WO2022059294A1 - Dispositif de conversion de puissance - Google Patents

Dispositif de conversion de puissance Download PDF

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Publication number
WO2022059294A1
WO2022059294A1 PCT/JP2021/024971 JP2021024971W WO2022059294A1 WO 2022059294 A1 WO2022059294 A1 WO 2022059294A1 JP 2021024971 W JP2021024971 W JP 2021024971W WO 2022059294 A1 WO2022059294 A1 WO 2022059294A1
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WIPO (PCT)
Prior art keywords
switching element
switching
pattern
state
control circuit
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PCT/JP2021/024971
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English (en)
Japanese (ja)
Inventor
翔吾 廣田
賢治 花村
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パナソニックＩｐマネジメント株式会社
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Publication of WO2022059294A1 publication Critical patent/WO2022059294A1/fr

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    • 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

Definitions

  • the present disclosure relates to a power conversion device that converts DC power into DC power of another voltage.
  • V2H Vehicle to Home
  • the V2H system can be charged and discharged between the storage battery mounted on the EV / PHEV and the power source / load in the home.
  • the electric power generated by a household photovoltaic power generation system can be charged into an EV / PHEV.
  • the storage battery mounted on the EV / PHEV can be used for peak shift of the load in the home and backup application.
  • DC / DC converters used in V2H systems are required to have a wide voltage range and isolation.
  • One of the DC / DC converters satisfying these requirements is a DAB (Dual Active Bridge) converter.
  • DAB converters generally have problems such as an increase in loss due to hard switching at low output and an increase in loss due to the flow of reactive current that is not related to power transmission.
  • a method has been proposed in which a PWM signal input to one of the legs of a bridge circuit composed of four switching elements is completely turned off and a phase shift is used (for example, Patent Document 1). reference).
  • the present disclosure has been made in view of these circumstances, and an object thereof is to provide a highly efficient isolated DC / DC converter.
  • the first leg in which the first switching element and the second switching element are connected in series, and the third switching element and the fourth switching element are connected in series.
  • a first bridge circuit having the second leg and the first leg and the second leg connected in parallel to the first DC unit, and a third switching element and a sixth switching element connected in series.
  • a second bridge circuit having a leg, a fourth leg in which a seventh switching element and an eighth switching element are connected in series, and the third leg and the fourth leg connected in parallel to a second DC unit, and the above-mentioned
  • An isolation transformer connected between the first bridge circuit and the second bridge circuit, a first inductance connected or formed in series between the first bridge circuit and the primary winding of the isolation transformer, and the first. It includes a second inductance connected or formed in series between a two-bridge circuit and a secondary winding of the isolation transformer, and a control circuit for controlling the first switching element-the eighth switching element.
  • a diode is connected or formed in antiparallel to each of the first switching element and the eighth switching element, and a capacitance is connected or formed in parallel to each of the first switching element and the eighth switching element.
  • the first bridge circuit has the first DC section and the primary winding of the isolation transformer except for the dead time.
  • the second bridge circuit has a first period in which both ends of the secondary winding of the isolation transformer are short-circuited in the second bridge circuit, and the secondary winding of the isolation transformer and the second DC unit. Includes a second period of conduction.
  • the control circuit controls at least one of the fifth switching element and the eighth switching element to be in the ON state during a period in which the voltage is boosted from the first DC unit to the second DC unit and power is transmitted.
  • FIG. 2 (a)-(c) are diagrams for explaining the operation according to the comparative example of the power conversion device. It is a figure which shows the switching timing 1 of the 1st switching element-the 8th switching element which concerns on Example (step-down mode).
  • 4 (a)-(d) are diagrams for explaining the operation according to the embodiment (step-down mode) of the power conversion device (No. 1).
  • 5 (a)-(d) are diagrams for explaining the operation according to the embodiment (step-down mode) of the power conversion device (No. 2).
  • 6 (a)-(b) are diagrams for explaining the mechanism of diode recovery loss generation.
  • FIG. It is a figure which shows the switching timing 2 of the 1st switching element-8th switching element which concerns on Example (step-down mode). It is a figure for demonstrating the structure of the power conversion apparatus which concerns on modification 1.
  • FIG. It is a figure which shows the switching timing of the 1st switching element-4th switching element which concerns on modification 1 (step-down mode). It is a figure which shows the switching timing 1 of the 1st switching element-the 8th switching element which concerns on an Example (boosting mode).
  • 11 (a)-(c) are diagrams for explaining the operation according to the embodiment (boost mode) of the power conversion device (No. 1).
  • 12 (a)-(c) are diagrams for explaining the operation according to the embodiment (boost mode) of the power conversion device (No. 2).
  • FIG. 1 is a diagram for explaining the configuration of the power conversion device 1 according to the embodiment.
  • the power conversion device 1 is an isolated bidirectional DC / DC converter (DAB converter), and converts the DC power supplied from the first DC power supply E1 and transmits it to the second DC power supply E2. Further, the power conversion device 1 converts the DC power supplied from the second DC power supply E2 and transmits it to the first DC power supply E1.
  • the power conversion device 1 can be stepped down for power transmission or stepped up for power transmission.
  • the first DC power supply E1 corresponds to, for example, a storage battery or an electric double layer capacitor mounted on an EV, or a stationary storage battery or an electric double layer capacitor.
  • the second DC power supply E2 corresponds to, for example, a DC bus connected to a commercial power system via an inverter. Other storage batteries, solar cells, fuel cells, and the like may be connected to the DC bus via another DC / DC converter.
  • the power conversion device 1 includes a primary side capacitor Ca, a first bridge circuit 11, a first inductance L1, an isolation transformer TR1, a second inductance L2, a second bridge circuit 12, a secondary side capacitor Cb, and a control circuit 13.
  • the primary side capacitor Ca is connected in parallel with the first DC power supply E1.
  • the secondary side capacitor Cb is connected in parallel with the second DC power supply E2.
  • an electrolytic capacitor is used for the primary side capacitor Ca and the secondary side capacitor Cb.
  • the first DC power supply E1 and the primary side capacitor Ca are collectively referred to as a first DC unit
  • the second DC power supply E2 and the secondary side capacitor Cb are collectively referred to as a second DC unit.
  • the first leg in which the first switching element Q1 and the second switching element Q2 are connected in series and the second leg in which the third switching element Q3 and the fourth switching element Q4 are connected in series are connected in parallel. It is a full bridge circuit configured by.
  • the first bridge circuit 11 is connected in parallel with the first DC unit, and the midpoint of the first leg and the midpoint of the second leg are connected to both ends of the primary winding n1 of the isolation transformer TR1, respectively.
  • the first bridge circuit 11 can convert the DC voltage on the primary side supplied from the first DC unit into an AC voltage and output it to the primary winding n1 of the isolation transformer TR1. Further, the first bridge circuit 11 can convert the AC voltage supplied from the primary winding n1 of the isolation transformer TR1 into a DC voltage and output it to the first DC unit.
  • the third leg in which the fifth switching element Q5 and the sixth switching element Q6 are connected in series and the fourth leg in which the seventh switching element Q7 and the eighth switching element Q8 are connected in series are connected in parallel. It is a full bridge circuit configured by.
  • the second bridge circuit 12 is connected in parallel with the second DC unit, and the midpoint of the third leg and the midpoint of the fourth leg are connected to both ends of the secondary winding n2 of the isolation transformer TR1, respectively.
