WO2025004326A1 - 電力変換装置、モータ駆動装置及び冷凍サイクル適用機器 - Google Patents

電力変換装置、モータ駆動装置及び冷凍サイクル適用機器 Download PDF

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Publication number
WO2025004326A1
WO2025004326A1 PCT/JP2023/024381 JP2023024381W WO2025004326A1 WO 2025004326 A1 WO2025004326 A1 WO 2025004326A1 JP 2023024381 W JP2023024381 W JP 2023024381W WO 2025004326 A1 WO2025004326 A1 WO 2025004326A1
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Prior art keywords
current
converter
semiconductor elements
power conversion
capacitor
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PCT/JP2023/024381
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English (en)
French (fr)
Japanese (ja)
Inventor
裕次 ▲高▼山
浩一 有澤
編絹 中林
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Priority to PCT/JP2023/024381 priority Critical patent/WO2025004326A1/ja
Priority to JP2025529355A priority patent/JPWO2025004326A1/ja
Publication of WO2025004326A1 publication Critical patent/WO2025004326A1/ja
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
    • H02M7/02—Conversion of AC power input into DC power output without possibility of reversal
    • H02M7/04—Conversion of AC power input into DC power output without possibility of reversal by static converters
    • H02M7/12—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • This disclosure relates to a power conversion device equipped with a converter that converts AC to DC and outputs the converted DC to a load, a motor drive device equipped with a power conversion device, and a refrigeration cycle application device.
  • Power supply current which is the current supplied from an AC power source, contains harmonic currents. Harmonic currents are frequency components with frequencies higher than the fundamental wave frequency. To suppress interference caused by harmonic currents, international regulations have been established for electronic devices that generate harmonic currents. To comply with these regulations, converters take measures to suppress the harmonic currents contained in the power supply current by chopping at AC (Alternating Current) or DC (Direct Current).
  • Patent Document 1 discloses a power conversion device equipped with a three-phase PWM (Pulse Width Modulation) converter.
  • a three-phase PWM converter is a converter that performs chopping in AC.
  • the power supply current is controlled to a sinusoidal shape, making it possible to suppress power supply harmonics, which are harmonic currents contained in the power supply current.
  • converters Unlike rectifier circuits, converters have a circuit configuration with upper and lower arm semiconductor elements connected in series. With this circuit configuration, there is a possibility that a phenomenon called an upper and lower arm short circuit may occur, in which both the upper and lower arm semiconductor elements are mistakenly turned on at the same time.
  • an upper or lower arm short circuit occurs, a large short circuit current flows through the upper and lower arm semiconductor elements. If the amount of current flowing through the semiconductor elements at this time exceeds the short circuit tolerance of the semiconductor elements, the semiconductor elements will be damaged. Therefore, in order to prevent damage to the semiconductor elements, it is necessary to quickly detect the upper and lower arm short circuit and take protective action.
  • the present disclosure has been made in consideration of the above, and aims to obtain a power conversion device that can quickly detect short circuits in the upper and lower arms and protect semiconductor elements.
  • the power conversion device includes a converter that converts AC to DC and outputs the DC to a load, a capacitor that smoothes the output voltage of the converter, a first current detector that detects a first current flowing between the converter and the low potential side of the capacitor, and a first control unit that controls the operation of the converter.
  • the first control unit performs a protective operation on the converter depending on the polarity of the detected value of the first current.
  • the power conversion device disclosed herein has the advantage of being able to quickly detect short circuits in the upper and lower arms and protect the semiconductor elements.
  • FIG. 1 is a diagram showing a configuration example of a motor drive device including a power conversion device according to a first embodiment
  • FIG. 1 is a diagram showing operational waveforms of main parts of a power conversion device according to the first embodiment
  • FIG. 1 is a diagram for explaining the main points of the configuration of a power conversion device according to a first embodiment.
  • FIG. 1 is a block diagram showing an example of a hardware configuration for implementing the functions of a control unit according to a first embodiment
  • FIG. 13 is a diagram showing a configuration example of a converter provided in a power conversion device according to a second embodiment
  • FIG. 11 is a diagram for explaining the main points of the operation of the motor drive device according to the third embodiment
  • FIG. 13 is a diagram showing a configuration example of an air conditioner according to a fourth embodiment.
