Summary of the invention
The object of the present invention is to provide a kind of uninterruptible power supply provider, when it can or interrupt at city's electrical anomaly, provide sine wave output AC voltage.
Another object of the present invention is to provide a kind of uninterruptible power supply provider that sine wave output AC voltage can be provided, it can provide sine wave output AC voltage with the line design of simplification and preferable power-efficient.
A preferred embodiment of the present invention proposes a kind of uninterruptible power supply provider, and it comprises battery pack; The DC-to-DC converter unit is coupled to this battery pack, and it is set at the direct voltage that the direct voltage that this battery pack is provided converts full-wave rectification to; And inverter, be coupled to this DC-to-DC converter unit, its direct voltage that is set at this full-wave rectification converts sine wave output AC voltage to, wherein this DC-to-DC converter unit is made up of a plurality of DC-to-DC converter, be connected to this battery pack after the mutual parallel connection of a plurality of inputs of wherein said a plurality of DC-to-DC converter, and a plurality of outputs of described a plurality of DC-to-DC converter are connected to this inverter after the series connection mutually, each DC-to-DC converter is set at the direct current voltage transitions that this battery pack is provided and becomes output dc voltage, wherein the output dc voltage of described a plurality of DC-to-DC converter is formed mutually the direct voltage of this full-wave rectification, and described one of them DC-to-DC converter of a plurality of DC-to-DC converter has high frequency transformer and forms isolated current fed full-bridge direct current-direct current transducer, and all the other described DC-to-DC converter are non-isolated DC-to-DC converter.
Uninterruptible power supply provider of the present invention also comprises the energy recuperation transducer, is coupled between the output and this battery pack of this DC-to-DC converter unit, and its excess energy that is set at this uninterruptible power supply provider is recycled to this battery pack.
Uninterruptible power supply provider of the present invention, wherein this energy recuperation transducer is made up of DC-to-DC converter.
Uninterruptible power supply provider of the present invention, wherein this energy recuperation transducer is set at this uninterruptible power supply provider during with the commercial power supply power supply, to this batteries charging.
Uninterruptible power supply provider of the present invention, also comprise controller, its direct voltage and reference voltage that is set at this full-wave rectification that this DC-to-DC converter unit is exported is made comparisons, and controls the switch switching of this DC-to-DC converter unit, this inverter and this energy recuperation transducer according to comparative result.
Uninterruptible power supply provider of the present invention also comprises the energy recuperation transducer, is coupled to the input of this inverter, and its excess energy that is set at this uninterruptible power supply provider is recycled to this battery pack.
Uninterruptible power supply provider of the present invention, wherein this energy recuperation transducer is set at this uninterruptible power supply provider during with the commercial power supply power supply, to this batteries charging.
Uninterruptible power supply provider of the present invention, also comprise digitial controller, its direct voltage and reference voltage that is set at this full-wave rectification that this DC-to-DC converter unit is exported is made comparisons, and controls the switch switching of this DC-to-DC converter unit, this inverter and this energy recuperation transducer according to comparative result.
Uninterruptible power supply provider of the present invention, wherein this DC-to-DC converter unit is made up of first DC-to-DC converter and second DC-to-DC converter, and in the whole cycle of the output voltage of this DC-to-DC converter unit, one of them of this first DC-to-DC converter and this second DC-to-DC converter carried out switch with variable duty cycle and switched, and the another one DC-to-DC converter is carried out the switch switching with fixing duty cycle.
Uninterruptible power supply provider of the present invention, wherein this DC-to-DC converter unit is made up of first DC-to-DC converter and second DC-to-DC converter, and in the whole cycle of the output voltage of this DC-to-DC converter unit, this first DC-to-DC converter and this second DC-to-DC converter are all carried out switch with variable duty cycle and are switched.