  • the second bridge circuit 12 can convert the DC voltage on the secondary side supplied from the second DC section into an AC voltage and output it to the secondary winding n2 of the isolation transformer TR1. Further, the second bridge circuit 12 can convert the AC voltage supplied from the secondary winding n2 of the isolation transformer TR1 into a DC voltage and output it to the second DC unit.
  • a first diode D1 to an eighth diode D8 are connected or formed in antiparallel to each of the first switching element Q1 to the eighth switching element Q8. Further, the first capacitance C1 to the eighth capacitance C8 are connected or formed in parallel to the first switching element Q1 to the eighth switching element Q8, respectively.
  • an IGBT Insulated Gate Bipolar Transistor
  • MOSFET Metal-Oxide-Semiconductor Field-Effect Transistor
  • an external diode element is connected between the emitter and collector of the first switching element Q1 to the eighth switching element Q8 as the first diode D1 to the eighth diode D8, respectively.
  • an external capacitor may be connected between the collector and the emitter of the first switching element Q1-eighth switching element Q8 as the first capacitance C1-8th capacitance C8, or the first switching element Q1-eighth switching element Q8.
  • the parasitic capacitance formed between the collector and the emitter of the above is used as the first capacitance C1 to the eighth capacitance C8.
  • the parasitic diode formed between the source and drain of the 1st switching element Q1-8th switching element Q8 is used as the 1st diode D1-8th diode D8, or an external diode element is used. Are connected as the first diode D1-the eighth diode D8, respectively.
  • the parasitic capacitance formed between the source and drain of the first switching element Q1-8th switching element Q8 is used as the first capacitance C1-eighth capacitance C8, or the first switching element Q1-eighth switching element.
  • An external capacitor is connected between the source and drain of Q8 as the first capacitance C1 and the eighth capacitance C8, respectively.
  • the capacitance values of the first capacitance C1 and the eighth capacitance C8 connected or formed in parallel to the first switching element Q1- and the eighth switching element Q8 correspond to each other. That is, the capacitance values between the emitter and collector of the first switching element Q1 and the eighth switching element Q8 or between the source and drain are substantially the same. Similarly, all the resistance values of the first diode D1-8th diode D8 connected or formed in antiparallel to the first switching element Q1-8th switching element Q8 are also supported. As described above, all the configurations of the first leg to the fourth leg correspond to each other, which contributes to the reduction of the manufacturing cost and the circuit area. Moreover, it is possible to flexibly correspond to any switching pattern.
  • the isolation transformer TR1 is connected between the AC terminal of the first bridge circuit 11 and the AC terminal of the second bridge circuit 12.
  • the isolation transformer TR1 converts the output voltage of the first bridge circuit 11 connected to the primary winding n1 according to the turns ratio of the primary winding n1 and the secondary winding n2, and is connected to the secondary winding n2. It is output to the second bridge circuit 12. Further, the isolation transformer TR1 converts the output voltage of the second bridge circuit 12 connected to the secondary winding n2 according to the turns ratio of the secondary winding n2 and the primary winding n1, and connects to the primary winding n1. It is output to the first bridge circuit 11.
  • the first inductance L1 is connected or formed in series between the AC terminal of the first bridge circuit 11 and the primary winding n1 of the isolation transformer TR1.
  • the second inductance L2 is connected or formed in series between the AC terminal of the second bridge circuit 12 and the secondary winding n2 of the isolation transformer TR1.
  • the first inductance L1 is composed of a reactor element connected between the midpoint of the first leg of the first bridge circuit 11 and the primary winding n1 of the isolation transformer TR1.
  • the second inductance L2 is composed of a reactor element connected between the midpoint of the third leg of the second bridge circuit 12 and the secondary winding n2 of the isolation transformer TR1.
  • the first inductance L1 may be composed of the leakage inductance of the primary winding n1 formed between the midpoint of the first leg of the first bridge circuit 11 and the primary winding n1 of the isolation transformer TR1.
  • the second inductance L2 may be composed of the leakage inductance of the secondary winding n2 formed between the midpoint of the third leg of the second bridge circuit 12 and the secondary winding n2 of the isolation transformer TR1. ..
  • a first voltage sensor that detects the voltage across the first DC section
  • a first current sensor that detects the current flowing through the first DC section
  • a second voltage sensor that detects the voltage across the second DC section.
  • a second voltage sensor and a second current sensor for detecting the current flowing through the second DC unit are provided, and their respective detection values are output to the control circuit 13.
  • the control circuit 13 controls the first switching element Q1 to the eighth switching element Q8 by supplying a drive signal (PWM (Pulse Width Modulation) signal) to the gate terminal of the first switching element Q1 to the eighth switching element Q8. do.
  • PWM Pulse Width Modulation
  • the configuration of the control circuit 13 can be realized by the collaboration of hardware resources and software resources, or only by hardware resources. Analog devices, microcomputers, DSPs, ROMs, RAMs, ASICs, FPGAs, and other LSIs can be used as hardware resources. Programs such as firmware can be used as software resources.
  • the control circuit 13 executes the following control as basic control.
  • the current value (discharge current value) detected by the first current sensor is the current command value.
  • the first switching element Q1 to the eighth switching element Q8 are controlled so that the voltage value (discharge voltage value) detected by the first voltage sensor maintains the voltage command value.
  • the current value on the secondary side detected by the second current sensor may be controlled, or the voltage value on the secondary side detected by the second voltage sensor may be controlled.
  • the current value (charging current value) detected by the first current sensor is a current command.
  • the first switching element Q1 to the eighth switching element Q8 are controlled so as to maintain the value or so that the voltage value (charging voltage value) detected by the first voltage sensor maintains the voltage command value.
  • the current value on the secondary side detected by the second current sensor may be controlled, or the voltage value on the secondary side detected by the second voltage sensor may be controlled.
  • the DAB converter has a symmetrical configuration on the primary side and the secondary side, and can transmit power in both directions.
  • the operation of the power conversion device 1 will be described.
  • FIG. 2A are diagrams for explaining the operation according to the comparative example of the power conversion device 1.
  • the control circuit 13 turns on the first switching element Q1, the fourth switching element Q4, the sixth switching element Q6, and the seventh switching element Q7, and the second switching element Q2.
  • the third switching element Q3, the fifth switching element Q5, and the eighth switching element Q8 are controlled to be in the off state.
  • the first DC power supply E1 charges the first inductance L1
  • the second DC power supply E2 charges the second inductance L2.
  • the control circuit 13 turns on the first switching element Q1, the fourth switching element Q4, the fifth switching element Q5, and the eighth switching element Q8, and the second switching element Q2,
  • the third switching element Q3, the sixth switching element Q6, and the seventh switching element Q7 are controlled to be in the off state.
  • the power of the first DC power supply E1 the power stored in the first inductance L1
  • the power stored in the second inductance L2 are transmitted to the second DC power supply E2.
  • the control circuit 13 turns on the second switching element Q2, the third switching element Q3, the fifth switching element Q5, and the eighth switching element Q8, the first switching element Q1, and the fourth switching.
  • the element Q4, the sixth switching element Q6, and the seventh switching element Q7 are controlled to be in the off state.
  • the first DC power supply E1 charges the first inductance L1
  • the second DC power supply E2 charges the second inductance L2.
  • the control circuit 13 turns on the second switching element Q2, the third switching element Q3, the sixth switching element Q6, and the seventh switching element Q7, the first switching element Q1, and the fourth switching.
  • the element Q4, the fifth switching element Q5, and the eighth switching element Q8 are controlled to be in the off state.