  • Embodiment 1. 1 is a diagram showing an example of the configuration of a motor drive device 100 including a power conversion device 50 according to a first embodiment.
  • the power conversion device 50 according to the first embodiment is a power conversion device that converts an AC voltage output from a three-phase power supply 110, which is a three-phase AC power supply, into a DC voltage and applies the DC voltage to a load 130.
  • the motor drive device 100 according to the first embodiment is a drive device that converts DC power output from the power conversion device 50 into AC power and supplies the converted AC power to a motor 120 to drive the motor 120.
  • the phases of the three-phase power supply 110 are represented by R, S, and T, and are called the "R phase", the "S phase”, and the "T phase", respectively.
  • the power conversion device 50 includes a converter 3, a capacitor 4, a shunt resistor 7 for current detection, a current detection unit 10, a voltage detection unit 11, a control unit 14 which is a first control unit, and a drive circuit 16 which is a first drive circuit.
  • the motor drive device 100 according to the first embodiment includes the power conversion device 50, and further includes a noise filter 1, a reactor 2, current detectors 5a and 5b, a phase voltage detection unit 6, a control unit 15 which is a second control unit, and a load 130, as shown in Fig. 1.
  • the load 130 includes a shunt resistor 8 for current detection, an inverter 9, a current detection unit 12, a drive circuit 17 which is a second drive circuit, current detectors 18a and 18b, and a motor 120.
  • the shunt resistor 8, the inverter 9, the current detection unit 12, the drive circuit 17, and the current detectors 18a and 18b, excluding the motor 120 are components of the motor drive device 100.
  • the converter 3 is electrically connected to the three-phase power supply 110 by electrical wiring 70a, 70b, and 70c, which are first electrical wiring.
  • the noise filter 1 is disposed between the three-phase power supply 110 and the reactor 2.
  • the noise filter 1 operates to reduce noise currents flowing in and out of the power conversion device 50.
  • the reactor 2 is disposed between the noise filter 1 and the converter 3.
  • the reactor 2 is a device that includes circuit elements that temporarily store electrical energy supplied from the three-phase power supply 110.
  • the reactor 2 also operates to reduce noise currents flowing in and out of the power conversion device 50.
  • the current detectors 5a and 5b detect the power supply current, which is an alternating current flowing between the three-phase power supply 110 and the power conversion device 50, and output the detection value of the power supply current to the control unit 14.
  • An example of the current detectors 5a and 5b is an ACCT (Alternating Current Transformer). Note that FIG. 1 shows an example in which the current detector 5a detects the R-phase current Ir and the current detector 5b detects the T-phase current It, but this example is not limiting.
  • the current detectors 5a and 5b only need to detect the current of any two of the three phases, and the current of the remaining phase can be calculated by utilizing the fact that the power supply current is three-phase balanced.
  • the phase voltage detection unit 6 detects the R-phase voltage Vr, S-phase voltage Vs, and T-phase voltage Vt, which are the phase voltages of each of the three phases output by the three-phase power supply 110, and outputs the detection values to the control unit 14.
  • the capacitor 4 is electrically connected to the converter 3 by electrical wiring 72a, 72b, which is the second electrical wiring.
  • the converter 3 converts the AC voltage output from the three-phase power source 110 into a DC voltage and outputs it to the electrical wiring 72a, 72b.
  • the electrical wiring 72a, 72b is called the "DC busbar", and the voltage between the electrical wiring 72a and the electrical wiring 72b is called the "busbar voltage”.
  • Capacitor 4 smoothes the output voltage of converter 3.
  • Capacitor 4 is electrically connected to electrical wiring 72a, 72b by electrical wiring 74a, 74b, which is a third electrical wiring, respectively. Therefore, in the configuration of FIG. 1, the capacitor voltage, which is the voltage across capacitor 4, is equal to the bus voltage.
  • the connection point between electrical wiring 74a and electrical wiring 72a constitutes terminal P
  • the connection point between electrical wiring 74b and electrical wiring 72b constitutes terminal N.
  • Terminal P is the high-potential side terminal of capacitor 4
  • terminal N is the low-potential side terminal of capacitor 4.
  • the voltage smoothed by capacitor 4 is applied to inverter 9.
  • the voltage detection unit 11 detects the bus voltage Vdc and outputs the detection value of the bus voltage Vdc to the control unit 14 and the control unit 15.
