WO2013108376A1 - 電力変換装置 - Google Patents
電力変換装置 Download PDFInfo
- Publication number
- WO2013108376A1 WO2013108376A1 PCT/JP2012/050917 JP2012050917W WO2013108376A1 WO 2013108376 A1 WO2013108376 A1 WO 2013108376A1 JP 2012050917 W JP2012050917 W JP 2012050917W WO 2013108376 A1 WO2013108376 A1 WO 2013108376A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- converter
- phase
- group
- power
- voltage
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F30/00—Fixed transformers not covered by group H01F19/00
- H01F30/04—Fixed transformers not covered by group H01F19/00 having two or more secondary windings, each supplying a separate load, e.g. for radio set power supplies
-
- 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
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/483—Converters with outputs that each can have more than two voltages levels
- H02M7/4835—Converters with outputs that each can have more than two voltages levels comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage
-
- 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
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/483—Converters with outputs that each can have more than two voltages levels
- H02M7/49—Combination of the output voltage waveforms of a plurality of converters
Definitions
- the present invention relates to a power converter, and more particularly to a power converter connected to a three-phase system via a transformer.
- Patent Document 1 Japanese Patent Application Laid-Open No. 2010-233411
- Patent Document 1 does not require a reactor in a power converter configured by cascading unit converters connected to a power system via a transformer. And it aims at providing the power converter device which can reduce volume and weight.
- a power conversion device described in Japanese Patent Application Laid-Open No. 2010-233411 is connected to a three-phase power system via a transformer, and the three-phase power system and active or reactive power.
- Converter comprising a circuit in which the secondary winding of the transformer has six terminals as open windings, and three converter arms are star-connected to the three terminals of the secondary winding.
- a first converter group is connected, and a second converter group comprising a circuit in which another three converter arms are star-connected to the three terminals of the secondary winding is connected to the first converter.
- the neutral point (star-connected point) of the group and the neutral point (star-connected point) of the second converter group are used as output terminals of the power converter, respectively.
- Patent Document 1 In the power conversion device described in Japanese Patent Application Laid-Open No. 2010-233411 (Patent Document 1), one-third of the direct current component of the current ID flowing through the load 123 flows through the transformer as an excitation current. Since it is necessary to pass the magnetic flux for the current, it was necessary to increase the core cross-sectional area of the transformer. As a result, there is a problem that the size of the transformer becomes large and the cost of the transformer increases.
- a main object of the present invention is to provide a power conversion device capable of reducing the cross-sectional area of the iron core and reducing the cost.
- a power converter includes a three-phase transformer linked to a three-phase power system, and the three-phase transformer includes a primary winding group that receives the three-phase power of the three-phase power system, and a primary winding group.
- the first secondary winding group and the second secondary winding group that receive the power transferred from the first converter group, and the first converter group connected corresponding to the first to second secondary windings, respectively.
- a primary winding group having first to third primary windings, each of the first secondary winding groups having a neutral point at one end of each of the primary winding groups.
- First to third secondary windings connected to each other, and the second secondary winding group includes fourth to sixth secondary windings each having one end star-connected at a neutral point.
- first and second secondary winding groups are connected to each other, and the first converter group includes first to third The second ends of the secondary windings have first to third converter arms connected to the respective one ends, and the second converter group includes the other ends of the fourth to sixth secondary windings.
- a DC output terminal group to which at least one of the ends is connected.
- the DC output terminal group includes a positive DC output terminal and a negative DC output terminal.
- the other ends of the first to third converter arms are both connected to the positive DC output terminal.
- the other ends of the sixth to sixth converter arms are both connected to the negative DC output terminal.
- power is supplied to a load device connected to the DC output terminal group
- the power conversion device further includes a control circuit for transferring power to the load device
- the control circuit includes first to sixth conversions. Adjust the voltage applied to the DC output terminals.
- each of the first to sixth converter arms has a plurality of unit converters connected in cascade.
- the unit converter includes a full bridge circuit or a bidirectional chopper circuit.
- the unit converter has a DC capacitor for smoothing the output of the full bridge circuit or the bidirectional chopper circuit.
- the cross-sectional area of the iron core can be reduced, and the cost can be reduced.
- FIG. 3 is a diagram illustrating an example of an internal configuration of a unit converter 120.
- FIG. 6 is a diagram illustrating another example of the internal configuration of the unit converter 120.
- FIG. It is a figure which shows the equivalent circuit with respect to the alternating current component of a power converter device. It is a figure which shows the equivalent circuit with respect to the direct current
- FIG. 1 is a circuit diagram showing a configuration of a power converter according to an embodiment of the present invention.
- the power conversion device includes a three-phase transformer 101.
- Three-phase transformer 101 includes a transformer 105, a positive converter group 112, a negative converter group 116, and a control circuit 500.
- each phase of the three-phase power system 100 is referred to as a U phase, a V phase, and a W phase.
- Phase voltages are expressed as VU, VV, and VW.
- the current flowing through each phase of the three-phase power system 100 is referred to as a system current and is represented as IU, IV, IW.
- FIG. 2 is a diagram showing a configuration of the transformer 105 in the embodiment of the present invention. 1 and 2, transformer 105 includes a primary winding group 200 and two secondary winding groups 201A and 201B.
- primary winding group 200 includes U-phase terminal 102, V-phase terminal 103, and W-phase terminal 104.