  • the power of the first DC power supply E1 the power stored in the first inductance L1
  • the power stored in the second inductance L2 are transmitted to the second DC power supply E2.
  • the power of the second DC power supply E2 is charged to the second inductance L2 in the first state (see FIG. 2A) and the third state (not shown).
  • the electric power stored in the second inductance L2 is discharged to the second DC power supply E2. That is, a reactive current that is not related to power transmission is flowing on the secondary side. Wasteful loss is generated by the flow of this reactive current.
  • FIG. 2C shows the current flow when the voltage of the first DC power supply E1 drops significantly with respect to the voltage of the second DC power supply E2 in the second state shown in FIG. 2B. ..
  • the direction of the current is reversed, and the current flows back from the second DC power supply E2 to the first DC power supply E1.
  • FIG. 3 is a diagram showing switching timing 1 of the first switching element Q1 to the eighth switching element Q8 according to the embodiment (step-down mode).
  • 4 (a)-(d) are diagrams for explaining the operation according to the embodiment (step-down mode) of the power conversion device 1 (No. 1).
  • 5 (a)-(d) are diagrams for explaining the operation according to the embodiment (step-down mode) of the power conversion device 1 (No. 2).
  • the control circuit 13 turns on the first switching element Q1 and the fourth switching element Q4, and the remaining switching elements (second switching element Q2, third switching element Q3, first).
  • the 5 switching element Q5, the 6th switching element Q6, the 7th switching element Q7, and the 8th switching element Q8) are controlled to be in the off state (first switching pattern P1 (see FIG. 3)).
  • the first DC power supply E1 and the primary winding n1 of the isolation transformer TR1 are conducting. Further, since the fifth switching element Q5- and the eighth switching element Q8 on the secondary side are all in the off state, the second bridge circuit 12 is a diode bridge circuit, via the fifth diode D5 and the eighth diode D8. Is rectifying. In the first state, the first DC power supply E1 transmits power to the second DC power supply E2 via the fifth diode D5 and the eighth diode D8 while charging the first inductance L1 and the second inductance L2. ..
  • the control circuit 13 turns on the fourth switching element Q4 and the eighth switching element Q8, and the remaining switching elements (first switching element Q1, second switching element Q2, first).
  • the 3 switching element Q3, the 5th switching element Q5, the 6th switching element Q6, and the 7th switching element Q7) are controlled to be in the off state (second switching pattern P2 (see FIG. 3)).
  • both ends of the primary winding n1 of the isolation transformer TR1 are short-circuited in the first bridge circuit 11, and the first inductance L1, the isolation transformer TR1 and the second inductance L2 are electrically cut off from the first DC power supply E1. Will be done.
  • the eighth switching element Q8 on the secondary side is in the ON state, and rectification is performed via the fifth diode D5 and the eighth switching element Q8.
  • the eighth switching element Q8 is diode rectified or synchronously rectified. Since synchronous rectification has less loss than diode rectification, the loss on the secondary side is reduced as compared with the case where the current passes through the eighth diode D8 in the off state of the eighth switching element Q8.
  • the control circuit 13 controls all the first switching element Q1 to the eighth switching element Q8 to the off state (dead time Td (see FIG. 3)).
  • a current flows from the first inductance L1 to the first DC power supply E1 via the third diode D3 and the second diode D2.
  • a current flows from the second inductance L2 to the second DC power supply E2 via the fifth diode D5 and the eighth diode D8.
  • the fourth state shown in FIG. 4D shows the state after the residual power of the first inductance L1 and the second inductance L2 has disappeared in the dead time Td.
  • the current does not flow in the ideal state, but in reality, the resonance current flows in the opposite direction to the previous one.
  • resonance occurs between the second inductance L2 and the fifth capacitance C5 to the eighth capacitance C8, and a resonance current flows.
  • resonance current flows through both the high-side path of the second inductance L2, the seventh capacitance C7, and the fifth capacitance C5 and the low-side path of the second inductance L2, the eighth capacitance C8, and the sixth capacitance C6.
  • resonance occurs between the first inductance L1 and the first capacitance C1 to the fourth capacitance C4, and a resonance current flows.
  • resonance current flows through both the high-side path of the first inductance L1, the first capacitance C1, and the third capacitance C3 and the low-side path of the first inductance L1, the second capacitance C2, and the fourth capacitance C4.
  • the control circuit 13 turns on the second switching element Q2 and the third switching element Q3, and the remaining switching elements (first switching element Q1, fourth switching element Q4, first).
  • the 5 switching element Q5, the 6th switching element Q6, the 7th switching element Q7, and the 8th switching element Q8) are controlled to be in the off state (third switching pattern P3 (see FIG. 3)).
  • the first DC power supply E1 and the primary winding n1 of the isolation transformer TR1 are conducting. Further, in the fifth state, since all the fifth switching elements Q5- and the eighth switching elements Q8 are in the off state, the second bridge circuit 12 is a diode bridge circuit, and the seventh diode D7 and the sixth diode D6 are used. It is rectifying through. In the fifth state, the first DC power supply E1 transmits power to the second DC power supply E2 via the seventh diode D7 and the sixth diode D6 while charging the first inductance L1 and the second inductance L2. ..
  • the control circuit 13 turns on the third switching element Q3 and the seventh switching element Q7, and the remaining switching elements (first switching element Q1, second switching element Q2, first). 4
  • the switching element Q4, the fifth switching element Q5, the sixth switching element Q6, and the eighth switching element Q8) are controlled to be in the off state (fourth switching pattern P4 (see FIG. 3)).
  • both ends of the primary winding n1 of the isolation transformer TR1 are short-circuited in the first bridge circuit 11, and the first inductance L1, the isolation transformer TR1 and the second inductance L2 are electrically cut off from the first DC power supply E1.
  • the seventh switching element Q7 on the secondary side is in the ON state, and rectification is performed via the sixth diode D6 and the seventh switching element Q7.
  • the seventh switching element Q7 is diode rectified or synchronously rectified. Since the synchronous rectification has a smaller loss than the diode rectification, the loss on the secondary side is reduced as compared with the case where the current passes through the 7th diode D7 in the off state of the 7th switching element Q7.
  • the control circuit 13 controls all the first switching element Q1 to the eighth switching element Q8 to the off state (dead time Td (see FIG. 3)).
  • a current flows from the first inductance L1 to the first DC power supply E1 via the first diode D1 and the fourth diode D4.
  • a current flows from the second inductance L2 to the second DC power supply E2 via the seventh diode D7 and the sixth diode D6.
  • the eighth state shown in FIG. 5D shows the state after the residual power of the first inductance L1 and the second inductance L2 has disappeared in the dead time Td.
  • the current does not flow in the ideal state, but in reality, the resonance current flows in the opposite direction to the previous one.
  • resonance occurs between the second inductance L2 and the fifth capacitance C5 to the eighth capacitance C8, and a resonance current flows.
  • resonance current flows through both the high-side path of the second inductance L2, the fifth capacitance C5, and the seventh capacitance C7 and the low-side path of the second inductance L2, the sixth capacitance C6, and the eighth capacitance C8.
  • resonance occurs between the first inductance L1 and the first capacitance C1 to the fourth capacitance C4, and a resonance current flows.
  • a resonance current flows through both the high-side path of the first inductance L1, the third capacitance C3, and the first capacitance C1 and the low-side path of the first inductance L1, the fourth capacitance C4, and the second capacitance C2.
  • the period of the first switching pattern P1 and the third switching pattern P3 is defined as the first period
  • the period of the second switching pattern P2 and the fourth switching pattern P4 is defined as the second period.
