WO2024043124A1 - 電力変換装置 - Google Patents

電力変換装置 Download PDF

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Publication number
WO2024043124A1
WO2024043124A1 PCT/JP2023/029341 JP2023029341W WO2024043124A1 WO 2024043124 A1 WO2024043124 A1 WO 2024043124A1 JP 2023029341 W JP2023029341 W JP 2023029341W WO 2024043124 A1 WO2024043124 A1 WO 2024043124A1
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WIPO (PCT)
Prior art keywords
terminal
switching
capacitor
power conversion
switches
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2023/029341
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English (en)
French (fr)
Japanese (ja)
Inventor
凌佑 前田
弘治 東山
豊 掃部
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Panasonic Intellectual Property Management Co Ltd
Original Assignee
Panasonic Intellectual Property Management Co Ltd
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Filing date
Publication date
Application filed by Panasonic Intellectual Property Management Co Ltd filed Critical Panasonic Intellectual Property Management Co Ltd
Priority to CN202380049267.7A priority Critical patent/CN119422321A/zh
Priority to EP23857237.4A priority patent/EP4580028A4/en
Priority to JP2024542759A priority patent/JPWO2024043124A1/ja
Publication of WO2024043124A1 publication Critical patent/WO2024043124A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0048—Circuits or arrangements for reducing losses
    • H02M1/0054—Transistor switching losses
    • H02M1/0058—Transistor switching losses by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero
    • 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
    • H02M7/4815—Resonant converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • 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
    • H02M7/4815—Resonant converters
    • H02M7/4818—Resonant converters with means for adaptation of resonance frequency, e.g. by modification of capacitance or inductance of resonance circuits
    • 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
    • H02M7/53—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 using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—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 using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/5387—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 using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
    • 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
    • H02M7/53—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 using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—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 using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/539—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 using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters with automatic control of output wave form or frequency
    • H02M7/5395—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 using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters with automatic control of output wave form or frequency by pulse-width modulation

Definitions

  • the present disclosure relates to a power conversion device, and more specifically, to a power conversion device capable of converting DC power into AC power.
  • Patent Document 1 discloses a power conversion device that converts direct current to multiphase alternating current.
  • the power conversion device disclosed in Patent Document 1 includes a main switching means (power conversion circuit), two capacitors, one coil (resonant inductor), a plurality of auxiliary switch elements, and a control means.
  • the main switching circuit is composed of a pair of main switch elements connected in series between both terminals of a DC power supply, and the main switching circuit is configured to have a multi-phase It is provided for each phase of AC.
  • the two capacitors divide the voltage of the DC power supply.
  • One end of the coil is connected to a voltage dividing point formed by two capacitors.
  • the plurality of auxiliary switch elements connect the other end of the coil and the output point of each phase.
  • power conversion efficiency may decrease due to changes in load conditions.
  • An object of the present disclosure is to provide a power conversion device that can improve power conversion efficiency.
  • a power conversion device includes a first DC terminal, a second DC terminal, a power conversion circuit, a plurality of AC terminals, a plurality of switches, a plurality of resonance capacitors, and a resonance inductor. , a regenerative capacitor, and a control device.
  • the power conversion circuit includes a plurality of first switching elements and a plurality of second switching elements.
  • a plurality of switching circuits in which the plurality of first switching elements and the plurality of second switching elements are connected in series on a one-to-one basis are connected in parallel to each other.
  • the plurality of first switching elements are connected to the first DC terminal, and the plurality of second switching elements are connected to the second DC terminal.
  • the plurality of AC terminals correspond one-to-one to the plurality of switching circuits. Each of the plurality of AC terminals is connected to a connection point between the first switching element and the second switching element in the corresponding switching circuit.
  • the plurality of switches correspond one-to-one to the plurality of switching circuits. Each of the plurality of switches has a first end connected to the connection point of the first switching element and the second switching element in the corresponding switching circuit, and a second end commonly connected to the common connection point. .
  • the plurality of resonance capacitors correspond one-to-one to the plurality of switches. Each of the plurality of resonance capacitors is connected between the first end and the second DC terminal of the corresponding switch.
  • the resonant inductor has a first end and a second end.
  • the control device applies a PWM signal whose potential changes between a high level and a low level to each of the plurality of first switching elements and the plurality of second switching elements.
  • the control device performs a first control operation. In the first control operation, the control device is configured to control a period between a high level period of a PWM signal to the first switching element and a high level period of a PWM signal to the second switching element for each of the plurality of switching circuits. Set dead time to .
  • the control device overlaps the high level period of a control signal to a switch corresponding to each of the plurality of switching circuits among the plurality of switches with the dead time, and The start point of the dead time is advanced by an additional time than the start point of the dead time.
  • the control device generates control signals for two of the plurality of switches based on the detected potential of the fourth terminal of the regeneration capacitor and the polarity of the plurality of output currents output from the plurality of AC terminals.
  • a second control operation in which the high-level periods of the control signals of the plurality of switches are overlapped, and a third control operation in which the high-level periods of the control signals of the plurality of switches are not overlapped are switched.
  • a power conversion device includes a first DC terminal, a second DC terminal, a power conversion circuit, a plurality of AC terminals, a plurality of switches, a plurality of resonance circuits, and a regeneration capacitor. and a control device.
  • the power conversion circuit includes a plurality of first switching elements and a plurality of second switching elements.
  • a plurality of switching circuits in which the plurality of first switching elements and the plurality of second switching elements are connected in series on a one-to-one basis are connected in parallel to each other.
  • the plurality of first switching elements are connected to the first DC terminal, and the plurality of second switching elements are connected to the second DC terminal.
  • the plurality of AC terminals correspond one-to-one to the plurality of switching circuits. Each of the plurality of AC terminals is connected to a connection point between the first switching element and the second switching element in the corresponding switching circuit.
  • the plurality of switches correspond one-to-one to the plurality of switching circuits. A first end of each of the plurality of switches is connected to the connection point of the first switching element and the second switching element in the corresponding switching circuit.
  • the plurality of resonant circuits correspond one-to-one to the plurality of switches and have variable resonant frequencies.
  • the regeneration capacitor has a third end and a fourth end. In the regenerative capacitor, the third end is connected to the first DC terminal or the second DC terminal, and the fourth end is connected to the plurality of resonance circuits.
  • the control device applies a PWM signal whose potential changes between a high level and a low level to each of the plurality of first switching elements and the plurality of second switching elements.
  • Each of the plurality of resonant circuits includes a resonant capacitor connected between the first end and the second DC terminal of the corresponding one of the plurality of switches, and a corresponding one of the plurality of switches. and a resonant inductor connected between the second end of the switch and the fourth end of the regenerative capacitor.
  • the control device sets a dead time between a high level period of the PWM signal to the first switching element and a high level period of the PWM signal to the second switching element for each of the plurality of switching circuits.
  • the control device performs a first control operation.
  • the control device overlaps the high level period of a control signal to a switch corresponding to each of the plurality of switching circuits among the plurality of switches with the dead time, and
  • the start point of the dead time is advanced by an additional time than the start point of the dead time.
  • the control device changes the resonant frequency of at least one resonant circuit among the plurality of resonant circuits according to the potential at the fourth end of the regeneration capacitor.
  • FIG. 1 is a circuit diagram of a system including a power conversion device according to a first embodiment.
  • FIG. 2 is an explanatory diagram of the operation when the control device performs the first control operation in the above power converter.
  • FIG. 3 is another diagram illustrating the operation when the control device performs the first control operation in the power conversion device described above.
  • FIG. 4 is an explanatory diagram of the operation of the control device in the above power converter.
  • FIG. 5 is a diagram showing changes over time in duty corresponding to voltage commands for each of three phases in an AC load connected to a plurality of AC terminals of the power converter device.
  • FIG. 6 is a timing chart when the control device independently controls the two-phase switches in the power conversion device described above.
  • FIG. 1 is a circuit diagram of a system including a power conversion device according to a first embodiment.
  • FIG. 2 is an explanatory diagram of the operation when the control device performs the first control operation in the above power converter.
  • FIG. 3 is another diagram illustrating the operation when the
  • FIG. 7 is a timing chart when the control device performs simultaneous control on two-phase switches in the power conversion device described above.
  • FIG. 8 is a timing chart when the control device simultaneously controls two-phase switches in the power converter device.
  • FIG. 9 is a timing chart when the control device independently controls the two-phase switches in the power conversion device described above.
  • FIG. 10 is a timing chart when the control device performs simultaneous control on two-phase switches in the power conversion device described above.
  • FIG. 11 is a timing chart when the control device independently controls the two-phase switches in the power conversion device described above.
  • FIG. 12 is a timing chart showing another example in which the control device simultaneously controls two-phase switches in the power conversion device described above.
  • FIG. 13 is a circuit diagram of a system including a power conversion device according to Modification 1 of Embodiment 1.
  • FIG. 14 is a circuit diagram of a system including a power conversion device according to a second modification of the first embodiment.
  • FIG. 15 is a circuit diagram of a system including a power conversion device according to Modification 3 of Embodiment 1.
  • FIG. 16 is a circuit diagram of a system including a power conversion device according to a fourth modification of the first embodiment.
  • FIG. 17 is a circuit diagram of a system including a power conversion device according to a fifth modification of the first embodiment.
  • FIG. 18 is a circuit diagram of a system including the power conversion device according to the second embodiment.
  • FIG. 19 is a circuit diagram of a system including the power conversion device according to the third embodiment.
  • FIG. 19 is a circuit diagram of a system including the power conversion device according to the third embodiment.
  • FIG. 20 is a circuit diagram of a power conversion device according to Embodiment 4.
  • FIG. 21 is a timing chart for explaining an example of the operation of the above power conversion device.
  • FIG. 22 is a timing chart for explaining another example of the operation of the power converter device as described above.
  • FIG. 23 is a circuit diagram of a system including the power conversion device according to the fifth embodiment.
  • the power converter device 100 includes, for example, a first DC terminal 31, a second DC terminal 32, a plurality of (for example, three) AC terminals 41, A DC power source E1 is connected between the first DC terminal 31 and the second DC terminal 32, and an AC load RA1 is connected to the plurality of AC terminals 41.
  • AC load RA1 is, for example, a three-phase motor.
  • Power converter 100 converts DC output from DC power supply E1 into AC power and outputs it to AC load RA1.
  • the DC power source E1 includes, for example, a solar cell or a fuel cell.
  • the DC power supply E1 may include a DC-DC converter.
  • the AC power is, for example, three-phase AC power having a U phase, a V phase, and a W phase.
  • the power conversion device 100 includes a power conversion circuit 11, a plurality (for example, three) of switches 8, a plurality of (for example, three) resonance capacitors 9, a regeneration capacitor 15, a resonance inductor L0, A control device 50 is provided. Moreover, the power conversion device 100 further includes a protection circuit 17 and a capacitor C10. Each of the plurality of switches 8 is, for example, a bidirectional switch.
  • the power conversion circuit 11 includes a plurality of (for example, three) first switching elements 1 and a plurality of (for example, three) second switching elements 2.