  • the current detection unit 10 detects the converter current I1, which is the first current flowing between the converter 3 and the terminal N of the capacitor 4. In the configuration of FIG. 1, the converter current I1 flows through the shunt resistor 7, so this is detected.
  • the current detection unit 10 converts the voltage value generated by the converter current I1 flowing through the shunt resistor 7 into a current value and outputs it to the control unit 14.
  • the shunt resistor 7 and the current detection unit 10 will be collectively referred to as the "first current detector" as appropriate.
  • the converter 3 comprises six semiconductor elements Q1 to Q6 that are connected in a three-phase bridge.
  • the semiconductor elements Q1 and Q2 are connected in series in this order, and the connection point 3a of the semiconductor elements Q1 and Q2 is electrically connected to the R phase of the three-phase power supply 110.
  • the semiconductor elements Q3 and Q4 are connected in series in this order, and the connection point 3b of the semiconductor elements Q3 and Q4 is electrically connected to the S phase of the three-phase power supply 110.
  • the semiconductor elements Q5 and Q6 are connected in series in this order, and the connection point 3c of the semiconductor elements Q5 and Q6 is electrically connected to the T phase of the three-phase power supply 110.
  • the semiconductor elements Q1, Q3, and Q5 arranged on the upper side of the circuit diagram are sometimes referred to as the "upper arm elements,” and the semiconductor elements Q2, Q4, and Q6 arranged on the lower side of the circuit diagram are sometimes referred to as the "lower arm elements.”
  • the side of the three-phase power supply 110 where the connection points 3a to 3c are located, as viewed from the converter 3, is sometimes referred to as the "AC side”
  • the side of the load 130 is sometimes referred to as the "DC side.”
  • the semiconductor elements Q1 to Q6 each have diodes D1 to D6 connected in parallel.
  • the diodes D1 to D6 are connected so that the anodes are located on the AC side and the cathodes are located on the DC side.
  • the semiconductor elements Q1 to Q6 are IGBTs (Insulated Gate Bipolar Transistors), but MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) may be used instead of IGBTs. Note that in the case of MOSFETs, because of their structure they have a built-in parasitic diode, a configuration in which the diodes D1 to D6 are not connected in parallel may also be used.
  • the inverter 9 converts direct current to alternating current. More specifically, the inverter 9 converts the output voltage of the power conversion device 50 into an alternating current voltage and applies it to a motor 120 provided in a load 130.
  • a motor 120 provided in a load 130.
  • An example of an apparatus in which the motor 120 is mounted is a blower or compressor in an air conditioner.
  • An air conditioner is an example of an apparatus that applies a refrigeration cycle.
  • the current detection unit 12 detects the inverter current I2, which is the second current flowing between the inverter 9 and the terminal N of the capacitor 4. In the configuration of FIG. 1, the inverter current I2 flows through the shunt resistor 8, and is detected. The current detection unit 12 converts the voltage value generated by the inverter current I2 flowing through the shunt resistor 8 into a current value and outputs it to the control unit 15. In this document, the shunt resistor 8 and the current detection unit 12 will be collectively referred to as the "second current detector" as appropriate.
  • the inverter 9 comprises six semiconductor elements Q21 to Q26 which are connected in a three-phase bridge.
  • the semiconductor elements Q21, Q22 are connected in series in this order, and the connection point 9a of the semiconductor elements Q21, Q22 is electrically connected to the U-phase of the motor 120.
  • the semiconductor elements Q23, Q24 are connected in series in this order, and the connection point 9b of the semiconductor elements Q23, Q24 is electrically connected to the V-phase of the motor 120.
  • the semiconductor elements Q25, Q26 are connected in series in this order, and the connection point 9c of the semiconductor elements Q25, Q26 is electrically connected to the W-phase of the motor 120.
  • the side of the converter 3 is the DC side
  • the side of the motor 120 where the connection points 9a to 9c are located is the AC side.
  • the former will be referred to as the "first semiconductor element” and the latter as the "second semiconductor element.”
  • the semiconductor elements Q21 to Q26 each include a diode D21 to D26 connected in parallel.
  • the diodes D21 to D26 are connected so that their cathodes are on the DC side and their anodes are on the AC side.