  • the control circuit 13 changes from the second period to the first period.
  • a dead time Td for turning off the first switching element Q1 to the eighth switching element Q8 is inserted.
  • the dead time Td that turns off all the first switching element Q1 to the eighth switching element Q8 is not inserted, a diode recovery loss occurs.
  • FIGS. 6 (a)-(b) are diagrams for explaining the mechanism of diode recovery loss generation.
  • FIG. 6A shows another switching pattern of the dead time Td between the second switching pattern P2 and the third switching pattern P3.
  • the third switching element Q3 on the primary side turns on.
  • a reverse bias voltage is applied to the fourth diode D4 connected to the fourth switching element Q4, and a recovery current flows in the reverse direction.
  • a through current flows through the third switching element Q3 and the fourth diode D4, and the loss increases.
  • FIG. 6B shows another switching pattern of the dead time Td between the fourth switching pattern P4 and the first switching pattern P1.
  • the current does not flow in the ideal state, but in reality, the resonance current flows in the opposite direction to the previous one.
  • the secondary side resonance occurs between the second inductance L2 and the fifth capacitance C5 to the eighth capacitance C8, and a resonance current flows.
  • resonance current flows through both the high-side path of the second inductance L2, the fifth capacitance C5, and the seventh capacitance C7 and the low-side path of the second inductance L2, the sixth capacitance C6, and the eighth capacitance C8.
  • a current flows in the high side path of the first inductance L1, the third diode D3, and the first switching element Q1.
  • the fourth switching element Q4 on the primary side turns on.
  • a reverse bias voltage is applied to the third diode D3, and a recovery current flows in the reverse direction.
  • a through current flows through the third diode D3 and the fourth switching element Q4, and the loss increases.
  • the first switching element Q1-first during the transition from the second switching pattern P2 to the third switching pattern P3 and during the transition from the fourth switching pattern P4 to the first switching pattern P1.
  • a dead time Td in which all switching elements Q8 are turned off is inserted.
  • the current flowing through the 4th diode D4 or the 3rd diode D3 can be suppressed, and the recovery loss of the 4th diode D4 or the 3rd diode D3 can be reduced.
  • the control circuit 13 supplies power from the first DC unit to the second DC unit by adjusting the duty ratio of the drive signal supplied to the first switching element Q1 and the second switching element Q2. Controls the voltage or current of the power to be used. As the on-time of the drive signal supplied to the first switching element Q1 and the second switching element Q2 becomes longer (the larger the duty ratio), the amount of electric power transmitted from the first DC unit to the second DC unit increases.
  • the control circuit 13 alternately controls the third switching element Q3 and the fourth switching element Q4 to be in the ON state for half the time of the switching cycle fsw (excluding the dead time Td).
  • step-down mode power is transmitted from the first DC section to the second DC section by the PWM method.
  • the phase shift method it is not possible to provide a period in which all the first switching elements Q1 to the fourth switching elements Q4 on the primary side are in the off state, and the above-mentioned diode recovery loss occurs. Cannot be prevented.
  • the control circuit 13 When the control circuit 13 transitions from the dead time Td to the first switching pattern P1, the control circuit 13 turns on the fourth switching element Q4 in synchronization with the turn-on of the first switching element Q1. That is, the first switching element Q1 and the fourth switching element Q4 are turned on substantially at the same time.
  • the control circuit 13 transitions from the first switching pattern P1 to the second switching pattern P2, the control circuit 13 turns on the eighth switching element Q8 in synchronization with the turn-off of the first switching element Q1. That is, the turn-off of the first switching element Q1 and the turn-on of the eighth switching element Q8 are performed substantially at the same time. As a result, the synchronous rectification period of the eighth switching element Q8 can be maximized, and the loss reduction effect of the synchronous rectification of the eighth switching element Q8 can be maximized.
  • the control circuit 13 When the control circuit 13 transitions from the second switching pattern P2 to the dead time Td, the control circuit 13 turns off the eighth switching element Q8 in synchronization with the turnoff of the fourth switching element Q4. That is, the fourth switching element Q4 and the eighth switching element Q8 are turned off substantially at the same time.
  • the control circuit 13 is the first switching element Q1 so that the total time of the on time of the first switching element Q1, the on time of the eighth switching element Q8, and the dead time Td is half the time of the switching cycle fsw. And the eighth switching element Q8 are controlled.
  • the on-time of the eighth switching element Q8 changes adaptively according to the on-time of the first switching element Q1.
  • the control circuit 13 transitions from the dead time Td to the third switching pattern P3, the control circuit 13 turns on the third switching element Q3 in synchronization with the turn-on of the second switching element Q2. That is, the second switching element Q2 and the third switching element Q3 are turned on substantially at the same time.
  • the control circuit 13 transitions from the third switching pattern P3 to the fourth switching pattern P4, the control circuit 13 turns on the seventh switching element Q7 in synchronization with the turn-off of the second switching element Q2. That is, the turn-off of the second switching element Q2 and the turn-on of the seventh switching element Q7 are performed substantially at the same time. As a result, the synchronous rectification period of the 7th switching element Q7 can be maximized, and the loss reduction effect of the synchronous rectification of the 7th switching element Q7 can be maximized.
  • the control circuit 13 When the control circuit 13 transitions from the fourth switching pattern P4 to the dead time Td, the control circuit 13 turns off the seventh switching element Q7 in synchronization with the turnoff of the third switching element Q3. That is, the third switching element Q3 and the seventh switching element Q7 are turned off substantially at the same time.
  • the second switching element Q2 has a total time of the on time of the second switching element Q2, the on time of the seventh switching element Q7, and the dead time Td, which is half the time of the switching cycle fsw. And the 7th switching element Q7 are controlled.
  • the on-time of the seventh switching element Q7 changes adaptively according to the on-time of the second switching element Q2.
  • the control circuit 13 synchronizes the period of the first switching pattern P1 with the period of the third switching pattern P3. That is, the period of the first switching pattern P1 and the period of the third switching pattern P3 are controlled to substantially the same time. Further, the control circuit 13 synchronizes the period of the second switching pattern P2 with the period of the fourth switching pattern P4. That is, the period of the second switching pattern P2 and the period of the fourth switching pattern P4 are controlled to substantially the same time. As a result, the operation becomes positive and negative symmetrical, and it is possible to suppress the occurrence of DC demagnetization in the transformer.
  • the control circuit 13 constantly uses the fifth switching element Q5 and the sixth switching element Q6. Controlled to the off state. In this respect, the control circuit 13 may control the 7th switching element Q7 and the 8th switching element Q8 to be always off.
  • the control circuit 13 may control the 7th switching element Q7 and the 8th switching element Q8 to be always off.
  • synchronous rectification is performed by the fifth switching element Q5 instead of the eighth switching element Q8.
  • synchronous rectification is performed by the sixth switching element Q6 instead of the seventh switching element Q7.
  • FIG. 7 is a diagram showing switching timing 2 of the first switching element Q1 to the eighth switching element Q8 according to the embodiment (step-down mode).
  • the switching timing 1 of the first switching element Q1 to the eighth switching element Q8 shown in FIG. 3 an example of stepping down from the first DC unit to the second DC unit to supply electric power has been described.
  • the control circuit 13 supplies a drive signal supplied to the first switching element Q1-fourth switching element Q4 and a drive signal supplied to the fifth switching element Q5-eighth switching element Q8. You can replace it.