Another preferred embodiment of the present invention proposes a kind of method that makes uninterruptible power supply provider that sine wave output AC voltage is provided, this method comprises the following step: battery pack is provided, DC-to-DC converter unit and inverter, wherein this DC-to-DC converter unit is made up of a plurality of DC-to-DC converter, and described one of them DC-to-DC converter of a plurality of DC-to-DC converter has high frequency transformer and forms isolated current fed full-bridge direct current-direct current transducer, and all the other described DC-to-DC converter are non-isolated DC-to-DC converter.Then, provide cell voltage to this DC-to-DC converter unit by this battery pack.Then, convert this cell voltage to a plurality of output dc voltages via described a plurality of DC-to-DC converter.Then, a plurality of output dc voltage additions are become the direct voltage of full-wave rectification.At last, the direct voltage of this full-wave rectification converts sine wave output AC voltage to via this inverter.
Method of the present invention, wherein this DC-to-DC converter unit is made up of first DC-to-DC converter and second DC-to-DC converter, this first DC-to-DC converter converts this cell voltage to direct voltage via the first switching device regulating action, and second DC-to-DC converter converts this cell voltage to direct voltage via second switch device regulating action, wherein this first switching device regulating action reaches by variable duty cycle, and this second switch device regulating action reaches by fixing duty cycle.
Method of the present invention, wherein this DC-to-DC converter unit is made up of first DC-to-DC converter and second DC-to-DC converter, this first DC-to-DC converter converts this cell voltage to direct voltage via the first switching device regulating action, and this second DC-to-DC converter converts this cell voltage to direct voltage via second switch device regulating action, and wherein this first switching device regulating action and this second switch device regulating action all reach by variable duty cycle.
Method of the present invention also comprises following steps: provide energy recycle device; And the excess energy of this uninterruptible power supply provider is recycled to this battery pack by this energy recycle device.
Description of drawings
Fig. 1 shows the part system block diagram of known uninterruptible power supply provider;
Fig. 2 shows the system block diagram according to uninterruptible power supply provider of the present invention;
Fig. 3 shows the circuit diagram according to the DC-to-DC converter unit of uninterruptible power supply provider of the present invention;
Fig. 4 shows the circuit diagram according to first preferred embodiment of the DC-to-DC converter unit of uninterruptible power supply provider of the present invention and inverter and energy recuperation transducer;
Fig. 5 shows the circuit diagram according to second preferred embodiment of the DC-to-DC converter unit of uninterruptible power supply provider of the present invention and inverter and energy recuperation transducer;
Fig. 6 shows the circuit diagram according to the 3rd preferred embodiment of the DC-to-DC converter unit of uninterruptible power supply provider of the present invention and inverter and energy recuperation transducer;
Fig. 7 shows the circuit diagram according to a kind of distortion of the DC-to-DC converter unit of uninterruptible power supply provider of the present invention and inverter and energy recuperation transducer;
Fig. 8 (A) shows the output voltage waveform of first DC-to-DC converter, second DC-to-DC converter and DC-to-DC converter unit; And
Fig. 8 (B) shows the output voltage waveform of first DC-to-DC converter, second DC-to-DC converter and DC-to-DC converter unit.
Wherein, description of reference numerals is as follows:
21 DC-to-DC converter, 22 inverters, 23 batteries
100 uninterruptible power supply providers, 10 battery pack, 11 DC-to-DC converter unit
12 inverters, 13 energy recuperation transducers, 14 digitial controllers
15 relays, 16 input filters, 111 first DC-to-DC converter
112 second DC-to-DC converter 411,421,132,712,713 switching devices
412 high frequency transformers, 413 rectifier circuits, 131 transformers
133 rectifier diodes
Embodiment
Advantage of the present invention and feature describe in detail by following embodiment conjunction with figs., obtain more deep understanding.
The preferred embodiment that embodies feature of the present invention and advantage will be described in detail in the explanation of back.It is noted that the components identical label represents components identical.Be understood that the present invention can have various variations on different embodiment, it does not depart from the scope of the present invention, and explanation wherein and Reference numeral be in itself with explaining, and is not in order to restriction the present invention.
The system configuration of uninterruptible power supply provider of the present invention is shown in Fig. 2.As shown in Figure 2, uninterruptible power supply provider 100 of the present invention comprises input filter (input filter) 16, relay (relay) 15, battery pack (battery pack) 10, DC-to-DC converter unit (DC-DC converter unit) 11, inverter (inverter) 12, digitial controller (digital controller) 14 and energy recuperation transducer (energyrecycle converter) 13.Input filter 16 is set at the electromagnetic interference of the input ac voltage that civil power is supplied and eliminates.Relay 15 is coupled to the output of input filter 16, its input ac voltage that is controlled in of accepting digitial controller 14 is just often closed so that input ac voltage is sent to load, provides and open when input ac voltage interrupts or be unusual so that the power supply supply switched to by inverter 12.Battery pack 10 is set at when input ac power storage power just often, and unusual or discharge its stored energy when interrupting when input ac power.DC-to-DC converter unit 11 is made up of a plurality of DC-to-DC converter, it is coupled to battery pack 10 and is set at and receives the electric current that battery pack 10 is exported, so that the direct voltage of battery pack 10 is converted to the direct voltage (full-waverectifed DC voltage) of full-wave rectification.Inverter 12 is coupled to the output of DC-to-DC converter unit 11, and its direct voltage with the full-wave rectification that DC-to-DC converter unit 11 is exported converts sine wave output AC voltage to.Energy recuperation transducer 13 is coupled to the input of inverter 12, and its excess energy that is set at uninterruptible power supply provider 100 is recycled to battery pack 10.The switch that digitial controller 14 is set at control relay 15 switches, and control DC-to-DC converter unit 11, inverter 12 and energy recuperation transducer 13 switch inside are switched.It is noted that in whole part of specification the identical circuit element of components identical numbering expression.
Fig. 3 shows the structural representation of DC-to-DC converter unit 11.As shown in Figure 3, DC-to-DC converter unit 11 is made up of first DC-to-DC converter 111 and second DC-to-DC converter 112 in the present embodiment, wherein first DC-to-DC converter 111 and the voltage input end of second DC-to-DC converter 112 are to be connected to battery 10 after in parallel mutually, and its voltage output end is for being connected to the input of inverter 12 after the series connection mutually.First DC-to-DC converter 111 is set at the direct voltage that receives battery pack 10 shown in Figure 1, and converts the direct voltage of battery pack 10 to first output dc voltage Vd1.Second DC-to-DC converter 112 is set at the direct voltage that receives battery pack 10 shown in Figure 1, and converts the direct voltage of battery pack 10 to second output dc voltage Vd2.First output dc voltage of first DC-to-DC converter 111 and second output dc voltage of second DC-to-DC converter 112 are set at addition on the output of DC-to-DC converter unit 11, and its summation is the direct voltage Vd of full-wave rectification.
Fig. 4 shows the circuit diagram according to first preferred embodiment of the DC-to-DC converter unit of uninterruptible power supply provider of the present invention and inverter and energy recuperation transducer.As shown in Figure 4, first DC-to-DC converter 111 is current fed full-bridge direct current-direct current transducer (current-fedfull-bridge DC-DC converter), and it is made up of switching device 411, high frequency transformer 412 and rectifier circuit 413.In Fig. 4, first DC-to-DC converter 111 is set at and receives the direct voltage that battery pack 10 is provided, and converts a square wave alternating-current voltage to by the direct voltage that the repeat switch operation of switching device 411 is provided battery pack 10.This square wave alternating-current voltage is transformed into an alternating voltage with magnitude of voltage of being wanted by using high frequency transformer 412, and by using rectifier circuit 413 to convert the first output dc voltage Vd1 to.Second DC-to-DC converter 112 is made up of step-down controller (buck converter), and it comes down to the second output dc voltage Vd2 by switching device 421 with the direct voltage of battery pack 10.Switching device 411 switches by digitial controller shown in Figure 1 14 controls with the switch of switching device 421.
The notable attribute of uninterruptible power supply provider of the present invention is that DC-to-DC converter unit 11 is made up of two DC-to-DC converter 111,112, and wherein each DC-to-DC converter is set at the output dc voltage Vd of the DC-to-DC converter unit 11 that a part is provided.By DC-to-DC converter 111 is connected with the output of DC-to-DC converter 112, DC-to-DC converter 111 and the output dc voltage of DC-to-DC converter 112 direct voltage that becomes a full-wave rectification just capable of being combined.Whereby, the direct voltage of inverter 12 full-wave rectification that DC-to-DC converter unit 11 can be provided converts sine wave AC voltage to so that output.
First DC-to-DC converter 111 has multiple combination with the output voltage waveforms of DC-to-DC converter 112.First kind possible is combined as the direct voltage that first DC-to-DC converter 111 first output dc voltage Vd1 that is exported and the second output dc voltage Vd2 that second DC-to-DC converter 112 is exported are the identical full-wave rectification of waveform, and wherein the summation of the direct voltage of these full-wave rectifications equals the magnitude of voltage of the output dc voltage Vd of DC-to-DC converter unit 11.The waveform that second kind possible is combined as the first output dc voltage Vd1 that first DC-to-DC converter 111 exported is the waveform of similar halfwave rectifier, and the waveform of the second output dc voltage Vd2 that second DC-to-DC converter 112 is exported is trapezoidal wave (trapezoid wave), shown in Fig. 8 (A).The waveform that the third is possible is combined as the first output dc voltage Vd1 that first DC-to-DC converter 111 exported is the waveform of similar halfwave rectifier and the hybrid waveform (composite) of sawtooth like ripple (sawtooth wave), and the waveform of the second output dc voltage Vd2 that second DC-to-DC converter 112 is exported is square wave (squarewave), shown in Fig. 8 (B).
See also Fig. 4 and Fig. 8 (A), the advantage of uninterruptible power supply provider of the present invention is described with the voltage waveform of the circuit structure of Fig. 4 and Fig. 8 (A) now.The voltage of supposing battery pack shown in Figure 1 10 is half of voltage peak of the output voltage V d of DC-to-DC converter unit 11.Because the output of first DC-to-DC converter 111 and second DC-to-DC converter 112 is for connecting, the output current of first DC-to-DC converter 111 and second DC-to-DC converter 112 is equal to load current.Therefore the power output of first DC-to-DC converter 111 and second DC-to-DC converter 112 just can by the comparison first output dc voltage Vd1 the area on the time shaft and the second output dc voltage Vd2 on time shaft area and obtain.By the voltage oscillogram of Fig. 8 (A) as can be known, the power output of first DC-to-DC converter 111 surpass DC-to-DC converter unit 11 gross output 60%, and the power output of second DC-to-DC converter 112 is less than 40% of the gross output of DC-to-DC converter unit 11.So, the volume of transformer of DC-to-DC converter unit 11 will significantly reduce.In addition, in time cycle t1-t3, second DC-to-DC converter 112 is not carried out copped wave and is handled (chopping), and therefore second DC-to-DC converter, 112 inside can not produce switching loss (switchingloss).In addition, since the power output of second DC-to-DC converter 112 in time cycle t1-t3 surpass DC-to-DC converter unit 11 gross output 50%, can reduce the power loss (power loss) of DC-to-DC converter unit 11 whereby significantly.
As shown in the above description, the distribution of the output voltage of first DC-to-DC converter 111 and second DC-to-DC converter 112 and power output is quite flexible.Therefore, the switch of DC-to-DC converter unit 11 adjusting (switching regulation) can adopt the various control skill to reach.For instance, in the time of can setting output voltage V d when DC-to-DC converter unit 11 less than particular value, by first DC-to-DC converter 111 and second DC-to-DC converter 112 one of them DC-to-DC converter, the output voltage V d of DC-to-DC converter unit 11 is provided fully as first DC-to-DC converter 111.Therefore, during this period of time, another DC-to-DC converter just can not produce any switching loss, thereby can improve the conversion efficiency of DC-to-DC converter unit 11 yet.When the output voltage V d of DC-to-DC converter unit 11 is equal to or greater than this particular value, one of them DC-to-DC converter of first DC-to-DC converter 111 and second DC-to-DC converter 112 is carried out switch with fixing duty cycle (duty cycle) and is switched, the another one DC-to-DC converter then provides the waveform compensation of output voltage, makes DC-to-DC converter unit 11 can export the direct voltage of the full-wave rectification of being wanted.That is to say that in the whole cycle of output voltage, DC-to-DC converter is set at the switch that carries out high frequency with variable duty cycle to be switched, and the another one DC-to-DC converter is set at and carries out switch with fixing duty cycle and switch.