- the secondary winding groups 201A and 201B include a u-phase positive terminal 106, a v-phase positive terminal 107, a w-phase positive terminal 108, a u-phase negative terminal 109, and a v-phase negative terminal 110. And a w-phase negative terminal 111.
- the turn ratio of the primary winding group 200 and the secondary winding groups 201A and 201B is 1: n / 2: n / 2.
- FIG. 2 shows the polarity of the magnetomotive force generated in each iron core by each winding of the transformer 105 and the connection of each winding.
- the transformer 105 has iron cores 202 to 204.
- the primary winding group 200 is delta-connected, and the primary windings 205, 206, and 207 between the U-phase and V-phase, between the V-phase and W-phase, and between the W-phase and U-phase are wound around the iron cores 202, 203, and 204, respectively. It has been turned.
- the number of turns of the primary windings 205 to 207 is substantially equal.
- Secondary winding group 201A is star-connected, and includes u-phase winding 208A, v-phase winding 209A, and w-phase winding 210A. The number of turns of the windings 208A to 210A is substantially equal.
- Secondary winding group 201B is star-connected, and includes u-phase winding 208B, v-phase winding 209B, and w-phase winding 210B. The number of turns of the windings 208B to 210B is substantially equal. Further, the neutral points of the secondary winding group 201A and the secondary winding group 201B are connected to each other. The secondary windings 208A and 208B are wound around the iron core 202, the secondary windings 209A and 209B around the iron core 203, and the secondary windings 210A and 210B around the iron core 204.
- the voltage across the u-phase winding 208A is represented as Vu
- the voltage across the v-phase winding 209A is represented as Vv
- the voltage across the w-phase winding 210A is represented as Vw.
- the voltage across u-phase winding 208B is represented as Vu
- the voltage across v-phase winding 209B is represented as Vv
- the voltage across w-phase winding 210B is represented as Vw.
- a load device 123 is connected between the positive DC output terminal 121 and the negative DC output terminal 122 of the power converter.
- the voltage applied to the load device 123 is represented as Vdc, and the current flowing through the load device 123 is represented as Idc.
- the positive-side converter group 112 includes a u-phase positive-side converter arm 113, a v-phase positive-side converter arm 114, and a w-phase positive-side converter arm 115.
- the negative converter group 116 includes a u-phase negative converter arm 117, a v-phase negative converter arm 118, and a w-phase negative converter arm 119.
- the converter arm means a circuit in which one or a plurality of unit converters are cascade-connected.
- the unit converter for example, a bidirectional chopper circuit as shown in FIG.
- Each transducer arm has at least two terminals. In the present embodiment, these two terminals are referred to as a terminal and b terminal, respectively.
- the voltage up to the a terminal with respect to the b terminal is referred to as an arm voltage.
- the arm voltage is represented by the sum of the voltage difference (hereinafter referred to as cell voltage) across the unit converter included in the converter arm.
- Each converter arm 113 to 115, 117 to 119 has an a terminal (not shown) and a b terminal (not shown).
- Each of the converter arms 113 to 115 and 117 to 119 is a circuit in which one or a plurality of unit converters 120 are cascade-connected.
- the a terminal of the u-phase positive converter arm 113 is connected to the positive DC output terminal 121, and the b terminal is connected to the u-phase positive terminal 106 of the transformer 105.
- the arm voltage of u-phase positive side converter arm 113 is represented as Vup.
- the a terminal of the v-phase positive converter arm 114 is connected to the positive DC output terminal 121, and the b terminal is connected to the v-phase positive terminal 107 of the transformer 105.
- the arm voltage of the v-phase positive converter arm 114 is represented as Vvp.
- the a terminal of the w-phase positive converter arm 115 is connected to the positive DC output terminal 121, and the b terminal is connected to the w-phase positive terminal 108 of the transformer 105.
- the arm voltage of the w-phase positive converter arm 115 is represented as Vwp.
- the a terminal of the u-phase negative converter arm 117 is connected to the u-phase negative terminal 109 of the transformer 105, and the b terminal is connected to the negative DC output terminal 122.
- the arm voltage of u-phase negative side converter arm 117 is represented as Vun.
- the a terminal of the v-phase negative converter arm 118 is connected to the v-phase negative terminal 110 of the transformer 105, and the b terminal is connected to the negative DC output terminal 122.
- the arm voltage of the v-phase negative converter arm 118 is represented as Vvn.
- the a terminal of the v-phase negative converter arm 119 is connected to the w-phase negative terminal 111 of the transformer 105, and the b terminal is connected to the negative DC output terminal 122.
- the arm voltage of the w-phase negative converter arm 119 is represented as Vwn.
- the current flowing through u-phase positive converter arm 113 is u-phase arm current Iu
- the current flowing through v-phase positive converter arm 114 is v-phase arm current Iv
- w-phase positive side The current flowing through the converter arm 115 will be expressed as w-phase arm current Iw.
- the current flowing through the u-phase negative converter arm 117 is referred to as u-phase arm current Ix
- the current flowing through the v-phase negative converter arm 118 is defined as v-phase arm current Iy
- the current is expressed as w-phase arm current Iz.
- the voltages supplied to the u-phase positive terminal 106, the v-phase positive terminal 107, and the w-phase positive terminal 108 are represented as a voltage Vu, a voltage Vv, and a voltage Vw, respectively.
- voltages supplied to the u-phase negative terminal 109, the v-phase negative terminal 110, and the w-phase negative terminal 111 are represented as a voltage Vu, a voltage Vv, and a voltage Vw, respectively. .