  • a plurality of (for example, three) switching circuits 10 in which a plurality of first switching elements 1 and a plurality of second switching elements 2 are connected in series in a one-to-one manner are connected in parallel to each other.
  • a plurality of first switching elements 1 are connected to a first DC terminal 31, and a plurality of second switching elements 2 are connected to a second DC terminal 32.
  • the plurality of AC terminals 41 correspond to the plurality of switching circuits 10 on a one-to-one basis.
  • Each of the plurality of AC terminals 41 is connected to a connection point 3 between the first switching element 1 and the second switching element 2 in the corresponding switching circuit 10.
  • the plurality of switches 8 correspond one-to-one to the plurality of switching circuits 10.
  • a first end 81 of each of the plurality of switches 8 is connected to a connection point 3 between the first switching element 1 and the second switching element 2 in the corresponding switching circuit 10.
  • the plurality of resonance capacitors 9 correspond one-to-one to the plurality of switches 8.
  • Each of the plurality of resonance capacitors 9 is connected between the first end 81 of the corresponding switch 8 and the second DC terminal 32.
  • the resonant inductor L0 has a first end and a second end, and the first end is connected to the common connection point 25.
  • Regeneration capacitor 15 has a third end 153 and a fourth end 154.
  • the regenerative capacitor 15 has a third end 153 connected to the second DC terminal 32 and a fourth end 154 connected to the common connection point 25.
  • the control device 50 controls the plurality of first switching elements 1, the plurality of second switching elements 2, and the plurality of switches 8.
  • the switching circuits 10 corresponding to the U phase, V phase, and W phase will be referred to as the switching circuit 10U, the switching circuit 10V, and the switching circuit, respectively. It is also sometimes referred to as 10W.
  • the 1st switching element 1 and the 2nd switching element 2 of 10 U of switching circuits may be called 1 U of 1st switching elements, and 2 U of 2nd switching elements.
  • the 1st switching element 1 and the 2nd switching element 2 of the switching circuit 10V may be called the 1st switching element 1V and the 2nd switching element 2V.
  • the 1st switching element 1 and the 2nd switching element 2 of the switching circuit 10W may be called the 1st switching element 1W and the 2nd switching element 2W.
  • the connection point 3 between the first switching element 1U and the second switching element 2U is referred to as the connection point 3U
  • the connection point 3 between the first switching element 1V and the second switching element 2V is referred to as the connection point 3V
  • the connection point 3 between the first switching element 1U and the second switching element 2V is referred to as the connection point 3V.
  • the connection point 3 between the first switching element 1W and the second switching element 2W may be referred to as the connection point 3W.
  • the AC terminal 41 connected to the connection point 3U will be referred to as an AC terminal 41U
  • the AC terminal 41 connected to the connection point 3V will be referred to as an AC terminal 41V
  • the AC terminal 41 connected to the connection point 3W will be referred to as an AC terminal 41V.
  • the terminal 41 may also be referred to as an AC terminal 41W.
  • the resonance capacitor 9 connected in parallel to the second switching element 2U will be referred to as a resonance capacitor 9U
  • the resonance capacitor 9 connected in parallel to the second switching element 2V will be referred to as a resonance capacitor 9V.
  • the resonance capacitor 9 connected in parallel to the second switching element 2W may also be referred to as a resonance capacitor 9W.
  • the switch 8 connected to the connection point 3U is referred to as a switch 8U
  • the switch 8 connected to the connection point 3V is referred to as a switch 8V
  • the switch 8 connected to the connection point 3W is referred to as a switch 8W. It is also sometimes called.
  • the high potential side output terminal (positive electrode) of the DC power source E1 is connected to the first DC terminal 31, and the low potential side output terminal (negative electrode) of the DC power source E1 is connected to the second DC terminal 32.
  • the U phase, V phase, and W phase of the AC load RA1 are connected to three AC terminals 41U, 41V, and 41W, respectively.
  • each of the plurality of (for example, three) first switching elements 1 and the plurality of (for example, three) second switching elements 2 has a control terminal, a first main terminal, and a second main terminal.
  • Control terminals of the plurality of first switching elements 1 and the plurality of second switching elements 2 are connected to the control device 50.
  • the first main terminal of the first switching element 1 is connected to the first DC terminal 31, and the second main terminal of the first switching element 1 is connected to the second switching element 2.
  • the second main terminal of the second switching element 2 is connected to the second DC terminal 32 .
  • the first switching element 1 is a high-side switching element (P-side switching element), and the second switching element 2 is a low-side switching element (N-side switching element).
  • Each of the plurality of first switching elements 1 and the plurality of second switching elements 2 is, for example, an IGBT (Insulated Gate Bipolar Transistor). Therefore, the control terminal, first main terminal, and second main terminal of each of the plurality of first switching elements 1 and the plurality of second switching elements 2 are a gate terminal, a collector terminal, and an emitter terminal, respectively.
  • the power conversion circuit 11 includes a plurality (three) of first diodes 4 connected one-to-one in antiparallel to a plurality (three) of first switching elements 1, and a plurality of (three) second switching elements 2. It further includes a plurality (three) of second diodes 5 that are connected one-to-one in antiparallel to each other.
  • the anode of the first diode 4 is connected to the second main terminal (emitter terminal) of the first switching element 1 corresponding to this first diode 4
  • the cathode of the first diode 4 is connected to the second main terminal (emitter terminal) of the first switching element 1 corresponding to the first diode 4.
  • the anode of the second diode 5 is connected to the second main terminal (emitter terminal) of the second switching element 2 corresponding to this second diode 5
  • the cathode of the second diode 5 is connected to the second main terminal (emitter terminal) of the second switching element 2 corresponding to the second diode 5. is connected to the first main terminal (collector terminal) of the second switching element 2 corresponding to this second diode 5.
  • the U phase of the AC load RA1 is connected to the connection point 3U between the first switching element 1U and the second switching element 2U via the AC terminal 41U.
  • the V phase of the AC load RA1 is connected to the connection point 3V between the first switching element 1V and the second switching element 2V via the AC terminal 41V.
  • the W phase of the AC load RA1 is connected to the connection point 3W between the first switching element 1W and the second switching element 2W via the AC terminal 41W.
  • the plurality of resonance capacitors 9 correspond one-to-one to the plurality of switches 8. Each of the plurality of resonance capacitors 9 is connected between the first end 81 of the corresponding switch 8 and the second DC terminal 32.
  • Power conversion device 100 has a plurality of resonant circuits.
  • the plurality of resonant circuits include a resonant circuit having a resonant capacitor 9U and a resonant inductor L0, a resonant circuit having a resonant capacitor 9V and a resonant inductor L0, and a resonant capacitor 9W and a resonant inductor L0. and a resonant circuit.
  • the plurality of resonant circuits share a resonant inductor L0.
  • Each of the plurality of switches 8 includes, for example, two first IGBTs 6 and two second IGBTs 7 connected in antiparallel.
  • the collector terminal of the first IGBT 6 and the emitter terminal of the second IGBT 7 are connected, and the emitter terminal of the first IGBT 6 and the collector terminal of the second IGBT 7 are connected.
  • the emitter terminal of the first IGBT 6 is connected to the connection point 3 of the switching circuit 10 corresponding to the switch 8 having the first IGBT 6.
  • the collector terminal of the second IGBT 7 is connected to the connection point 3 of the switching circuit 10 corresponding to the switch 8 having the second IGBT 7.
  • the switch 8U is connected to the connection point 3U between the first switching element 1U and the second switching element 2U.
  • the switch 8V is connected to the connection point 3V between the first switching element 1V and the second switching element 2V.
  • the switch 8W is connected to the connection point 3W between the first switching element 1W and the second switching element 2W.
  • the first IGBT 6 and the second IGBT 7 of the switch 8U will be referred to as the first IGBT 6U and the second IGBT 7U, respectively
  • the first IGBT 6 and the second IGBT 7 of the switch 8V will be referred to as the first IGBT 6V and the second IGBT 7V, respectively
  • the The first IGBT 6 and the second IGBT 7 may also be referred to as a first IGBT 6W and a second IGBT 7W, respectively.
  • the plurality of switches 8 are controlled by a control device 50.
  • the first IGBT 6U, the second IGBT 7U, the first IGBT 6V, the second IGBT 7V, the first IGBT 6W, and the second IGBT 7W are controlled by the control device 50.
  • the resonant inductor L0 has a first end and a second end. In the resonant inductor L0, the first end of the resonant inductor L0 is connected to the common connection point 25. The second end of the resonant inductor L0 is connected to the fourth end 154 of the regenerative capacitor 15.
  • the regenerative capacitor 15 is connected between the second end of the resonant inductor L0 and the second DC terminal 32.
  • the regeneration capacitor 15 is, for example, a film capacitor.
  • the protection circuit 17 includes a third diode 13 and a fourth diode 14.
  • the third diode 13 is connected between the common connection point 25 and the first DC terminal 31.
  • the anode of the third diode 13 is connected to the common connection point 25.
  • the cathode of the third diode 13 is connected to the first DC terminal 31.
  • the fourth diode 14 is connected between the common connection point 25 and the second DC terminal 32.
  • the anode of the fourth diode 14 is connected to the second DC terminal 32.
  • the cathode of the fourth diode 14 is connected to the common connection point 25. Therefore, the fourth diode 14 is connected in series to the third diode 13.
  • Capacitor C10 is connected between the first DC terminal 31 and the second DC terminal 32, and is connected in parallel to the power conversion circuit 11.
  • Capacitor C10 is, for example, an electrolytic capacitor.
  • the control device 50 controls the plurality of first switching elements 1, the plurality of second switching elements 2, and the plurality of switches 8.
  • the execution body of the control device 50 includes a computer system.
  • a computer system includes one or more computers.
  • a computer system mainly consists of a processor and a memory as hardware.
  • the function of the control device 50 as an execution entity in the present disclosure is realized by the processor executing a program recorded in the memory of the computer system.
  • the program may be pre-recorded in the computer system's memory, or may be provided via a telecommunications line, or may be stored in a non-temporary storage device such as a memory card, optical disk, hard disk drive (magnetic disk), etc. that can be read by the computer system. It may also be provided recorded on a digital recording medium.
  • a processor of a computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI).
  • the plurality of electronic circuits may be integrated into one chip, or may be provided in a distributed manner over a plurality of chips.
  • a plurality of chips may be integrated into one device, or may be distributed and provided in a plurality of devices.
  • the control device 50 outputs PWM (Pulse Width Modulation) signals SU1, SV1, and SW1 that control on/off of the plurality of first switching elements 1U, 1V, and 1W, respectively.
  • PWM Pulse Width Modulation
  • Each of the PWM signals SU1, SV1, and SW1 has, for example, a first potential level (hereinafter also referred to as low level) and a second potential level higher than the first potential level (hereinafter also referred to as high level). ) is a signal that changes between.
  • the first switching elements 1U, 1V, and 1W are turned on when the PWM signals SU1, SV1, and SW1 are at a high level, and turned off when they are at a low level.
