system and the AC bus 106, and represents a Point of Common Coupling (PCC) between the system 100 and the commercial power grid.
- PCC Point of Common Coupling
- the inverters 102 convert DC power generated by the PV modules 104 into AC power, and meter out AC current that is in-phase with the AC commercial power grid voltage.
- the system 100 couples the generated AC power to the commercial power grid via the load center 108.
- the generated power may be coupled to appliances, and/or energy generated may be stored for later use; for example, the generated energy may be stored utilizing batteries, heated water, hydro pumping, H 2 0-to-hydrogen conversion, or the like.
- the system 100 may comprise other types of renewable energy generators in addition to or in place of the inverters 102, such as wind turbines, hydroelectric systems, or the like.
- the system 100 further comprises a control module 1 10 coupled to the AC bus 106.
- the control module 1 10 is capable of issuing command and control signals to the inverters 102 in order to control the functionality of the inverters 102.
- each of the inverters 102 applies voltage compensation to locally measured voltages (i.e., voltages measured at the inverter 102) when determining a monitored voltage for comparison to relevant voltage regulatory requirements.
- voltage compensation corrects for a voltage drop that occurs along the AC bus 106 between the inverters 102 and the PCC and allows the inverters 102 to determine monitoring voltage levels with respect to the PCC (i.e., corrected monitoring voltage levels) for ensuring compliance with the relevant voltage regulatory requirements.
- the corresponding inverter 102 may be deactivated or, alternatively, AC voltage regulation may be performed.
- the control module 1 10 may receive one or more voltage samples (i.e., measurements) indicating a voltage proximate (i.e., at or near) the PCC. The control module 1 10 may then broadcast these PCC voltage samples V pec to one or more inverters 102 for determining the corresponding corrected monitoring voltage as described further below.
- the PCC voltage samples V pcc may be obtained by a measurement unit 1 12 deployed at or near the load center 108; in some embodiments, the measurement unit 1 12 and the control module 1 10 may be a single integrated unit.
- the measurement unit 1 12 may sample the voltage proximate the PCC, for example, utilizing an analog to digital (A/D) converter, and communicate the PCC voltage samples V pcc to the control module 1 10 for broadcast to the inverters 102.
- the measurement unit 1 12 may convert the voltage samples to a root mean square (RMS) value prior to transmission to the controller 1 10; alternatively, the controller 1 10 or the inverters 102 may perform such conversion.
- RMS root mean square
- One example of such a measurement unit may be found in commonly assigned U.S.
- the measurement unit 1 12 may communicate the PCC voltage samples V pcc to the control module 1 10 utilizing power line communication (PLC), and the control module 1 10 may then broadcast the PCC voltage samples V pcc to the inverters 102 utilizing PLC; alternatively, other wired and/or wireless communication techniques may be utilized.
- the PCC voltage samples V pcc may be obtained by the measurement unit 1 12 and communicated directly (i.e., without the use of the controller 1 10) to one or more inverters 102 utilizing any of the communications techniques previously mentioned.
- control module 1 10 may determine the corrected monitoring voltage for one of more of the inverters 102, determine whether each corrected monitoring voltage is within required limits, and/or initiate deactivation of one or more inverters 102 for which the corrected monitoring voltage levels exceed required limits.
- FIG. 2 is a block diagram of a control module 1 10 in accordance with one or more embodiments of the present invention.
- the control module 1 10 comprises a communications transceiver 202 coupled to at least one central processing unit (CPU) 204.
- the CPU 204 is additionally coupled to support circuits 206, and a memory 208.
- the CPU 204 may comprise one or more conventionally available microprocessors.
- the CPU 204 may include one or more application specific integrated circuits (ASIC).
- ASIC application specific integrated circuits
- the support circuits 206 are well known circuits used to promote functionality of the central processing unit. Such circuits include, but are not limited to, a cache, power supplies, clock circuits, buses, network cards, input/output (I/O) circuits, and the like.
- the memory 208 may comprise random access memory, read only memory, removable disk memory, flash memory, and various combinations of these types of memory.
- the memory 208 is sometimes referred to as main memory and may, in part, be used as cache memory or buffer memory.
- the memory 208 generally stores the operating system 214 of the control module 1 10.
- the operating system 214 may be one of a number of commercially available operating systems such as, but not limited to, SOLARIS from SUN Microsystems, Inc., AIX from IBM Inc., HP-UX from Hewlett Packard Corporation, LINUX from Red Hat Software, Windows 2000 from Microsoft Corporation, and the like.
- the memory 208 may store various forms of application software, such as inverter control software 210 for operably controlling the inverters 102.
- the communications transceiver 202 communicably couples the control module 1 10 to the inverters 102 to facilitate command and control of the inverters 102.
- the communications transceiver 202 may utilize wireless or wired communication techniques for such communication.
- FIG. 3 is a block diagram of an inverter 102 in accordance with one or more embodiments of the present invention.
- the inverter 102 comprises a power conversion module 302, a conversion control module 304, a voltage monitoring module 306, an AC current sampler 308, and an AC voltage sampler 310.
- the power conversion module 302 is coupled to the PV module 104 and acts to convert DC current from the PV module 104 to AC output current.
- the conversion control module 304 is coupled to the AC voltage sampler 310 for receiving an AC voltage reference signal from the commercial power grid, and to the power conversion module 302 for providing operative control and driving the power conversion module 302 to inject the generated AC output current in phase with the grid as required by the relevant standards.
- the voltage monitoring module 306 is coupled to the conversion control module 304, the AC current sampler 308, and the AC voltage sampler 310.
- the AC current sampler 308 is coupled to an output terminal of the power conversion module 302, and the AC voltage sampler 310 is coupled across both output terminals of the power conversion module 302.
- the AC current sampler 308 and the AC voltage sampler 310 obtain samples (i.e., measurements) of the AC inverter current and AC inverter voltage, respectively, at the output of the power conversion module 302 and provide such inverter output current and voltage samples to the voltage monitoring module 306.
- the AC current sampler 308 and the AC voltage sampler 310 may each comprise an A/D converter for obtaining the inverter output current and voltage samples, respectively.
- the inverter output current may be estimated based on DC input voltage and current to the inverter 102 and the AC voltage output from the inverter 102.
- the voltage monitoring module 306 may be comprised of hardware, software, or a combination thereof, and comprises at least one CPU 314 coupled to support circuits 316, memory 318, and a communications transceiver 324.
- the communications transceiver 324 is further coupled to at least one of the output lines from the power conversion module 302 for communicating via PLC, for example, with the control module 1 10 and/or the measurement unit 1 12.
- the communications transceiver 324 may utilize wireless and/or other wired communications techniques for such communication.
- the CPU 314 may comprise one or more conventionally available microprocessors. Alternatively, the CPU 314 may include one or more application specific integrated circuits (ASIC).
- the support circuits 316 are well known circuits used to promote functionality of the central processing unit. Such circuits include, but are not limited to, a cache, power supplies, clock circuits, buses, network cards, input/output (I/O) circuits, and the like.
- the memory 318 may comprise random access memory, read only memory, removable disk memory, flash memory, and various combinations of these types of memory.
- the memory 318 is sometimes referred to as main memory and may, in part, be used as cache memory or buffer memory.
- the memory 318 generally stores the operating system (OS) 320 of the voltage monitoring module 306.
- the OS 320 may be one of a number of commercially available OSs such as, but not limited to, Linux, Real-Time Operating System (RTOS), and the like.
- the memory 318 may store various forms of application software, such as voltage monitoring module (VMM) software 322 for determining a corrected monitoring voltage corresponding to the inverter 102.
- VMM voltage monitoring module
- the voltage monitoring module 306 determines a correction coefficient K v based on an inverter output voltage sample (i.e., a measurement of the inverter output voltage) received from the AC voltage sampler 310, and a PCC voltage sample that indicates a measurement of a voltage proximate the PCC.
- the PCC voltage sample is an RMS value obtained by the measurement unit 1 12 and communicated from the control module 1 10 as previously described.
- the voltage monitoring module 306 determines the correction coefficient, K v , as follows:
- K v V pcc / V me as 0) [0034] where V pcc is the PCC voltage sample and V m ⁇ as is the inverter output voltage sample.
- the voltage monitoring module 306 computes an output power of the inverter, P m ⁇ a s-
- the voltage monitoring module 306 utilizes the inverter output voltage sample V meas and an inverter output current sample received from the AC current sampler 308, as well as phase angle, to determine the output power of the inverter, P mea s-
- the voltage monitoring module 306 may calculate P m eas based on DC voltage and DC current pertaining to the inverter 102 (for example, DC voltage and DC current samples obtained by the conversion control module 304) and a conversion efficiency of the inverter 102.