- one ends of converter arms 113 to 115 are all connected to positive DC output terminal 121, and one ends of converter arms 117 to 119 are both connected to negative DC output terminal 122.
- the present invention is not limited to this, and at least one of the one ends of the converter arms 113 to 115 is connected to the positive side DC output terminal 121, and at least one of the one ends of the converter arms 117 to 119 is the negative side.
- the DC output terminal 122 may be connected.
- control circuit 500 controls the direct current Idc, the voltages Vu, Vv, Vw of each phase, and the direct current voltage command value Vdc * in order to control the alternating current I to a desired value.
- control is performed in response to the direct current command value Idc * and the alternating current command value I *.
- FIG. 3 is a diagram illustrating an example of the internal configuration of the unit converter 120.
- the unit converter is a full bridge circuit.
- the unit converter 120 is a two-terminal circuit having an x terminal 300 and a y terminal 301, and includes an x-phase positive switching element 302, an x-phase negative switching element 303, a y-phase positive switching element 304, and y Phase negative side switching element 305 and energy storage element 306 are included.
- the switching elements 302 to 305 are self-extinguishing power semiconductor elements represented by IGBTs.
- the energy storage element 306 is a capacitor, a storage battery, or the like.
- the voltage up to the x terminal with respect to the y terminal is referred to as a cell voltage Vcell of the unit converter.
- the unit converter 120 may be a bidirectional chopper circuit.
- FIG. 4 is a diagram illustrating another example of the internal configuration of the unit converter 120.
- the bidirectional chopper includes a positive side switching element 403, a negative side switching element 404, and an energy storage element 405.
- the switching elements 403 and 404 are self-extinguishing power semiconductor elements represented by IGBT.
- the energy storage element 405 is a capacitor, a storage battery, or the like. In the present embodiment, this voltage in FIG. 4 is also expressed as a cell voltage Vcell.
- the arm voltage can be controlled by the switching state of the switching elements constituting the unit converter 120.
- the x-phase switching elements 302 and 303 are turned on and off alternately.
- the y-phase switching elements 304 and 305 are alternately turned on and off.
- the cell voltage Vcell is substantially the same as the voltage VC of the energy storage element 306 without depending on the current Icell. equal.
- the cell voltage Vcell is almost zero without depending on the current Icell.
- the cell voltage Vcell is almost zero without depending on the current Icell.
- the cell voltage Vcell does not depend on the current Icell, and the polarity of the voltage VC of the energy storage element 306 Is approximately equal to the inverted voltage.
- the cell voltage Vcell is determined depending on the polarity of the current Icell.
- Icell is positive
- the cell voltage Vcell is substantially equal to the voltage VC of the energy storage element 306.
- Icell is negative
- the cell voltage Vcell is substantially equal to a voltage obtained by inverting the polarity of the voltage VC of the energy storage element 306.
- the unit converter 120 is a bidirectional chopper (FIG. 4)
- the cell voltage Vcell is substantially equal to the voltage VC of the energy storage element 405 without depending on the current Icell.
- the cell voltage Vcell is determined depending on the polarity of the current Icell.
- Icell When Icell is positive, the cell voltage Vcell is substantially equal to the voltage VC of the energy storage element 405.
- Icell is negative, the cell voltage Vcell is approximately equal to zero.
- FIG. 5 is a diagram showing an equivalent circuit for an AC component having a frequency of the power system 100 of the power converter.
- equivalent circuit 1010 supplies reactances 502 and 602 (transformer winding reactance is Xu), positive-side power converter 503 and negative-side power exchanger 603, and voltage Vu.
- Power sources 501 and 601 (voltage Vu is a transformer no-load secondary voltage) and V1 and V2 that supply DC voltage Vdc / 2 are included.
- the power source V1 is connected between the positive DC output terminal 121 and the node N2, and the voltage value of the power source V1 during this period is Vdc / 2.
- the power supply V2 is connected between the node N2 and the negative DC output terminal 122, and the voltage value of the power supply V2 during this period is Vdc / 2.
- a positive power converter 503, a reactance 502, and a power source 501 are connected in series between the positive DC output terminal 121 and the node N1.
- a power source 601, a reactance 602, and a negative power exchanger 603 are connected in series between the node N1 and the negative DC output terminal 122 in this order.
- equations (1) and (2) are established.
- Varmup Vdc / 2 ⁇ Vu + j ⁇ Xu ⁇ I (1a)
- Varmun Vdc / 2 + Vu ⁇ j ⁇ Xu ⁇ I (2a)
- the alternating current I can be controlled to a desired value by controlling the positive arm voltage Varmup and the negative arm voltage Varmun to predetermined values, respectively. it can.
- the alternating current I increases. Conversely, if the positive arm voltage Varmup is decreased and at the same time the negative arm voltage Varmun is increased by the same amount, the alternating current I decreases.
- FIG. 6 is a diagram showing an equivalent circuit for the DC component of the power converter.
- an equivalent circuit for the DC component in the u phase will be shown and described.
- the configuration of equivalent circuit 1020 includes winding resistors 502A and 602A instead of winding reactances 502 and 602 of equivalent circuit 1010 shown in FIG. Since other configurations of equivalent circuit 1020 are similar to those of equivalent circuit 1010, description thereof will not be repeated here.
- Equation (3) is established from the equivalent circuit 1020.