  • control device 50 outputs PWM signals SU2, SV2, and SW2 that control on/off of the plurality of second switching elements 2U, 2V, and 2W, respectively.
  • Each of the PWM signals SU2, SV2, and SW2 has, for example, a first potential level (hereinafter also referred to as low level) and a second potential level higher than the first potential level (hereinafter also referred to as high level). ) is a signal that changes between.
  • the second switching elements 2U, 2V, and 2W are turned on when the PWM signals SU2, SV2, and SW2 are at a high level, and turned off when they are at a low level.
  • the control device 50 uses a sawtooth wave carrier signal (see FIG. 2) to generate PWM signals SU1, SV1, and SW1 corresponding to the plurality of first switching elements 1U, 1V, and 1W, respectively, and the plurality of second switching elements. PWM signals SU2, SV2, and SW2 corresponding to 2U, 2V, and 2W are generated. More specifically, the control device 50 generates PWM signals SU1 and SU2 to be applied to the first switching element 1U and the second switching element 2U, respectively, based on at least the carrier signal and the U-phase voltage command.
  • control device 50 generates PWM signals SV1 and SV2 to be applied to the first switching element 1V and the second switching element 2V, respectively, based on at least the carrier signal and the V-phase voltage command. Further, the control device 50 generates PWM signals SW1 and SW2 to be applied to the first switching element 1W and the second switching element 2W, respectively, based on at least the carrier signal and the W-phase voltage command.
  • the U-phase voltage command, the V-phase voltage command, and the W-phase voltage command are, for example, sinusoidal signals whose phases differ from each other by 120°, and the amplitudes (voltage command values) of each change with time.
  • the length of one cycle of the U-phase voltage command, the V-phase voltage command, and the W-phase voltage command is the same. Further, the length of one cycle of the U-phase voltage command, the V-phase voltage command, and the W-phase voltage command is longer than the length of one cycle of the carrier signal.
  • the control device 50 compares the U-phase voltage command and the carrier signal to generate a PWM signal SU1 to be applied to the first switching element 1U. Further, the control device 50 inverts the PWM signal SU1 applied to the first switching element 1U to generate a PWM signal SU2 applied to the second switching element 2U.
  • control device 50 controls the period between the period when the PWM signal SU1 is at a high level and the period when the PWM signal SU2 is at a high level so that the on periods of the first switching element 1U and the second switching element 2U do not overlap.
  • the dead time Td (see FIG. 2) is set to .
  • the control device 50 compares the V-phase voltage command and the carrier signal to generate a PWM signal SV1 to be applied to the first switching element 1V. Further, the control device 50 inverts the PWM signal SV1 applied to the first switching element 1V to generate a PWM signal SV2 applied to the second switching element 2V.
  • the control device 50 also controls the period between the period when the PWM signal SV1 is at a high level and the period when the PWM signal SV2 is at a high level so that the on periods of the first switching element 1V and the second switching element 2V do not overlap.
  • the dead time Td (see FIG. 2) is set to .
  • the control device 50 compares the W-phase voltage command and the carrier signal to generate a PWM signal SW1 to be applied to the first switching element 1W. Further, the control device 50 inverts the PWM signal SW1 applied to the first switching element 1W to generate a PWM signal SW2 applied to the second switching element 2W.
  • the control device 50 also controls the period between the period when the PWM signal SW1 is at a high level and the period when the PWM signal SW2 is at a high level so that the on periods of the first switching element 1W and the second switching element 2W do not overlap.
  • the dead time Td (see FIG. 3) is set to .
  • the U-phase voltage command, the V-phase voltage command, and the W-phase voltage command are, for example, sinusoidal signals whose phases differ by 120 degrees from each other, and the amplitudes of each change with time. Therefore, the duty of the PWM signal SU1, the duty of the PWM signal SV1, and the duty of the PWM signal SW1 change, for example, in the form of a sine wave whose phases are different from each other by 120 degrees, as shown in FIG. Similarly, the duty of the PWM signal SU2, the duty of the PWM signal SV2, and the duty of the PWM signal SW2 change in the form of a sine wave whose phases are different from each other by 120°.
  • the control device 50 generates each PWM signal SU1, SU2, SV1, SV2, SW1, SW2 based on the carrier signal, each voltage command, and information regarding the state of AC load RA1. For example, if the AC load RA1 is a three-phase motor, the information regarding the state of the AC load RA1 can be obtained from a plurality of Contains the detected value from the current sensor.
  • the plurality of switches 8, the plurality of resonance inductors L0, the plurality of resonance capacitors 9, and the regeneration capacitor 15 are provided to perform zero-voltage soft switching of the plurality of first switching elements 1 and the plurality of second switching elements 2. There is.
  • control device 50 also controls the plurality of switches 8 in addition to the plurality of first switching elements 1 and second switching elements 2 of the power conversion circuit 11.
  • the control device 50 generates control signals SU6, SU7, SV6, SV7, SW6, and SW7 that control on/off of the first IGBT 6U, the second IGBT 7U, the first IGBT 6V, the second IGBT 7V, the first IGBT 6W, and the second IGBT 7W. It outputs to the respective gate terminals of the 2 IGBT 7U, the first IGBT 6V, the second IGBT 7V, the first IGBT 6W, and the second IGBT 7W.
  • the switch 8U flows through the path of regeneration capacitor 15 - resonance inductor L0 - switch 8U - resonance capacitor 9U and charges the resonance capacitor 9U. Pass charging current.
  • the switch 8U flows through the path of resonance capacitor 9U, switch 8U, resonance inductor L0, and regeneration capacitor 15 to remove the charge of the resonance capacitor 9U. Pass the discharge current to discharge.
  • the switch 8V flows through the path of regeneration capacitor 15 - resonance inductor L0 - switch 8V - resonance capacitor 9V and charges the resonance capacitor 9V. Pass charging current.
  • the switch 8V flows through the path of resonance capacitor 9V - switch 8V - resonance inductor L0 - regeneration capacitor 15, and charges the resonance capacitor 9V. Pass the discharge current to discharge.
  • the switch 8W flows through the path of regeneration capacitor 15 - resonance inductor L0 - switch 8W - resonance capacitor 9W and charges the resonance capacitor 9W. Pass charging current.
  • the switch 8W flows through the path of resonance capacitor 9W, switch 8W, resonance inductor L0, and regeneration capacitor 15 to remove the charge of the resonance capacitor 9W. Pass the discharge current to discharge.
  • the first IGBT 6U of the switch 8U may change from a state where the first IGBT 6U of the switch 8U is in an on state and a current iL0 is flowing with positive polarity to the resonance inductor L0 to an off state of the first IGBT 6U of the switch 8U.
  • the current iL0 flowing through the resonant inductor L0 is regenerated to the power conversion circuit 11 via the third diode 13 until the energy of the resonant inductor L0 is consumed and the current iL0 becomes zero.
  • the second IGBT 7U of the switch 8U may go from a state where the second IGBT 7U is in an on state and a current iL0 is flowing in the resonant inductor L0 with negative polarity to a state where the second IGBT 7U becomes an off state.
  • the current iL0 flowing through the resonant inductor L0 flows through the path of the fourth diode 14, the resonant inductor L0, and the regenerative capacitor 15 until the energy of the resonant inductor L0 is consumed and the current iL0 becomes zero.
  • the first IGBT 6V of the switch 8V changes from a state where the first IGBT 6V of the switch 8V is in an on state and a current iL0 is flowing in the resonant inductor L0 with positive polarity to an off state.
  • the current iL0 flowing through the resonant inductor L0 is regenerated to the power conversion circuit 11 via the third diode 13 until the energy of the resonant inductor L0 is consumed and the current iL0 becomes zero.
  • the second IGBT 7V of the switch 8V may be in the on state and the current iL0 is flowing in the resonant inductor L0 with negative polarity, and then the second IGBT 7V may be in the off state.
  • the current iL0 flowing through the resonant inductor L0 continues in the path of the fourth diode 14 - the resonant inductor L0 - the regeneration capacitor 15 until the energy of the resonant inductor L0 is consumed and the current iL0 becomes zero. flows.
  • the first IGBT 6W of the switch 8W may turn off from a state where the first IGBT 6W of the switch 8W is in the on state and current iL0 is flowing in the resonant inductor L0 with positive polarity. .
  • the current iL0 flowing through the resonant inductor L0 is regenerated to the power conversion circuit 11 via the third diode 13 until the energy of the resonant inductor L0 is consumed and the current iL0 becomes zero.
  • the second IGBT 7W of the switch 8W may go from a state where the second IGBT 7W is in an on state and a current iL0 is flowing in the resonant inductor L0 with negative polarity to a state where the second IGBT 7W becomes an off state.
  • the current iL0 flowing through the resonant inductor L0 flows through the path of the fourth diode 14 - the resonant inductor L0 - the regeneration capacitor 15 until the energy of the resonant inductor L0 is consumed and the current iL0 becomes zero.
  • control device 50 performs zero voltage soft switching control for each of the plurality of first switching elements 1 and the plurality of second switching elements 2 will be described with reference to FIGS. 1 to 3.
  • the control device 50 controls the high level period of the PWM signals SU1, SV1, SW1 to the first switching elements 1U, 1V, 1W and the second switching elements 2U, 2V, 2V, A dead time Td is set between the high level periods of the PWM signals SU2, SV2, and SW2 to 2W.
  • the high level period of the control signal to the switch 8 corresponding to each of the plurality of switching circuits 10 among the plurality of switches 8 overlaps with the dead time Td, and the start point of the high level period is set to overlap with the dead time Td.
  • the start point of the dead time Td is advanced by an additional time.
  • the first control operation will be explained in more detail below.
  • the control device 50 turns on the first IGBT 6 corresponding to the first switching element 1 to be subjected to zero voltage soft switching control. Thereby, the control device 50 causes the resonant inductor L0 and the resonant capacitor 9 connected to the first switching element 1 to resonate, charges the resonant capacitor 9 from the regenerative capacitor 15, and charges the resonant capacitor 9 from the regenerative capacitor 15. Make the voltage across both ends zero.
  • the control device 50 turns on the second IGBT 7 corresponding to the second switching element 2 to be subjected to zero voltage soft switching control. Thereby, the control device 50 causes the resonant inductor L0 and the resonant capacitor 9 connected to the second switching element 2 to resonate, and discharges from the resonant capacitor 9 to the regenerative capacitor 15, so that the second switching element 2 Make the voltage across both ends zero.
  • the resonance capacitor 9 is charged and discharged via the switch 8 so that the dead time Td described above and the half cycle of LC resonance ( ⁇ LC) are made to match.
  • the power conversion device 100 can realize zero voltage soft switching.
  • ⁇ LC representing a half period of LC resonance
  • L is the inductance of the resonant inductor L0
  • C is the capacitance of the resonant capacitor 9.
  • FIG. 2 shows PWM signals SU1 and SU2 applied from the control device 50 to the first switching element 1U and second switching element 2U of the switching circuit 10U, respectively.
  • FIG. 2 also shows a control signal SU6 given from the control device 50 to the first IGBT 6U of the switch 8U, an output current iU flowing to the U phase of the AC load RA1, a current iL0 flowing to the resonance inductor L0, and the first switching element.