- the voltage monitoring module 306 utilizes K v for computing the corrected monitoring voltage V ⁇ rr upon obtaining inverter output current and voltage samples linv and Vinv, respectively (e.g., inverter output current and voltage samples obtained subsequent to the samples utilized to compute K v ).
- the voltage monitoring module 306 determines the corrected monitoring voltage V COrr as follows:
- V corr V, nv * (1-(( P, nv * (1- K v ))/P meas )) (H)
- K v is the correction coefficient
- V mv and P, nv are the inverter output voltage and power, respectively
- P m eas is the inverter output power determined at the time K v was computed.
- P, nv is computed based on inverter output current and voltage samples obtained by the AC current sampler 308 and the AC voltage sampler 310, respectively.
- the voltage monitoring module 306 periodically computes V corr based on one or more of an updated inverter output power measurement P ⁇ nv , an updated inverter output voltage measurement V, nv , or an updated K v (e.g., K v may be updated upon receiving a new valid V P cc measurement message).
- Vco rr as well as all corresponding voltage, current, power, and control parameters are determined at least once every line cycle (e.g., every 16.6667 milliseconds). If a new valid Vpcc measurement message is not received within an aging time window, K v is reset to "1 " until a valid V pcc message is received.
- a linear aging function may be utilized; alternatively, a nonlinear aging function, or a combination of a linear and a nonlinear aging functions may be utilized.
- K v is reset to "1 " until a new valid V pcc measurement message is received and a new K v determined.
- the valid output power range may be some percentage of the rated total inverter power, for example, within the range of 5% to 20% of the inverter power rating.
- K v may be reset to "1 " in the event that the inverter output power P, nv exceeds a maximum power deviation.
- the corrected monitoring voltage V ⁇ rr provides a more accurate estimate of the voltage at the PCC than the inverter output voltage alone for determining compliance with regulatory requirements pertaining to voltage levels at the PCC.
- the voltage monitoring module 306 determines whether the corrected monitoring voltage V corr is within a required voltage range with respect to the regulatory requirements; in the event the corrected monitoring voltage V ⁇ rr exceeds the required voltage range, the voltage monitoring module 306 provides a deactivation signal to the conversion control module 304 to deactivate the power conversion module 302 or, alternatively, AC voltage regulation may be performed.
- one or more of determining the corrected monitoring voltage V corr , determining compliance with regulatory requirements, and/or deactivation of one or more inverters as a result of one or more corrected monitoring voltage levels exceeding a required voltage range may be performed by the control module 1 10.
- FIG. 4 is a flow diagram of a method 400 for determining a corrected monitoring voltage in accordance with one or more embodiments of the present invention.
- AC current from a DG system comprising at least one DC-AC inverter is coupled to a commercial power grid at a PCC.
- each inverter of the DG system may utilize the method 400.
- a controller for the DG system may utilize the method 400 for determining one or more corrected monitoring voltages and/or driving the corresponding inverters accordingly.
- the method 400 begins at step 402 and proceeds to step 404.
- a correction coefficient K v of an inverter has an initial value of "1 ".
- the method 400 proceeds to step 406, where a voltage sample (i.e., measurement) indicating a voltage proximate the PCC ⁇ "V pcc "), is obtained.
- the PCC voltage sample V pcc may be received by the inverter as part of a validated message transmitted to the inverter; for example, the message may be broadcasted from a control module coupled to the DG system and validated utilizing conventional communication techniques, such as addressing and checksums (e.g., cyclic redundancy check, or CRC).
- a data logger e.g., the measurement unit 1 12 previously described
- the data logger may sample (i.e., measure) the voltage proximate the PCC, convert the voltage sample to an RMS value, and communicate the resulting PCC voltage sample V pcc to the controller for broadcast to the one or more inverters of the DG system.
- the PCC voltage sample V pcc may be converted to an RMS value at the controller or the inverter.
- the data logger may directly communicate the PCC voltage sample V pcc to the inverters utilizing wireless and/or wired communications techniques.
- step 407 a voltage sample of an AC output voltage of the inverter (V meas ) is obtained, for example, by an AC voltage sampler of the inverter.
- step 408 a new K v is determined as follows:
- an output power of the inverter ⁇ Pmeas is determined based on V meas and a sample of the AC output current from the inverter obtained, for example, by an AC current sampler of the inverter.
- inverter output current and voltage samples are obtained ⁇ V m and I m v, respectively) and utilized to determine the inverter output power (P, nv ).
- a corrected monitoring voltage is determined as follows:
- V corr V, nv * (1-(( P, nv * (1- K v ))/P meas )) (iv)
- the inverter may compare the corrected monitoring voltage to the regulatory limits to make the determination; alternatively, the corrected monitoring voltage may be communicated, for example to the controller or the measurement unit, for determining compliance with the regulatory limits. If the result of such determination is no, the method 400 proceeds to step 422, where the inverter is deactivated; alternatively, AC voltage regulation may be performed. In some embodiments where the inverter is deactivated, upon determining that the corrected monitoring voltage exceeds required limits, the inverter may cease power production; alternatively, the inverter may receive a control signal from the controller or the measurement unit causing the inverter to cease power product. The method 400 then proceeds to step 424 where it ends. If the result of the determination at step 414 is yes, the method 400 proceeds to step 416.
- V pcc may be determined and communicated to the inverter at least once every line cycle (e.g., every 16.6667 milliseconds). If a new valid V pcc measurement message has been received, the method 400 returns to step 407. If a new valid V pcc measurement has not been received, the method 400 proceeds to step 418. At step 418, a determination is made whether an aging time window for K v has been exceeded.
- a linear aging function may be applied to K v such that K v reaches a value of 1 at the end of the aging time window; alternatively, a nonlinear aging function, or a combination of linear and nonlinear aging functions, may be utilized. If the aging time window has been exceeded, the method 400 returns to step 404. If the aging time window has not been exceeded, the method 400 proceeds to step 419.
- inverter output current and voltage samples (V ⁇ nv and l ⁇ nv , respectively) are obtained and utilized to determine a new inverter output power P, nv .
- the valid output power range may be some percentage of the rated total inverter power, for example, within the range of 5% to 20% of the inverter power rating. If the inverter output power P, nv is within the valid output power range, the method 400 returns to step 412. If the inverter output power exceeds the output power range, K v is reset to 1 and the method 400 returns to step 404.
Abstract
A method and apparatus for determining a corrected monitoring voltage, at least a portion of the method being performed by a computing system comprising at least one processor. The method comprises generating power at a first location; monitoring the generated power by measuring a first voltage proximate the first location; measuring a second voltage proximate a second location, the first and the second locations electrically coupled; and determining, based on the measured second voltage, a corrected monitoring voltage to compensate the measured first voltage for a distance between the first and the second locations.
Description
METHOD AND APPARATUS FOR DETERMINING A CORRECTED MONITORING
VOLTAGE
BACKGROUND OF THE INVENTION Field of the Invention
[0001] Embodiments of the present disclosure generally relate to power systems and, more particularly, to a method and apparatus for determining a corrected monitoring voltage.
Description of the Related Art
[0002] Solar panels have historically been deployed in mostly remote applications, such as remote cabins in the wilderness or satellites, where commercial power was not available. Due to the high cost of installation, solar panels were not an economical choice for generating power unless no other power options were available. However, the worldwide growth of energy demand is leading to a durable increase in energy cost. In addition, it is now well established that the fossil energy reserves currently being used to generate electricity are rapidly being depleted. These growing impediments to conventional commercial power generation make solar panels a more attractive option to pursue.
[0003] Solar panels, or photovoltaic (PV) modules, convert energy from sunlight received into direct current (DC). The PV modules cannot store the electrical energy they produce, so the energy must either be dispersed to an energy storage system, such as a battery or pumped hydroelecthcity storage, or dispersed by a load. One option to use the energy produced is to employ one or more inverters to convert the DC current into an alternating current (AC) and couple the AC current to the commercial power grid. The power produced by such a distributed generation (DG) system can then be sold to the commercial power company.