  • the state of charging the second inductance L2 from the second DC power supply E2 does not occur as in the comparative example (see FIG. 2A), so that the reactive power is generated. It can be suppressed. Further, since the resonance current can be suppressed from flowing to the antiparallel diode of the switching element during the dead time, the recovery loss of the diode can be reduced. Further, the conduction loss of the diode can be reduced by performing synchronous rectification with the eighth switching element Q8 or the seventh switching element Q7 on the secondary side in the state 2 and the state 5. As a result, the conversion efficiency of the DAB converter during the step-down operation can be improved.
  • the voltage of the first DC power supply E1 is the voltage of the second DC power supply E2 because the state in which the first DC power supply E1 and the second DC power supply E2 are conductive without passing through the diode does not occur. Even if the voltage drops significantly with respect to the voltage of, the direction of the current does not reverse, and the current does not flow back from the second DC power supply E2 to the first DC power supply E1. This makes it possible to prevent the occurrence of hard switching.
  • FIG. 8 is a diagram for explaining the configuration of the power conversion device 1 according to the modification 1.
  • the second bridge circuit 12 uses four bridge-connected diode elements (fifth diode D5-8th diode D8) instead of the fifth switching element Q5-8th switching element Q8. ).
  • the power conversion device 1 according to the first modification is an isolated unidirectional DC / DC converter that cannot transmit power from the second DC unit to the first DC unit.
  • FIG. 9 is a diagram showing the switching timing of the first switching element Q1 to the fourth switching element Q4 according to the modification 1 (step-down mode).
  • the control circuit 13 turns the first switching element Q1 and the fourth switching element Q4 on, and the second switching element Q2 and the third switching element Q3 off.
  • the control circuit 13 controls the fourth switching element Q4 in the on state and the first switching element Q1, the second switching element Q2, and the third switching element Q3 in the off state.
  • the control circuit 13 controls all the first switching element Q1 to the fourth switching element Q4 in the off state.
  • the control circuit 13 controls the second switching element Q2 and the third switching element Q3 in the on state, and the first switching element Q1 and the fourth switching element Q4 in the off state.
  • the control circuit 13 controls the third switching element Q3 in the on state and the first switching element Q1, the second switching element Q2, and the fourth switching element Q4 in the off state.
  • the control circuit 13 controls all the first switching elements Q1 to the fourth switching element Q4 in the off state.
  • step-down mode except that power cannot be transmitted from the secondary side to the primary side and synchronous rectification cannot be performed using the 8th switching element Q8 or the 7th switching element Q7 on the secondary side. It has the same effect as that of the above embodiment (step-down mode).
  • Modification 2 (step-down mode)
  • the control circuit 13 constantly controls the fifth switching element Q5 to the eighth switching element Q8 in the off state.
  • the control circuit 13 turns on the first switching element Q1 and the fourth switching element Q4, and the remaining switching elements (second switching element Q2). , The third switching element Q3, the fifth switching element Q5, the sixth switching element Q6, the seventh switching element Q7, and the eighth switching element Q8) are controlled to the off state.
  • the control circuit 13 turns on the fourth switching element Q4, and the remaining switching elements (first switching element Q1, second switching element Q2, third switching element Q3, fifth switching element Q5, The sixth switching element Q6, the seventh switching element Q7, and the eighth switching element Q8) are controlled to be in the off state.
  • the control circuit 13 controls all the first switching element Q1 to the eighth switching element Q8 to the off state.
  • the control circuit 13 turns on the second switching element Q2 and the third switching element Q3, and the remaining switching elements (first switching element Q1, fourth switching element Q4, fifth switching element Q5, The sixth switching element Q6, the seventh switching element Q7, and the eighth switching element Q8) are controlled to be in the off state.
  • the control circuit 13 turns on the third switching element Q3, and the remaining switching elements (first switching element Q1, second switching element Q2, fourth switching element Q4, fifth switching element Q5, The sixth switching element Q6, the seventh switching element Q7, and the eighth switching element Q8) are controlled to be in the off state.
  • the control circuit 13 controls all the first switching elements Q1 to the eighth switching elements Q8 in the off state.
  • the modified example 2 (step-down mode) the same effect as that of the modified example 1 (step-down mode) is obtained.
  • power can be transmitted from the second DC unit to the first DC unit.
  • FIG. 10 is a diagram showing switching timing 1 of the first switching element Q1 to the eighth switching element Q8 according to the embodiment (boost mode).
  • 11 (a)-(c) are diagrams for explaining the operation according to the embodiment (boost mode) of the power conversion device 1 (No. 1).
  • 12 (a)-(c) are diagrams for explaining the operation according to the embodiment (boost mode) of the power conversion device 1 (No. 2).
  • the control circuit 13 turns on the first switching element Q1, the fourth switching element Q4 and the sixth switching element Q6, the second switching element Q2, the third switching element Q3,
  • the fifth switching element Q5, the seventh switching element Q7, and the eighth switching element Q8 are controlled to be in the off state (fifth switching pattern P5 (see FIG. 10)).
  • the first DC power supply E1 and the primary winding n1 of the isolation transformer TR1 are conducting. Further, both ends of the secondary winding n2 of the isolation transformer TR1 are short-circuited in the second bridge circuit 12, and the first inductance L1, the isolation transformer TR1 and the second inductance L2 are electrically cut off from the second DC power supply E2. .. In the first state, the first DC power supply E1 charges the first inductance L1 and the second inductance L2 with electric power.
  • the control circuit 13 turns on the first switching element Q1, the fourth switching element Q4 and the eighth switching element Q8, the second switching element Q2, the third switching element Q3,
  • the fifth switching element Q5, the sixth switching element Q6, and the seventh switching element Q7 are controlled to be in the off state (sixth switching pattern P6 (see FIG. 10)).
  • the first DC power supply E1 and the primary winding n1 of the isolation transformer TR1 are conducting.
  • the eighth switching element Q8 on the secondary side is in the ON state, and rectification is performed via the fifth diode D5 and the eighth switching element Q8.
  • the eighth switching element Q8 is diode rectified or synchronously rectified.
  • the rectified state the secondary winding n2 of the isolation transformer TR1 and the second DC power supply E2 are conductive. Since synchronous rectification has less loss than diode rectification, the loss on the secondary side is reduced as compared with the case where the current passes through the eighth diode D8 in the off state of the eighth switching element Q8.
  • the control circuit 13 turns on the fifth switching element Q5, the first switching element Q1, the second switching element Q2, the third switching element Q3, and the fourth switching element Q4.
  • the sixth switching element Q6, the seventh switching element Q7, and the eighth switching element Q8 are controlled to be in the off state (first primary side dead time Td'(see FIG. 10)).
  • the fifth switching element Q5 on the secondary side is in the ON state, and rectification is performed via the fifth switching element Q5 and the eighth diode D8.
  • the fifth switching element Q5 is diode rectified or synchronously rectified. Since synchronous rectification has less loss than diode rectification, the loss on the secondary side is reduced as compared with the case where the current passes through the fifth diode D5 in the off state of the fifth switching element Q5.
  • the ZVS (zero voltage switching) operation is performed by turning on the fifth switching element Q5, and the switching loss can be reduced. Further, when the current passes through the eighth diode D8 in the off state of the eighth switching element Q8, it is possible to prevent the direction of the current flowing to the secondary side from being reversed.
  • the control circuit 13 turns on the second switching element Q2, the third switching element Q3, and the fifth switching element Q5, the first switching element Q1, the fourth switching element Q4,
  • the sixth switching element Q6, the seventh switching element Q7, and the eighth switching element Q8 are controlled to be in the off state (seventh switching pattern P7 (see FIG. 10)).