  • the voltage across both ends of 1U is V1U .
  • FIG. 2 shows PWM signals SV1 and SV2 applied from the control device 50 to the first switching element 1V and the second switching element 2V of the switching circuit 10V, respectively.
  • FIG. 2 also shows a control signal SV6 applied from the control device 50 to the first IGBT 6V of the switch 8V, an output current iV flowing to the V phase of the AC load RA1, a current iL0 flowing to the resonance inductor L0, and the first switching element. A voltage across both ends of 1V is shown.
  • FIG. 2 illustrates a dead time Td that is set in the control device 50 to prevent the first switching element 1 and the second switching element 2 of the same phase from being turned on at the same time.
  • FIG. 2 shows an additional time Tau set for the control signal SU6 of the first IGBT 6U of the switch 8U in the control device 50, and an additional time Tav set for the control signal SV6 of the first IGBT 6V of the switch 8V. Illustrated. Additional time Tau and additional time Tav will be described later.
  • FIG. 3 shows PWM signals SW1 and SW2 applied from the control device 50 to the first switching element 1W and the second switching element 2W of the switching circuit 10W, respectively.
  • FIG. 3 shows a control signal SW6 applied from the control device 50 to the first IGBT 6W of the switch 8W, and an output current iW flowing into the W phase of the AC load RA1. Further, FIG. 3 shows a current iL0 flowing through the resonant inductor L0. Further, FIG. 3 shows the voltage V 1W across the first switching element 1W.
  • FIG. 3 shows a dead time Td set in the control device 50 to prevent the first switching element 1W and the second switching element 2W from being turned on at the same time. Further, FIG. 3 shows the additional time Taw set in the control device 50 with respect to the control signal SW6 of the first IGBT 6W of the switch 8W. The additional time Taw will be described later.
  • the above-mentioned additional time Tau is such that the start time t1 of the high level period of the control signal SU6 is earlier than the start time t2 of the dead time Td, so that the high level period of the control signal SU6 is earlier than the dead time Td. This is the time set to make it longer.
  • the length of additional time Tau is set based on the value of output current iU. In order to start LC resonance from the start time t2 of the dead time Td, it is desirable that the value of the current iL0 match the value of the output current iU at the start time t2 of the dead time Td.
  • the end point of the high-level period of the control signal SU6 may be the same as the end point t3 of the dead time Td or later.
  • FIG. 2 shows an example in which the end point of the high level period of the control signal SU6 is set to be the same as the end point t3 of the dead time Td.
  • the control device 50 sets the high level period of the control signal SU6 to Tau+Td.
  • the voltage V 1U across the first switching element 1U becomes zero at the end time t3 of the dead time Td.
  • the current iL0 flowing through the resonant inductor L0 starts flowing from the start time t1 of the high level period of the control signal SU6, and reaches zero at the time t4 when an additional time Tau has elapsed from the end time t3 of the dead time Td.
  • the current iL0 at this time since iL0 ⁇ iU from the start time t2 of the dead time Td, the current iL0 in the shaded area with respect to the current waveform in the fifth row from the top in FIG. 2 flows into the resonance capacitor 9U. LC resonance occurs.
  • the current iL0 is regenerated to the power conversion circuit 11 via the third diode 13 directly connected to the resonant inductor L0 after the end time t3 of the dead time Td.
  • the detection result or signal processing value of the output current iU at this time As the detection result or signal processing value of the output current iU at this time, the detection value at the carrier cycle to which the additional time Tau is added or at the timing closest to the carrier cycle is used. Further, as the estimated value of the output current iU at this time, a value obtained by estimating the output current iU in the carrier period to which the additional time Tau is added is used.
  • FIG. 4 shows the voltage V 1U across the first switching element 1U and the voltage V 2U across the second switching element 2U.
  • the polarity of the currents i9U, i9V, and i9W is positive, and in the case of a charging operation in which the resonant capacitors 9U, 9V, and 9W are charged, the polarity is positive.
  • the polarities of the currents i9U, i9V, and i9W become negative.
  • the current i9U is also illustrated.
  • the above-mentioned additional time Tav is such that the high level period of the control signal SV6 is made earlier than the start time t6 of the dead time Td, so that the high level period of the control signal SV6 is earlier than the dead time Td. This is the time set to make it longer.
  • the length of the additional time Tav is set based on the value of the output current iV. In order to start LC resonance from the start time t6 of the dead time Td, it is desirable that the value of the current iL0 match the value of the output current iV at the start time t6 of the dead time Td.
  • the end point of the high level period of the control signal SV6 may be the same as the end time point t7 of the dead time Td or later.
  • FIG. 2 shows an example in which the end point of the high level period of the control signal SV6 is set to be the same as the end point t7 of the dead time Td.
  • the control device 50 sets the high level period of the control signal SV6 to Tav+Td.
  • the voltage V 1V across the first switching element 1V becomes zero at the end time t7 of the dead time Td.
  • the current iL0 flowing through the resonant inductor L0 starts flowing at the start time t5 of the high level period of the control signal SV6, and reaches zero at the time t8 when an additional time Tav has elapsed from the end time t7 of the dead time Td.
  • the current iL0 at this time since iL0 ⁇ iV from the start time t6 of the dead time Td, the current iL0 in the shaded area of the current waveform in the 10th row from the top in FIG. 2 flows into the resonance capacitor 9V. LC resonance occurs.
  • the current iL0 is regenerated to the power conversion circuit 11 via the third diode 13 directly connected to the resonant inductor L0 after the end time t7 of the dead time Td.
  • a detection value at the carrier cycle to which the additional time Tav is added or at the timing closest to the carrier cycle is used.
  • the estimated value of the output current iV at this time a value obtained by estimating the output current iV in the carrier cycle to which the additional time Tav is added is used.
  • the resonance capacitor 9V can be charged without turning on the first IGBT 6V of the switch 8V, and zero-voltage soft switching of the first switching element 1V can be realized.
  • the above-mentioned additional time Taw is such that the start time t9 of the high level period of the control signal SW6 is earlier than the start time t10 of the dead time Td, so that the high level period of the control signal SW6 is made earlier than the dead time Td. This is the time set to make it longer.
  • the length of the additional time Taw is set based on the value of the output current iW. In order to start LC resonance from the start time t10 of the dead time Td, it is desirable that the value of the current iL0 match the value of the output current iW at the start time t10 of the dead time Td.
  • the end point of the high level period of the control signal SW6 may be the same as the end time point t11 of the dead time Td or later.
  • FIG. 3 an example is shown in which the end point of the high level period of the control signal SW6 is set to be the same as the end time point t11 of the dead time Td.
  • the control device 50 sets the high level period of the control signal SW6 to Taw+Td.
  • the voltage V 1W across the first switching element 1W becomes zero at the end time t11 of the dead time Td.
  • the current iL0 flowing through the resonant inductor L0 starts flowing at the start time t9 of the high level period of the control signal SW6, and reaches zero at the time t12 when an additional time Taw has elapsed from the end time t11 of the dead time Td.
  • the current iL0 in the shaded area with respect to the current waveform in the fourth row from the top in FIG. 3 flows into the resonance capacitor 9W. LC resonance occurs.
  • the current iL0 is regenerated to the power conversion circuit 11 via the third diode 13 directly connected to the resonant inductor L0.
  • the resonance capacitor 9W can be charged without turning on the first IGBT 6W of the switch 8W, and zero-voltage soft switching of the first switching element 1W can be realized. .
  • the power conversion device 100 causes the resonance capacitor 9 and resonance inductor L0 associated with the switching element targeted for zero-voltage soft switching among the plurality of first switching elements 1 and the plurality of second switching elements 2 to resonate.
  • the voltage across the resonant capacitor 9 related to the switching element targeted for zero-voltage soft switching changes according to the amplitude of the resonant voltage centered on the potential V15 of the fourth end 154 of the regenerative capacitor 15. .
  • the voltage across the switching element changes from the voltage value Vd (see FIGS. 2 and 3) of the DC power supply E1 applied between the first DC terminal 31 and the second DC terminal 32 to 0, so that it becomes zero. Voltage soft switching is realized.
  • the potential V15 at the fourth end 154 of the regenerative capacitor 15 changes depending on the amount of charge or discharge of the regenerative capacitor 15 for each resonance between the resonant capacitor 9 and the resonant inductor L0. Further, the potential V15 at the fourth end 154 of the regenerative capacitor 15 changes depending on the amount of charge and discharge of the regenerative capacitor 15 for each carrier period.
  • the amount of charged charge or the amount of discharged charge related to the output currents iU, iV, and iW of the U phase, V phase, and W phase is determined for each carrier cycle.
  • the output currents iU, iV, and iW of each phase the current with the largest absolute value has the largest amount of charge.
  • the amount of charge and discharge of the regenerative capacitor 15 deviates every carrier cycle.
  • the output currents iU, iV, and iW of each phase are sinusoidal and have a phase difference of 120 degrees, so that regeneration is not possible.
  • the charging and discharging in the regenerative capacitor 15 are balanced, and fluctuations in the potential V15 at the fourth end 154 of the regenerative capacitor 15 are suppressed.
  • the control device 50 controls the high level period of the PWM signals SU1, SV1, SW1 to the first switching elements 1U, 1V, 1W and the second switching elements 2U, 2V, 2V, A dead time Td is set between the high level periods of the PWM signals SU2, SV2, and SW2 to 2W.
  • the high level period of the control signal to the switch 8 corresponding to each of the plurality of switching circuits 10 among the plurality of switches 8 overlaps with the dead time Td, and the start point of the high level period is set to overlap with the dead time Td.
  • the start point of the dead time Td is advanced by an additional time.
  • the control device 50 performs only the first control operation, for example, when the motor that is the AC load RA1 locks as a change in the state of the load, the output current iU of each phase, iV and iW each take on different constant values. Then, in the power conversion device 100, the difference between the potential V15 of the fourth end 154 of the regenerative capacitor 15 with respect to the ground potential and the half value (Vd/2) of the voltage value Vd of the DC power supply E1 becomes large.
  • the amplitude of the resonant voltage becomes small, and the zero voltage soft switching is performed. may not be possible.
  • control device 50 determines that two-phase resonant currents corresponding to two switching circuits 10 among the plurality of switching circuits 10 simultaneously flow through the resonant inductor L0 while performing the first control operation. , is configured to be able to perform either independent control or simultaneous control.
  • Independent control means that when it is determined that a two-phase resonant current flows through the resonant inductor L0, the high-level periods of two control signals to two switches 8 through which resonant current flows among the plurality of switches 8 overlap. This includes control for shifting the high level period of at least one of the two control signals so as to eliminate the period.
  • FIG. 6 shows two switches 8U, 8V, 8W out of three switches 8U, 8V, 8W so as to eliminate overlapping periods of high level periods of two control signals SV7, SW7 of two switches 8V, 8W.
  • the control signals SV7 and SW7 are shown when the high level periods of the control signals SV7 and SW7 are shifted.