See also Fig. 4 and Fig. 8 (B), with the circuit structure of Fig. 4 and the voltage waveform of Fig. 8 (B) the control skill that the switch of above-mentioned DC-to-DC converter unit 11 is regulated is described now.In this example, 421 on the switch of second DC-to-DC converter 112 can carry out low frequency copped wave (low-frequencychopping), therefore the switching loss of switch 421 just can be ignored, and the requirement to the high frequency characteristics of switch 421 simultaneously also can reduce.In time cycle t0-t1 and time cycle t3-t4, second DC-to-DC converter 112 is set at fixing duty cycle (duty cycle is 0) carries out the switch switching, and the output voltage V d of DC-to-DC converter unit 11 is provided fully by first DC-to-DC converter 111.In time cycle t1-t3, second DC-to-DC converter 112 is set at fixing duty cycle (duty cycle is 1) carries out the switch switching, and first DC-to-DC converter 111 is set at and carries out switch with variable duty cycle and switch, and provides waveform compensation with the output voltage V d to DC-to-DC converter unit 11.
The control skill that the switch of another alternative DC-to-DC converter unit 11 is regulated is described as follows.As the output voltage V d of DC-to-DC converter unit 11 during, provide the output voltage V d of DC-to-DC converter unit 11 fully by one of them DC-to-DC converter of first DC-to-DC converter 111 and second DC-to-DC converter 112 less than particular value.When the output voltage of this DC-to-DC converter reaches maximum, keep maximum voltage output, and another DC-to-DC converter is started working and is provided Waveform Control with the output voltage V d to DC-to-DC converter unit 11.That is to say that in the whole cycle of output voltage, first DC-to-DC converter 111 and second DC-to-DC converter 112 all are to carry out switch with variable duty cycle to switch.This control skill can obtain further to understand with reference to Fig. 8 (A).
The advantage of above-mentioned control skill is only to need just all DC-to-DC converter of may command DC-to-DC converter unit 11 of a controller, and can guarantee working with the minimized number transducer at any time.Utilize this control skill, the switching loss of DC-to-DC converter unit 11 is minimized, and the conversion efficiency of DC-to-DC converter unit 11 (conversion efficiency) is promoted.
It is noted that, second DC-to-DC converter 112 can realize by non-isolated direct current transducer (non-isolated DC-DC converter), for example step-down controller (buck converter), boost converter (boost converter), buck-boost transducer (buck-boost converter), Qiu Ke transducer (cuk converter).In addition, second DC-to-DC converter 112 also can be realized by isolated DC transducer (isolated DC-DC converter), for example current fed half-bridge DC-to-DC converter (current-fed half-bridge DC-DC converter), current fed full-bridge direct current-direct current transducer (current-fed full-bridge DC-DC converter), current fed push-pull type DC-to-DC converter (current-fed push-pull DC-DC converter), forward converter (forward converter), flyback converter (flyback converter).As shown in Figure 5, in second preferred embodiment of the present invention, second DC-to-DC converter 112 is realized by current fed full-bridge direct current-direct current transducer.
In Fig. 4, DC-to-DC converter unit 11 is made up of first DC-to-DC converter 111 and second DC-to-DC converter 112, and the voltage input end of first DC-to-DC converter 111 and second DC-to-DC converter 112 for parallel connection voltage output end mutually for to connect mutually.The advantage of this structure is to reduce the voltage stress (voltagestress) on the output of DC-to-DC converter unit 11.See also Fig. 6, it shows the circuit diagram according to the 3rd preferred embodiment of the DC-to-DC converter unit of uninterruptible power supply provider of the present invention and inverter and energy recuperation transducer, wherein first DC-to-DC converter 111 realizes with the current fed full-bridge direct current-direct current transducer of buck (buckcurrent-fed full-bridge DC-DC converter), and second DC-to-DC converter 112 realizes with step-down controller.If adopt a single current fed formula DC-to-DC converter to realize DC-to-DC converter unit 11, under the situation of the output AC voltage of inverter 12 output 220V, be arranged at the suffered voltage stress of rectifier circuit on the primary side (secondary side) of transformer of current fed formula DC-to-DC converter inside equals output AC voltage to I haven't seen you for ages peak value 311V.Under the situation that side circuit is implemented, the suffered voltage stress of rectifier circuit can be bigger.But if select to adopt the servant's of opening up structure of the present invention to realize DC-to-DC converter unit 11 with two DC-to-DC converter, described two output voltage peak values that DC-to-DC converter provided can be 155.5V.So, the suffered voltage stress of rectifier diode that is arranged on the primary side of transformer just can reduce, and also can reduce the power loss of DC-to-DC converter unit 11 simultaneously.
Energy recuperation transducer 13 is set at the excess energy (redundant energy) of recovery uninterruptible power supply provider 100 to battery pack 10.The output of supposing uninterruptible power supply provider 100 is connected to underload (light load), and this load is a resistive load.As shown in Figure 4, make that DC-to-DC converter unit 11 does not provide any energy to output capacitance even be positioned at the flash-over characteristic of the output capacitance on the output of DC-to-DC converter unit 11, it is consistent with the given waveform of the direct voltage Vd of full-wave rectification that voltage waveform on this output capacitance can not keep, thereby cause the output voltage V d of minimum DC-to-DC converter unit 11 non-vanishing.In addition, suppose that uninterruptible power supply provider 100 is when inductive load (inductive load) is powered, because the output voltage of uninterruptible power supply provider 100 and output current phase place is inconsistent, when causing the output voltage commutation, output current can oppositely flow into inverter 12.Even at this moment DC-to-DC converter unit 11 does not provide any energy to output capacitance, the voltage on this output capacitance also can rise because of the reverse inflow of inductive current, thereby causes the change of voltage waveform.In these examples, voltage on the output capacitance on the output of DC-to-DC converter unit 11 equals the direct voltage that superposeed on the direct voltage of a full-wave rectification, this direct voltage has been represented the excess energy of uninterruptible power supply provider 100.For fear of the idle of energy and high performance output voltage is provided, uninterruptible power supply provider 100 of the present invention adopts energy recuperation transducers 13 that these excess energies are reclaimed to battery pack 10 chargings.
By analyzing as can be known, because the excess energy that underload produced can occur in the descending branch (trailing edge) of the direct voltage Vd of the full-wave rectification of being exported DC-to-DC converter unit 11, time cycle t2~t4 of Fig. 8 (A) for example, because the excess energy that inductive load produced then usually occurs in the ascent stage (rising edge) of this direct voltage Vd, for example time cycle t0~t2 of Fig. 8 (A).
In a preferred embodiment of the invention, energy recuperation transducer 13 is a buck-boost transducer (buck-boost converter), as Fig. 4 and shown in Figure 6.The operation principle of energy recuperation transducer 13 is described with the example of Fig. 6 now.If digitial controller shown in Figure 1 14 detects when needing to reclaim excess energy, digitial controller 14 will detect the instantaneous value of the output voltage of DC-to-DC converter unit 11 at this moment.If this instantaneous value is higher than cell voltage, energy recuperation transducer 13 will start decompression mode.Otherwise, then start boost mode, excess energy is transferred on the battery pack 10 from the output of DC-to-DC converter unit 11.
In addition, energy recuperation transducer 13 can also serve as the charger of battery pack 10.When the normal and battery pack 10 of civil power needs charging, inverter 12 will act as a rectifying bridge type circuit (rectifying bridge circuit) that does not have voltage stabilizing control (unregulated), thereby form a fixing direct voltage at the output of DC-to-DC converter unit 11.This direct voltage charges to battery pack 10 with decompression mode by energy recuperation transducer 13.