  • the first DC power supply E1 and the primary winding n1 of the isolation transformer TR1 are conducting. Further, both ends of the secondary winding n2 of the isolation transformer TR1 are short-circuited in the second bridge circuit 12, and the first inductance L1, the isolation transformer TR1 and the second inductance L2 are electrically cut off from the second DC power supply E2. .. In the fourth state, the first DC power supply E1 charges the first inductance L1 and the second inductance L2 with electric power.
  • the control circuit 13 turns on the second switching element Q2, the third switching element Q3, and the seventh switching element Q7, the first switching element Q1, the fourth switching element Q4,
  • the fifth switching element Q5, the sixth switching element Q6, and the eighth switching element Q8 are controlled to be in the off state (the eighth switching pattern P8 (see FIG. 10)).
  • the first DC power supply E1 and the primary winding n1 of the isolation transformer TR1 are conducting.
  • the seventh switching element Q7 on the secondary side is in the ON state, and rectification is performed via the seventh switching element Q7 and the sixth diode D6.
  • the secondary winding n2 of the isolation transformer TR1 and the second DC power supply E2 are conductive.
  • the secondary winding n2 of the isolation transformer TR1 and the second DC power supply E2 are conductive.
  • the seventh switching element Q7 is diode rectified or synchronously rectified.
  • the loss on the secondary side is reduced as compared with the case where the current passes through the 7th diode D7 in the off state of the 7th switching element Q7. Further, when the current passes through the sixth diode D6 in the off state of the sixth switching element Q6, it is possible to prevent the direction of the current flowing to the secondary side from being reversed.
  • the power of the first DC power supply E1, the power stored in the first inductance L1, and the power stored in the second inductance L2 are transmitted to the second DC power supply E2.
  • the control circuit 13 turns on the sixth switching element Q6, the first switching element Q1, the second switching element Q2, the third switching element Q3, and the fourth switching element Q4.
  • the fifth switching element Q5, the seventh switching element Q7, and the eighth switching element Q8 are controlled to be in the off state (second primary side dead time Td'(see FIG. 10)).
  • the sixth switching element Q6 on the secondary side is in the ON state, and rectification is performed via the seventh diode D7 and the sixth switching element Q6.
  • the sixth switching element Q6 is diode rectified or synchronously rectified. Since synchronous rectification has less loss than diode rectification, the loss on the secondary side is reduced as compared with the case where the current passes through the sixth diode D6 in the off state of the sixth switching element Q6.
  • the ZVS (zero voltage switching) operation is performed by turning on the sixth switching element Q6, and the switching loss can be reduced. Further, when the current passes through the seventh diode D7 in the off state of the seventh switching element Q7, it is possible to prevent the direction of the current flowing to the secondary side from being reversed.
  • the period of the fifth switching pattern P5 and the sixth switching pattern P6 is defined as the third period
  • the period of the seventh switching pattern P7 and the eighth switching pattern P8 is defined as the fourth period.
  • the control circuit 13 changes from the fourth period to the third period.
  • the primary side dead time Td' that turns off all the first switching element Q1 to the fourth switching element Q4 is inserted.
  • the control circuit 13 controls the first switching element Q1 to the fourth switching element Q4 so that the first DC power supply E1 and the primary winding n1 of the isolation transformer TR1 conduct with each other except for the primary side dead time Td'.
  • control circuit 13 inserts a secondary side dead time that turns off all the fifth switching element Q5 and the eighth switching element Q8 while switching from the fourth period to the third period. do not have. That is, the control circuit 13 controls at least one of the fifth switching element Q5- and the eighth switching element Q8 to be in the ON state during the period in which the voltage is boosted from the first DC unit to the second DC unit and power is transmitted. ..
  • FIG. 13 is a diagram showing the switching timing of the first switching element Q1 to the eighth switching element Q8 according to the comparative example (boost mode).
  • the control circuit 13 controls the 7th switching element Q7 and the 8th switching element Q8 to be always off on the secondary side, and alternately alternates the 5th switching element Q5 and the 6th switching element Q6. Control to the on state.
  • diode rectification or synchronous rectification is performed using the fifth switching element Q5 and the sixth switching element Q6.
  • the control circuit 13 is on the secondary side in order to prevent a through current from flowing through the fifth switching element Q5 and the sixth switching element Q6 when the fifth switching element Q5 and the sixth switching element Q6 are switched on / off.
  • the dead time Td'' is inserted.
  • FIG. 14A shows a state of the first secondary side dead time Td ′′ inserted between the turn-off of the fifth switching element Q5 and the turn-on of the sixth switching element Q6.
  • the secondary side is rectified via two diodes, the fifth diode D5 and the eighth diode D8. Since diode rectification has a larger loss than synchronous rectification, the loss on the secondary side increases as compared with the case where the current passes through the fifth switching element Q5 in the on state of the fifth switching element Q5.
  • FIG. 14B shows the state of the second secondary side dead time Td ′′ inserted between the turn-off of the sixth switching element Q6 and the turn-on of the fifth switching element Q5.
  • the secondary side is rectified via two diodes, the 7th diode D7 and the 6th diode D6. Since diode rectification has a larger loss than synchronous rectification, the loss on the secondary side increases as compared with the case where the current passes through the sixth switching element Q6 in the on state of the sixth switching element Q6.
  • the current flowing through the primary winding n1 of the isolation transformer TR1 is small, the current flowing through the secondary side may become zero during the period of the secondary side dead time Td''. be. In that case, the turn-on of the fifth switching element Q5 or the sixth switching element Q6 after the secondary side dead time Td ′′ becomes zero current switching (ZCS).
  • the control circuit 13 controls the fifth switching element Q5 to the on state by the seventh switching pattern P7 when the sixth switching element Q6 is controlled to the on state by the fifth switching pattern P5. ..
  • the second bridge is formed by alternately using the fifth switching element Q5 on the high side and the sixth switching element Q6 on the low side. In the circuit 12, it is possible to prevent heat from concentrating on the high side or the low side.
  • the control circuit 13 controls the eighth switching element Q8 in the on state in the sixth switching pattern P6, and controls the seventh switching element Q7 in the on state in the eighth switching pattern P8.
  • the loss on the secondary side can be reduced by synchronously rectifying the seventh switching element Q7 or the eighth switching element Q8.
  • the control circuit 13 fixes the phase difference between the first leg and the second leg. Specifically, the control circuit 13 includes the phase difference between the first switching element Q1 on the first leg and the fourth switching element Q4 on the second leg, and the second switching element Q2 on the first leg and the third switching on the second leg. The phase difference of the element Q3 is fixed.
  • the control circuit 13 sets, for example, the phase difference between the first leg and the second leg to 0 °. In this case, from the first DC section to the second DC section while preventing a through current from flowing between the first switching element Q1 and the second switching element Q2, and between the third switching element Q3 and the fourth switching element Q4. It is possible to secure the maximum power transmission period.
  • the phase difference between the first leg and the second leg is not fixed at 0 °, so that the first DC section to the second DC section are not fixed.
  • the power transmission period to is shorter than that of the embodiment (boost mode). In particular, when the switching frequency is increased to a high frequency, the power transmission efficiency is greatly reduced.
  • the control circuit 13 controls the voltage or current of the electric power supplied from the first DC unit to the second DC unit by the ratio of the on time and the off time of the drive signal supplied to the fifth switching element Q5 or the sixth switching element Q6. do.
  • power is transmitted from the first DC unit to the second DC unit by the PWM method.