  • FIG. 6 shows control signals SU6, SV7, SW7 and a plurality of outputs for an example in which the motor, which is AC load RA1, is locked and the output currents iU, iV, and iW each have different constant values.
  • Simultaneous control means that when it is determined that a two-phase resonant current flows through the resonant inductor L0, the high-level periods of two control signals to two switches 8 through which resonant current flows among the plurality of switches 8 are overlapped. Including control. "Overlapping the high-level periods of two control signals” means to overlap the entire high-level period of the first control signal, which is one of the two control signals, and the second control signal, which is the remaining one. It is not limited to just repeating the entire high level period.
  • “Overlapping the high-level periods of the two control signals” means, at least, in the high-level period of the first control signal, the period corresponding to the dead time Td between the two PWM signals for determining this high-level period. This includes overlapping the entire period and the entire period corresponding to the dead time Td between the two PWM signals for determining this high level period in the high level period of the second control signal.
  • FIGS. 7 and 8 show two switches 8U, 8V, 8W so that the high level periods of two control signals SV7, SW7 of two switches 8V, 8W overlap within one period of the carrier signal.
  • the control signals SV7 and SW7 are shown when the high level periods of the control signals SV7 and SW7 are shifted.
  • FIGS. 7 and 8 show control signals SU6, SV7, SW7 and multiple The output currents iU, iV, and iW of , and the current iL0 flowing through the resonant inductor L0 are illustrated. Further, in FIG. 7, a potential V15 at the fourth end 154 of the regenerative capacitor 15 is illustrated. In FIGS.
  • the control device 50 of the power conversion device 100 acquires the detected potential of the potential V15 of the fourth end 154 of the regenerative capacitor 15. For example, the control device 50 acquires the detected potential every cycle of the carrier signal. For example, the control device 50 may store in advance the voltage value Vd of the DC voltage applied between the first DC terminal 31 and the second DC terminal 32, or may acquire the detection result of the voltage value Vd. It's okay. The control device 50 determines the content of the control operation based on the detected potential of the fourth end 154 of the regenerative capacitor 15, the value of Vd/2, and the detection results of the output currents iU, iV, and iW.
  • the control device 50 performs a second control operation based on the detected potential of the fourth end 154 of the regenerative capacitor 15 and the polarities of the plurality of output currents iU, iV, and iW output from the plurality of AC terminals 41. Switch between the third control operation and the third control operation.
  • the "detected potential of the fourth end 154 of the regenerative capacitor 15" is the detected potential of the potential V15 of the fourth end 154 of the regenerative capacitor 15 with respect to the ground potential.
  • the second control operation is an operation in which two switches 8 among the plurality of switches 8 are controlled simultaneously.
  • the third control operation is an operation in which two switches 8 among the plurality of switches 8 are independently controlled.
  • control device 50 shifts the high-level periods of the two control signals to two of the plurality of switches 8 so that the high-level periods of the two control signals overlap.
  • the control device 50 shifts the high-level periods of the two control signals to two of the plurality of switches 8 to eliminate overlap between the high-level periods.
  • the third control operation for example, as shown in FIG. is the same as the start point of the level period, but the present invention is not limited to this, and the remaining high level period of the second control signal may start after the end of the high level period of the first control signal. .
  • the control device 50 does not allow the high-level periods of the control signals of the plurality of switches 8 to overlap.
  • the control device 50 performs the second control operation when the first condition or the second condition is satisfied, and performs the third control operation when the third condition or the fourth condition is satisfied.
  • the first condition is that the detected potential of the fourth end 154 of the regenerative capacitor 15 is smaller than the first threshold Vth1, and the product (iU ⁇ iV ⁇ iW) of the plurality of output currents iU, iV, and iW is positive.
  • This is the condition.
  • iU, iV, and iW when calculating iU ⁇ iV ⁇ iW are instantaneous values, and are positive values, 0, or negative values.
  • the second condition is that the detected potential at the fourth end 154 of the regenerative capacitor 15 is greater than the second threshold Vth2, and the product of the plurality of output currents iU, iV, and iW is negative.
  • the third condition is that the detected potential at the fourth end 154 of the regenerative capacitor 15 is smaller than the first threshold Vth1, and the product of the plurality of output currents iU, iV, and iW is negative.
  • the fourth condition is that the detected potential at the fourth end 154 of the regenerative capacitor 15 is larger than the second threshold Vth2, and the product of the plurality of output currents iU, iV, and iW is positive.
  • the first threshold value Vth1 is smaller than a half value (that is, Vd/2) of the voltage value Vd applied between the first DC terminal 31 and the second DC terminal 32.
  • the second threshold value Vth2 is larger than Vd/2.
  • the first threshold value Vth1 is, for example, a value of 90% of Vd/2.
  • the second threshold value Vth2 is, for example, a value of 110% of Vd/2.
  • the control device 50 performs the above-described first control operation when the detected potential of the fourth end 154 of the regenerative capacitor 15 is greater than or equal to the first threshold value Vth1 and less than or equal to the second threshold value Vth2.
  • Table 1 shows the relationship between the first condition, second condition, third condition, and fourth condition, and the second control operation (two-phase simultaneous control) and third control operation (two-phase independent control).
  • iU x iV x iW is the product of the output currents iU, iV, and iW, when the polarity when flowing in the direction of the arrow in Figure 1 is positive, and the polarity when flowing in the opposite direction is negative.
  • iU x iV x iW if the value of sgn(iU) x sgn(iV) x sgn(iW) is positive "1", the product of multiple output currents iU, iV, iW is positive.
  • the first control operation is to overlap the high level period of the control signal to the switch 8 corresponding to each of the plurality of switching circuits 10 among the plurality of switches 8 with the dead time Td, and This is an operation in which the start time is advanced by an additional time than the start time of the dead time Td.
  • the high level period of the control signal to the switch 8U is the period when the potential level of the control signal SU6 to the first IGBT 6U is high level, or the period when the potential level of the control signal SU7 to the second IGBT 7U is high level.
  • the high level period of the control signal to the switch 8V is the period when the potential level of the control signal SV6 to the first IGBT 6V is high level, or the period when the potential level of the control signal SV7 to the second IGBT 7V is high level.
  • the high level period of the control signal to the switch 8W is the period when the potential level of the control signal SW6 to the first IGBT 6W is high level, or the period when the potential level of the control signal SW7 to the second IGBT 7W is high level.
  • the additional time for making the high level period of the control signal to the switch 8U earlier than the start of the dead time Td is the above-mentioned additional time Tau.
  • the additional time for making the high level period of the control signal to the switch 8V earlier than the start of the dead time Td is the above-mentioned additional time Tav.
  • the additional time for making the high-level period of the control signal to the switch 8W earlier than the start of the dead time Td is the above-mentioned additional time Taw.
  • the control device 50 performs the second control operation when determining that the first condition or the second condition is satisfied as described above, and performs the third control operation when determining that the third condition or the fourth condition is satisfied.
  • An example of the second control operation and an example of the third control operation will be described below based on FIGS. 9 to 12.
  • FIG. 9 shows a time chart of an example when the control device 50 determines that the first condition is satisfied and performs the second control operation (two-phase simultaneous control).
  • FIG. 10 shows a time chart of an example when the control device 50 determines that the second condition is satisfied and performs the second control operation (two-phase simultaneous control).
  • FIG. 11 shows a time chart of an example when the control device 50 determines that the third condition is satisfied and performs the third control operation (two-phase independent control).
  • FIG. 12 shows a time chart of an example when the control device 50 determines that the fourth condition is satisfied and performs the third control operation (two-phase independent control).
  • 9 to 12 show carrier signals, six PWM signals SU1, SU2, SV1, SV2, SW1, SW2, and three control signals among six control signals SU6, SU7, SV6, SV7, SW6, SW7. , is shown in the diagram. 9 to 12 also show the current iL0, the three output currents iU, iV, iW, the voltages V 2U , V 2V , V 2W across the three second switching elements 2U , 2V , 2W , and the regenerative The potential V15 at the fourth end 154 of the capacitor 15 is shown.
  • PWM signals related to control signal SV6 are PWM signals SV1 and SV2.
  • PWM signals related to control signal SV7 are PWM signals SV1 and SV2.
  • PWM signals related to control signal SW6 are PWM signals SW1 and SW2.
  • PWM signals related to control signal SW7 are PWM signals SW1 and SW2.
  • the potential V15 at the fourth end 154 of the regenerative capacitor 15 is detected every carrier cycle. Thereby, the control device 50 acquires the detected potential of the fourth end 154 of the regenerative capacitor 15 every carrier period.
  • the timing at which the control device 50 acquires the detected potential at the fourth end 154 of the regenerative capacitor 15 is, for example, the same as the timing at which the potential V15 at the fourth end 154 of the regenerative capacitor 15 is detected, but is not limited thereto. .
  • the control device 50 controls the The second control operation so that the high level period of the signal SV7 and the high level period of the control signal SW7 overlap.
  • the amplitude of the current iL0 flowing through the resonant inductor L0 increases and the amount of charge charged to the regenerative capacitor 15 increases, so that the potential V15 of the fourth end 154 of the regenerative capacitor 15 increases.
  • the first threshold value Vth1 or more can be set.
  • the control device 50 controls the The second control operation so that the high level period of the signal SV6 and the high level period of the control signal SW6 overlap.
  • the amplitude of the current iL0 flowing through the resonant inductor L0 increases and the amount of charge discharged to the regenerative capacitor 15 increases, so that the potential V15 of the fourth end 154 of the regenerative capacitor 15 increases.
  • the second threshold value Vth2 can be lower than or equal to the second threshold value Vth2.
  • the control device 50 controls the The third control operation so that the high level period of the signal SV7 and the high level period of the control signal SW7 do not overlap.
  • the amount of charge charged to the regeneration capacitor 15 increases, so that the potential V15 at the fourth end 154 of the regeneration capacitor 15 can be set to be equal to or higher than the first threshold value Vth1.
  • the control device 50 controls the The third control operation so that the high level period of the signal SV7 and the high level period of the control signal SW7 do not overlap.
  • the amplitude when the polarity of the current iL0 flowing through the resonant inductor L0 is negative becomes small, so the potential V15 at the fourth end 154 of the regenerative capacitor 15 is set to be equal to or lower than the second threshold value Vth2. be able to.
  • the control device 50 may include control in which the high-level periods of two control signals to two of the plurality of switches 8 are not shifted in the second control operation and the third control operation.
  • the control device 50 sets the high level period of the control signal to the switch 8 corresponding to each of the plurality of switching circuits 10 among the plurality of switches 8 to a dead time Td.
  • a first control operation is performed to overlap the dead time Td and to bring the start point of the high level period earlier than the start point of the dead time Td by an additional time.
  • the power conversion device 100 can realize zero-voltage soft switching of each of the plurality of first switching elements 1 and the plurality of second switching elements 2.
  • control device 50 of the power conversion device 100 performs the following based on the detected potential of the fourth end 154 of the regenerative capacitor 15 and the polarities of the plurality of output currents iU, iV, and iW output from the plurality of AC terminals 41.