  • the semiconductor elements Q21 to Q26 are IGBTs, but MOSFETs may be used instead of the IGBTs. Note that in the case of MOSFETs, because of their structure they have a built-in parasitic diode, a configuration in which the diodes D21 to D26 are not connected in parallel may also be used. Also, an IGCT (Integrated Gate Commutated Thyristor) may be used instead of the IGBTs.
  • IGCT Integrated Gate Commutated Thyristor
  • Current detectors 18a, 18b detect the three-phase motor current flowing between inverter 9 and motor 120, and output the detected motor current value to control unit 15.
  • An example of current detectors 18a, 18b is an ACCT. Note that FIG. 1 shows an example in which current detector 18a detects U-phase motor current Iu, and current detector 18b detects W-phase motor current Iw, but this is not limiting. Current detectors 18a, 18b only need to detect the current of any two of the three phases, and the current of the remaining phase can be found by calculation, taking advantage of the fact that the motor current is three-phase balanced.
  • the control unit 14 controls the operation of the converter 3. Specifically, the control unit 14 generates control signals S1 to S6 for controlling the bus voltage to a desired voltage while controlling the power supply current to a sinusoidal wave based on the detection values of the current detectors 5a and 5b, the detection value of the phase voltage detection unit 6, the detection value of the current detection unit 10, and the detection value of the voltage detection unit 11.
  • the control signals S1 to S6 are control signals for controlling each of the semiconductor elements Q1 to Q6 of the converter 3.
  • the control signals S1 to S6 generated by the control unit 14 are input to the drive circuit 16.
  • the control unit 15 also controls the operation of the inverter 9. Specifically, the control unit 15 generates control signals S21 to S26 for rotating the motor 120 at a desired rotation speed based on the detection value of the voltage detection unit 11, the detection value of the current detection unit 12, and the detection values of the current detectors 18a and 18b.
  • the control signals S21 to S26 are control signals for controlling the semiconductor elements Q21 to Q26 of the inverter 9, respectively.
  • the control signals S21 to S26 generated by the control unit 15 are input to the drive circuit 17.
  • the drive circuit 16 generates drive pulses G1 to G6 based on the control signals S1 to S6.
  • the semiconductor elements Q1 to Q6 of the converter 3 perform switching operations in response to the drive pulses G1 to G6.
  • the drive circuit 17 generates drive pulses G21 to G26 based on the control signals S21 to S26.
  • the semiconductor elements Q21 to Q26 of the inverter 9 perform switching operations in response to the drive pulses G21 to G26.
  • control units 14 and 15 are provided inside the motor drive device 100, but this is not a limitation.
  • the control unit 14 may be provided inside the power conversion device 50, and the control unit 15 may be provided inside the load 130.
  • the control units 14 and 15 are configured as separate control units, but this is not a limitation.
  • the control units 14 and 15 may be integrated into a common control unit that controls both the converter 3 and the inverter 9.
  • FIG. 2 is a diagram showing the operating waveforms of the main parts of the power conversion device 50 according to the first embodiment. From the top, FIG. 2 shows the waveforms of the phase voltages of each of the three phases, the phase currents of each of the three phases, and the bus voltage Vdc. The horizontal axis of FIG. 2 represents time.
  • the upper part of FIG. 2 shows the waveforms of the R-phase voltage Vr, the S-phase voltage Vs, and the T-phase voltage Vt, which are sinusoidal voltage waveforms.
  • the meaning of the period T1 will be described later.
  • the middle part of FIG. 2 shows the waveforms of the R-phase current Ir, the S-phase current Is, and the T-phase current It, which are sinusoidal current waveforms. These sinusoidal current waveforms are obtained by PWM control of the semiconductor elements Q1 to Q6 of the converter 3. By making the R-phase current Ir, the S-phase current Is, and the T-phase current It sinusoidal current waveforms, power supply harmonics are suppressed.
  • the bus voltage Vdc shows the waveform of the bus voltage Vdc, which is controlled to be almost constant.
  • the bus voltage Vdc does not necessarily have to be controlled to be constant.
  • FIG. 3 is a diagram for explaining the main points of the configuration of the power conversion device 50 according to the first embodiment.
  • the three-phase power source 110, reactor 2, converter 3, capacitor 4, and shunt resistor 7 are shown, which are extracted from FIG. 1.