  • the control circuit 13 is a fifth switching element so that the total time (excluding the dead time) of the on time of the fifth switching element Q5 and the on time of the seventh switching element Q7 is half the time of the switching cycle fsw. It controls Q5 and the 7th switching element Q7.
  • the fifth switching element Q5 and the fifth switching element Q5 and the fifth switching element Q5 so that the total time (excluding the dead time) of the on-time of the fifth switching element Q5 and the on-time of the eighth switching element Q8 is half the time of the switching cycle fsw. 8 Controls the switching element Q8.
  • the sixth switching is performed so that the total time (excluding the dead time) of the on time of the sixth switching element Q6 and the on time of the eighth switching element Q8 is half the time of the switching cycle fsw.
  • the element Q6 and the eighth switching element Q8 are controlled.
  • the sixth switching element Q6 and the sixth switching element Q6 so that the total time (excluding the dead time) of the on-time of the sixth switching element Q6 and the on-time of the seventh switching element Q7 is half the time of the switching cycle fsw. 7 Controls the switching element Q7.
  • the control circuit 13 When the control circuit 13 transitions from the sixth switching pattern P6 to the first primary side dead time Td', the control circuit 13 turns on the fifth switching element Q5 in synchronization with the turn-off of the first switching element Q1 and the fourth switching element Q4. Let me. That is, the turn-off of the first switching element Q1 and the fourth switching element Q4 and the turn-on of the fifth switching element Q5 are performed substantially at the same time. By accelerating the turn-on of the fifth switching element Q5 from the turn-on of the second switching element Q2 and the third switching element Q3, the fifth switching element Q5 tends to be in zero voltage switching (ZVS), and the efficiency is improved.
  • ZVS zero voltage switching
  • the control circuit 13 turns on the sixth switching element Q6 in synchronization with the turn-off of the second switching element Q2 and the third switching element Q3 when transitioning from the eighth switching pattern P8 to the second primary side dead time Td'. Let me. That is, the turn-off of the second switching element Q2 and the third switching element Q3 and the turn-on of the sixth switching element Q6 are performed substantially at the same time. By accelerating the turn-on of the sixth switching element Q6 from the turn-on of the first switching element Q1 and the fourth switching element Q4, the sixth switching element Q6 is likely to become zero voltage switching (ZVS), and the efficiency is improved.
  • ZVS zero voltage switching
  • the control circuit 13 synchronizes the period of the fifth switching pattern P5 with the period of the seventh switching pattern P7. That is, the period of the fifth switching pattern P5 and the period of the seventh switching pattern P7 are controlled to substantially the same time. Further, the control circuit 13 synchronizes the period of the sixth switching pattern P6 with the period of the eighth switching pattern P8. That is, the period of the sixth switching pattern P6 and the period of the eighth switching pattern P8 are controlled to substantially the same time. As a result, the operation becomes positive and negative symmetrical, and it is possible to suppress the occurrence of DC demagnetization in the transformer.
  • the control circuit 13 uses the fifth switching element Q5 and the sixth switching element Q6.
  • the circuit was short-circuited in the second bridge circuit 12, and diode rectification or synchronous rectification was performed using the seventh switching element Q7 and the eighth switching element Q8.
  • the roles of the fifth switching element Q5 and the sixth switching element Q6 and the seventh switching element Q7 and the eighth switching element Q8 may be exchanged. In that case, the switching patterns of the 5th switching element Q5 and the 8th switching element Q8 are exchanged, and the switching patterns of the 6th switching element Q6 and the 7th switching element Q7 are exchanged.
  • FIG. 15 is a diagram showing switching timing 2 of the first switching element Q1 to the eighth switching element Q8 according to the embodiment (boost mode).
  • the switching timing 1 of the first switching element Q1 to the eighth switching element Q8 shown in FIG. 10 an example of boosting the voltage from the first DC unit to the second DC unit to supply electric power has been described. In this respect, it is also possible to boost power from the second DC section to the first DC section.
  • the control circuit 13 supplies a drive signal supplied to the first switching element Q1-fourth switching element Q4 and a drive signal supplied to the fifth switching element Q5-eighth switching element Q8. You can replace it.
  • the state of charging the second inductance L2 from the second DC power supply E2 does not occur as in the comparative example (see FIG. 2A), so that the reactive power is generated. It can be suppressed.
  • the conduction loss of the diode can be reduced by performing synchronous rectification by the eighth switching element Q8 or the seventh switching element Q7 on the secondary side. Further, by not providing a dead time on the secondary side, it is possible to suppress the fifth switching element Q5-the eighth switching element Q8 from becoming zero current switching (ZCS), and the fifth switching element Q5-eighth. The switching loss of the switching element Q8 can be reduced. As a result, the conversion efficiency of the DAB converter during the step-up operation can be improved.
  • the voltage of the first DC power supply E1 is the voltage of the second DC power supply E2 because the state in which the first DC power supply E1 and the second DC power supply E2 are conductive without passing through the diode does not occur. Even if the voltage drops significantly with respect to the voltage of, the direction of the current does not reverse, and the current does not flow back from the second DC power supply E2 to the first DC power supply E1. This makes it possible to prevent the occurrence of hard switching.
  • the fifth switching pattern P5-8th switching pattern P8 may be read as the first switching pattern P1-fourth switching pattern P4 in the boost mode. Further, the third period and the fourth period may be read as the first period and the second period of the boost mode.
  • the first switching element Q1 to the eighth switching element Q8 are composed of a wide bandgap semiconductor using silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), diamond (C), or the like. Switching elements may be used.
  • the embodiment may be specified by the following items.
  • [Item 1] It has a first leg in which a first switching element (Q1) and a second switching element (Q2) are connected in series, and a second leg in which a third switching element (Q3) and a fourth switching element (Q4) are connected in series. Then, the first bridge circuit (11) in which the first leg and the second leg are connected in parallel to the first DC unit (E1, Ca), It has a third leg in which the fifth switching element (Q5) and the sixth switching element (Q6) are connected in series, and a fourth leg in which the seventh switching element (Q7) and the eighth switching element (Q8) are connected in series.
  • the second bridge circuit (12) in which the third leg and the fourth leg are connected in parallel to the second DC unit (E2, Cb),
  • An isolation transformer (TR1) connected between the first bridge circuit (11) and the second bridge circuit (12),
  • a first inductance (L1) connected or formed in series between the first bridge circuit (11) and the primary winding (n1) of the isolation transformer (TR1).
  • a second inductance (L2) connected or formed in series between the second bridge circuit (12) and the secondary winding (n2) of the isolation transformer (TR1)
  • a control circuit (13) for controlling the first switching element (Q1) -the eighth switching element (Q8) is provided.
  • a diode (D1-D8) is connected or formed in antiparallel to each of the first switching element (Q1) and the eighth switching element (Q8).
  • a capacitance (C1-C8) is connected or formed in parallel to each of the first switching element (Q1) and the eighth switching element (Q8).
  • the primary winding (n1) of the isolation transformer (TR1) is electrically connected to the first DC unit (E1, Ca) except for the dead time.
  • the second bridge circuit (12) has a first period in which both ends of the secondary winding (n2) of the isolation transformer (TR1) are short-circuited in the second bridge circuit (12), and the isolation transformer (TR1). ) Includes a second period in which the secondary winding (n2) and the second DC unit (E2, Cb) are conductive.