  • a second control operation in which two of the plurality of switches 8 are controlled simultaneously and a third control operation in which two of the plurality of switches 8 are independently controlled are switched.
  • the power conversion device 100 is able to suppress fluctuations in the potential V15 of the regenerative capacitor 15, and compared to the case where nothing is done to the fluctuations in the potential V15 of the regenerative capacitor 15, the power converter 100 is able to suppress fluctuations in the potential V15 of the regenerative capacitor 15.
  • the ratio increases, resulting in improved power conversion efficiency and reduced noise.
  • the control device 50 performs the second control operation when the first condition or the second condition is satisfied, and performs the third control operation when the third condition or the fourth condition is satisfied. Therefore, it is possible to suppress fluctuations in the potential V15 of the regenerative capacitor 15 regardless of the polarity of the plurality of output currents iU, iV, and iW output from the plurality of AC terminals 41.
  • the control device 50 in the power conversion device 100 shifts the high-level periods of two control signals to two switches 8 among the plurality of switches 8, and overlap each other.
  • the power conversion device 100 can increase the absolute value of the current iL0 flowing through the resonance inductor L0, and can increase the amount of adjustment (change width) of the potential V15 of the regenerative capacitor 15.
  • the control device 50 in the power conversion device 100 shifts the high-level periods of the two control signals to two of the plurality of switches 8 to Eliminate duplication.
  • the power conversion device 100 can reduce the absolute value of the current iL0 flowing through the resonant inductor L0.
  • Modification 1 A power conversion device 100A according to Modification 1 of Embodiment 1 will be described with reference to FIG. 13. Regarding the power converter device 100A according to Modification 1 of Embodiment 1, the same components as those of the power converter device 100 (see FIG. 1) according to Embodiment 1 are given the same reference numerals, and description thereof will be omitted.
  • the first IGBT 6 and the second IGBT 7 are connected in anti-series in each of the plurality of switches 8.
  • the collector terminal of the first IGBT 6 and the collector terminal of the second IGBT 7 are connected, and the emitter terminal of the first IGBT 6 is connected to the collector terminal of the plurality of switching circuits 10.
  • the second IGBT 7 is connected to the connection point 3 of the corresponding switching circuit 10, and the emitter terminal of the second IGBT 7 is connected to the common connection point 25.
  • Each of the plurality of switches 8 further includes a diode 61 connected in anti-parallel to the first IGBT 6 and a diode 71 connected in anti-parallel to the second IGBT 7.
  • each of the first IGBT 6 and the second IGBT 7 may be replaced with a MOSFET or a bipolar transistor.
  • the diode 61 and the diode 71 in FIG. 26 may each be replaced by a parasitic diode of the replaced element, or an element built into one chip of the replaced element.
  • the diode 61 and the diode 71 are not limited to being externally attached to the first IGBT 6 and the second IGBT 7, respectively, but may be elements built into one chip.
  • Modification 2 A power conversion device 100A according to a second modification of the first embodiment will be described with reference to FIG. 14. Regarding the power converter device 100A according to the second modification of the first embodiment, the same components as those of the power converter device 100 (see FIG. 1) according to the first embodiment are given the same reference numerals, and the description thereof will be omitted.
  • the first MOSFET 6A and the second MOSFET 7A are connected in anti-series in each of the plurality of switches 8.
  • the drain terminal of the first MOSFET 6A and the drain terminal of the second MOSFET 7A are connected in each of the plurality of switches 8.
  • Each of the plurality of switches 8 further includes a diode 61 connected in anti-parallel to the first MOSFET 6A, and a diode 71 connected in anti-parallel to the second MOSFET 7A.
  • the source terminal of the second MOSFET 7A is connected to the common connection point 25.
  • the source terminal of the first MOSFET 6A is connected to the connection point 3 of the switching circuit 10 corresponding to the switch 8 having the first MOSFET 6A.
  • Control signals SU6 and SU7 are applied from the control device 50 to the first MOSFET 6A and the second MOSFET 7A of the switch 8U.
  • Control signals SV6 and SV7 are applied from the control device 50 to the first MOSFET 6A and second MOSFET 7A of the switch 8V.
  • Control signals SW6 and SW7 are applied from the control device 50 to the first MOSFET 6A and second MOSFET 7A of the switch 8W.
  • Modification 3 A power conversion device 100A according to a third modification of the first embodiment will be described with reference to FIG. 15. Regarding the power converter device 100A according to the third modification of the first embodiment, the same components as those of the power converter device 100 (see FIG. 1) according to the first embodiment are given the same reference numerals, and the description thereof will be omitted.
  • a diode 63 is connected in series to the first MOSFET 6A, and a diode 73 is connected in series to the second MOSFET 7A.
  • a series circuit of the first MOSFET 6A and the diode 63 and a series circuit of the second MOSFET 7A and the diode 73 are connected in antiparallel.
  • Modification 4 A power conversion device 100A according to a fourth modification of the first embodiment will be described with reference to FIG. 16.
  • the same components as those of power converter device 100 (see FIG. 1) according to Embodiment 1 are given the same reference numerals, and description thereof will be omitted.
  • each of the plurality of switches 8 includes one MOSFET 80, a diode 83 connected in anti-parallel to the MOSFET 80, and two diodes 84 connected in anti-parallel to the MOSFET 80. , 85, and a series circuit of two diodes 86 and 87 connected antiparallel to the MOSFET 80.
  • the connection point between the diode 84 and the diode 85 in the switch 8 (the first end 81 of the switch 8) is connected to the connection point 3 of the corresponding switching circuit 10 among the plurality of switching circuits 10.
  • a connection point between the diode 86 and the diode 87 (the second end 82 of the switch 8) is connected to the common connection point 25.
  • the switch 8 is in the on state when the MOSFET 80 is in the on state, and the switch 8 is in the off state when the MOSFET 80 is in the off state.
  • the MOSFETs 80 of the plurality of switches 8 are controlled by the control device 50.
  • the control device 50 outputs a control signal SU8 that controls the on/off of the MOSFET 80 of the switch 8U, a control signal SV8 that controls the on/off of the MOSFET 80 of the switch 8V, and a control signal SW8 that controls the on/off of the MOSFET 80 of the switch 8W. .
  • a resonant current flows through the resonant circuit including the resonant inductor L0 and the resonant capacitor 9 when the MOSFET 80 is in the on state.
  • the charging current including the resonant current is transmitted through the regenerative capacitor 15 - resonant inductor L0 - diode 86 - MOSFET 80 - diode 85 - resonant It flows through the path of capacitor 9.
  • a discharge current including a resonant current flows through the resonant capacitor 9 - diode 84 - MOSFET 80 - diode 87 - resonant inductor L0 - It flows through the path of the regeneration capacitor 15.
  • each of the plurality of MOSFETs 80 may be replaced with an IGBT.
  • each of the plurality of switches 8 may include, for example, a bipolar transistor or a GaN-based GIT (Gate Injection Transistor) instead of the MOSFET 80.
  • Modification 5 A power conversion device 100A according to a fifth modification of the first embodiment will be described with reference to FIG. 17. Regarding the power conversion device 100A according to the fifth modification of the first embodiment, the same components as those of the power conversion device 100 (see FIG. 1) according to the first embodiment are given the same reference numerals, and the description thereof will be omitted.
  • each of the plurality of switches 8 is a dual gate type GaN-based GIT having a first source terminal, a first gate terminal, a second gate terminal, and a second source terminal.
  • a control signal SU6 is applied between the first gate terminal and the first source terminal of the dual gate type GaN-based GIT constituting the switch 8U, and the control signal SU6 is applied between the second gate terminal and the second source terminal.
  • a control signal SU7 is applied between the terminals.
  • a control signal SV6 is applied between the first gate terminal and the first source terminal of the dual gate type GaN-based GIT that constitutes the switch 8V, and a control signal SV7 is applied between the second gate terminal and the second source terminal.
  • a control signal SW6 is applied between the first gate terminal and the first source terminal of the dual gate type GaN-based GIT that constitutes the switch 8W, and a control signal SW7 is applied between the second gate terminal and the second source terminal.
  • the power conversion device 100B according to the second embodiment is different from the power conversion device 100B according to the first embodiment in that it further includes a capacitor 16 connected between the second end of the resonance inductor L0 and the first DC terminal 31. (See Figure 1).
  • the same components as those in the power conversion device 100 according to the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.
  • the power conversion device 100B does not include the capacitor C10 in the power conversion device 100 according to the first embodiment.
  • Capacitor 16 is connected in series to regenerative capacitor 15. Therefore, in the power conversion device 100B, a series circuit of the capacitor 16 and the regenerative capacitor 15 is connected between the first DC terminal 31 and the second DC terminal 32.
  • the capacitance of the capacitor 16 is the same as that of the regenerative capacitor 15. "The capacitance of the capacitor 16 is the same as the capacitance of the regenerative capacitor 15" does not mean only when the capacitance of the capacitor 16 completely matches the capacitance of the regenerative capacitor 15; It may be within the range of 95% or more and 105% or less of the capacitance of the capacitor 15.
  • the potential V15 at the fourth end 154 of the regenerative capacitor 15 is a value obtained by dividing the voltage value Vd of the DC power supply E1 by the capacitor 16 and the regenerative capacitor 15. Therefore, the potential V15 at the fourth end 154 of the regenerative capacitor 15 becomes Vd/2.
  • the control device 50 may store in advance the value of the potential V15 at the fourth end 154 of the regenerative capacitor 15.
  • the control device 50 of the power conversion device 100B according to the second embodiment performs the first control operation, the second control operation, and the third control operation, similarly to the control device 50 of the power conversion device 100 according to the first embodiment. Therefore, the power conversion device 100B according to the second embodiment can improve power conversion efficiency similarly to the power conversion device 100 according to the first embodiment.
  • the power conversion device 100C according to the third embodiment is different from the power conversion device 100C according to the first embodiment in that the regeneration capacitor 15 is connected between the second end of the resonance inductor L0 and the first DC terminal 31. (See Figure 1).
  • the same components as those in the power converter device 100 according to the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.
  • the control device 50 of the power conversion device 100C according to the third embodiment performs the first control operation, the second control operation, and the third control operation similarly to the control device 50 of the power conversion device 100 according to the first embodiment. Therefore, the power conversion device 100C according to the third embodiment can improve power conversion efficiency similarly to the power conversion device 100 according to the first embodiment.
  • Embodiment 4 a power conversion device 100D according to Embodiment 4 will be described based on FIG. 20.
  • the same components as those in the power conversion device 100 (see FIG. 1) according to the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.
  • the fourth end 154 of the regenerative capacitor 15 is connected to the plurality of resonance circuits 20.
  • Each of the plurality of resonance circuits 20 includes a resonance capacitor 9 and a resonance inductor L4.
  • the resonance capacitor 9 is connected between the first end 81 of a corresponding one of the plurality of switches 8 and the second DC terminal 32 .
  • the resonant inductor L4 is connected between the second end 82 of a corresponding one of the plurality of switches 8 and the fourth end 154 of the regenerative capacitor 15.