  • FIG. 3 shows an example in which semiconductor elements Q5 and Q6 cause upper and lower arm short circuit.
  • semiconductor elements Q5 and Q6 cause upper and lower arm short circuit.
  • a short circuit current flows through the path indicated by the thick dashed arrow line. Because the resistance value of shunt resistor 7 is small, the short circuit current is large. Therefore, if the amount of current flowing through semiconductor elements Q5 and Q6 exceeds the short circuit withstand capacity of semiconductor elements Q5 and Q6, semiconductor elements Q5 and Q6 will be damaged.
  • the power conversion device 50 therefore first detects that an upper or lower arm short circuit has occurred.
  • the upper or lower arm short circuit is detected based on the polarity of the converter current I1 flowing through the shunt resistor 7.
  • the direction of the current flowing during power running is indicated by a thick solid arrow, but this direction is opposite to that of the upper or lower arm short circuit current. Therefore, the polarity of the voltage generated across the shunt resistor 7 is opposite between the current during power running and the upper or lower arm short circuit current, and this phenomenon is utilized.
  • a relay for breaking electrical connection is disposed at a key point in the circuit section.
  • the circle in the figure indicates the position of the relay.
  • the relay is disposed at one of positions B1 and B2.
  • Position B1 is an arbitrary position in the electrical wiring 72a
  • position B2 is an arbitrary position in the electrical wiring 72b.
  • control unit 14 determines that an upper or lower arm short circuit may have occurred, it performs control to open the relay disposed at either position B1 or B2 as a protective operation for the converter 3.
  • the detection value being significant means that the detection value is equal to or higher than a level at which it can be determined that an upper or lower arm short circuit may have occurred. This control quickly cuts off the short-circuit current that was flowing due to a short circuit in the upper and lower arms, making it possible to protect the semiconductor element through which the short-circuit current was flowing.
  • the relay may be located at any one of positions B3 and B4 instead of either position B1 or B2.
  • Position B3 is any position on the electrical wiring 74a
  • position B4 is any position on the electrical wiring 74b. Even in this case, the short-circuit current can be quickly interrupted by opening the relay located at either position B3 or B4.
  • the relays may be placed at any two of positions B5 to B7.
  • Position B5 is any position on the electrical wiring 70a
  • position B6 is any position on the electrical wiring 70b
  • position B7 is any position on the electrical wiring 70c. Opening each of the relays placed at any two of positions B5 to B7 cuts off the power supply to the capacitor 4. Therefore, since there is no power supply source that is the source of the short-circuit current, it becomes possible to quickly cut off the short-circuit current that was flowing due to the short circuit in the upper and lower arms.
  • control may be implemented to turn off the semiconductor elements Q1 to Q6.
  • the power supply to the capacitor 4 is cut off, so that it is possible to cut off the short-circuit current that was flowing due to the short circuit between the upper and lower arms.
  • FIG. 4 is a block diagram showing an example of a hardware configuration for realizing the functions of the control units 14 and 15 according to the first embodiment.
  • a configuration including a processor 201 that performs calculations and a memory 202 that stores programs read by the processor 201 can be used, as shown in FIG. 4.
  • the processor 201 is an example of a computing means.
  • the processor 201 may be a computing means called a microprocessor, a microcomputer, a CPU (Central Processing Unit), or a DSP (Digital Signal Processor).
  • Examples of the memory 202 include non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), an EEPROM (registered trademark) (Electrically EPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD (Digital Versatile Disc).
  • the memory 202 holds programs that execute the functions of the control units 14 and 15.
  • the processor 201 receives and transmits the necessary information and stores it in the memory 202, and the processor 201 executes the programs held in the memory 202 and refers to the data and tables stored in the memory 202, thereby executing the above-mentioned processing.
  • the results of calculations by the processor 201 can be stored in the memory 202.
  • the power conversion device includes a converter that converts AC to DC and outputs the DC to a load, a capacitor that smoothes the output voltage of the converter, a first current detector that detects a first current flowing between the converter and the low potential side of the capacitor, and a first control unit that controls the operation of the converter.
  • the first control unit performs a protective operation on the converter based on the polarity of the detected value of the first current.
  • the protection operation for the converter can be performed by turning off all of the first semiconductor elements.
  • a relay may be inserted in the first electrical wiring for electrically connecting the AC power source and the converter, the second electrical wiring for electrically connecting the converter and the capacitor, or the third electrical wiring for electrically connecting the capacitor to the second electrical wiring.
  • a protective operation for the converter can be performed by opening any of the relays inserted in the first, second, or third electrical wiring.
  • FIG. 5 is a diagram showing a configuration example of a converter 3 provided in a power conversion device 50 according to embodiment 2. Components that are the same as or equivalent to those in Fig. 3 are given the same reference numerals, and duplicated explanations will be omitted.
  • semiconductor elements Q2, Q4, and Q6, which are lower arm elements, are provided with a sense terminal St.
  • the sense terminal St is configured so that a minute current that is correlated with the emitter current flowing in semiconductor element Q2 flows through it.
  • the sense terminals St in semiconductor elements Q4 and Q6.
  • the magnitude of the current flowing in the sub-path is about one hundredth to one thousandth of the current flowing in the main path.
  • resistor 7a One end of resistor 7a is connected to sense terminal St. The other end of resistor 7a is connected to terminal N.
  • Resistor 7a may be a resistor formed inside semiconductor elements Q2, Q4, and Q6, or may be a resistor or resistor provided outside semiconductor elements Q2, Q4, and Q6.
  • the current detection unit 10 detects the voltage generated by the current flowing through the resistor 7a.
  • the current detection unit 10 converts the voltage generated across the resistor 7a into a collector current and transmits it to the control unit 14.
  • the control unit 14 detects the upper and lower arm short circuits based on the polarity of the detection value of the current detection unit 10. In this way, in the second embodiment, the current flowing between the sense terminal St and the low potential side terminal N of the capacitor 4 can be used as the first current to perform a protective operation for the converter 3.
  • the converter has a plurality of first semiconductor elements connected in a three-phase bridge, and the lower arm elements of the first semiconductor elements have a sense terminal.
  • the first current detector detects the current flowing between the sense terminal and the low potential side terminal of the capacitor as the first current, and the first control unit performs a protective operation on the converter based on the polarity of the detected value of the first current.
  • Embodiment 3 In the third embodiment, a description will be given of the main points of the operation of motor drive device 100 shown in Fig. 1.
  • Fig. 6 is a diagram for explaining the main points of the operation of motor drive device 100 according to the third embodiment.
  • the upper and lower arm short circuit described in embodiment 1 can also occur in the semiconductor elements Q21 to Q26 of the inverter 9.
  • Figure 6 shows an example in which the semiconductor elements Q21, Q22 cause an upper and lower arm short circuit.
  • a short-circuit current flows through the path indicated by the thick dashed arrow line. Because the resistance value of the shunt resistor 8 is small, the short-circuit current is large. Therefore, if the amount of current flowing through the semiconductor elements Q21, Q22 exceeds the short-circuit resistance of the semiconductor elements Q21, Q22, the semiconductor elements Q21, Q22 will be damaged.
  • the motor drive device 100 according to the third embodiment therefore detects that an upper or lower arm short circuit has occurred based on the inverter current I2 flowing through the shunt resistor 8.
  • the direction of the upper and lower arm short circuit currents is the same as the direction of the current flowing during power running, as indicated by the thick solid arrow line.
  • the motor drive device 100 according to the third embodiment compares the detected value of the inverter current I2 with a threshold value, and when the detected value of the inverter current I2 exceeds the threshold value, a protective operation is performed on the inverter 9.
  • the protective operation of the first or second embodiment is performed as a protective operation for the inverter 9, and then control is performed to turn off the semiconductor elements Q21 to Q26.
  • the short-circuit current flowing due to the short circuit of the upper and lower arms is quickly cut off, making it possible to protect the semiconductor elements through which the short-circuit current was flowing.
  • the power supply to the capacitor 4 is cut off, and as a result, the power supply source that is the source of the short-circuit current is eliminated, making it possible to quickly cut off the short-circuit current flowing due to the short circuit of the upper and lower arms.
  • FIG. 6 illustrates an example of an inverter 9 having the configuration shown in FIG. 1, the configuration is not limited to this.
  • the semiconductor elements Q22, Q24, and Q26 which are the lower arm elements, may have a sense terminal St, as in the semiconductor elements Q2, Q4, and Q6 shown in FIG. 5.