- Varmup + Varmun-2Ru ⁇ Idc / 3 Vdc (3)
- the u-phase voltage (transformer no-load secondary voltage) Vu is canceled and does not appear in the equation (3).
- the following formula (3a) is obtained by transforming the formula (3).
- Varmup + Varmun 2Ru ⁇ Idc / 3 + Vdc (3a)
- the DC current Idc can be controlled to a desired value by controlling the sum of the positive arm voltage Varmup and the negative arm voltage Varmn to a predetermined value.
- the direct current Idc increases, and if the arm voltages Varmup and Varmun are decreased, the direct current Idc decreases.
- FIG. 7 is a diagram showing a main configuration of a control circuit 500 that controls the arm voltages Varmup and Varmun.
- control circuit 500 includes adders 701A to 701D, subtracters 702A to 702D, a direct current controller 710, an alternating current controller 720, and an amplifier 730.
- the subtractor 702A supplies a direct current value (Idc * ⁇ Idc) obtained by subtracting a direct current (detected value) Idc from the direct current command value Idc * to the direct current controller 710 (amplification factor g1).
- the subtractor 702B supplies an alternating current value (I * ⁇ I) obtained by subtracting the alternating current (detected value) I from the alternating current command value I * to the alternating current controller 720 (amplification factor g2).
- the adder 701A adds the direct current (g1 ⁇ (Idc * ⁇ Idc)) amplified by the direct current controller 710 and the alternating current (g2 ⁇ (I * ⁇ I)) amplified by the alternating current controller 720. To do.
- the subtractor 702C subtracts the alternating current (g2 ⁇ (I * ⁇ I)) amplified by the alternating current controller 720 from the direct current (g1 ⁇ (Idc * ⁇ Idc)) amplified by the direct current controller 710. To do.
- the output current of the adder 701A is (g1 ⁇ (Idc * ⁇ Idc) + g2 ⁇ (I * ⁇ I)) / 2
- the output current of the subtractor 702C is (g1 ⁇ (Idc * ⁇ Idc) ⁇ g2 ⁇ (I * -I)) / 2.
- the subtractor 702D subtracts the transformer secondary voltage detection value from the current output from the adder 701A.
- the adder 701B adds the current output from the subtractor 702C and the transformer secondary voltage detection value.
- the output current of the subtractor 702D is (g1 ⁇ (Idc * ⁇ Idc) + g2 ⁇ (I * ⁇ I)) / 2 ⁇ Vu
- the output current of the adder 701B is (g1 ⁇ (Idc * ⁇ Idc) ⁇ g2 ⁇ (I * ⁇ I)) / 2 + Vu.
- the adder 701C adds the current output from the subtractor 702D and the output voltage obtained by amplifying the DC voltage command value Vdc * by the amplifier 730 (amplification factor of 1/2) to obtain the positive arm voltage command value.
- the positive side arm voltage Varmup is output.
- the adder 701D adds the current output from the adder 701B and the output voltage obtained by amplifying the DC voltage command value Vdc * by the amplifier 730 (amplification factor 1/2) as a negative arm voltage command value.
- the negative arm voltage Varmun is output.
- the positive arm voltage Varmup as the positive arm voltage command value is (g1 ⁇ (Idc * ⁇ Idc) + g2 ⁇ (I * ⁇ I)) / 2 ⁇ Vu + Vdc * / 2, while the negative arm voltage command As a value, the negative side arm voltage Varmun is (g1 ⁇ (Idc * ⁇ Idc) ⁇ g2 ⁇ (I * ⁇ I)) / 2 + Vu + Vdc * / 2.
- the direct current / alternating current can be adjusted by setting the arm voltage.
- the direct current and the alternating current can be adjusted by performing the same operation in the v phase and the w phase, the description will not be repeated here.
- FIG. 8 is a diagram for explaining the power conversion operation by the power conversion device.
- these are examples of operation waveforms of the power converter, and the voltages VU, VV, VW and phase currents IU, IV, IW of the three-phase power system 100 and the secondary voltage Vu of each phase.
- Vdc DC voltage
- Idc DC current
- the amplitudes of the voltages VU, VV, and VW of the power system are substantially equal to each other. Furthermore, the voltages VU, VV, VW of the power system have a phase difference of 120 degrees.
- phase currents IU, IV, IW at this time are also substantially equal in amplitude. Further, the currents VU, VV, VW have a phase difference of 120 degrees.
- the amplitudes of the secondary voltages Vu, Vv, and Vw of each phase are substantially equal to each other.
- the voltages Vu, Vv, Vw of each phase have a phase difference of 120 degrees.
- the power system voltage VU and the u-phase secondary voltage Vu have a phase difference of approximately 30 degrees.
- the relationship between the other voltages VV and VW and the secondary voltages Vv and Vw is substantially the same.
- the arm voltage Vup of the positive-side converter arm 113 includes a DC component substantially equal to Vdc / 2 and an AC component having a phase difference of approximately 180 degrees from the u-phase secondary voltage Vu. have.
- voltage Vun of negative side converter arm 117 has a direct current component substantially equal to Vdc / 2 and an alternating current component having a phase difference of about 180 degrees from u-phase secondary voltage Vu.
- the arm current Iu flowing through the positive converter arm 113 has an AC component having a phase difference of approximately 180 degrees from the secondary voltage Vu and a DC component substantially equal to Idc / 3.