  • the resonant inductor L4 connected to the switch 8U will be referred to as a resonant inductor L11
  • the resonant inductor L4 connected to the switch 8V will be referred to as a resonant inductor L21
  • the resonant inductor L4 connected to the switch 8W will be referred to as a resonant inductor L21
  • the inductor L4 may also be referred to as a resonant inductor L31.
  • the inductance of the resonant inductor L11, the inductance of the resonant inductor L21, and the inductance of the resonant inductor L31 are the same.
  • Each of the plurality of resonance circuits 20 includes a second resonance inductor L5 that is different from the first resonance inductor L4, which is the resonance inductor L4, and a changeover switch 18 connected to the second resonance inductor L5.
  • a series circuit of the second resonant inductor L5 and the changeover switch 18 is connected in parallel to the first resonant inductor L4.
  • the resonant frequency of each of the plurality of resonant circuits 20 changes depending on whether the changeover switch 18 is turned on or off.
  • the second resonant inductor L5 and changeover switch 18 of the series circuit connected in parallel to the first resonant inductor L11 may be referred to as the second resonant inductor L12 and the changeover switch 18U.
  • the second resonant inductor L5 and the changeover switch 18 in the series circuit connected in parallel to the first resonant inductor L21 may be referred to as the second resonant inductor L22 and the changeover switch 18V.
  • the second resonant inductor L5 and the changeover switch 18 in the series circuit connected in parallel to the first resonant inductor L31 may be referred to as the second resonant inductor L32 and the changeover switch 18W.
  • the inductance of the second resonant inductor L12, the inductance of the second resonant inductor L22, and the inductance of the second resonant inductor L32 are the same.
  • Each of the changeover switches 18U, 18V, and 18W is, for example, an IGBT.
  • the changeover switches 18U, 18V, and 18W are controlled by control signals SU3, SV3, and SW3 from the control device 50.
  • Each of the changeover switches 18U, 18V, and 18W is not limited to an IGBT, but may be a MOSFET, a GIT, or a bipolar transistor, for example.
  • the control device 50 controls the high level period of the PWM signals SU1, SV1, SW1 to the first switching element 1 and the high level period of the PWM signals SU2, SV2, SW2 to the second switching element for each of the plurality of switching circuits 10.
  • a dead time Td is set between.
  • the control device 50 performs a first control operation.
  • the high level period of the control signal to the switch 8 corresponding to each of the plurality of switching circuits 10 among the plurality of switches 8 overlaps with the dead time Td, and the start point of the high level period is set to the dead time. Advance the start point of Td by an additional time.
  • the control device 50 changes the resonant frequency of at least one resonant circuit 20 among the plurality of resonant circuits 20 according to the potential V15 of the fourth end 154 of the regenerative capacitor 15.
  • FIGS. 21 and 22 show a carrier signal, three control signals SU6, SU7, SV6, SV7, SW6, and SW7, currents iL1, iL2, iL3, and three second switching elements 2U. , 2V , and 2W , respectively, and the potential V15 at the fourth end 154 of the regenerative capacitor 15 are shown.
  • the timing of detecting the potential V15 at the fourth end 154 of the regenerative capacitor 15 is indicated by an arrow.
  • the potential V15 at the fourth end 154 of the regenerative capacitor 15 is detected every carrier cycle. Thereby, the control device 50 acquires the detected potential of the fourth end 154 of the regenerative capacitor 15 every carrier period.
  • the timing at which the control device 50 acquires the detected potential at the fourth end 154 of the regenerative capacitor 15 is, for example, the same as the timing at which the potential V15 at the fourth end 154 of the regenerative capacitor 15 is detected, but is not limited thereto. .
  • the control device 50 turns on one changeover switch 18U among the three changeover switches 18U, 18V, and 18W, for example.
  • the high level period of the control signal SU6 to the first IGBT 6U of the switch 8U is shortened (in FIG. 21, the control signal SU6 before shortening is shown by a two-dot chain line).
  • the resonant period of the resonant circuit 20 including the first resonant inductor L11 and the resonant capacitor 9U among the three resonant circuits 20 is shortened, so that the discharge charge from the regenerative capacitor 15 is reduced. It is possible to reduce the amount, and it becomes possible to make the potential V15 of the fourth end 154 of the regenerative capacitor 15 larger than the first threshold value Vth1.
  • the control device 50 when the detected potential of the fourth end 154 of the regenerative capacitor 15 is larger than the second threshold value Vth2, the control device 50, for example, switches one changeover switch 18U out of the three changeover switches 18U, 18V, and 18W. It is turned on to shorten the high level period of the control signal SU7 of the switch 8U to the second IGBT 7U (in FIG. 22, the control signal SU7 before shortening is shown by a two-dot chain line). As a result, in the power conversion device 100, the resonant period of the resonant circuit 20 including the first resonant inductor L11 and the resonant capacitor 9U among the three resonant circuits 20 is shortened. It is possible to reduce the amount, and it becomes possible to make the potential V15 of the fourth end 154 of the regenerative capacitor 15 larger than the first threshold value Vth1.
  • the control device 50 changes the resonance period of at least one resonance circuit 20 among the plurality of resonance circuits 20 according to the potential V15 of the fourth end 154 of the regeneration capacitor 15. let As a result, the power converter 100D according to the fourth embodiment suppresses fluctuations in the potential V15 of the fourth end 154 of the regenerative capacitor 15 even when the motor of the AC load RA1 locks and the load state changes, for example. This makes it possible to improve power conversion efficiency.
  • Embodiment 5 a power conversion device 100E according to Embodiment 5 will be described based on FIG. 23.
  • the same components as those in the power conversion device 100D according to the fourth embodiment are denoted by the same reference numerals, and the description thereof will be omitted.
  • each of the plurality (three) resonant circuits 20 includes a resonant inductor L4.
  • the resonant inductor L4 connected to the switch 8U will be referred to as a resonant inductor L1
  • the resonant inductor L4 connected to the switch 8V will be referred to as a resonant inductor L2
  • the resonant inductor L4 connected to the switch 8W will be referred to as a resonant inductor L2.
  • Inductor L4 may also be referred to as resonance inductor L3.
  • the inductance of the resonant inductor L1, the inductance of the resonant inductor L2, and the inductance of the resonant inductor L3 are the same.
  • each of the plurality of resonance circuits 20 is connected to a second resonance capacitor 91 that is different from the first resonance capacitor 9 that is the resonance capacitor 9, and to the second resonance capacitor 91.
  • a selector switch 92 is provided in each of the plurality of resonant circuits 20, a series circuit of a second resonant capacitor 91 and a changeover switch 92 is connected in parallel to the first resonant capacitor 9. The resonant frequency of each of the plurality of resonant circuits 20 changes depending on whether the changeover switch 92 is turned on or off.
  • the first resonance capacitor 9 connected to the switch 8U will be referred to as a first resonance capacitor 9U
  • the first resonance capacitor 9 connected to the switch 8V will be referred to as a first resonance capacitor 9V
  • the switch The first resonance capacitor 9 connected to 8W may also be referred to as a first resonance capacitor 9W
  • the second resonance capacitor 91 connected to the switch 8U is called a second resonance capacitor 91U
  • the second resonance capacitor 91 connected to the switch 8V is called a second resonance capacitor 91V
  • the switch 8W The second resonance capacitor 91 connected to the second resonance capacitor 91W may be referred to as a second resonance capacitor 91W.
  • changeover switch 92 connected in series to the second resonance capacitor 91U is referred to as a changeover switch 92U
  • the changeover switch 92 connected in series to the second resonance capacitor 91V is referred to as a changeover switch 92V
  • the changeover switch 92 connected in series to the capacitor 91W may also be referred to as a changeover switch 92W.
  • the capacitance of the second resonance capacitor 91U, the capacitance of the second resonance capacitor 91V, and the capacitance of the second resonance capacitor 91W are the same.
  • Each of the changeover switches 92U, 92V, and 92W is, for example, an IGBT.
  • the changeover switches 92U, 92V, and 92W are controlled by control signals SU9, SV9, and SW9 from the control device 50.
  • Each of the changeover switches 92U, 92V, and 92W is not limited to an IGBT, but may be a MOSFET, a GIT, or a bipolar transistor, for example.
  • the control device 50 controls the high level period of the PWM signals SU1, SV1, SW1 to the first switching element 1 and the high level period of the PWM signals SU2, SV2, SW2 to the second switching element for each of the plurality of switching circuits 10.
  • a dead time Td is set between.
  • the control device 50 performs a first control operation.
  • the high level period of the control signal to the switch 8 corresponding to each of the plurality of switching circuits 10 among the plurality of switches 8 overlaps with the dead time Td, and the start point of the high level period is set to the dead time. Advance the start point of Td by an additional time.
  • the control device 50 changes the resonance period by switching on/off the changeover switch 92 of at least one resonance circuit 20 among the plurality of resonance circuits 20 according to the potential V15 of the fourth end 154 of the regeneration capacitor 15. .
  • the power conversion device 100E according to the fifth embodiment suppresses fluctuations in the potential V15 of the fourth end 154 of the regenerative capacitor 15, for example, even when the motor of the AC load RA1 locks and the load state changes. This makes it possible to suppress fluctuations in the potential V15 at the fourth end 154 of the regenerative capacitor 15, and to improve power conversion efficiency.
  • Embodiments 1 to 5 and the like described above are only one of various embodiments of the present disclosure. Embodiments 1 to 5 described above can be modified in various ways depending on the design, etc., as long as the objective of the present disclosure can be achieved.
  • each of the plurality of first switching elements 1 and the plurality of second switching elements 2 is not limited to an IGBT, but may be a MOSFET.
  • each of the plurality of first diodes 4 may be replaced by a parasitic diode or the like of a MOSFET that constitutes the corresponding first switching element 1.
  • each of the plurality of second diodes 5 may be replaced by a parasitic diode of a MOSFET constituting the corresponding second switching element 2.
  • the MOSFET is, for example, a Si-based MOSFET or a SiC-based MOSFET.
  • Each of the plurality of first switching elements 1 and the plurality of second switching elements 2 may be, for example, a bipolar transistor or a GaN-based GIT.
  • a plurality of The parasitic capacitance between both ends of the two switching elements 2 may also serve as a plurality of resonance capacitors 9.
  • each of the plurality of switches 8 in Embodiments 2 to 5 other than Embodiment 1 may have the configuration shown in any of the examples in FIGS. 13 to 17, for example.
  • the power converters 100, 100A, 100B, 100C, 100D, and 100E are not limited to a configuration that outputs three-phase AC, but may have a configuration that outputs polyphase AC of three or more phases.
  • the power conversion device (100; 100A; 100B; 100C) includes a first DC terminal (31), a second DC terminal (32), a power conversion circuit (11), and a plurality of AC terminals ( 41), a plurality of switches (8), a plurality of resonance capacitors (9), a resonance inductor (L0), a regeneration capacitor (15), and a control device (50).
  • the power conversion circuit (11) includes a plurality of first switching elements (1) and a plurality of second switching elements (2).
