WO2002084853A1 - A switching resonant power supply - Google Patents

A switching resonant power supply Download PDF

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Publication number
WO2002084853A1
WO2002084853A1 PCT/PL2001/000034 PL0100034W WO02084853A1 WO 2002084853 A1 WO2002084853 A1 WO 2002084853A1 PL 0100034 W PL0100034 W PL 0100034W WO 02084853 A1 WO02084853 A1 WO 02084853A1
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WIPO (PCT)
Prior art keywords
resonant
capacitors
capacitor
crl
supply
Prior art date
Application number
PCT/PL2001/000034
Other languages
French (fr)
Inventor
Jerzy Dora
Urszula Dora
Ryszard Parosa
Edward Reszke
Original Assignee
Plazmatronika S.A.
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Priority to PCT/PL2001/000034 priority Critical patent/WO2002084853A1/en
Publication of WO2002084853A1 publication Critical patent/WO2002084853A1/en

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Classifications

    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33573—Full-bridge at primary side of an isolation transformer
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/01—Resonant DC/DC converters
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33571—Half-bridge at primary side of an isolation transformer
    • 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
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

  • the subject of the present disclosure is a switching-mode resonant power supply with quasi-resonant inversion of energy, which can be applied as mains power supply of general usage, resistant to changes in loading conditions as well as dedicated to perform energizing of loads with non-linear current-voltage characteristics.
  • the known and routinely used switching-mode resonant power supplies consist of inverters, usually full-bridge or half-bridge, which have 4 or 2 controllable switching active devices, e.g. power transistors, and a resonant circuit comprising a load which is implied to that circuit immediately or by means of an output transformer.
  • Series resonant inverters have their loads connected in series with resonant capacitor and resonant inductor while the parallel resonant inverters have loads connected in parallel to one of those reactance elements either to the inductor or capacitor as explained in text books like e.g. Barli ⁇ ski R., Nowak M.,technika T ⁇ rystorowa [ Thyristor Techniques], 3-rd Edition WNT Warsaw, 1994.
  • the distinctive feature of power supply with power recirculation is its immanent resistance to withstand short conditions and to maintain constant Q-factor of series resonant tank circuit.
  • the inconvenience of such a design is that in the circuit devoted for the recirculation of power one has to use full size transformers with apparent power ratings equal practically to power ratings of the output transformer. It is connected with higher costs, bigger size, and heavier weight of the device.
  • constant value of the Q-factor of the tank circuit, underlined in the above mentioned patent P-313150 seems not to be desirable in practice, because, when using the low loss elements, a constant Q should result as close to zero values of voltage across the capacitors' terminals in the short conditions.
  • the Q factor of series resonant tank circuit is supposed to lie within (1 ⁇ Q ⁇ 3). It also follows that the amount of energy oscillating in the tank circuit must be limited to such values that active elements in the whole circuit would get exposed neither to overvoltages, having magnitudes greater than the rail-to-rail DC supply nor to overcurrents bigger than allowable current ratings for the elements used.
  • the subject of the present invention is switching-type series resonant power supply with half- or full- bridge configurations of switching elements.
  • a capacitive divider is introduced comprising two capacitors such that their series connection value is equal to the desired resonant value while both capacitors are performing the desired transformation ratio n.
  • a transformer-less diode limiter has been introduced as a means for recirculation of power back to the rails of DC source.
  • the operation of this limiter is such that magnitudes of voltage at the point under control cannot exceed the value of DC supply voltage.
  • magnitudes of voltage on the capacitor divider with division ratio n would not be higher than n-fold the value of DC supply.
  • the second capacitor may have the role of the blocking capacitor or can even be replaced by a short.
  • the essence of the present invention is the introduction of diode limiter connected to at least one of capacitors existing in series resonant circuit in such a way as to enable transmission of the excess of resonant energy to be directed back to the source of DC supply.
  • Power supply according to the present invention without the use of additional transformer realizes return of energy excess taken out of the resonant circuit of resonant inverter either having the full- or half- bridge configurations. If one uses, in the circuit built according to the present invention, the elements characterized with low dissipation than one can expect in the short output conditions the DC rail current drawn to be reduced almost to negligible values while the output short current can still reach appreciable levels.
  • the capacitor Cr2 has been divided by two capacitors each having the value of 2Cr2.
  • Capacitor Crl has been placed on the axis of symmetry and there are 4 diodes Dol-Do4 which connected by pairs Dol,Do2 and Do3,Do4 form two parallel-type voltage limiters which connect both terminals of capacitor Crl with DC rails of the inverter. Connections of those limiters are provided by means of two series chokes, which are introduced symmetrically on both sides of the rails. As a result of functioning of the limiters Dol ,Do2 and respectively Do3,Do4 the voltage magnitudes across Crl are limited to the value of DC voltage between the rails.
  • Fig. l b and Fig. l c show the examples of realization of power supplies according to the present invention with 2 semiconductor switches Ti and T2 jumpered with diodes Dl and D2.
  • the capacitor Crl is connected with two blocking capacitors CB1 and CB2 while in the circuit of Fig. 1 c those capacitors have been replaced by two equal capacitors 1 /2 Cr which form a 1 :2 divider situated between the rails of DC supply.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