[0004] In order to mitigate potential safety hazards, a DG coupled to a commercial power grid must be operated in accordance with relevant regulatory requirements, such as IEEE-1547. As part of meeting the IEEE-1547 requirements, an inverter within a DG must be deactivated under certain circumstances, including
line frequency or line voltage operating outside of pre-defined limits. The IEEE- 1547 standard specifies that such voltage requirements must be met at a Point of Common Coupling (PCC) between the commercial power system and the DG (i.e., a point of demarcation between the public utility service and the DG).
[0005] For installations where an inverter within a DG is located a significant distance from the PCC, an output voltage measured at the inverter may be higher than a voltage measured at the PCC due a voltage drop along the line from the inverter to the PCC. In some circumstances, the measured voltage at the inverter may exceed the required voltage range although the voltage at the PCC remains within the required range, resulting in the inverter unnecessarily shutting down and thereby reducing energy production. Additionally, as the inverter ceases power production and the voltage at the inverter is reduced to acceptable levels, the inverter once again activates and begins producing power, resulting in a continued oscillation that negatively impacts power production.
[0006] Therefore, there is a need for a method and apparatus for correcting a monitoring voltage measured at an inverter.
SUMMARY OF THE INVENTION
[0007] Embodiments of the present invention generally relate to a method and apparatus for determining a corrected monitoring voltage, at least a portion of the method being performed by a computing system comprising at least one processor. The method comprises generating power at a first location; monitoring the generated power by measuring a first voltage proximate the first location; measuring a second voltage proximate a second location, the first and the second locations electrically coupled; and determining, based on the measured second voltage, a corrected monitoring voltage to compensate the measured first voltage for a distance between the first and the second locations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention,
briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0009] Figure 1 is a block diagram of a system for distributed generation (DG) in accordance with one or more embodiments of the present invention;
[0010] Figure 2 is a block diagram of a control module in accordance with one or more embodiments of the present invention;
[0011] Figure 3 is a block diagram of an inverter in accordance with one or more embodiments of the present invention; and
[0012] Figure 4 is a flow diagram of a method for determining a corrected monitoring voltage in accordance with one or more embodiments of the present invention.
DETAILED DESCRIPTION
[0013] Figure 1 is a block diagram of a system 100 for distributed generation (DG) in accordance with one or more embodiments of the present invention. This diagram only portrays one variation of the myriad of possible system configurations. The present invention can function in a variety of distributed power generation environments and systems.
[0014] The system 100 comprises a plurality of inverters 102i, 1022 . . . 102n, collectively referred to as inverters 102, a plurality of PV modules 104i, 1042. . . 104n, collectively referred to as PV modules 104, an AC bus 106, and a load center 108.
[0015] Each inverter 1 O215 1022 . . . 102n is coupled to a PV module 104-,, 1042. . . 104n, respectively. In some embodiments, a DC-DC converter may be coupled between each PV module 104 and each inverter 102 (e.g., one converter per PV
module 104). Alternatively, multiple PV modules 104 may be coupled to a single inverter 102 (i.e., a centralized inverter); in some such embodiments, a DC-DC converter may be coupled between the PV modules 104 and the centralized inverter.
[0016] The inverters 102 are coupled to the AC bus 106, which in turn is coupled to the load center 108. The load center 108 houses connections between incoming power lines from a commercial power grid distribution system and the AC bus 106, and represents a Point of Common Coupling (PCC) between the system 100 and the commercial power grid. The inverters 102 convert DC power generated by the PV modules 104 into AC power, and meter out AC current that is in-phase with the AC commercial power grid voltage. The system 100 couples the generated AC power to the commercial power grid via the load center 108. Additionally or alternatively, the generated power may be coupled to appliances, and/or energy generated may be stored for later use; for example, the generated energy may be stored utilizing batteries, heated water, hydro pumping, H20-to-hydrogen conversion, or the like. In some alternative embodiments, the system 100 may comprise other types of renewable energy generators in addition to or in place of the inverters 102, such as wind turbines, hydroelectric systems, or the like.
[0017] The system 100 further comprises a control module 1 10 coupled to the AC bus 106. The control module 1 10 is capable of issuing command and control signals to the inverters 102 in order to control the functionality of the inverters 102.
[0018] In accordance with one or more embodiments of the present invention, each of the inverters 102 applies voltage compensation to locally measured voltages (i.e., voltages measured at the inverter 102) when determining a monitored voltage for comparison to relevant voltage regulatory requirements. Such voltage compensation corrects for a voltage drop that occurs along the AC bus 106 between the inverters 102 and the PCC and allows the inverters 102 to determine monitoring voltage levels with respect to the PCC (i.e., corrected monitoring voltage levels) for ensuring compliance with the relevant voltage regulatory requirements. In the event that a corrected monitoring voltage exceeds required limits, the corresponding
inverter 102 may be deactivated or, alternatively, AC voltage regulation may be performed.
[0019] In some embodiments, the control module 1 10 may receive one or more voltage samples (i.e., measurements) indicating a voltage proximate (i.e., at or near) the PCC. The control module 1 10 may then broadcast these PCC voltage samples V pec to one or more inverters 102 for determining the corresponding corrected monitoring voltage as described further below. The PCC voltage samples Vpcc may be obtained by a measurement unit 1 12 deployed at or near the load center 108; in some embodiments, the measurement unit 1 12 and the control module 1 10 may be a single integrated unit. The measurement unit 1 12 may sample the voltage proximate the PCC, for example, utilizing an analog to digital (A/D) converter, and communicate the PCC voltage samples Vpcc to the control module 1 10 for broadcast to the inverters 102. The measurement unit 1 12 may convert the voltage samples to a root mean square (RMS) value prior to transmission to the controller 1 10; alternatively, the controller 1 10 or the inverters 102 may perform such conversion. One example of such a measurement unit may be found in commonly assigned U.S. patent application Serial No. 12/657,447 entitled "Method and Apparatus for Characterizing a Circuit Coupled to an AC Line" and filed January 21 , 2010, which is herein incorporated in its entirety by reference.
[0020] In some embodiments, the measurement unit 1 12 may communicate the PCC voltage samples Vpcc to the control module 1 10 utilizing power line communication (PLC), and the control module 1 10 may then broadcast the PCC voltage samples Vpcc to the inverters 102 utilizing PLC; alternatively, other wired and/or wireless communication techniques may be utilized. In one or more alternative embodiments, the PCC voltage samples Vpcc may be obtained by the measurement unit 1 12 and communicated directly (i.e., without the use of the controller 1 10) to one or more inverters 102 utilizing any of the communications techniques previously mentioned.
[0021] In some alternative embodiments, the control module 1 10 may determine the corrected monitoring voltage for one of more of the inverters 102, determine
whether each corrected monitoring voltage is within required limits, and/or initiate deactivation of one or more inverters 102 for which the corrected monitoring voltage levels exceed required limits.
[0022] Figure 2 is a block diagram of a control module 1 10 in accordance with one or more embodiments of the present invention. The control module 1 10 comprises a communications transceiver 202 coupled to at least one central processing unit (CPU) 204. The CPU 204 is additionally coupled to support circuits 206, and a memory 208. The CPU 204 may comprise one or more conventionally available microprocessors. Alternatively, the CPU 204 may include one or more application specific integrated circuits (ASIC). The support circuits 206 are well known circuits used to promote functionality of the central processing unit. Such circuits include, but are not limited to, a cache, power supplies, clock circuits, buses, network cards, input/output (I/O) circuits, and the like.
[0023] The memory 208 may comprise random access memory, read only memory, removable disk memory, flash memory, and various combinations of these types of memory. The memory 208 is sometimes referred to as main memory and may, in part, be used as cache memory or buffer memory. The memory 208 generally stores the operating system 214 of the control module 1 10. The operating system 214 may be one of a number of commercially available operating systems such as, but not limited to, SOLARIS from SUN Microsystems, Inc., AIX from IBM Inc., HP-UX from Hewlett Packard Corporation, LINUX from Red Hat Software, Windows 2000 from Microsoft Corporation, and the like.
[0024] The memory 208 may store various forms of application software, such as inverter control software 210 for operably controlling the inverters 102. The communications transceiver 202 communicably couples the control module 1 10 to the inverters 102 to facilitate command and control of the inverters 102. The communications transceiver 202 may utilize wireless or wired communication techniques for such communication.
[0025] Figure 3 is a block diagram of an inverter 102 in accordance with one or more embodiments of the present invention. The inverter 102 comprises a power
conversion module 302, a conversion control module 304, a voltage monitoring module 306, an AC current sampler 308, and an AC voltage sampler 310.