  • a plurality of switching circuits (10) each having a plurality of first switching elements (1) and a plurality of second switching elements (2) connected in series in a one-to-one manner are connected in parallel to each other.
  • a plurality of first switching elements (1) are connected to a first DC terminal (31), and a plurality of second switching elements (2) are connected to a second DC terminal (32). has been done.
  • the plurality of AC terminals (41) correspond one-to-one to the plurality of switching circuits (10).
  • Each of the plurality of AC terminals (41) is connected to a connection point (3) between the first switching element (1) and the second switching element (2) in the corresponding switching circuit (10).
  • the plurality of switches (8) correspond one-to-one to the plurality of switching circuits (10).
  • Each of the plurality of switches (8) has a first end (81) connected to a connection point (3) between the first switching element (1) and the second switching element (2) in the corresponding switching circuit (10).
  • a second end (82) of the cage is commonly connected to a common connection point (25).
  • the plurality of resonance capacitors (9) correspond one-to-one to the plurality of switches (8).
  • Each of the plurality of resonance capacitors (9) is connected between the first end (81) of the corresponding switch (8) and the second DC terminal (32).
  • the resonant inductor (L0) has a first end and a second end. In the resonant inductor (L0), the first end of the resonant inductor (L0) is connected to the common connection point (25).
  • the regeneration capacitor (15) has a third end (153) and a fourth end (154).
  • the regenerative capacitor (15) has a third end (153) connected to the first DC terminal (31) or the second DC terminal (32).
  • the control device (50) supplies PWM signals (SU1, SV1) whose potentials change between high level and low level to each of the plurality of first switching elements (1) and the plurality of second switching elements (2). , SW1, SU2, SV2, SW2).
  • the control device (50) performs a first control operation. In the first control operation, the control device (50) controls the high level period of the PWM signal (SU1, SV1, SW1) to the first switching element (1) and the second switching element for each of the plurality of switching circuits (10).
  • a dead time (Td) is set between the high level period of the PWM signals (SU2, SV2, SW2).
  • the control device (50) sets the high level period of the control signal to the switch (8) corresponding to each of the plurality of switching circuits (10) among the plurality of switches (8) as a dead time (Td). ), and the start time of the high level period is advanced by an additional time than the start time of the dead time (Td).
  • the control device (50) determines the detected potential of the fourth terminal (154) of the regenerative capacitor (15) and the polarity of the plurality of output currents (iU, iV, iW) output from the plurality of AC terminals (41). Based on the second control operation, the high-level periods of the control signals of two of the plurality of switches (8) overlap, and the second control operation does not overlap the high-level periods of the control signals of the plurality of switches (8). 3. Switch between control operations.
  • the control device (50) performs the second control operation when the first condition or the second condition is satisfied.
  • the third control operation is performed when the third condition or the fourth condition is satisfied.
  • the first condition is that the detected potential at the fourth end (154) of the regenerative capacitor (15) is 2 minutes of the voltage value (Vd) applied between the first DC terminal (31) and the second DC terminal (32). is smaller than a first threshold value (Vth1), which is smaller than 1, and the product of a plurality of output currents (iU, iV, iW) is positive.
  • the second condition is that the detected potential of the fourth end (154) of the regenerative capacitor (15) is 2 minutes of the voltage value (Vd) applied between the first DC terminal (31) and the second DC terminal (32). is larger than a second threshold value (Vth2) which is larger than 1, and the product of a plurality of output currents (iU, iV, iW) is negative.
  • the third condition is that the detected potential of the fourth terminal (154) of the regenerative capacitor (15) is 2 minutes of the voltage value (Vd) applied between the first DC terminal (31) and the second DC terminal (32). is smaller than a first threshold value (Vth1), which is smaller than 1, and the product of a plurality of output currents (iU, iV, iW) is negative.
  • the fourth condition is that the detected potential of the fourth end (154) of the regenerative capacitor (15) is 2 minutes of the voltage value (Vd) applied between the first DC terminal (31) and the second DC terminal (32).
  • the condition is that the second threshold value (Vth2) is greater than 1, and the product of the plurality of output currents (iU, iV, iW) is positive.
  • the power conversion device (100; 100A; 100B; 100C) according to the third aspect is based on the first or second aspect.
  • the control device (50) shifts the high-level periods of the two control signals to two of the plurality of switches (8) so that the high-level periods overlap with each other.
  • the absolute value of the current (iL0) flowing through the resonant inductor (L0) can be increased, and the amount of adjustment (change width) of the potential (V15) of the regenerative capacitor (15) can be increased.
  • the power conversion device (100; 100A; 100B; 100C) according to the fourth aspect is based on the first or second aspect.
  • the control device (50) shifts the high-level periods of the two control signals to two of the plurality of switches (8) so that some of the high-level periods overlap with each other. .
  • the absolute value of the current (iL0) flowing through the resonant inductor (L0) can be increased, and the amount of adjustment (change width) of the potential (V15) of the regenerative capacitor (15) can be increased.
  • the power conversion device (100; 100A; 100B; 100C) according to the fifth aspect is based on any one of the first to fourth aspects.
  • the control device (50) shifts the high-level periods of the two control signals to two of the plurality of switches (8) to eliminate overlap between the high-level periods.
  • the absolute value of the current (iL0) flowing through the resonance inductor (L0) can be reduced.
  • a power conversion device (100; 100A; 100B; 100C) according to the sixth aspect is based on any one of the first to fifth aspects.
  • the control device (50) includes control that does not shift the high-level periods of two control signals to two switches (8) among the plurality of switches (8).
  • a power conversion device (100D; 100E) includes a first DC terminal (31), a second DC terminal (32), a power conversion circuit (11), and a plurality of AC terminals (41). It includes a plurality of switches (8), a plurality of resonance circuits (20), a regeneration capacitor (15), and a control device (50).
  • the power conversion circuit (11) includes a plurality of first switching elements (1) and a plurality of second switching elements (2).
  • a plurality of switching circuits (10) each having a plurality of first switching elements (1) and a plurality of second switching elements (2) connected in series in a one-to-one manner are connected in parallel to each other.
  • a plurality of first switching elements (1) are connected to a first DC terminal (31), and a plurality of second switching elements (2) are connected to a second DC terminal (32). has been done.
  • the plurality of AC terminals (41) correspond one-to-one to the plurality of switching circuits (10).
  • Each of the plurality of AC terminals (41) is connected to a connection point (3) between the first switching element (1) and the second switching element (2) in the corresponding switching circuit (10).
  • the plurality of switches (8) correspond one-to-one to the plurality of switching circuits (10).
  • Each of the plurality of switches (8) has a first end (81) connected to a connection point (3) between the first switching element (1) and the second switching element (2) in the corresponding switching circuit (10).
  • the plurality of resonant circuits (20) correspond one-to-one to the plurality of switches (8) and have variable resonant frequencies.
  • the regeneration capacitor (15) has a third end (153) and a fourth end (154). In the regenerative capacitor (15), the third end (153) is connected to the first DC terminal (31) or the second DC terminal (32), and the fourth end (154) is connected to the plurality of resonant circuits (20). It is connected to the.
  • a control device (50) provides a PWM signal whose potential changes between a high level and a low level to each of the plurality of first switching elements (1) and the plurality of second switching elements (2).
  • Each of the plurality of resonant circuits (20) is a resonant circuit connected between the first end (81) of the corresponding switch (8) among the plurality of switches (8) and the second DC terminal (32).
  • a resonance device connected between the capacitor (9) and the second end (82) of the corresponding switch (8) among the plurality of switches (8) and the fourth end (154) of the regenerative capacitor (15). and an inductor (L4).
  • the control device (50) determines the high level period of the PWM signal to the first switching element (1) and the high level period of the PWM signal to the second switching element (2) for each of the plurality of switching circuits (10).
  • a dead time (Td) is set in between.
  • the control device (50) performs a first control operation.
  • the control device (50) sets the high level period of the control signal to the switch (8) corresponding to each of the plurality of switching circuits (10) among the plurality of switches (8) as a dead time (Td). ), and the start time of the high level period is advanced by an additional time than the start time of the dead time (Td).
  • the control device (50) controls the resonance period of at least one of the plurality of resonance circuits (20) according to the potential (V15) of the fourth end (154) of the regeneration capacitor (15). change.
  • each of the plurality of resonant circuits (20) is separate from the first resonant inductor (L4) that is the resonant inductor (L4). a second resonant inductor (L5), and a changeover switch (18) connected to the second resonant inductor (L5).
  • a series circuit of a second resonant inductor (L5) and a changeover switch (18) is connected in parallel to a first resonant inductor (L4).
  • the resonant frequency of each of the plurality of resonant circuits (20) changes depending on whether the changeover switch (18) is turned on or off.
  • each of the plurality of resonance circuits (20) is separate from the first resonance capacitor (9) which is the resonance capacitor (9). a second resonance capacitor (91), and a changeover switch (92) connected to the second resonance capacitor (91).
  • a series circuit of a second resonant capacitor (91) and a changeover switch (92) is connected in parallel to the first resonant capacitor (9). The resonant frequency of each of the plurality of resonant circuits (20) changes depending on whether the changeover switch (92) is turned on or off.
  • Second resonance capacitor Changeover switch 100, 100A, 100B, 100C, 100D, 100E Power converter iU, iV, iW Output current L0 Resonant inductor L1 First resonant inductor L2 Second resonant inductor L3 Third resonant inductor L4 First resonant inductor L5 Second resonance inductor Td Dead time Vd Voltage value Vth1 First threshold Vth2 Second threshold

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)
PCT/JP2023/029341 2022-08-26 2023-08-10 電力変換装置 Ceased WO2024043124A1 (ja)

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EP23857237.4A EP4580028A4 (en) 2022-08-26 2023-08-10 POWER CONVERTER
JP2024542759A JPWO2024043124A1 (https=) 2022-08-26 2023-08-10

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WO2025238983A1 (ja) * 2024-05-14 2025-11-20 パナソニックＩｐマネジメント株式会社 電力変換装置

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Publication number Priority date Publication date Assignee Title
JP2010233306A (ja) 2009-03-26 2010-10-14 Nissan Motor Co Ltd 電力変換装置
JP2015181329A (ja) * 2014-03-04 2015-10-15 パナソニックＩｐマネジメント株式会社 電力変換装置
WO2020255459A1 (ja) * 2019-06-18 2020-12-24 株式会社日立産機システム 電力変換装置

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JP2011078204A (ja) * 2009-09-30 2011-04-14 Fuji Electric Systems Co Ltd 電力変換装置及びその制御方法

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JP2010233306A (ja) 2009-03-26 2010-10-14 Nissan Motor Co Ltd 電力変換装置
JP2015181329A (ja) * 2014-03-04 2015-10-15 パナソニックＩｐマネジメント株式会社 電力変換装置
WO2020255459A1 (ja) * 2019-06-18 2020-12-24 株式会社日立産機システム 電力変換装置

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Publication number Priority date Publication date Assignee Title
WO2025238983A1 (ja) * 2024-05-14 2025-11-20 パナソニックＩｐマネジメント株式会社 電力変換装置

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