- the arm current Ix flowing through the negative-side converter arm 117 has an AC component substantially in phase with the secondary voltage Vu and a DC component substantially equal to Idc / 3.
- the amplitudes of the arm current Iu and the arm current Ix are substantially equal.
- FIG. 9 is a diagram illustrating a configuration of the power conversion device of the study example.
- the configuration of the power conversion device of the study example includes a secondary winding group 201X instead of the secondary winding groups 201A and 201B in the configuration of the power conversion device of the present embodiment.
- the other structure of the power converter device of an examination example is the same as that of the power converter device of this Embodiment, description is not repeated here.
- one secondary winding group 201X is provided for the positive-side converter group 112 and the negative-side converter group 116, and power is supplied to the load device 123.
- 123 receives power from 123.
- the u-phase current Iu on the positive side of the secondary winding is expressed by the following equation.
- Equation (7) The first term on the right side of Equation (7) indicates a DC component, and the second term on the right side of Equation (7) indicates an AC component.
- the turns ratio of the primary winding of the primary winding group 200, the corresponding secondary winding in the secondary winding group 201A, and the corresponding secondary winding in the secondary winding group 201B is 1: n. / 2: Since n / 2, and only the alternating current is transmitted, the u-phase current IUX of the primary winding group 200 is expressed by the following equation.
- the excitation current of the DC component that has become a problem in the power conversion device of the study example is that of the DC magnetomotive force of the two secondary windings wound around the same iron core in the power conversion device of the present embodiment. Since the component is canceled, no exciting current flows. Therefore, the mounting area and cost can be reduced without having to increase the cross-sectional area of the iron core of the transformer.
- the power converter according to the present embodiment shown in FIG. 1 does not have a configuration with one secondary winding as in the power converter of the study example, but instead is on the positive converter group 112 side.
- the negative side converter group 116 side by providing the secondary winding groups 201A and 201B, respectively, the DC component of the magnetomotive force can be canceled, and there is no need to increase the cross-sectional area of the iron core of the transformer, Cost can be reduced.
- the power conversion device of the present embodiment includes a three-phase transformer 105 linked to a three-phase power system 100, and the three-phase transformer 105 is a three-phase power system.
- the primary winding group 200 that receives the three-phase power
- the secondary winding group 201A and the secondary winding group 201B that receive the power transferred from the primary winding group
- the secondary winding groups 201A and 201B respectively.
- the primary winding group 200 includes primary windings 205 to 207
- the secondary winding group 201A has a neutral point at one end of each of the primary winding group 200 and the converter group 116.
- the secondary winding group 201B has secondary windings 208B to 210B that are star-connected at a neutral point at one end of each secondary winding 208A to 210A. roll
- the neutral points of each of the groups 201A and 201B are connected to each other, and the converter group 112 has converter arms 113 to 115 in which the other ends of the secondary windings 208A to 210A are connected to the respective one ends.
- Converter group 116 includes converter arms 117 to 119 in which the other ends of secondary windings 208B to 210B are connected to the respective one ends, and at least one of the other ends of converter arms 113 to 115, and A DC output terminal group (121, 122) to which at least one of the other ends of the converter arms 117 to 119 is connected.
- the DC output terminal groups 121 and 122 include a positive DC output terminal 121 and a negative DC output terminal 122, and the other ends of the converter arms 113 to 115 are both positive. The other end of each of the converter arms 117 to 119 is connected to the negative DC output terminal 122.
- power is supplied to a load device 123 connected to the DC output terminal group (121, 122), and the power conversion device 500 transmits and receives power to the load device.
- the control circuit 500 adjusts the voltages of the converter arms 113 to 115 and 117 to 119, and controls the voltages applied to the DC output terminal groups (121, 122).
- each of the converter arms 113 to 115 and 117 to 119 has a plurality of unit converters 120 connected in cascade.
- the unit converter 120 includes a full bridge circuit or a bidirectional chopper circuit.
- the unit converter 120 includes DC capacitors 306 and 405 for smoothing the output of the full bridge circuit or the bidirectional chopper circuit.
- the primary winding of the transformer 105 may be a delta connection, a star connection, or may be three single-phase transformers.