[0026] The power conversion module 302 is coupled to the PV module 104 and acts to convert DC current from the PV module 104 to AC output current. The conversion control module 304 is coupled to the AC voltage sampler 310 for receiving an AC voltage reference signal from the commercial power grid, and to the power conversion module 302 for providing operative control and driving the power conversion module 302 to inject the generated AC output current in phase with the grid as required by the relevant standards.
[0027] The voltage monitoring module 306 is coupled to the conversion control module 304, the AC current sampler 308, and the AC voltage sampler 310. The AC current sampler 308 is coupled to an output terminal of the power conversion module 302, and the AC voltage sampler 310 is coupled across both output terminals of the power conversion module 302. The AC current sampler 308 and the AC voltage sampler 310 obtain samples (i.e., measurements) of the AC inverter current and AC inverter voltage, respectively, at the output of the power conversion module 302 and provide such inverter output current and voltage samples to the voltage monitoring module 306. The AC current sampler 308 and the AC voltage sampler 310 may each comprise an A/D converter for obtaining the inverter output current and voltage samples, respectively. In some other embodiments, rather than being directly measured, the inverter output current may be estimated based on DC input voltage and current to the inverter 102 and the AC voltage output from the inverter 102.
[0028] The voltage monitoring module 306 may be comprised of hardware, software, or a combination thereof, and comprises at least one CPU 314 coupled to support circuits 316, memory 318, and a communications transceiver 324. The communications transceiver 324 is further coupled to at least one of the output lines from the power conversion module 302 for communicating via PLC, for example, with the control module 1 10 and/or the measurement unit 1 12. In alternative
embodiments, the communications transceiver 324 may utilize wireless and/or other wired communications techniques for such communication.
[0029] The CPU 314 may comprise one or more conventionally available microprocessors. Alternatively, the CPU 314 may include one or more application specific integrated circuits (ASIC). The support circuits 316 are well known circuits used to promote functionality of the central processing unit. Such circuits include, but are not limited to, a cache, power supplies, clock circuits, buses, network cards, input/output (I/O) circuits, and the like.
[0030] The memory 318 may comprise random access memory, read only memory, removable disk memory, flash memory, and various combinations of these types of memory. The memory 318 is sometimes referred to as main memory and may, in part, be used as cache memory or buffer memory. The memory 318 generally stores the operating system (OS) 320 of the voltage monitoring module 306. The OS 320 may be one of a number of commercially available OSs such as, but not limited to, Linux, Real-Time Operating System (RTOS), and the like.
[0031] The memory 318 may store various forms of application software, such as voltage monitoring module (VMM) software 322 for determining a corrected monitoring voltage corresponding to the inverter 102.
[0032] To determine the corrected monitoring voltage, the voltage monitoring module 306 determines a correction coefficient Kv based on an inverter output voltage sample (i.e., a measurement of the inverter output voltage) received from the AC voltage sampler 310, and a PCC voltage sample that indicates a measurement of a voltage proximate the PCC. In some embodiments, the PCC voltage sample is an RMS value obtained by the measurement unit 1 12 and communicated from the control module 1 10 as previously described. The voltage monitoring module 306 determines the correction coefficient, Kv, as follows:
[0033] Kv = Vpcc / Vmeas 0)
[0034] where Vpcc is the PCC voltage sample and Vmθas is the inverter output voltage sample.
[0035] Additionally, when Kv is computed, the voltage monitoring module 306 computes an output power of the inverter, Pmθas- In some embodiments, the voltage monitoring module 306 utilizes the inverter output voltage sample Vmeas and an inverter output current sample received from the AC current sampler 308, as well as phase angle, to determine the output power of the inverter, Pmeas- Alternatively, the voltage monitoring module 306 may calculate Pmeas based on DC voltage and DC current pertaining to the inverter 102 (for example, DC voltage and DC current samples obtained by the conversion control module 304) and a conversion efficiency of the inverter 102.
[0036] In some embodiments, the inverter 102 is pre-set with an initial Kv =1 and determines a new Kv upon receiving a valid Vpcc measurement message. Such a message may be validated utilizing conventional communication techniques, such as addressing and checksums (e.g., cyclic redundancy check, or CRC). If the new Kv is within an acceptable correction coefficient range, the voltage monitoring module 306 utilizes the new Kv to determine a corrected monitoring voltage; if the new Kv is not within the acceptable correction coefficient range, Kv remains at its preset value until a next Vpcc is obtained. In some embodiments, the acceptable correction coefficient range is 0.95 < Kv < 1.05.
[0037] The voltage monitoring module 306 utilizes Kv for computing the corrected monitoring voltage V∞rr upon obtaining inverter output current and voltage samples linv and Vinv, respectively (e.g., inverter output current and voltage samples obtained subsequent to the samples utilized to compute Kv). The voltage monitoring module 306 determines the corrected monitoring voltage VCOrr as follows:
[0038] Vcorr = V,nv * (1-(( P,nv * (1- Kv))/Pmeas)) (H)
[0039] where Kv is the correction coefficient, Vmv and P,nv are the inverter output voltage and power, respectively, and Pmeas is the inverter output power determined at the time Kv was computed. P,nv is computed based on inverter output current and
voltage samples obtained by the AC current sampler 308 and the AC voltage sampler 310, respectively.
[0040] The voltage monitoring module 306 periodically computes Vcorr based on one or more of an updated inverter output power measurement Pιnv, an updated inverter output voltage measurement V,nv, or an updated Kv (e.g., Kv may be updated upon receiving a new valid VPcc measurement message). In some embodiments, Vcorr as well as all corresponding voltage, current, power, and control parameters are determined at least once every line cycle (e.g., every 16.6667 milliseconds). If a new valid Vpcc measurement message is not received within an aging time window, Kv is reset to "1 " until a valid Vpcc message is received. In some embodiments, a linear aging function may be utilized; alternatively, a nonlinear aging function, or a combination of a linear and a nonlinear aging functions may be utilized.
[0041] In the event that the inverter output power P,nv moves outside of a valid output power range for the current Kv, Kv is reset to "1 " until a new valid Vpcc measurement message is received and a new Kv determined. The valid output power range may be some percentage of the rated total inverter power, for example, within the range of 5% to 20% of the inverter power rating. In some embodiments, Kv may be reset to "1 " in the event that the inverter output power P,nv exceeds a maximum power deviation.
[0042] The corrected monitoring voltage V∞rr provides a more accurate estimate of the voltage at the PCC than the inverter output voltage alone for determining compliance with regulatory requirements pertaining to voltage levels at the PCC. In some embodiments, the voltage monitoring module 306 determines whether the corrected monitoring voltage Vcorr is within a required voltage range with respect to the regulatory requirements; in the event the corrected monitoring voltage V∞rr exceeds the required voltage range, the voltage monitoring module 306 provides a deactivation signal to the conversion control module 304 to deactivate the power conversion module 302 or, alternatively, AC voltage regulation may be performed. In some alternative embodiments, one or more of determining the corrected monitoring voltage Vcorr, determining compliance with regulatory requirements,
and/or deactivation of one or more inverters as a result of one or more corrected monitoring voltage levels exceeding a required voltage range may be performed by the control module 1 10.
[0043] Figure 4 is a flow diagram of a method 400 for determining a corrected monitoring voltage in accordance with one or more embodiments of the present invention. In some embodiments, such as the embodiment described below, AC current from a DG system comprising at least one DC-AC inverter is coupled to a commercial power grid at a PCC. Although the embodiment below is described with respect to a single inverter, each inverter of the DG system may utilize the method 400. In alternative embodiments, a controller for the DG system may utilize the method 400 for determining one or more corrected monitoring voltages and/or driving the corresponding inverters accordingly.
[0044] The method 400 begins at step 402 and proceeds to step 404. At step 404, a correction coefficient Kv of an inverter has an initial value of "1 ". In some embodiments, the inverter may be preset with Kv =1 , for example, at a factory during manufacturing. The method 400 proceeds to step 406, where a voltage sample (i.e., measurement) indicating a voltage proximate the PCC {"Vpcc"), is obtained. The PCC voltage sample Vpcc may be received by the inverter as part of a validated message transmitted to the inverter; for example, the message may be broadcasted from a control module coupled to the DG system and validated utilizing conventional communication techniques, such as addressing and checksums (e.g., cyclic redundancy check, or CRC). In some embodiments, a data logger (e.g., the measurement unit 1 12 previously described) may be coupled proximate the PCC, for example, at a load center coupling the DG system to the commercial power grid. The data logger may sample (i.e., measure) the voltage proximate the PCC, convert the voltage sample to an RMS value, and communicate the resulting PCC voltage sample Vpcc to the controller for broadcast to the one or more inverters of the DG system. In some alternative embodiments, the PCC voltage sample Vpcc may be converted to an RMS value at the controller or the inverter. In some other alternative embodiments, the data logger may directly communicate the PCC
voltage sample Vpcc to the inverters utilizing wireless and/or wired communications techniques.