  • the control circuit (13) is During the period of boosting the voltage from the first DC unit (E1, Ca) to the second DC unit (E2, Cb) and transmitting power, the fifth switching element (Q5) -the eighth switching element (Q8). Control at least one on, A power conversion device (1). According to this, the period for performing synchronous rectification can be lengthened, and high efficiency can be achieved.
  • the control circuit (13) is When boosting the voltage from the first DC unit (E1, Ca) to the second DC unit (E2, Cb) to transmit power.
  • the second bridge circuit (Q1) with the first switching element (Q1) and the fourth switching element (Q4) turned on, and the second switching element (Q2) and the third switching element (Q3) turned off. 12) is the second pattern in the rectified state, The isolation transformer (TR1) with the second switching element (Q2) and the third switching element (Q3) on, and the first switching element (Q1) and the fourth switching element (Q4) off.
  • the second bridge circuit (Q2) with the second switching element (Q2) and the third switching element (Q3) turned on, and the first switching element (Q1) and the fourth switching element (Q4) turned off. 12) is controlled including the fourth pattern of the rectified state.
  • the period in which the first pattern and the third pattern operate correspond to the first period.
  • the period in which the second pattern and the fourth pattern operate correspond to the second period.
  • the control circuit (13) is When the sixth switching element (Q6) is controlled to be in the ON state in the first pattern, the fifth switching element (Q5) is controlled to be in the ON state in the third pattern. When the seventh switching element (Q7) is controlled to be in the ON state in the first pattern, the eighth switching element (Q8) is controlled to be in the ON state in the third pattern.
  • the power conversion device (1) according to item 2, characterized in that.
  • the upper switching element (Q5, Q7) and the lower switching element (Q6, Q8) can be used alternately, and the upper or lower switching element can be used. It is possible to prevent heat from concentrating.
  • the control circuit (13) is In the second pattern, the eighth switching element (Q8) or the fifth switching element (Q5) is controlled to be in the ON state. In the fourth pattern, the seventh switching element (Q7) or the sixth switching element (Q6) is controlled to be in the ON state.
  • the control circuit (13) is The phase difference between the first leg and the second leg is fixed. The ratio of the on-time to the off-time of the drive signal supplied to the fifth switching element (Q5) or the seventh switching element (Q7) and the sixth switching element (Q6) or the eighth switching element (Q8). Controls the voltage or current of the electric power supplied from the first DC unit (E1, Ca) to the second DC unit (E2, Cb).
  • the power conversion device (1) according to item 3 characterized in that. According to this, power control can be performed by the PWM method.
  • the control circuit (13) is The phase difference between the first leg and the second leg is set to 0 °.
  • the power conversion device (1) according to item 5 characterized in that.
  • the control circuit (13) is The fifth switching element (Q5) or the eighth switching element (Q8) is turned on in synchronization with the turn-off of the first switching element (Q1) and the fourth switching element (Q4).
  • the sixth switching element (Q6) or the seventh switching element (Q7) is turned on in synchronization with the turn-off of the second switching element (Q2) and the third switching element (Q3).
  • the power conversion device (1) according to any one of items 1 to 6, characterized in that. According to this, the turn-on of the fifth switching element (Q5) or the eighth switching element (Q8) is accelerated from the turn-on of the second switching element (Q2) and the third switching element (Q3), so that the fifth switching element is turned on.
  • the control circuit (13) is Synchronize the period of the first pattern with the period of the third pattern, Synchronize the period of the second pattern with the period of the fourth pattern.
  • the power conversion device (1) according to any one of items 2 to 4, wherein the power conversion device (1) is characterized in that. According to this, the operation becomes positive and negative symmetrical, and the generation of DC demagnetization can be suppressed.
  • the control circuit (13) is When boosting the voltage from the second DC unit (E2, Cb) to the first DC unit (E1, Ca) to transmit power.
  • the drive signal supplied to the first switching element (Q1) -the fourth switching element (Q4) and the drive signal supplied to the fifth switching element (Q5) -the eighth switching element (Q8) are exchanged.
  • the power conversion device (1) according to any one of items 1 to 8, wherein the power conversion device (1) is characterized in that. According to this, bidirectional operation becomes possible.
  • This disclosure is available for DAB converters.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

L'invention concerne un convertisseur en pont double actif (DAB) pour lequel, lorsque la puissance est augmentée d'une première unité de courant continu (CC) à une seconde unité de CC et transmise, la première unité de CC et un enroulement primaire (n1) d'un transformateur d'isolation (TR1) dans un premier circuit à pont (11) sont raccordés électriquement à des moments autres que le temps mort. Un second circuit à pont (12) présente une première période pendant laquelle les deux extrémités d'un enroulement secondaire (n2) d'un transformateur d'isolation (TR1) sont court-circuitées dans le second circuit à pont (12), et une seconde période pendant laquelle l'enroulement secondaire (n2) du transformateur d'isolation (TR1) et la seconde unité de CC sont raccordés électriquement. Pendant une période pendant laquelle la puissance est augmentée de la première unité de CC à la seconde unité de CC et transmise, le circuit de commande (13) commande au moins un élément de commutation parmi un cinquième élément de commutation (Q5) à un huitième élément de commutation (Q8) pour être dans un état de marche.
PCT/JP2021/024971 2020-09-16 2021-07-01 Dispositif de conversion de puissance WO2022059294A1 (fr)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115589159A (zh) * 2022-12-09 2023-01-10 惠州市乐亿通科技有限公司 双向变换电路、多模式控制方法及双向谐振变换器
WO2023246059A1 (fr) * 2022-06-20 2023-12-28 Oppo广东移动通信有限公司 Circuit de charge, dispositif électronique, système de charge et procédé de contrôle de charge

Citations (5)

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US5027264A (en) * 1989-09-29 1991-06-25 Wisconsin Alumni Research Foundation Power conversion apparatus for DC/DC conversion using dual active bridges
JP2017051082A (ja) * 2015-08-31 2017-03-09 サンケン電気株式会社 双方向ｄｃ／ｄｃコンバータ
JP2017121165A (ja) * 2015-12-24 2017-07-06 株式会社安川電機 電力変換装置及び電力変換方法
JP2019041433A (ja) * 2017-08-22 2019-03-14 ダイヤモンド電機株式会社 コンバータ
JP2020010594A (ja) * 2018-07-10 2020-01-16 シャープ株式会社 Ｄｃ／ｄｃコンバータ

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5027264A (en) * 1989-09-29 1991-06-25 Wisconsin Alumni Research Foundation Power conversion apparatus for DC/DC conversion using dual active bridges
JP2017051082A (ja) * 2015-08-31 2017-03-09 サンケン電気株式会社 双方向ｄｃ／ｄｃコンバータ
JP2017121165A (ja) * 2015-12-24 2017-07-06 株式会社安川電機 電力変換装置及び電力変換方法
JP2019041433A (ja) * 2017-08-22 2019-03-14 ダイヤモンド電機株式会社 コンバータ
JP2020010594A (ja) * 2018-07-10 2020-01-16 シャープ株式会社 Ｄｃ／ｄｃコンバータ

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023246059A1 (fr) * 2022-06-20 2023-12-28 Oppo广东移动通信有限公司 Circuit de charge, dispositif électronique, système de charge et procédé de contrôle de charge
CN115589159A (zh) * 2022-12-09 2023-01-10 惠州市乐亿通科技有限公司 双向变换电路、多模式控制方法及双向谐振变换器
CN115589159B (zh) * 2022-12-09 2023-03-14 惠州市乐亿通科技有限公司 双向变换电路、多模式控制方法及双向谐振变换器

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