- the scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
- Rectifiers (AREA)
Abstract
Description
本発明の電力変換装置の構成について、図1を用いて説明する。
二次巻線グループ201Aはスター結線されており、u相巻線208Aと、v相巻線209Aと、w相巻線210Aとを含む。巻線208A~210Aの巻数は略等しくなる。二次巻線グループ201Bはスター結線されており、u相巻線208Bと、v相巻線209Bと、w相巻線210Bとを含む。巻線208B~210Bの巻数は略等しくなる。さらに、二次巻線グループ201Aと二次巻線グループ201Bのそれぞれの中性点同士が接続される。二次巻線208A,208Bは鉄心202に、二次巻線209A,209Bに鉄心203に、二次巻線210A,210Bに鉄心204に巻回する。
図3は、単位変換器120の内部構成の一例を示す図である。図3を参照して、単位変換器はフルブリッジ回路である。単位変換器120は、x端子300とy端子301とを有する2端子回路であり、x相正側スイッチング素子302と、x相負側スイッチング素子303と、y相正側スイッチング素子304と、y相負側スイッチング素子305と、エネルギー蓄積素子306とを含む。スイッチング素子302~305は、IGBTに代表される自己消弧形電力用半導体素子である。また、エネルギー蓄積素子306は、コンデンサや蓄電池などである。本実施の形態では、y端子を基準としたx端子までの電圧を、単位変換器のセル電圧Vcellと呼ぶことにする。
図4は、単位変換器120の内部構成の別の一例を示す図である。図4を参照して、双方向チョッパは、正側スイッチング素子403と、負側スイッチング素子404と、エネルギー蓄積素子405とを含む。スイッチング素子403,404は、IGBTに代表される自己消弧形電力用半導体素子である。また、エネルギー蓄積素子405は、コンデンサや蓄電池などである。本実施の形態では、図4におけるこの電圧もセル電圧Vcellと表わすことにする。
x相スイッチング素子302,303はそれぞれ交互にオン・オフする。また、y相スイッチング素子304,305はそれぞれ交互にオン・オフする。
スイッチング素子403,404がそれぞれオン、オフする場合、電流Icellに依存することなく、セル電圧Vcellはエネルギー蓄積素子405の電圧VCに略等しい。
-Vu+j・Xu・I+Varmun=Vdc/2 (2)
なお、jは虚数を示す。これらを変形すると、式(1a)、式(2a)が成立する。
Varmun=Vdc/2+Vu-j・Xu・I (2a)
ここで、電圧Vdc,Vuおよび抵抗Xuは一定値であるため、正側アーム電圧Varmupと負側アーム電圧Varmunとをそれぞれ所定値に制御することにより交流電流Iを所望の値に制御することができる。
Varmup+Varmun-2Ru・Idc/3=Vdc (3)
この式(3)で明らかなようにu相電圧(変圧器無負荷二次電圧)Vuはキャンセルされて、式(3)には現れない。さらに式(3)を変形すると以下の式(3a)が得られる。
そうすると、直流電圧Vdc、巻線抵抗Ruは一定値なので、正側アーム電圧Varmupと負側アーム電圧Varmnとの和を所定値に制御することにより直流電流Idcを所望の値に制御することができる。
なお、v相、w相においてもそれぞれ同様な動作をさせることにより直流電流・交流電流を調整することができるため、ここでは説明は繰返さない。
[検討例]
図9は、検討例の電力変換装置の構成を示す図である。
正側直流出力端子121と負側直流出力端子122との間に流れる直流電流Idcとし、交流電流Iの交流電流波高値(I)とし、周波数ωを電源角周波数とすると、二次巻線のu相電流Iuは式(4)のように表される。
式(4)の右辺の第1項は電流Iuの直流成分を示し、式(4)の右辺の第2項は電流Iuの交流成分を示す。ここで、一次巻線グループ200の一次巻線と二次巻線グループ201Xにおいて対応する二次巻線との巻数比が1:nであり、伝達される電流は交流電流のみであるため、一次巻線グループ200のu相の電流IUXは次式のように表される。
一方、電流Iuの直流電流分の1/3・Idcは、この一次巻線グループ200の励磁電流として流れる。この電流によって発生するであろう磁束が変圧器を通過するために、変圧器の鉄心の断面積は増加する必要がある。
上記から右辺の第1項は、直流成分を示し、右辺の第2項は、交流成分を示す。次に、二次巻線の負側のu相電流Ixは次式のように表される。
式(7)の右辺の第1項は直流成分を示し、式(7)の右辺の第2項は交流成分を示す。ここで、一次巻線グループ200の一次巻線と、二次巻線グループ201Aにおいて対応する二次巻線と、二次巻線グループ201Bにおいて対応する二次巻線との巻数比が1:n/2:n/2であり、伝達される電流は交流電流のみであるため、一次巻線グループ200のu相の電流IUXは次式のように表される。
ここで、検討例の電力変換装置で問題となった直流成分の励磁電流は、本実施の形態の電力変換装置においては同一鉄心に巻回された2つの二次巻線で直流の起磁力の成分がキャンセルされるため、励磁電流は流れない。したがって、変圧器の鉄心の断面積を増加させる必要なく、実装面積およびコストを削減することができる。
図1、図2で示されるように、本実施の形態の電力変換装置は、三相電力系統100に連系する三相変圧器105を備え、三相変圧器105は、三相電力系統の三相電力を受ける一次巻線グループ200と、一次巻線グループから転送される電力を受ける二次巻線グループ201Aおよび二次巻線グループ201Bと、二次巻線グループ201A,201Bにそれぞれ対応して接続される変換器グループ112および変換器グループ116とを含み、一次巻線グループ200は、一次巻線205~207を有し、二次巻線グループ201Aは、各々の一方端が中性点でスター結線される二次巻線208A~210Aを有し、二次巻線グループ201Bは、各々の一方端が中性点でスター結線される二次巻線208B~210Bを有し、二次巻線グループ201A、201Bの各々の中性点は、互いに接続され、変換器グループ112は、二次巻線208A~210Aの他方端がそれぞれの一方端に接続される変換器アーム113~115を有し、変換器グループ116は、二次巻線208B~210Bの他方端がそれぞれの一方端に接続される変換器アーム117~119を有し、変換器アーム113~115の他方端のうち少なくとも一つと変換器アーム117~119の他方端のうち少なくとも一つとが接続される直流出力端子群(121,122)とを備える。
Claims (6)
- 三相電力系統(100)に連系する三相変圧器(105)を備え、
前記三相変圧器(105)は、
前記三相電力系統の三相電力を受ける一次巻線グループ(200)と、
前記一次巻線グループから転送される電力を受ける第1の二次巻線グループ(201A)および第2の二次巻線グループ(201B)と、
前記第1~第2の二次巻線グループ(201A,201B)にそれぞれ対応して接続される第1の変換器グループ(112)および第2の変換器グループ(116)とを含み、
前記一次巻線グループ(200)は、第1~第3の一次巻線(205~207)を有し、
前記第1の二次巻線グループ(201A)は、各々の一方端が中性点でスター結線される第1~第3の二次巻線(208A~210A)を有し、
前記第2の二次巻線グループ(201B)は、各々の一方端が中性点でスター結線される第4~第6の二次巻線(208B~210B)を有し、
前記第1および第2の二次巻線グループ(201A、201B)の各々の中性点は、互いに接続され、
前記第1の変換器グループ(112)は、前記第1~第3の二次巻線(208A~210A)の他方端がそれぞれの一方端に接続される第1~第3の変換器アーム(113~115)を有し、
前記第2の変換器グループ(116)は、前記第4~第6の二次巻線(208B~210B)の他方端がそれぞれの一方端に接続される第4~第6の変換器アーム(117~119)を有し、