Fig. 7 has shown the circuit diagram according to a kind of distortion of the DC-to-DC converter unit of uninterruptible power supply provider of the present invention and inverter and energy recuperation transducer, and wherein the part of energy recuperation transducer 13 can merge with second DC-to-DC converter 112.In this example, second DC-to-DC converter 112 is made up of step-down controller and energy recuperation transducer 13 is made up of the buck-boost transducer, and wherein energy recuperation transducer 13 is coupled between the input and second DC-to-DC converter 112 of inverter 12.Second DC-to-DC converter 112 has coupled an extra transistor switch 713 between the source terminal (source terminal) of mosfet transistor switch 712 and earth terminal, it is made up of bipolar junction transistor (bipolar junction transistor), and the output of energy recuperation transducer 13 is connected between mosfet transistor switch 712 and the output.Second DC-to-DC converter 112 will constitute a circuit of synchronous rectification, and it can reclaim automatically to the excess energy on the output capacitance of second DC-to-DC converter 112.Simultaneously, this extra transistor switch 713 also can act as the switching device of energy recuperation transducer 13 when boost mode is worked.
It is noted that energy recuperation transducer 13 also can be realized by any DC-to-DC converter.As shown in Figure 5, energy recuperation transducer 13 is realized by forward converter, it comprises transformer 131 and the transistor switch 132 that is coupled to the primary side (primary side) of transformer, and the rectifier diode (rectifying diode) 133 that is coupled to the primary side (secondary side) of transformer, wherein the excess energy that is set at when transistor switch 132 conductings (turu on) uninterruptible power supply provider 100 of the elementary winding of transformer 131 (primary winding) stores, and the energy that elementary winding is stored is sent to the primary side of transformation 131 devices when transistor switch 132 ends (turn off), so that charge to battery pack 10 via rectifier diode 133.
In order to realize above-mentioned circuit operation, digitial controller 14 is set at and is used for detecting the output voltage V d of DC-to-DC converter unit 11 and output voltage V d and reference voltage are made comparisons, so that the switch of controlling DC-to-DC converter unit 11, inverter 12 and energy recuperation transducer 13 according to the modulating signal of output pulse width as a result (PWM signals) relatively switches.
Comprehensive the above, the present invention proposes a kind of uninterruptible power supply provider, it can provide sine wave output AC voltage to load in city's electrical anomaly or interruption.The principal character of uninterruptible power supply provider of the present invention is that inner DC-to-DC converter unit is made up of first DC-to-DC converter and second DC-to-DC converter, wherein first DC-to-DC converter and the voltage input end of second DC-to-DC converter are mutual is coupled to battery pack after in parallel, and its voltage output end is coupled to the input of inverter mutually after the series connection.The switch of controlling described two DC-to-DC converter by the digitial controller of uninterruptible power supply provider switches, and first DC-to-DC converter and second DC-to-DC converter can be exported first output dc voltage and second output dc voltage respectively.Because first DC-to-DC converter and the mutual relation of connecting of the voltage output end of second DC-to-DC converter, second output dc voltage that first output dc voltage that first DC-to-DC converter is exported and second DC-to-DC converter are exported can addition becomes the direct voltage of full-wave rectification, so that convert the direct voltage of this full-wave rectification to sine wave output AC voltage by inverter.In addition, ratio value between the gross output of the power output of the power output of first DC-to-DC converter and second DC-to-DC converter and DC-to-DC converter unit can the elasticity adjustment, and the Circuits System of the Circuits System of first DC-to-DC converter and second DC-to-DC converter can design according to the demand in the practical application, can reduce the switching loss of DC-to-DC converter unit whereby significantly and promote the conversion efficiency of DC-to-DC converter unit.In addition, uninterruptible power supply provider of the present invention also provides an energy recuperation transducer, and it can reclaim the excess energy of uninterruptible power supply provider to battery pack, and the charger that also can be used as battery pack uses.
The present invention can make various modifications by knowing those skilled in the art, yet does not break away from the claimed scope of appended claims.