[0045] The method 400 proceeds to step 407, where a voltage sample of an AC output voltage of the inverter (Vmeas) is obtained, for example, by an AC voltage sampler of the inverter. At step 408, a new Kv is determined as follows:
[0046] Kv = Vpcc / Vmeas (Hi)
[0047] Additionally, at the time Kv is computed, an output power of the inverter {Pmeas) is determined based on Vmeas and a sample of the AC output current from the inverter obtained, for example, by an AC current sampler of the inverter.
[0048] At step 410, a determination is made whether Kv is within an acceptable correction coefficient range; in some embodiments, the acceptable correction coefficient range is 0.95 < Kv < 1.05. If it is determined that Kv is not within the acceptable correction coefficient range, the method 400 returns to step 404. If it is determined that Kv is within the acceptable correction coefficient range, the method 400 proceeds to step 41 1 .
[0049] At step 41 1 , inverter output current and voltage samples are obtained {Vm and Imv, respectively) and utilized to determine the inverter output power (P, nv). At step 412, a corrected monitoring voltage is determined as follows:
[0050] Vcorr = V,nv * (1-(( P,nv * (1- Kv))/Pmeas)) (iv)
[0051] At step 414, a determination is made whether the corrected monitoring voltage is within required regulatory limits. In some embodiments, the inverter may compare the corrected monitoring voltage to the regulatory limits to make the determination; alternatively, the corrected monitoring voltage may be communicated, for example to the controller or the measurement unit, for determining compliance with the regulatory limits. If the result of such determination is no, the method 400 proceeds to step 422, where the inverter is deactivated; alternatively, AC voltage regulation may be performed. In some embodiments where the inverter is deactivated, upon determining that the corrected monitoring voltage exceeds
required limits, the inverter may cease power production; alternatively, the inverter may receive a control signal from the controller or the measurement unit causing the inverter to cease power product. The method 400 then proceeds to step 424 where it ends. If the result of the determination at step 414 is yes, the method 400 proceeds to step 416.
[0052] At step 416, a determination is made whether a new valid Vpcc measurement message has been received. In some embodiments, Vpcc may be determined and communicated to the inverter at least once every line cycle (e.g., every 16.6667 milliseconds). If a new valid Vpcc measurement message has been received, the method 400 returns to step 407. If a new valid Vpcc measurement has not been received, the method 400 proceeds to step 418. At step 418, a determination is made whether an aging time window for Kv has been exceeded. In some embodiments, a linear aging function may be applied to Kv such that Kv reaches a value of 1 at the end of the aging time window; alternatively, a nonlinear aging function, or a combination of linear and nonlinear aging functions, may be utilized. If the aging time window has been exceeded, the method 400 returns to step 404. If the aging time window has not been exceeded, the method 400 proceeds to step 419.
[0053] At step 419, inverter output current and voltage samples (Vιnv and lιnv, respectively) are obtained and utilized to determine a new inverter output power P,nv. At step 420, a determination is made whether the inverter output power P,nv is within a valid output power range for the current Kv. The valid output power range may be some percentage of the rated total inverter power, for example, within the range of 5% to 20% of the inverter power rating. If the inverter output power P,nv is within the valid output power range, the method 400 returns to step 412. If the inverter output power exceeds the output power range, Kv is reset to 1 and the method 400 returns to step 404.
[0054] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing
from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Claims
1. A method for determining a corrected monitoring voltage, at least a portion of the method being performed by a computing system comprising at least one processor, the method comprising: generating power at a first location; monitoring the generated power by measuring a first voltage proximate the first location; measuring a second voltage proximate a second location, the first and the second locations electrically coupled; and determining, based on the measured second voltage, a corrected monitoring voltage to compensate the measured first voltage for a distance between the first and the second locations.
2. The method of claim 1 , wherein measuring the first voltage comprises obtaining a first and a third voltage measurement of the first voltage, wherein measuring the second voltage comprises obtaining a second voltage measurement of the second voltage, and wherein determining the corrected monitoring voltage comprises: obtaining a first power measurement proximate the first location; computing a correction coefficient based on the first and the second voltage measurements; obtaining a second power measurement proximate the first location; and computing the corrected monitoring voltage based on the first and the second power measurements, the third voltage measurement, and the correction coefficient.
3. The method of claim 2, further comprising: determining that the corrected monitoring voltage is not within an operating range; and disabling a device generating the power at the first location or performing AC voltage regulation.
4. The method of claim 2, further comprising determining, subsequent to computing the correction coefficient and prior to computing the corrected monitoring voltage, that the correction coefficient is within a correction coefficient range.
5. The method of claim 2, further comprising: determining that the correction coefficient has exceeded a time window; and setting the correction coefficient to a value of one.
6. The method of claim 2, further comprising: determining that the correction coefficient has not exceeded a time window; obtaining a third power measurement proximate the first location; determining whether the third power measurement is within an output power range; and resultant from determining whether the third power measurement is within the output power range, (i) setting the correction coefficient to a value of one, or (ii) recomputing the correction coefficient based on the third power measurement.
7. The method of claim 2, wherein the corrected monitoring voltage is computed as Vcorr = V3 * (1-(P2 * (1- (V2 / V1) ) /P1) ), wherein P1= the first power measurement, P2 = the second power measurement, \Λ = the first voltage measurement, V2 = the second voltage measurement, and V3 = the third voltage measurement.
8. An apparatus for determining a corrected monitoring voltage, comprising: a voltage monitoring module adapted for: monitoring power at a first location by measuring a first voltage proximate the first location; receiving a second voltage measurement of a second voltage proximate a second location, the second location electrically coupled to the first location; and determining, based on the second voltage measurement, a corrected monitoring voltage to compensate the measured first voltage for a distance between the first and the second locations.
9. The apparatus of claim 8, wherein the voltage monitoring module determines the corrected voltage by (i) obtaining a first and a third voltage measurement of the first voltage, (ii) obtaining a first power measurement proximate the first location, (iv) computing a correction coefficient based on the first and the second voltage measurements, (v) obtaining a second power measurement proximate the first location, and (v) computing the corrected monitoring voltage based on the first and the second power measurements, the third voltage measurement, and the correction coefficient.
10. The apparatus of claim 9, wherein the voltage monitoring module is further adapted for: determining that the corrected monitoring voltage is not within an operating range; and disabling the power generating device or performing AC voltage regulation.
11 . The apparatus of claim 9, wherein the voltage monitoring module is further adapted for determining, subsequent to computing the correction coefficient and prior to computing the corrected monitoring voltage, that the correction coefficient is within a correction coefficient range.
12. The apparatus of claim 9, wherein the voltage monitoring module is further adapted for: determining that the correction coefficient has exceeded a time window; and setting the correction coefficient to a value of one.
13. The apparatus of claim 9, wherein the voltage monitoring module is further adapted for: determining that the correction coefficient has not exceeded a time window; obtaining a third power measurement, the third power measurement measuring the output power from the power generating device; determining whether the third power measurement is within an output power range; and resultant from determining whether the third power measurement is within the output range, (i) setting the correction coefficient to a value of one, or (ii) recomputing the correction coefficient based on the third power measurement.
14. A system for determining a corrected monitoring voltage, the system comprising: an inverter, adapted for generating power at a first location and monitoring the generated power by measuring a first voltage proximate the first location; and a measurement unit, adapted for measuring a second voltage proximate a second location, the first and the second locations electrically coupled; wherein the inverter is further adapted for determining, based on the measured second voltage, a corrected monitoring voltage to compensate the measured first voltage for a distance between the first and the second locations.
15. The system of claim 14, wherein the inverter determines the corrected voltage by (i) obtaining a first and a third voltage measurement of the first voltage, (ii) receiving a second voltage measurement, obtained by the measurement unit, of the second voltage, (iii) obtaining a first power measurement proximate the first location, (iv) computing a correction coefficient based on the first and the second voltage measurements, (v) obtaining a second power measurement proximate the first location, and (v) computing the corrected monitoring voltage based on the first and the second power measurements, the third voltage measurement, and the correction coefficient.