A switching-mode resonant power supply comprising resonant inverter in a bridge configuration of the switching transistors T1-T4 jumpered with diodes DI-D4 or in a half-bridge configuration of the switching transistors jumpered respectively with diodes DI -D2 has been equipped with a transformer-less diode limiter Do 1 -Do4 or Do 1 -Do2 which is connected preferably using a choke inductance Ld to the capacitor Cr1 which is part of resonant capacitance comprising series connected capacitors Cr1 and Cr2 forming the resonant capacitance of the circuit. Capacitor Cr1 is also a part of capacitive voltage divider with the division ratio of nCr2/(CrI+Cr2). The limiting of voltage magnitudes across the Cr1 results in partial return of energy oscillating within the circuit bringing it back to the DC supply and it also aims at the limiting of the circuits Q-factor to the level of Q=I /n keeping a very low level of energy loss.

Description

A Switching Resonant Power Supply
The subject of the present disclosure is a switching-mode resonant power supply with quasi-resonant inversion of energy, which can be applied as mains power supply of general usage, resistant to changes in loading conditions as well as dedicated to perform energizing of loads with non-linear current-voltage characteristics.
The known and routinely used switching-mode resonant power supplies consist of inverters, usually full-bridge or half-bridge, which have 4 or 2 controllable switching active devices, e.g. power transistors, and a resonant circuit comprising a load which is implied to that circuit immediately or by means of an output transformer. Series resonant inverters have their loads connected in series with resonant capacitor and resonant inductor while the parallel resonant inverters have loads connected in parallel to one of those reactance elements either to the inductor or capacitor as explained in text books like e.g. Barliήski R., Nowak M., Technika Tχrystorowa [ Thyristor Techniques], 3-rd Edition WNT Warsaw, 1994.
There is also known an inverter, in which regulation of output voltage has been introduced by means of the special rectifier with its AC input, connected to the secondary winding of output transformer and with its DC output feeding the supply rails of the inverter, this way providing the energy from the output to be partially returned to the DC source (see page 235 ibid. Limitations and shortcomings one encounters when applying power supplies with such a voltage regulation result from the fact that special provisions to current limiting of semiconductor switches must be implemented when the immanent resistance against load short conditions is to be realized. A kind of such the provision has been described already in the 1970's in the book by Luciήski J., Uktady Tyrystorowe, [Thyristor Circuits], 3-rd Edition WKit Warsaw, 1978, in which (see page 228 Fig. 14.9) there was shown application of additional transformer and diode rectifier both acting as a means for limiting of resonant circuits Q-factor having the feature of the return of energy excess back to the rails of DC supply (seepage 229 ibid 10 row from top for the detailed description to this circuit). Another circuit devoted for limiting of the Q-factor of resonant tank which can also enable the recirculation of energy has been described in a Polish patent P-313150, in which a switching-mode resonant power supply has been presented as a full-bridge transistor arrangement having a very efficient Q-factor limiter comprising a separate transformer with its primary winding connected in parallel to the resonant capacitor while the secondary of this transformer with step down ratio, preferably 1.4: 1 , connected to the diode rectifier the output of which has been connected to the DC source. Using that circuit it was possible to recirculate the power in a practically loss free manner.
The distinctive feature of power supply with power recirculation is its immanent resistance to withstand short conditions and to maintain constant Q-factor of series resonant tank circuit. The inconvenience of such a design is that in the circuit devoted for the recirculation of power one has to use full size transformers with apparent power ratings equal practically to power ratings of the output transformer. It is connected with higher costs, bigger size, and heavier weight of the device. Moreover, constant value of the Q-factor of the tank circuit, underlined in the above mentioned patent P-313150, seems not to be desirable in practice, because, when using the low loss elements, a constant Q should result as close to zero values of voltage across the capacitors' terminals in the short conditions. At the same time, according to the assumptions known as optimal for resonant inverters [ibid\, the Q factor of series resonant tank circuit is supposed to lie within (1 <Q<3). It also follows that the amount of energy oscillating in the tank circuit must be limited to such values that active elements in the whole circuit would get exposed neither to overvoltages, having magnitudes greater than the rail-to-rail DC supply nor to overcurrents bigger than allowable current ratings for the elements used.