  • the sense terminal St of the semiconductor elements Q22, Q24, and Q26 can be configured to be electrically connected to the low potential side terminal N of the capacitor 4 via a resistor, as in FIG. 5. Even with this configuration, the protection operation according to embodiment 3 can be performed.
  • the motor drive device includes the power conversion device according to the first or second embodiment, an inverter that converts the output voltage of the power conversion device into an AC voltage and applies it to a motor provided in a load, and a second control unit that controls the operation of the inverter.
  • the second control unit performs a protective operation on the inverter.
  • the protective operation for the inverter can be performed by turning off all the second semiconductor elements after performing the protective operation according to the first or second embodiment.
  • Embodiment 4. 7 is a diagram showing a configuration example of an air conditioner 300 according to embodiment 4.
  • the air conditioner 300 according to embodiment 4 is an example of a refrigeration cycle applied device, and includes a motor 120 and the motor drive device 100 described in embodiment 1.
  • the air conditioner 300 also includes a compressor 81, a four-way valve 82, an outdoor heat exchanger 83, an expansion valve 84, an indoor heat exchanger 85, and a refrigerant piping 86.
  • the air conditioner 300 may be a separate type air conditioner in which the outdoor unit is separated from the indoor unit, or it may be an integrated type air conditioner in which the compressor 81, indoor heat exchanger 85, and outdoor heat exchanger 83 are provided in a single housing.
  • a compression mechanism 87 that compresses the refrigerant
  • a motor 120 that operates the compression mechanism 87.
  • the motor 120 is driven by a motor drive device 100.
  • a refrigeration cycle is formed by circulating the refrigerant through the compressor 81, four-way valve 82, outdoor heat exchanger 83, expansion valve 84, indoor heat exchanger 85, and refrigerant piping 86.
  • the components of the air conditioner 300 can also be applied to devices such as refrigerators or freezers equipped with a refrigeration cycle.
  • the motor 120 is used as the drive source for the compressor 81, but the motor 120 may be used as the drive source for driving each of the indoor unit blower and outdoor unit blower (not shown) instead of the compressor 81.
  • the motor 120 may be used as the drive source for each of the indoor unit blower, outdoor unit blower, and compressor 81, and the three motors 120 may be driven by the motor drive device 100.
  • the air conditioner 300 according to the fourth embodiment has been described as including the motor drive device 100 described in the first embodiment, the present invention is not limited to this.
  • the converter 3 included in the motor drive device 100 may be configured as shown in FIG. 5.
  • the inverter 9 included in the motor drive device 100 may be configured as shown in FIG. 6.
  • the air conditioner 300 according to embodiment 4 is equipped with a motor drive device 100 according to any one of embodiments 1 to 3, and is therefore able to enjoy the effects obtained from each of the embodiments.

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PCT/JP2023/024381 2023-06-30 2023-06-30 電力変換装置、モータ駆動装置及び冷凍サイクル適用機器 Ceased WO2025004326A1 (ja)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0678561A (ja) * 1992-08-26 1994-03-18 Hitachi Ltd 電力変換装置及びその制御方法
JP2001197745A (ja) * 2000-01-07 2001-07-19 Mitsubishi Electric Corp 電力変換装置の保護制御方法および保護制御装置
WO2008149530A1 (ja) * 2007-06-04 2008-12-11 Panasonic Corporation 電源制御装置およびその電源制御装置を有するヒートポンプ装置
WO2021038866A1 (ja) * 2019-08-30 2021-03-04 三菱電機株式会社 直流電源装置、モータ駆動装置、送風機、圧縮機及び空気調和機

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0678561A (ja) * 1992-08-26 1994-03-18 Hitachi Ltd 電力変換装置及びその制御方法
JP2001197745A (ja) * 2000-01-07 2001-07-19 Mitsubishi Electric Corp 電力変換装置の保護制御方法および保護制御装置
WO2008149530A1 (ja) * 2007-06-04 2008-12-11 Panasonic Corporation 電源制御装置およびその電源制御装置を有するヒートポンプ装置
WO2021038866A1 (ja) * 2019-08-30 2021-03-04 三菱電機株式会社 直流電源装置、モータ駆動装置、送風機、圧縮機及び空気調和機

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