前記第1~第3の変換器アーム(113~115)の他方端のうち少なくとも一つと前記第4~第6の変換器アーム(117~119)の他方端のうち少なくとも一つとが接続される直流出力端子群(121,122)とを備える、電力変換装置。 - 前記直流出力端子群(121,122)は、
正側直流出力端子(121)と、
負側直流出力端子(122)とを含み、
前記第1~第3の変換器アーム(113~115)の他方端はともに前記正側直流出力端子(121)に接続され、
前記第4~第6の変換器アーム(117~119)の他方端はともに前記負側直流出力端子(122)に接続される、請求項1に記載の電力変換装置。 - 前記直流出力端子群と接続される負荷装置(123)に電力を供給し、
前記電力変換装置は、
前記負荷装置に電力を授受するための制御回路(500)をさらに備え、
前記制御回路(500)は、前記第1~第6の変換器アーム(113~115,117~119)の電圧を調整し、前記直流出力端子群(121,122)に印加される電圧を制御する、請求項1に記載の電力変換装置。 - 前記第1~第6の変換器アーム(113~115,117~119)の各々は、カスケード接続された複数の単位変換器(120)を有する、請求項1に記載の電力変換装置。
- 前記単位変換器(120)は、
フルブリッジ回路または双方向チョッパ回路を含む、請求項4に記載の電力変換装置。 - 前記単位変換器(120)は、
前記フルブリッジ回路または前記双方向チョッパ回路の出力を平滑化させるための直流コンデンサ(306、405)を有する、請求項5に記載の電力変換装置。
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP16199328.2A EP3148068B1 (en) | 2012-01-18 | 2012-01-18 | Power conversion device |
DK12865949.7T DK2806552T3 (en) | 2012-01-18 | 2012-01-18 | Energy converter layout |
EP12865949.7A EP2806552B1 (en) | 2012-01-18 | 2012-01-18 | Power conversion device |
US14/368,673 US9343994B2 (en) | 2012-01-18 | 2012-01-18 | Power conversion apparatus having two secondary winding groups |
PCT/JP2012/050917 WO2013108376A1 (ja) | 2012-01-18 | 2012-01-18 | 電力変換装置 |
JP2013554145A JP5828912B2 (ja) | 2012-01-18 | 2012-01-18 | 電力変換装置 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2012/050917 WO2013108376A1 (ja) | 2012-01-18 | 2012-01-18 | 電力変換装置 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013108376A1 true WO2013108376A1 (ja) | 2013-07-25 |
Family
ID=48798825
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/050917 WO2013108376A1 (ja) | 2012-01-18 | 2012-01-18 | 電力変換装置 |
Country Status (5)
Country | Link |
---|---|
US (1) | US9343994B2 (ja) |
EP (2) | EP2806552B1 (ja) |
JP (1) | JP5828912B2 (ja) |
DK (1) | DK2806552T3 (ja) |
WO (1) | WO2013108376A1 (ja) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016116423A (ja) * | 2014-12-18 | 2016-06-23 | 株式会社日立製作所 | 電力変換装置及び電力変換装置の制御方法 |
JP2016135054A (ja) * | 2015-01-21 | 2016-07-25 | 株式会社東芝 | 電力変換装置 |
US11218079B2 (en) | 2018-03-09 | 2022-01-04 | Toshiba Mitsubishi-Electric Industrial Systems Corporation | Power conversion device |
US11342859B2 (en) * | 2018-07-10 | 2022-05-24 | Siemens Energy Global GmbH & Co. KG | Apparatus and method for supplying power to a high-capacity load |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2416486B1 (en) * | 2009-03-30 | 2018-05-30 | Hitachi, Ltd. | Power conversion device |
JP5894777B2 (ja) * | 2011-12-07 | 2016-03-30 | 株式会社日立製作所 | 電力変換装置 |
JP6038289B2 (ja) * | 2013-04-02 | 2016-12-07 | 三菱電機株式会社 | 電力変換装置 |
EP2863534B1 (en) * | 2013-10-16 | 2018-09-26 | General Electric Technology GmbH | Voltage source converter |
CN107408899B (zh) | 2015-02-25 | 2020-05-12 | 日立三菱水力株式会社 | 可变速发电电动装置以及可变速发电电动系统 |
DE102015109466A1 (de) * | 2015-06-15 | 2016-12-15 | Ge Energy Power Conversion Technology Limited | Stromrichter-Submodul mit Kurzschlusseinrichtung und Stromrichter mit diesem |
US10177681B2 (en) * | 2016-06-24 | 2019-01-08 | Infineon Technologies Austria Ag | Power converter including an autotransformer and power conversion method |
EP3627684B1 (en) * | 2017-05-17 | 2022-02-09 | Mitsubishi Electric Corporation | Power conversion device |
EP3614552B1 (en) * | 2018-08-24 | 2021-05-19 | General Electric Technology GmbH | Voltage source converter |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04271281A (ja) * | 1991-02-25 | 1992-09-28 | Sansha Electric Mfg Co Ltd | 電源装置 |