16. The system of claim 15, wherein the inverter is further adapted for: determining that the corrected monitoring voltage is not within an operating range; and disabling power production or performing AC voltage regulation.
17. The system of claim 15, wherein the inverter is further adapted for determining, subsequent to computing the correction coefficient and prior to computing the corrected monitoring voltage, that the correction coefficient is within a correction coefficient range.
18. The system of claim 15, wherein the inverter is further adapted for: determining that the correction coefficient has exceeded a time window; and setting the correction coefficient to a value of one.
19. The system of claim 15, wherein the inverter is further adapted for: determining that the correction coefficient has not exceeded a time window; obtaining a third power measurement proximate the first location; determining whether the third power measurement is within an output power range; and resultant from determining whether the third power measurement is within the output power range, (i) setting the correction coefficient to a value of one, or (ii) recomputing the correction coefficient based on the third power measurement.
20. The system of claim 15, wherein the corrected monitoring voltage is computed as V∞rr = V3 * (1-(P2 * (1- (V2 Z V1) ) /P1) ), wherein P1= the first power measurement, P2 = the second power measurement, \Λ = the first voltage measurement, V2 = the second voltage measurement, and V3 = the third voltage measurement.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA2751254A CA2751254A1 (en) | 2009-02-05 | 2010-02-05 | Method and apparatus for determining a corrected monitoring voltage |
EP10739161A EP2394207A2 (en) | 2009-02-05 | 2010-02-05 | Method and apparatus for determining a corrected monitoring voltage |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US20689109P | 2009-02-05 | 2009-02-05 | |
US61/206,891 | 2009-02-05 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2010091244A2 true WO2010091244A2 (en) | 2010-08-12 |
WO2010091244A3 WO2010091244A3 (en) | 2010-11-18 |
Family
ID=42397572
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2010/023307 WO2010091244A2 (en) | 2009-02-05 | 2010-02-05 | Method and apparatus for determining a corrected monitoring voltage |
Country Status (4)
Country | Link |
---|---|
US (2) | US8666561B2 (en) |
EP (1) | EP2394207A2 (en) |
CA (1) | CA2751254A1 (en) |
WO (1) | WO2010091244A2 (en) |
Families Citing this family (77)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10693415B2 (en) | 2007-12-05 | 2020-06-23 | Solaredge Technologies Ltd. | Testing of a photovoltaic panel |
US11881814B2 (en) | 2005-12-05 | 2024-01-23 | Solaredge Technologies Ltd. | Testing of a photovoltaic panel |
US11309832B2 (en) | 2006-12-06 | 2022-04-19 | Solaredge Technologies Ltd. | Distributed power harvesting systems using DC power sources |
US8013472B2 (en) | 2006-12-06 | 2011-09-06 | Solaredge, Ltd. | Method for distributed power harvesting using DC power sources |
US8963369B2 (en) | 2007-12-04 | 2015-02-24 | Solaredge Technologies Ltd. | Distributed power harvesting systems using DC power sources |
US11728768B2 (en) | 2006-12-06 | 2023-08-15 | Solaredge Technologies Ltd. | Pairing of components in a direct current distributed power generation system |
US9088178B2 (en) | 2006-12-06 | 2015-07-21 | Solaredge Technologies Ltd | Distributed power harvesting systems using DC power sources |
US11569659B2 (en) | 2006-12-06 | 2023-01-31 | Solaredge Technologies Ltd. | Distributed power harvesting systems using DC power sources |
US11855231B2 (en) | 2006-12-06 | 2023-12-26 | Solaredge Technologies Ltd. | Distributed power harvesting systems using DC power sources |
US8473250B2 (en) | 2006-12-06 | 2013-06-25 | Solaredge, Ltd. | Monitoring of distributed power harvesting systems using DC power sources |
US11296650B2 (en) | 2006-12-06 | 2022-04-05 | Solaredge Technologies Ltd. | System and method for protection during inverter shutdown in distributed power installations |
US8319471B2 (en) | 2006-12-06 | 2012-11-27 | Solaredge, Ltd. | Battery power delivery module |
US11735910B2 (en) | 2006-12-06 | 2023-08-22 | Solaredge Technologies Ltd. | Distributed power system using direct current power sources |
US8384243B2 (en) | 2007-12-04 | 2013-02-26 | Solaredge Technologies Ltd. | Distributed power harvesting systems using DC power sources |
US8947194B2 (en) | 2009-05-26 | 2015-02-03 | Solaredge Technologies Ltd. | Theft detection and prevention in a power generation system |
US11687112B2 (en) | 2006-12-06 | 2023-06-27 | Solaredge Technologies Ltd. | Distributed power harvesting systems using DC power sources |
US8319483B2 (en) | 2007-08-06 | 2012-11-27 | Solaredge Technologies Ltd. | Digital average input current control in power converter |
US8816535B2 (en) | 2007-10-10 | 2014-08-26 | Solaredge Technologies, Ltd. | System and method for protection during inverter shutdown in distributed power installations |
US7994657B2 (en) * | 2006-12-22 | 2011-08-09 | Solarbridge Technologies, Inc. | Modular system for unattended energy generation and storage |
US7755916B2 (en) | 2007-10-11 | 2010-07-13 | Solarbridge Technologies, Inc. | Methods for minimizing double-frequency ripple power in single-phase power conditioners |
US11264947B2 (en) | 2007-12-05 | 2022-03-01 | Solaredge Technologies Ltd. | Testing of a photovoltaic panel |
WO2009072076A2 (en) | 2007-12-05 | 2009-06-11 | Solaredge Technologies Ltd. | Current sensing on a mosfet |
JP2011507465A (en) | 2007-12-05 | 2011-03-03 | ソラレッジ テクノロジーズ リミテッド | Safety mechanism, wake-up method and shutdown method in distributed power installation |
EP2294669B8 (en) | 2008-05-05 | 2016-12-07 | Solaredge Technologies Ltd. | Direct current power combiner |
US8279642B2 (en) | 2009-07-31 | 2012-10-02 | Solarbridge Technologies, Inc. | Apparatus for converting direct current to alternating current using an active filter to reduce double-frequency ripple power of bus waveform |
CA2774401C (en) * | 2009-09-18 | 2019-01-15 | Queen's University At Kingston | Distributed power generation interface |
US8207637B2 (en) * | 2009-10-09 | 2012-06-26 | Solarbridge Technologies, Inc. | System and apparatus for interconnecting an array of power generating assemblies |
US8462518B2 (en) | 2009-10-12 | 2013-06-11 | Solarbridge Technologies, Inc. | Power inverter docking system for photovoltaic modules |
US8824178B1 (en) | 2009-12-31 | 2014-09-02 | Solarbridge Technologies, Inc. | Parallel power converter topology |
EP2529450A4 (en) | 2010-01-25 | 2014-10-22 | Enphase Energy Inc | Method and apparatus for interconnecting distributed power sources |
US9806445B2 (en) | 2010-01-25 | 2017-10-31 | Enphase Energy, Inc. | Method and apparatus for interconnecting distributed power sources |
TW201206008A (en) * | 2010-07-16 | 2012-02-01 | Chung Hsin Elec & Mach Mfg | Grid-connected power conversion circuitry and power converting method thereof |
USD666974S1 (en) | 2010-09-24 | 2012-09-11 | Solarbridge Technologies, Inc. | Y-junction interconnect module |
US8279649B2 (en) | 2010-10-11 | 2012-10-02 | Solarbridge Technologies, Inc. | Apparatus and method for controlling a power inverter |
US9160408B2 (en) * | 2010-10-11 | 2015-10-13 | Sunpower Corporation | System and method for establishing communication with an array of inverters |
US8503200B2 (en) | 2010-10-11 | 2013-08-06 | Solarbridge Technologies, Inc. | Quadrature-corrected feedforward control apparatus and method for DC-AC power conversion |
US10673229B2 (en) | 2010-11-09 | 2020-06-02 | Solaredge Technologies Ltd. | Arc detection and prevention in a power generation system |
GB2485527B (en) * | 2010-11-09 | 2012-12-19 | Solaredge Technologies Ltd | Arc detection and prevention in a power generation system |
US10673222B2 (en) | 2010-11-09 | 2020-06-02 | Solaredge Technologies Ltd. | Arc detection and prevention in a power generation system |
US9467063B2 (en) | 2010-11-29 | 2016-10-11 | Sunpower Corporation | Technologies for interleaved control of an inverter array |
US8842454B2 (en) | 2010-11-29 | 2014-09-23 | Solarbridge Technologies, Inc. | Inverter array with localized inverter control |
GB2483317B (en) | 2011-01-12 | 2012-08-22 | Solaredge Technologies Ltd | Serially connected inverters |
US8599587B2 (en) | 2011-04-27 | 2013-12-03 | Solarbridge Technologies, Inc. | Modular photovoltaic power supply assembly |
US9065354B2 (en) | 2011-04-27 | 2015-06-23 | Sunpower Corporation | Multi-stage power inverter for power bus communication |
US8611107B2 (en) | 2011-04-27 | 2013-12-17 | Solarbridge Technologies, Inc. | Method and system for controlling a multi-stage power inverter |
US8780592B1 (en) | 2011-07-11 | 2014-07-15 | Chilicon Power, LLC | Systems and methods for increasing output current quality, output power, and reliability of grid-interactive inverters |
US8922185B2 (en) | 2011-07-11 | 2014-12-30 | Solarbridge Technologies, Inc. | Device and method for global maximum power point tracking |
US9201103B2 (en) * | 2011-08-09 | 2015-12-01 | Source Photonics, Inc. | Circuits, architectures, apparatuses, methods and algorithms for determining a DC bias in an AC or AC-coupled signal |
JP5935268B2 (en) * | 2011-09-05 | 2016-06-15 | 住友電気工業株式会社 | Power generation control system |
US8284574B2 (en) | 2011-10-17 | 2012-10-09 | Solarbridge Technologies, Inc. | Method and apparatus for controlling an inverter using pulse mode control |
GB2498365A (en) | 2012-01-11 | 2013-07-17 | Solaredge Technologies Ltd | Photovoltaic module |
GB2498790A (en) | 2012-01-30 | 2013-07-31 | Solaredge Technologies Ltd | Maximising power in a photovoltaic distributed power system |
US9853565B2 (en) | 2012-01-30 | 2017-12-26 | Solaredge Technologies Ltd. | Maximized power in a photovoltaic distributed power system |
GB2498791A (en) | 2012-01-30 | 2013-07-31 | Solaredge Technologies Ltd | Photovoltaic panel circuitry |
USD707632S1 (en) | 2012-06-07 | 2014-06-24 | Enphase Energy, Inc. | Trunk connector |
USD708143S1 (en) | 2012-06-07 | 2014-07-01 | Enphase Energy, Inc. | Drop cable connector |
AT513059B1 (en) * | 2012-06-26 | 2014-06-15 | Roland Ing Ochenbauer | Apparatus and method for improving energy use |
US9276635B2 (en) | 2012-06-29 | 2016-03-01 | Sunpower Corporation | Device, system, and method for communicating with a power inverter using power line communications |
DE102012107165B4 (en) | 2012-08-03 | 2021-10-28 | Sma Solar Technology Ag | Inverters with separate detection of line voltages and procedures for operating inverters |
US9548619B2 (en) | 2013-03-14 | 2017-01-17 | Solaredge Technologies Ltd. | Method and apparatus for storing and depleting energy |
US9584044B2 (en) | 2013-03-15 | 2017-02-28 | Sunpower Corporation | Technologies for converter topologies |
US9564835B2 (en) | 2013-03-15 | 2017-02-07 | Sunpower Corporation | Inverter communications using output signal |
US9906037B2 (en) * | 2013-04-13 | 2018-02-27 | Honey Badger International Pty Ltd. | Energy generation load compensation |
KR101480533B1 (en) * | 2013-06-28 | 2015-01-08 | 한국전력공사 | Apparatus and method for interconnecting distributed generations into power grid |
AU2015267255B2 (en) * | 2014-05-25 | 2019-03-14 | Sunpower Corporation | Alternative energy source module array characterization |
CN107408820A (en) | 2014-12-16 | 2017-11-28 | Abb瑞士股份有限公司 | Energy plate arranges power dissipation |
CN107431097B (en) | 2015-01-28 | 2020-02-14 | Abb瑞士股份有限公司 | Energy panel arrangement closure |
US10404060B2 (en) | 2015-02-22 | 2019-09-03 | Abb Schweiz Ag | Photovoltaic string reverse polarity detection |
CN105807841B (en) * | 2016-03-08 | 2018-03-30 | 艾思玛新能源技术(上海)有限公司苏州高新区分公司 | A kind of power ring controls limit for tonnage method and apparatus |
US11177663B2 (en) | 2016-04-05 | 2021-11-16 | Solaredge Technologies Ltd. | Chain of power devices |
US11018623B2 (en) | 2016-04-05 | 2021-05-25 | Solaredge Technologies Ltd. | Safety switch for photovoltaic systems |
US9929665B2 (en) | 2016-04-20 | 2018-03-27 | International Business Machines Corporation | Remotely controllable modular power control device for power generation |
KR20170135063A (en) | 2016-05-30 | 2017-12-08 | 삼성전자주식회사 | Memory device and voltage generator including feedback control circuit |
JP6954357B2 (en) * | 2017-09-11 | 2021-10-27 | 東芝三菱電機産業システム株式会社 | Power generation system |
US11243331B2 (en) * | 2018-11-09 | 2022-02-08 | Itron, Inc. | Techniques for geolocation and cloud detection with voltage data from solar homes |
US11329487B2 (en) | 2020-06-25 | 2022-05-10 | General Electric Renovables Espana, S.L. | System and method for controlling a power generating system |
US11870251B2 (en) | 2021-08-04 | 2024-01-09 | General Electric Company | System and method for controlling a power generating system |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6339357B1 (en) * | 1997-08-12 | 2002-01-15 | Mitsubishi Denki Kabushiki Kaisha | Semiconductor integrated circuit device capable of externally monitoring internal voltage |
US6400212B1 (en) * | 1999-07-13 | 2002-06-04 | National Semiconductor Corporation | Apparatus and method for reference voltage generator with self-monitoring |
US20060250166A1 (en) * | 2005-05-04 | 2006-11-09 | Saft | Voltage to current to voltage cell voltage monitor (VIV) |
Family Cites Families (49)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA1228119A (en) * | 1983-08-16 | 1987-10-13 | Tadao Shibuya | Power supply equipment backup system for interruption of service |
US5373433A (en) * | 1992-05-05 | 1994-12-13 | Trace Engineering | Power inverter for generating voltage regulated sine wave replica |
US5784268A (en) * | 1996-09-20 | 1998-07-21 | General Signal Corporation | Inverter control for support of power factor corrected loads |
JP3372436B2 (en) * | 1996-11-28 | 2003-02-04 | オークマ株式会社 | Inverter control device |
JP3583586B2 (en) * | 1997-07-22 | 2004-11-04 | 株式会社東芝 | Power converter control device |
US6118676A (en) * | 1998-11-06 | 2000-09-12 | Soft Switching Technologies Corp. | Dynamic voltage sag correction |
JP3809316B2 (en) * | 1999-01-28 | 2006-08-16 | キヤノン株式会社 | Solar power plant |
JP2997782B1 (en) * | 1999-02-04 | 2000-01-11 | 大阪大学長 | Power supply equipment by quality |
US6404655B1 (en) * | 1999-12-07 | 2002-06-11 | Semikron, Inc. | Transformerless 3 phase power inverter |
JP3352662B2 (en) * | 2000-02-03 | 2002-12-03 | 関西電力株式会社 | Power system stabilizing apparatus and power system stabilizing method using secondary battery system |
DE60013177D1 (en) * | 2000-04-25 | 2004-09-23 | Sp Systems Pte Ltd | DYNAMIC SERIAL VOLTAGE COMPARATOR AND RELATED METHOD |
US6452289B1 (en) * | 2000-07-10 | 2002-09-17 | Satcon Technology Corporation | Grid-linked power supply |
US6281485B1 (en) * | 2000-09-27 | 2001-08-28 | The Aerospace Corporation | Maximum power tracking solar power system |
US6812592B2 (en) * | 2001-03-30 | 2004-11-02 | Mitsubishi Denki Kabushiki Kaisha | Voltage fluctuation compensating apparatus |
US6570779B2 (en) * | 2001-10-04 | 2003-05-27 | Kokusan Denki Co., Ltd. | Pulse with modulation inverter generation using a correction co-efficient and a reference to the ratio to obtain a real duty ratio |
US6686718B2 (en) * | 2001-11-27 | 2004-02-03 | York International Corp. | Control loop and method for variable speed drive ride-through capability improvement |
US20050125104A1 (en) * | 2003-12-05 | 2005-06-09 | Wilson Thomas L. | Electrical power distribution control systems and processes |
US7069117B2 (en) * | 2002-04-01 | 2006-06-27 | Programmable Control Services, Inc. | Electrical power distribution control systems and processes |
US7729810B2 (en) * | 2002-04-01 | 2010-06-01 | Programable Control Services, Inc. | Electrical power distribution control systems and processes |
US7158395B2 (en) * | 2003-05-02 | 2007-01-02 | Ballard Power Systems Corporation | Method and apparatus for tracking maximum power point for inverters, for example, in photovoltaic applications |
US7015597B2 (en) * | 2003-09-11 | 2006-03-21 | Square D Company | Power regulator for power inverter |
US7138924B2 (en) * | 2003-11-24 | 2006-11-21 | Square D Company | Disturbance direction detection in a power monitoring system |
US8139759B2 (en) * | 2004-04-16 | 2012-03-20 | Panasonic Corporation | Line state detecting apparatus and transmitting apparatus and receiving apparatus of balanced transmission system |
CA2476030A1 (en) * | 2004-06-09 | 2005-12-09 | Wilsun Xu | A power signaling based technique for detecting islanding conditions in electric power distribution systems |
DE102004048341A1 (en) * | 2004-10-01 | 2006-04-13 | Repower Systems Ag | Wind farm with robust reactive power regulation and method of operation |
US7158393B2 (en) * | 2005-03-11 | 2007-01-02 | Soft Switching Technologies Corporation | Power conversion and voltage sag correction with regenerative loads |
JP4649252B2 (en) * | 2005-03-23 | 2011-03-09 | 東芝三菱電機産業システム株式会社 | Power converter |
EP1713155B1 (en) * | 2005-04-12 | 2012-10-17 | DET International Holding Limited | Power supply arrangement |
KR100724489B1 (en) * | 2005-05-11 | 2007-06-04 | 엘에스산전 주식회사 | Arrangement for compensating the deviation of inverter input voltage and method therefor |
JP4506606B2 (en) * | 2005-07-28 | 2010-07-21 | 日産自動車株式会社 | Voltage detection device for battery pack |
US7508173B2 (en) * | 2005-12-08 | 2009-03-24 | General Electric Company | System and method for providing reactive power support with distributed energy resource inverter |
JP4365376B2 (en) * | 2006-02-14 | 2009-11-18 | 三菱電機株式会社 | Power converter |
AT504200B1 (en) * | 2006-09-04 | 2010-05-15 | Fronius Int Gmbh | METHOD FOR REGULATING INTERRUPTERS |
JP4893219B2 (en) * | 2006-10-16 | 2012-03-07 | 株式会社日立製作所 | Power converter |
US8013472B2 (en) * | 2006-12-06 | 2011-09-06 | Solaredge, Ltd. | Method for distributed power harvesting using DC power sources |
US7800349B2 (en) * | 2007-02-02 | 2010-09-21 | The Hong Kong Polytechnic University | Voltage dip and undervoltage compensator |
JP5030685B2 (en) * | 2007-06-27 | 2012-09-19 | 三菱電機株式会社 | Reactive power compensator and its control device |
US7877169B2 (en) * | 2007-08-21 | 2011-01-25 | Electro Industries/ Gauge Tech | System and method for synchronizing an auxiliary electrical generator to an electrical system |
EP2191563A2 (en) * | 2007-09-18 | 2010-06-02 | Flyback Energy, Inc. | Current waveform construction to generate ac power with low harmonic distortion from localized energy sources |
US7986539B2 (en) * | 2007-09-26 | 2011-07-26 | Enphase Energy, Inc. | Method and apparatus for maximum power point tracking in power conversion based on dual feedback loops and power ripples |
US7986122B2 (en) * | 2007-09-26 | 2011-07-26 | Enphase Energy, Inc. | Method and apparatus for power conversion with maximum power point tracking and burst mode capability |
EP2232690B1 (en) * | 2007-12-05 | 2016-08-31 | Solaredge Technologies Ltd. | Parallel connected inverters |
US7994658B2 (en) * | 2008-02-28 | 2011-08-09 | General Electric Company | Windfarm collector system loss optimization |
US8121741B2 (en) * | 2008-05-09 | 2012-02-21 | International Business Machines Corporation | Intelligent monitoring of an electrical utility grid |
US20090284758A1 (en) * | 2008-05-19 | 2009-11-19 | Toyonaka Kenkyusho Co., Ltd. | Displacement measuring method, displacement measuring apparatus and displacement measuring target |
US7839024B2 (en) * | 2008-07-29 | 2010-11-23 | General Electric Company | Intra-area master reactive controller for tightly coupled windfarms |
US20100094479A1 (en) * | 2008-10-10 | 2010-04-15 | Keefe Robert A | System and Method for Providing Voltage Control in a Power Line Distribution Network |
US8860241B2 (en) * | 2008-11-26 | 2014-10-14 | Tigo Energy, Inc. | Systems and methods for using a power converter for transmission of data over the power feed |
EP2389717A2 (en) | 2009-01-21 | 2011-11-30 | Enphase Energy, Inc. | Method and apparatus for characterizing a circuit coupled to an ac line |
-
2010
- 2010-02-05 CA CA2751254A patent/CA2751254A1/en not_active Abandoned
- 2010-02-05 US US12/701,262 patent/US8666561B2/en active Active
- 2010-02-05 WO PCT/US2010/023307 patent/WO2010091244A2/en active Application Filing
- 2010-02-05 EP EP10739161A patent/EP2394207A2/en not_active Withdrawn
-
2014
- 2014-03-04 US US14/197,087 patent/US9509142B2/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6339357B1 (en) * | 1997-08-12 | 2002-01-15 | Mitsubishi Denki Kabushiki Kaisha | Semiconductor integrated circuit device capable of externally monitoring internal voltage |
US6400212B1 (en) * | 1999-07-13 | 2002-06-04 | National Semiconductor Corporation | Apparatus and method for reference voltage generator with self-monitoring |
US20060250166A1 (en) * | 2005-05-04 | 2006-11-09 | Saft | Voltage to current to voltage cell voltage monitor (VIV) |
Also Published As
Publication number | Publication date |
---|---|
US9509142B2 (en) | 2016-11-29 |
US20140185344A1 (en) | 2014-07-03 |
WO2010091244A3 (en) | 2010-11-18 |
US20100195357A1 (en) | 2010-08-05 |
EP2394207A2 (en) | 2011-12-14 |
CA2751254A1 (en) | 2010-08-12 |
US8666561B2 (en) | 2014-03-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8666561B2 (en) | Method and apparatus for determining a corrected monitoring voltage | |
US7944083B2 (en) | Method and apparatus for characterizing a circuit coupled to an AC line | |
US9755430B2 (en) | Virtual inverter for power generation units | |
US8183852B2 (en) | Method and apparatus for determining AC voltage waveform anomalies | |
US9785168B2 (en) | Power generation amount prediction apparatus, method for correcting power generation amount prediction, and natural energy power generation system | |
US8942856B2 (en) | Power converter and methods of controlling the same | |
US8787052B2 (en) | Methods and systems for controlling a power conversion device | |
EP3157156A1 (en) | Method and apparatus for improved burst mode during power conversion | |
US20130274946A1 (en) | Methods and systems for controlling a power plant | |
EP2328259A1 (en) | System and method for power management in a photovoltaic installation | |
EP2922170B1 (en) | Control device for voltage source converter and operating method thereof | |
US20210320502A1 (en) | Grid interconnection device and server | |
JP2020022241A (en) | Hybrid power generation system and power control device | |
US9063194B2 (en) | Starting of photovoltaic system | |
WO2013043862A1 (en) | Method and apparatus for power module output power regulation | |
WO2015095013A1 (en) | Method and apparatus for maximum power point tracking for multi-input power converter | |
CN115600853B (en) | Intelligent control equipment for AC/DC hybrid micro-grid in transformer area | |
US20230369890A1 (en) | Methods and systems for estimating the operational status of an electrical generator in a distributed energy resource system | |
EP3920357A1 (en) | System for managing power flow or energy in a nano- or microgrid | |
CN105244908A (en) | Plug-and-play solar wind power integration control system and method | |
CN103988138A (en) | Automatic voltage regulation for photovoltaic systems |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 10739161 Country of ref document: EP Kind code of ref document: A2 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2751254 Country of ref document: CA |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2010739161 Country of ref document: EP |