The subject of the present invention is switching-type series resonant power supply with half- or full- bridge configurations of switching elements. In a power supply made according to the present invention, a capacitive divider is introduced comprising two capacitors such that their series connection value is equal to the desired resonant value while both capacitors are performing the desired transformation ratio n. Afterwards, to one of these capacitors a transformer-less diode limiter has been introduced as a means for recirculation of power back to the rails of DC source. The operation of this limiter is such that magnitudes of voltage at the point under control cannot exceed the value of DC supply voltage. As a consequence magnitudes of voltage on the capacitor divider with division ratio n would not be higher than n-fold the value of DC supply. Obviously, when nl the divider gets reduced to a single capacitor. In such the case the second capacitor may have the role of the blocking capacitor or can even be replaced by a short.
The essence of the present invention is the introduction of diode limiter connected to at least one of capacitors existing in series resonant circuit in such a way as to enable transmission of the excess of resonant energy to be directed back to the source of DC supply.
Power supply according to the present invention without the use of additional transformer realizes return of energy excess taken out of the resonant circuit of resonant inverter either having the full- or half- bridge configurations. If one uses, in the circuit built according to the present invention, the elements characterized with low dissipation than one can expect in the short output conditions the DC rail current drawn to be reduced almost to negligible values while the output short current can still reach appreciable levels.
The subject of the present invention is shown in the drawings where Fig. I a illustrates a series resonant inverter forming a bridge configuration with transistor switches TI -T4 connected in parallel with diodes Dl -D4 in which along the bridge diagonal a series resonant tank circuit was placed with series connected capacitors the resonant value of those is Cr=Crl*n, where n=Cr21 (Crl+Cr2) - is division ratio of capacitive divider. In order to point out the full symmetry of this electronic circuit the capacitor Cr2 has been divided by two capacitors each having the value of 2Cr2. Capacitor Crl has been placed on the axis of symmetry and there are 4 diodes Dol-Do4 which connected by pairs Dol,Do2 and Do3,Do4 form two parallel-type voltage limiters which connect both terminals of capacitor Crl with DC rails of the inverter. Connections of those limiters are provided by means of two series chokes, which are introduced symmetrically on both sides of the rails. As a result of functioning of the limiters Dol ,Do2 and respectively Do3,Do4 the voltage magnitudes across Crl are limited to the value of DC voltage between the rails.
In the example shown in Fig.l diodes Dol-Do4 form a bridge similar to an ordinary bridge rectifier. This would not has been so if inductive chokes were situated as in Fig. 1 b where they are playing the role of current smoothers acting separately for each of diode limiters. The inductive chokes in Fig. 1 a, which realize half-value of the inductance 1 /2Ld, can conveniently be wound on a common X-former in order to achieve the high degree of inductive coupling, which would compensate for the dc current magnetization of the core. Capacitors Crl and the twice- repeated 2Cr2 form capacitive voltage divider. As a coarse of action of the limiters with diodes Dol-Do4 the Q-factor of the resonant circuit takes the values as in Table 1.
Table 1.
Figure imgf000004_0001
It comes out from Table 1 that in all practical cases the value of Cr2 must fulfil condition that Cr2>Cr, where Cr is resonant capacitance of the tank circuit. Fig. l b and Fig. l c show the examples of realization of power supplies according to the present invention with 2 semiconductor switches Ti and T2 jumpered with diodes Dl and D2.
In the circuit of Fig. l b the capacitor Crl is connected with two blocking capacitors CB1 and CB2 while in the circuit of Fig. 1 c those capacitors have been replaced by two equal capacitors 1 /2 Cr which form a 1 :2 divider situated between the rails of DC supply.
The operation principle for both circuits is similar to operation of the circuit of Fig. l a. Naturally, under assumption that sequentially and periodically at the frequency close to that of the circuits resonant frequency there are activated one by one uneven switches TI ,(T3) and then the even ones T2,(T4) and that at the same time the roles of chokes Ld are also similar to the roles of l /2Ld inductances shown in Fig. 1 a. Taking into consideration the implication of symmetry for impedances which load the switches in bridge configuration as in Fig. l a one can suggest symmetrical distribution of inductance Lr into two inductors of i/2Lr values and symmetrical distribution of chokes such to form two 1 /2 Ld inductances and moreover a respective distribution of load resistance into two resistors of 1 /2R values.
In the circuits of Fig. 1 b and Fig. 1 c the symmetry against the DC rails is not necessarily important, especially when considering only a steady state operation. Therefore one can omit using of blocking capacitors CB as in Fig. 1 b and also omit the use of two half-valued elements 1 /2Crl, consequently having one Crl capacitor connected immediately to one of the supply rails. It is also worth stressing that in all above described circuits the load-receiver of the inverters usable output power have been represented by resistor R which plays the role of real load or which just substitutes for a real load being connected to the circuitry by means of an appropriate output transformer (not shown in this disclosure). Anyhow, in one of practical realizations of the circuit from Fig. 1 a the use of transformer, which split the real load into two equal resistances 1 /2R, has appeared desired.

Claims

Patent Claims
1. A switching-mode resonant power supply in a bridge configuration of transistor switches TI -T4 equipped with RLC resonant tank circuit which is placed along the diagonal of the bridge, having the distinctive feature that in order to enable the return of the energy from the resonant circuit to the rails of DC supply the resonant circuit has a series connected capacitor Crl placed centrally symmetrically against the simultaneously switching transistors and its terminals are connected by means of two voltage limiters comprising two pairs of diodes Dol ,Do2 and respectively Do3,Do4 connected from the side of their cathodes with positive rail of DC supply and from the side of their anodes connected with the negative rail, preferably by means of smoothing chokes 1 /2Lk, while along the diagonal of the bridge built up of four transistors TI - T4 symmetrically cn both sides of capacitor Cr2 there are connected in series two capacitors 2Crl , two resistors 1 /2 R and two half-rated resonant inductances 1 /2Lr which similarly to smoothing chokes 1 /2Lk can be wound using common X-formers. Two capacitors 2Crl along with capacitor Cr2 create resonant capacitance of Cr=Crl *Cr2/(Cri+Cr2) and at the same time these capacitors form a voltage divider with the ratio of n=Cr2/(Crl+Cr2).
2. A switching-mode resonant power supply in a half-bridge configuration of switching transistors T1 -T2 comprising a series resonant circuit RLC composed of resonant inductance Lr, load resistor R and resonant capacitor Cr having the distinctive feature that in order to obtain partial return of the energy back to supply DC rails the resonant capacitor comprises two series connected capacitors with total capacitance of Cr=Crl*Cr2/(Crl+Cr2) and the common point of connection between both the capacitors being the output of the voltage divider with division ratio of n=Cr2/(Crl+Cr2) is connected to the rails of DC supply by means of a parallel-type voltage limiter with diodes Do and Do2 preferably connected in series with chokes Ld which smoothes their peak currents and assuming that one of these capacitors can be replaced with short or with blocking capacitance while the second one with parallel connection of two capacitors 1 /2Crl .
PCT/PL2001/000034 2001-04-17 2001-04-17 A switching resonant power supply WO2002084853A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4410935A (en) * 1981-03-23 1983-10-18 General Signal Corporation Current overload protection for inverter of uninterruptible power supply system
US5438498A (en) * 1993-12-21 1995-08-01 Raytheon Company Series resonant converter having a resonant snubber
EP1009094A2 (en) * 1998-12-08 2000-06-14 Matsushita Electric Industrial Co., Ltd. Switching power supply apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4410935A (en) * 1981-03-23 1983-10-18 General Signal Corporation Current overload protection for inverter of uninterruptible power supply system
US5438498A (en) * 1993-12-21 1995-08-01 Raytheon Company Series resonant converter having a resonant snubber
EP1009094A2 (en) * 1998-12-08 2000-06-14 Matsushita Electric Industrial Co., Ltd. Switching power supply apparatus

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
MATSUO H ET AL: "New soft-commutated PWM inverter with AC current transformer", INDUSTRIAL ELECTRONICS, CONTROL, AND INSTRUMENTATION, 1993. PROCEEDINGS OF THE IECON '93., INTERNATIONAL CONFERENCE ON MAUI, HI, USA 15-19 NOV. 1993, NEW YORK, NY, USA,IEEE, 15 November 1993 (1993-11-15), pages 1275 - 1280, XP010109198, ISBN: 0-7803-0891-3 *
YONEMORI H ET AL: "Advanced soft-switching sinewave PWM high-frequency inverter-link cycloconverter incorporating voltage-clamped quasi-resonant and capacitive snubber techniques", PROCEEDINGS OF THE INDUSTRY APPLICATIONS SOCIETY ANNUAL MEETING. DEARBORN, SEPT. 28 - OCT. 1, 1991, NEW YORK, IEEE, US, vol. 2, 28 September 1991 (1991-09-28), pages 795 - 802, XP010056226, ISBN: 0-7803-0453-5 *

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