JP2010233411A (ja) | 2009-03-30 | 2010-10-14 | Hitachi Ltd | 電力変換装置 |
JP2010239723A (ja) * | 2009-03-31 | 2010-10-21 | Hitachi Ltd | 電力変換装置 |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2416486B1 (en) * | 2009-03-30 | 2018-05-30 | Hitachi, Ltd. | Power conversion device |
-
2012
- 2012-01-18 US US14/368,673 patent/US9343994B2/en active Active
- 2012-01-18 WO PCT/JP2012/050917 patent/WO2013108376A1/ja active Application Filing
- 2012-01-18 JP JP2013554145A patent/JP5828912B2/ja active Active
- 2012-01-18 EP EP12865949.7A patent/EP2806552B1/en not_active Not-in-force
- 2012-01-18 DK DK12865949.7T patent/DK2806552T3/en active
- 2012-01-18 EP EP16199328.2A patent/EP3148068B1/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04271281A (ja) * | 1991-02-25 | 1992-09-28 | Sansha Electric Mfg Co Ltd | 電源装置 |
JP2010233411A (ja) | 2009-03-30 | 2010-10-14 | Hitachi Ltd | 電力変換装置 |
JP2010239723A (ja) * | 2009-03-31 | 2010-10-21 | Hitachi Ltd | 電力変換装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP2806552A4 |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016116423A (ja) * | 2014-12-18 | 2016-06-23 | 株式会社日立製作所 | 電力変換装置及び電力変換装置の制御方法 |
JP2016135054A (ja) * | 2015-01-21 | 2016-07-25 | 株式会社東芝 | 電力変換装置 |
WO2016117445A1 (ja) * | 2015-01-21 | 2016-07-28 | 株式会社 東芝 | 電力変換装置 |
US11218079B2 (en) | 2018-03-09 | 2022-01-04 | Toshiba Mitsubishi-Electric Industrial Systems Corporation | Power conversion device |
US11342859B2 (en) * | 2018-07-10 | 2022-05-24 | Siemens Energy Global GmbH & Co. KG | Apparatus and method for supplying power to a high-capacity load |
Also Published As
Publication number | Publication date |
---|---|
JP5828912B2 (ja) | 2015-12-09 |
EP3148068A1 (en) | 2017-03-29 |
EP3148068B1 (en) | 2017-08-23 |
DK2806552T3 (en) | 2017-01-09 |
EP2806552A4 (en) | 2015-12-30 |
JPWO2013108376A1 (ja) | 2015-05-11 |
EP2806552B1 (en) | 2016-11-23 |
US9343994B2 (en) | 2016-05-17 |
EP2806552A1 (en) | 2014-11-26 |
US20140369096A1 (en) | 2014-12-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5828912B2 (ja) | 電力変換装置 | |
JP6181132B2 (ja) | 電力変換装置 | |
JP4898899B2 (ja) | 電力変換装置 | |
US5455759A (en) | Symmetrical, phase-shifting, fork transformer | |
US20140268970A1 (en) | Matrix converter and method for controlling matrix converter | |
JP4898898B2 (ja) | 3相電力変換装置 | |
JP5894763B2 (ja) | 電力変換装置 | |
US7474188B2 (en) | 40° phase-shifting autotransformer | |
US20080037190A1 (en) | Converter topology and methods for interfacing an electrical machine to electrical power grid | |
JP2008178180A (ja) | 整流回路 | |
JP6121582B2 (ja) | 電力変換装置 | |
KR101465973B1 (ko) | 멀티레벨 인버터를 적용한 연료전지용 전력변환장치 및 중성점 전위 불평형 저감 방법 | |
JPH11187576A (ja) | 分散型電源装置 | |
JP2009153297A (ja) | 自励式変換器の制御装置 | |
JPH05207660A (ja) | 電源障害対策装置 | |
JP7099351B2 (ja) | 双方向絶縁型dc-dcコンバータおよび制御方法 | |
JP6311050B2 (ja) | 電力変換装置 | |
WO2023214462A1 (ja) | 電力変換装置 | |
JP2018019447A (ja) | 電源装置 | |
JP6775441B2 (ja) | 電源装置 | |
JP3395310B2 (ja) | 半導体電力変換装置 | |
WO2019102547A1 (ja) | 電力変換システム | |
KR20230026777A (ko) | 커패시터 중성점 전압 보상 방법 및 장치 | |
JPH0453160Y2 (ja) | ||
JP2021191187A (ja) | 電力変換装置及びその運転方法 |
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: 12865949 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2013554145 Country of ref document: JP Kind code of ref document: A |
|
REEP | Request for entry into the european phase |
Ref document number: 2012865949 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14368673 Country of ref document: US Ref document number: 2012865949 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |