WO2025083878A1 - 電力変換装置、モータ駆動装置および冷凍サイクル適用機器 - Google Patents

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

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Publication number
WO2025083878A1
WO2025083878A1 PCT/JP2023/038022 JP2023038022W WO2025083878A1 WO 2025083878 A1 WO2025083878 A1 WO 2025083878A1 JP 2023038022 W JP2023038022 W JP 2023038022W WO 2025083878 A1 WO2025083878 A1 WO 2025083878A1
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WIPO (PCT)
Prior art keywords
switching element
switching
conductive
power conversion
conversion device
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PCT/JP2023/038022
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English (en)
French (fr)
Japanese (ja)
Inventor
遥 松尾
翔英 堤
泰章 古庄
陽 寺田
浩一 有澤
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Priority to JP2025552579A priority Critical patent/JPWO2025083878A1/ja
Priority to PCT/JP2023/038022 priority patent/WO2025083878A1/ja
Publication of WO2025083878A1 publication Critical patent/WO2025083878A1/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
    • H02M1/00—Details of apparatus for conversion
    • 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
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static 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
    • H02M7/02—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
    • 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
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/16—Modifications for eliminating interference voltages or currents

Definitions

  • This disclosure relates to a power conversion device that performs power conversion, a motor drive device, and a refrigeration cycle application device.
  • Patent Document 1 discloses a technology in which a motor drive device controls the on/off of switching elements included in the converter based on zero crossings of the AC power supply detected by a power supply zero cross detection unit, and controls the on/off of switching elements included in the inverter based on bus current detected by a bus current detection unit, etc.
  • the on/off periods of switching elements in power converters such as converters and inverters can be controlled according to the detection values of each detection unit.
  • the switching speed of switching elements in power converters such as converters and inverters can also be adjusted by the circuit configuration of the drive circuit that supplies current or power to the switching elements.
  • ringing that occurs in the switching elements varies depending on the switching speed of the switching elements. For example, the faster the switching speed is, the larger the ringing that occurs in the switching elements becomes, and the slower the switching speed is, the smaller the ringing becomes. Since the correct current value cannot be detected when ringing is occurring in the switching element, it is desirable for the current detection unit to detect the current value after the ringing has converged.
  • the present disclosure has been made in consideration of the above, and aims to obtain a power conversion device that can improve the accuracy of current detection.
  • the present disclosure is a power conversion device that performs power conversion.
  • the power conversion device includes one or more switching elements included in at least one of one or more power converters that perform power conversion, and a current detector that is arranged on a path of a current flowing through the power converter, and the waveform shape of the pulse-like current waveform detected by the current detector changes.
  • the power conversion device disclosed herein has the effect of improving the accuracy of current detection.
  • FIG. 1 is a diagram showing a configuration example of a power conversion device according to a first embodiment
  • FIG. 1 is a first diagram showing a rectification/boosting portion of a converter included in a power conversion device according to a first embodiment
  • FIG. 2 is a second diagram showing a rectification/boosting portion of a converter included in a power conversion device according to the first embodiment
  • FIG. 3 is a third diagram showing a rectification step-up portion of a converter included in a power conversion device according to the first embodiment
  • FIG. 4 is a fourth diagram showing a rectification step-up portion of a converter included in a power conversion device according to the first embodiment
  • FIG. 1 is a diagram showing a configuration example of a power conversion device according to a first embodiment
  • FIG. 1 is a first diagram showing a rectification/boosting portion of a converter included in a power conversion device according to a first embodiment
  • FIG. 2 is a second diagram showing a rectification/boosting portion of a converter included in
  • FIG. 5 is a diagram showing a rectification and boosting portion of a converter included in a power conversion device according to a first embodiment.
  • FIG. 13 is a diagram showing an example of turn-on joule loss, turn-on current, and turn-on voltage when the switching speed of the switching element of the inverter in the power conversion device according to the first embodiment is slowed down.
  • FIG. 13 is a diagram showing an example of turn-on joule loss, turn-on current, and turn-on voltage when the switching speed of the switching element of the inverter in the power conversion device according to the first embodiment is increased;
  • a diagram showing an example of the relationship between noise and loss generated by a typical switching element.
  • FIG. 1 is a first diagram showing an effect obtained by changing the switching speed of a switching element of an inverter in a power conversion device according to a first embodiment
  • FIG. 2 is a second diagram showing an effect obtained by changing the switching speed of the switching elements of the inverter in the power conversion device according to the first embodiment
  • FIG. 1 is a diagram showing a configuration example of a waveform shape change unit of a power conversion device according to a first embodiment
  • FIG. 1 is a first diagram showing a relationship between a gate current output by a waveform shape modification unit and a gate voltage indicating a rise speed of a switching element in a power conversion device according to a first embodiment
  • FIG. 2 is a second diagram showing the relationship between the gate current output by the waveform shape modification unit and the gate voltage indicating the rise speed of the switching element in the power conversion device according to the first embodiment
  • FIG. 3 is a third diagram showing the relationship between the gate current output by the waveform shape modification unit and the gate voltage indicating the rise speed of the switching element in the power conversion device according to the first embodiment
  • FIG. 1 is a diagram showing an example of the relationship between a basic pulse output by a basic pulse generating unit and a gate current output by a waveform shape changing unit in a power conversion device according to a first embodiment
  • FIG. 1 is a diagram showing an example of a state quantity detection unit that is a current detector using switching elements and shunt resistors included in an inverter of a power conversion device according to a first embodiment
  • FIG. 1 is a diagram showing an example of a switching pattern of a switching element of an inverter in which a state quantity detection unit, which is a current detector using a shunt resistor, can detect a current in the power conversion device according to the first embodiment
  • FIG. 1 is a diagram showing an example of a switching pattern of a switching element of an inverter in which a state quantity detection unit, which is a current detector using a shunt resistor, cannot detect a current in the power conversion device according to the first embodiment
  • FIG. 1 is a diagram showing an example of a state quantity detection unit that is a current detector using switching elements and shunt resistors included in an inverter of a power conversion device according to a first embodiment
  • FIG. 1 is a diagram showing an example of a switching pattern of
  • FIG. 1 is a diagram showing an example of a control state when there is no phase in which current detection is not possible in the power conversion device according to the first embodiment
  • FIG. 1 is a diagram showing an example of a control state when there is a phase in which current detection is not possible in the power conversion device according to the first embodiment
  • FIG. 1 is a diagram showing an example of a region of a command voltage vector that cannot be used in motor control in the power conversion device according to the first embodiment
  • FIG. 1 is a first diagram showing a relationship between a switching speed of a switching element and a current detection timing in a power conversion device according to a first embodiment
  • FIG. 2 is a second diagram showing the relationship between the switching speed of the switching element and the current detection timing in the power conversion device according to the first embodiment
  • FIG. 2 is a diagram showing an example of a relationship between the carrier frequency of a carrier signal used in inverter control in the power conversion device according to the first embodiment and the current detectable ratio calculated from equation (1);
  • FIG. 13 is a diagram showing an example of a relationship between the carrier frequency of a carrier signal used in controlling an inverter in a power conversion device according to the first embodiment and a maximum current detection wait time.
  • a flowchart showing an operation of changing a waveform shape of a switching waveform of a switching element in a power conversion device according to a first embodiment.
  • FIG. 1 is a diagram showing an example of a hardware configuration for implementing a control unit included in a power conversion device according to a first embodiment;
  • FIG. 1 is a diagram showing a configuration example of a power conversion device according to a second embodiment
  • FIG. 13 is a diagram showing a configuration example of a power conversion device according to a third embodiment
  • FIG. 13 is a diagram showing a configuration example of a power conversion device according to a fourth embodiment
  • FIG. 13 is a diagram showing a configuration example of a refrigeration cycle application device according to a fifth embodiment.
  • FIG. 1 is a diagram showing a configuration example of a power conversion device 1 according to a first embodiment.
  • the power conversion device 1 is connected to a commercial power source 110 and a motor 314.
  • the power conversion device 1 converts a first AC voltage of a power source voltage Vs supplied from the commercial power source 110, which is an AC power source, into a second AC voltage having a desired amplitude and phase, and supplies the second AC voltage to the motor 314.
  • the commercial power source 110 is a single-phase AC power source in the example of FIG. 1, but may be a three-phase AC power source.
  • the power conversion device 1 includes a state quantity detection unit 501, a converter 130, a capacitor 210, a state quantity detection unit 502, an inverter 310, a state quantity detection unit 503, a state quantity detection unit 504, a state quantity detection unit 505, and a control unit 400.
  • the power conversion device 1 and the motor 314 constitute a motor drive device 2.
  • the state quantity detection unit 501 detects state quantities that indicate the operating state of the power conversion device 1.
  • the state quantity detection unit 501 detects, for example, the voltage value of the AC voltage of the power supply voltage Vs supplied from the commercial power supply 110 to the converter 130, and the current value of the AC voltage of the power supply voltage Vs supplied from the commercial power supply 110 to the converter 130.
  • the state quantity detection unit 501 may also detect zero crossings of the power supply voltage Vs supplied from the commercial power supply 110 to the converter 130.
  • the converter 130 is a power converter that converts the AC voltage of the power supply voltage Vs supplied from the commercial power supply 110 into a DC voltage.
  • the converter 130 includes rectifier elements 131-134, a reactor 135, a switching element 136, a freewheeling diode 137, a diode 138, and a drive circuit 150.
  • the converter 130 has a bridge circuit formed by the rectifier elements 131-134, rectifies the first AC voltage of the power supply voltage Vs supplied from the commercial power supply 110, boosts the rectified DC voltage, and outputs it.
  • the rectified DC voltage may be referred to as the first DC voltage
  • the boosted DC voltage i.e., output to the capacitor 210
  • the second DC voltage boosted DC voltage
  • the drive circuit 150 generates a drive signal for actually driving the switching element 136 based on a basic pulse generated by a basic pulse generating unit 410 of the control unit 400 described later.
  • the switching element 136 may be, for example, an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), a bipolar transistor, etc., but is not limited to these.
  • the converter 130 includes a rectifier section 161 of a bridge circuit including rectifier elements 131 to 134, and a boost section 162 including a reactor 135, a switching element 136, a freewheel diode 137, and a diode 138, but the configuration of the converter 130 is not limited to the example of FIG. 1.
  • FIG. 2 is a first diagram showing a rectifier boost section of the converter 130 included in the power conversion device 1 according to the first embodiment.
  • FIG. 3 is a second diagram showing a rectifier boost section of the converter 130 included in the power conversion device 1 according to the first embodiment.
  • FIG. 4 is a third diagram showing a rectifier boost section of the converter 130 included in the power conversion device 1 according to the first embodiment.
  • FIG. 5 is a fourth diagram showing a rectifier boost section of the converter 130 included in the power conversion device 1 according to the first embodiment.
  • FIG. 6 is a fifth diagram showing a rectifier boost section of the converter 130 included in the power conversion device 1 according to the first embodiment.
  • the converter 130 may be configured to include a rectifier boost unit 163 consisting of a reactor 135, switching elements 136a and 136b, freewheel diodes 137a and 137b, and rectifier elements 133 and 134, as shown in FIG. 2.
  • the rectifier boost unit 163 shown in FIG. 2 is a totem-pole bridgeless circuit.
  • the converter 130 may be configured to include a rectifier boost unit 163 consisting of a reactor 135, switching elements 136b and 136d, freewheel diodes 137b and 137d, and rectifier elements 131 and 133, as shown in FIG. 3.
  • the rectifier boost unit 163 shown in FIG. 3 is a half-bridgeless circuit.
  • the converter 130 may be configured to include a rectifier boost unit 163 consisting of a reactor 135, switching elements 136a to 136d, and freewheel diodes 137a to 137d, as shown in FIG. 4.
  • the rectifying boost unit 163 shown in Fig. 4 is a full-bridgeless circuit.
  • the converter 130 may be configured to include a rectifying unit 161 including rectifying elements 131 to 134, and a boost unit 162 including reactors 135a and 135b, switching elements 136a and 136b, freewheeling diodes 137a and 137b, and diodes 138a and 138b, as shown in Fig. 5.
  • the boost unit 162 shown in Fig. 5 is an interleaved circuit.
  • the converter 130 may be configured to include a rectifying boost unit 163 including a reactor 135, a first rectifying circuit including rectifying elements 131 to 134, a switching element 136, a freewheeling diode 137, and a second rectifying circuit including rectifying elements 131a to 134a, as shown in Fig. 6.
  • the rectifier boost unit 163 shown in FIG. 6 is a simple PAM (Pulse Amplitude Modulation) circuit in which a first rectifier circuit and a second rectifier circuit are connected in parallel, a switching element 136 is connected to the output terminal of the first rectifier circuit, and a capacitor 210 that supplies a second DC voltage to the inverter 310 is connected to the output terminal of the second rectifier circuit.
  • PAM Pulse Amplitude Modulation
  • the converter 130 has a rectifier 161 that converts the first AC voltage supplied from the commercial power source 110 into a first DC voltage, and a booster 162 that boosts the first DC voltage to a second DC voltage greater than the first DC voltage, or a rectifier booster 163 that rectifies the first AC voltage and boosts it to a second DC voltage having an effective value greater than the effective value of the first AC voltage.
  • the converter 130 is configured to include at least six elements such as rectifier elements and switching elements.
  • the power conversion device 1 may be a three-phase three-wire power conversion device or a three-phase four-wire power conversion device. In this embodiment, the converter 130 only needs to have a rectifier function and does not need to have a boost function. In the following, the power conversion device 1 will be described using the configuration shown in FIG. 1 as an example.
  • Capacitor 210 is connected to the output terminal of converter 130 and smoothes the DC voltage converted by converter 130.
  • Capacitor 210 is, for example, an electrolytic capacitor or a film capacitor.
  • the state quantity detection unit 502 detects state quantities that indicate the operating state of the power conversion device 1.
  • the state quantity detection unit 502 detects, for example, the voltage value of the DC voltage supplied from the capacitor 210 to the inverter 310.
  • the inverter 310 is a power converter connected to both ends of the capacitor 210.
  • the inverter 310 has switching elements 311a to 311f and freewheeling diodes 312a to 312f.
  • the inverter 310 turns on and off the switching elements 311a to 311f under the control of the control unit 400, converts the DC voltage output from the converter 130 and the capacitor 210 into a second AC voltage having a desired amplitude and phase, that is, generates a second AC voltage, and outputs it to the motor 314.
  • the inverter 310 converts the second DC voltage into a second AC voltage and outputs it.
  • the switching elements 311a to 311f are, for example, IGBTs, MOSFETs, bipolar transistors, etc., but are not limited to these.
  • the circuit configuration of the inverter 310 is not particularly limited, and may be a full bridge circuit, a single-phase bridge circuit, a half bridge circuit, etc.
  • the inverter 310 includes a waveform shape changer 340 that can change the waveform shape of the switching waveform of the switching elements 311a to 311f without physically switching the gate resistors or the like.
  • the waveform shape changer 340 can output two or more waveform shapes as the waveform shapes of the switching waveforms of the switching elements 311a to 311f. In the example of FIG.
  • the waveform shape changer 340 is configured to be able to change the waveform shape of the switching waveform of the switching elements 311a to 311f, but it is possible to change the waveform shape of the switching waveform of at least one of the switching elements 311a to 311f.
  • the inverter 310 may also be configured to include a waveform shape changer 340 for each of the switching elements 311a to 311f. The detailed operation of the waveform shape changer 340 will be described later.
  • the state quantity detection unit 503 detects a state quantity indicating the operating state of the power conversion device 1.
  • the state quantity detection unit 503 detects, for example, the voltage value of the second AC voltage supplied from the inverter 310 to the motor 314, which is the load, and the current value of the second AC voltage supplied from the inverter 310 to the motor 314, which is the load.
  • the state quantity detection unit 504 detects a state quantity indicating the operating state of the power conversion device 1.
  • the state quantity detection unit 504 detects, for example, the current value of the DC voltage supplied from the capacitor 210 to the inverter 310.
  • the state quantity detection unit 505 detects a state quantity indicating the operating state of the power conversion device 1.
  • the state quantity detection unit 505 detects, for example, the current flowing through the switching elements 311b, 311d, and 311f.
  • the method of detecting the current in the state quantity detection units 501 to 505 that can detect the current includes, but is not limited to, a method of measuring the current using a shunt resistor, a method using a DCCT (Direct Current Current Transformer), an ACCT (Alternating Current Transformer), etc.
  • the state quantity detection unit 501 is arranged on the path of the current flowing to the converter 130, which is a power converter, and can detect the current flowing to the converter 130 as a state quantity.
  • the state quantity detection unit 504 is arranged on the path of the current flowing to the inverter 310, which is a power converter, and can detect the current flowing to the inverter 310 as a state quantity. In the example of FIG. 1, the state quantity detection unit 504 is arranged on the N line of the power conversion device 1, but it may also be arranged on the P line.
  • the control unit 400 acquires the state quantities detected by the state quantity detection units 501-505 from the state quantity detection units 501-505, and controls the operation of the converter 130 and the inverter 310 based on the acquired state quantities; specifically, it controls the on/off of the switching element 136 of the converter 130, and controls the on/off of the switching elements 311a-311f of the inverter 310.
  • the control unit 400 includes a basic pulse generation unit 410 and a waveform shape setting unit 420.
  • the basic pulse generating unit 410 has a duty ratio according to the state quantity detected by the state quantity detecting units 501 to 505, and generates a basic pulse for controlling the operation of the switching element 136 of the converter 130.
  • the basic pulse generating unit 410 also has a duty ratio according to the state quantity detected by the state quantity detecting units 501 to 505, and generates a basic pulse for controlling the operation of the switching elements 311a to 311f of the inverter 310.
  • the basic pulse is, for example, a PWM (Pulse Width Modulation) signal having a duty ratio according to the state quantity detected by the state quantity detecting units 501 to 505.
  • the basic pulse generating unit 410 outputs a basic pulse for controlling the operation of the switching element 136 of the converter 130 to the converter 130, and outputs a basic pulse for controlling the operation of the switching elements 311a to 311f of the inverter 310 to the waveform shape setting unit 420.
  • the waveform shape setting unit 420 sets the waveform shape of the switching waveform of the switching elements 311a to 311f when the switching waveform of the switching elements 311a to 311f is changed by the waveform shape changing unit 340 of the inverter 310 according to the state quantities detected by the state quantity detection units 501 to 505, and outputs a control signal to reflect the set value indicating the set waveform shape.
  • the waveform shape setting unit 420 controls the magnitude of the drive signal that the waveform shape changing unit 340 of the inverter 310 actually outputs to the switching elements 311a to 311f to drive the switching elements 311a to 311f, and the timing of outputting the drive signal.
  • the waveform shape setting unit 420 outputs a control signal for controlling the operation of the waveform shape changing unit 340 to the waveform shape changing unit 340.
  • the control unit 400 may be configured to have a waveform shape setting unit 420 for each waveform shape modification unit 340, i.e., six waveform shape setting units 420.
  • the control unit 400 acquires the state quantities detected by the state quantity detection units 501 to 505 from the state quantity detection units 501 to 505, and controls the operation of the converter 130 and the inverter 310 based on the acquired state quantities, but this is not limited to this.
  • the control unit 400 can control the operation of the converter 130 and the inverter 310 based on the state quantity acquired from at least one of the state quantity detection units 501 to 505.
  • the state quantity detection units 501 to 505 detect the voltage or current input to each component of the power conversion device 1, the voltage or current output from each component of the power conversion device 1, etc. as state quantities in the above example, but the detection targets are not limited to these.
  • the installation positions of the state quantity detection units 501 to 505 are not limited to the example of FIG. 1.
  • the power conversion device 1 may have a state quantity detection unit at any position other than that shown in the figure, as long as the state quantity can be detected.
  • the power conversion device 1 may have a state quantity detection unit at a position where it can detect the state quantities, such as noise generated by the power conversion device 1, the motor 314, etc., losses generated by the power conversion device 1, the motor 314, etc., and the temperature of each component of the power conversion device 1, the motor 314, etc.
  • control unit 400 may combine the functions of the basic pulse generating unit 410 and the waveform shape setting unit 420 into a single configuration.
  • the motor 314 is a load connected to the power conversion device 1.
  • the motor 314 is, for example, a compressor motor for driving a compressor.
  • the motor 314 rotates according to the amplitude and phase of the second AC voltage supplied from the inverter 310, and performs a compression operation.
  • the load torque of the motor 314 that drives the compressor can often be considered as a constant torque load.
  • the motor 314 may be Y-connected or ⁇ -connected, or may be capable of switching between Y-connection and ⁇ -connection, for the motor windings (not shown).
  • the load connected to the power conversion device 1, i.e., the inverter 310 is not limited to the motor 314 for driving a compressor, and may be a fan motor or the like.
  • the load connected to the power conversion device 1 is not limited to the motor 314, and may be a load other than the motor 314.
  • the power conversion device 1 can change the waveform shapes of the switching waveforms of the switching elements 311a to 311f of the inverter 310 by the waveform shape setting unit 420 and the waveform shape changing unit 340. Specifically, the power conversion device 1 can change the switching speed, delay time, etc. of the switching elements 311a to 311f of the inverter 310.
  • FIG. 7 is a diagram showing an example of turn-on joule loss, turn-on current, and turn-on voltage when the switching speed of the switching elements 311a to 311f of the inverter 310 in the power conversion device 1 according to embodiment 1 is slowed down.
  • FIG. 8 is a diagram showing an example of turn-on joule loss, turn-on current, and turn-on voltage when the switching speed of the switching elements 311a to 311f of the inverter 310 in the power conversion device 1 according to embodiment 1 is fastened.
  • A indicates turn-on joule loss
  • B indicates turn-on current
  • C indicates turn-on voltage.
  • the horizontal axis indicates time.
  • the turn-on current is the current flowing through the switching element 311a
  • the turn-on voltage is the voltage across the switching element 311a
  • the turn-on joule loss is the product of the turn-on current and the turn-on voltage
  • the measurement target is not limited to the switching element 311a, and may be the other switching elements 311b to 311f.
  • 7 and 8 show the difference in characteristics depending on the switching speed of the switching elements 311a to 311f of the inverter 310, and the specific values of "slow” and "fast” switching speeds are not important. As shown in FIGS.
  • the waveform shape modification unit 340 is configured by a digital gate driver.
  • the switching elements 311a to 311f of the inverter 310 and the waveform shape modification unit 340 are configured by a digital gate driver module. This allows the power conversion device 1 to change the switching speed of the switching elements 311a to 311f of the inverter 310 by changing the command value of the software without changing the hardware, and to control the noise and loss generated by the switching elements 311a to 311f to a desired state.
  • Figure 9 shows an example of the relationship between noise and loss generated by a typical switching element. As mentioned above, there is a trade-off between noise and loss generated by a switching element. Therefore, as shown in Figure 9, in a typical switching element, increasing the switching speed increases the noise but decreases the loss, and decreasing the switching speed decreases the noise but increases the loss.
  • Figure 10 is a first diagram showing the effect obtained by changing the switching speed of the switching elements 311a to 311f of the inverter 310 in the power conversion device 1 according to embodiment 1. Even if the power conversion device 1 is operating within the noise range specified for the product in which the power conversion device 1 is mounted, when the load state of the motor 314 changes from a light load to a heavy load, the curve showing the characteristics of the noise and losses generated by the switching elements 311a to 311f shifts to the upper right as shown in Figure 10, resulting in an increase in noise. In other words, in the power conversion device 1, the heavier the load, the greater the noise.
  • the power conversion device 1 can reduce the noise generated by the switching elements 311a to 311f by slowing down the switching speed of the switching elements 311a to 311f. Similarly, even if the power conversion device 1 is operating within the loss range specified for the product in which the power conversion device 1 is installed, when the load state of the motor 314 changes from a light load to a heavy load, the curve showing the characteristics of the noise and loss generated by the switching elements 311a to 311f shifts to the upper right as shown in FIG. 10, resulting in increased loss. In other words, in the power conversion device 1, the heavier the load, the greater the loss. Therefore, the power conversion device 1 can reduce the loss generated by the switching elements 311a to 311f by increasing the switching speed of the switching elements 311a to 311f.
  • the waveform shape setting unit 420 changes the set value of the waveform shape of the switching waveform of the switching elements 311a to 311f so that the noise generated in the switching elements 311a to 311f meets the specified requirements while reducing the loss generated in the switching elements 311a to 311f.
  • the waveform shape setting unit 420 changes the set value of the waveform shape of the switching waveform of the switching elements 311a to 311f so that the noise generated in the switching elements 311a to 311f meets the specified requirements while reducing the loss generated in the switching elements 311a to 311f.
  • FIG. 11 is a second diagram showing the effect obtained by changing the switching speed of the switching elements 311a to 311f of the inverter 310 in the power conversion device 1 according to the first embodiment.
  • the power conversion device 1 specifically the waveform shape changer 340, divides, for example, the turn-on period or turn-off period into two or more periods in one switching operation of the switching elements 311a to 311f, and changes the amplitude of the gate current or gate voltage for the switching elements 311a to 311f to a different magnitude in each divided period.
  • the power conversion device 1 can obtain the characteristics of noise and loss generated by the switching elements 311a to 311f that could not be obtained with general switching elements such as those shown in FIG. 9.
  • FIG. 12 is a diagram showing an example of the configuration of the waveform shape modification unit 340 of the power conversion device 1 according to embodiment 1.
  • Figure 12 is also a diagram showing an example of the configuration of one digital gate driver module formed by the waveform shape modification unit 340 and the switching element 311a.
  • the waveform shape modification unit 340 is included in the inverter 310, which is a power converter including the switching element 311a, as shown in Figure 1.
  • the waveform shape change unit 340 includes n P-channel MOSFETs (PMOSs) for turn-on, n PreDrivers for operating the n PMOSs, n N-channel MOSFETs (NMOSs) for turn-off, and n PreDrivers for operating the n NMOSs.
  • PMOSs P-channel MOSFETs
  • NMOSs N-channel MOSFETs
  • PreDrivers for operating the n NMOSs.
  • the waveform shape changing unit 340 is connected to the control power supply Vdd and the ground GND.
  • the waveform shape changing unit 340 changes the number of PMOS or NMOS to be operated based on the control signal from the waveform shape setting unit 420, thereby changing the amplitude value of the gate current I G, which is a drive signal to be output to the switching element 311a, into n ways during each of the turn-on period and the turn-off period, and can adjust the switching speed of the switching element 311a.
  • the waveform shape changing unit 340 can increase the absolute value of the gate current I G to be output to the switching element 311a as the number of PMOS or NMOS to be operated increases, and can increase the switching speed of the switching element 311a.
  • the waveform shape changing unit 340 can adjust the switching speed of the switching element 311a more finely as the number of PMOS and NMOS provided inside increases, and the faster the response of the increase and decrease of the gate current I G , the more fine the adjustment of the gate current I G can be made in one switching period.
  • the control signal from the waveform shape setting unit 420 may be an analog signal or a digital signal as long as it can change the number of PMOS or NMOS to be operated by the waveform shape changing unit 340.
  • the example of Fig. 12 shows that there are m parallel control signals from the waveform shape setting unit 420 to the waveform shape changing unit 340, but this is only an example and the number of control signals is not limited to m.
  • the number of control signals may be a number that can indicate whether each PMOS and each NMOS can operate or not, or it may be one if it is an analog signal that indicates a voltage or the like.
  • FIG. 13 is a first diagram showing the relationship between the gate current I G output by the waveform shape modification unit 340 in the power conversion device 1 according to the first embodiment and the gate voltage V G indicating the rising speed of the switching element 311a.
  • FIG. 14 is a second diagram showing the relationship between the gate current I G output by the waveform shape modification unit 340 in the power conversion device 1 according to the first embodiment and the gate voltage V G indicating the rising speed of the switching element 311a.
  • the waveform shape modification unit 340 can make the rising speed of the gate voltage V G faster, that is, the switching speed of the switching element 311a faster, as the gate current I G outputted is increased. Also, as shown in FIG. 13 and FIG.
  • the waveform shape modification unit 340 can make the rising speed of the gate voltage V G slower, that is, the switching speed of the switching element 311a slower, as the gate current I G outputted is decreased.
  • the power conversion device 1 can reduce the output gate current I G to slow down the switching speed when it is desired to reduce noise generated in the switching element 311a, and can increase the output gate current I G to speed up the switching speed when it is desired to reduce loss generated in the switching element 311a, as shown in Fig. 10.
  • the waveforms of the gate current I G and gate voltage V G shown in Figs. 13 and 14 are ideal examples, and in reality, it takes time for the gate current I G to reach a constant current value, as shown in Figs. 7 and 8.
  • the waveform shape modification unit 340 can divide the turn-on period and change the magnitude of the gate current I G in each period. That is, the waveform shape modification unit 340 can finely adjust the magnitude of the gate current I G in one turn-on period.
  • the power conversion device 1 can perform control to reduce the loss generated in the switching element 311a while reducing the noise generated in the switching element 311a, as shown in FIG. 11, compared to the case where the same gate current I G is output during the turn-on period.
  • Fig. 16 is a diagram showing an example of the relationship between the basic pulse output by the basic pulse generating unit 410 and the gate current I G output by the waveform shape changing unit 340 in the power conversion device 1 according to the first embodiment.
  • the waveform shape changing unit 340 may divide the period during which the gate current I G is output during the turn-on period of the switching element 311a, and may first output the gate current I G of the current Ig2 with a large amplitude and then output the gate current I G of the current Ig1 with a small amplitude, or may first output the gate current I G of the current Ig1 with a small amplitude and then output the gate current I G of the current Ig2 with a large amplitude.
  • the waveform shape modification unit 340 may divide the period during which the gate current I G is output during the turn-off period of the switching element 311 a, and first output the gate current I G of a current -Ig2 with a large amplitude and then output the gate current I G of a current -Ig1 with a small amplitude, or first output the gate current I G of a current -Ig1 with a small amplitude and then output the gate current I G of a current -Ig2 with a large amplitude.
  • the waveform shape modification unit 340 can divide at least one of the turn-on period and the turn-off period of the switching element 311a into two or more periods and change the amplitude of the gate current I G for the switching element 311a to a different magnitude in each divided period based on the control signal output from the waveform shape setting unit 420.
  • the waveform shape modification unit 340 includes a plurality of transistors, and can change the amplitude of the gate current I G by changing the number of transistors to be operated based on the control signal output from the waveform shape setting unit 420.
  • the waveform shape changing unit 340 can change the output pattern of the gate current I G for each switching period of the switching element 311a.
  • the waveform shape changing unit 340 can change the switching waveform to a different waveform shape for each switching period of the switching element 311a during operation of the power conversion device 1.
  • the waveform shape setting unit 420 can change the set value of the waveform shape of the switching waveform of the switching element 311a at the same period as the switching period of the switching element 311a.
  • the waveform shape setting unit 420 may change the set value of the waveform shape of the switching waveform of the switching element 311a at a period that is a positive integer multiple of the switching period of the switching element 311a.
  • the configuration of the waveform shape modification unit 340 shown in FIG. 12 is merely an example and is not limited to this.
  • the waveform shape modification unit 340 can adjust the switching speed of the switching element 311a more finely by digital control using multiple MOSs (Metal Oxide Semiconductors), compared to analog control that physically switches the gate resistance.
  • the waveform shape modification unit 340 may use transistors other than MOSs for the transistors used internally.
  • the waveform shape changing unit 340 changes the number of PMOS or NMOS to be operated according to the acquired control signal, and outputs the gate current I G according to the number of PMOS or NMOS to be operated to the switching element 311a, but this is not limited to the above.
  • the waveform shape changing unit 340 may store in advance an output pattern, i.e., a waveform shape, of the gate current I G according to the control signal, and output the gate current I G in an output pattern, i.e., a waveform shape, according to the acquired control signal.
  • the waveform shape changing unit 340 may store a control signal acquired in the past and an output pattern, i.e., a waveform shape of the gate current I G when the control signal was acquired in the past, and output the gate current I G in the output pattern, i.e., a waveform shape stored when the same control signal was acquired.
  • the waveform shape changing unit 340 can reduce the processing load when outputting the gate current I G by storing an output pattern, i.e., a waveform shape, of the gate current I G according to the control signal.
  • the waveform shape changing unit 340 adjusts the switching speed of the switching element 311a by changing the gate current I G as the drive signal output to the switching element 311a, and changes the waveform shape of the switching waveform of the switching element 311a, but is not limited to this.
  • the waveform shape changing unit 340 sets the drive signal output to the switching element 311a as the gate voltage V G , and by changing the gate voltage V G , it can similarly adjust the switching speed of the switching element 311a and change the waveform shape of the switching waveform of the switching element 311a.
  • the waveform shape modification unit 340 can divide at least one of the turn-on period and the turn-off period of the switching element 311a into two or more periods and change the amplitude of the gate voltage V G for the switching element 311a to a different magnitude in each divided period based on the control signal output from the waveform shape setting unit 420.
  • the waveform shape modification unit 340 includes a plurality of transistors, and can change the amplitude of the gate voltage V G by changing the number of transistors to be operated based on the control signal output from the waveform shape setting unit 420.
  • the waveform shape of the pulsed current waveform detected by the current detector arranged on the path of the current flowing through the power converter changes.
  • the power conversion device 1 can change the waveform shape of the pulsed current waveform detected by the current detector by changing the waveform shape of the switching waveform of the switching element.
  • the power converter is at least one of the converter 130 and the inverter 310.
  • the current detector arranged on the path of the current flowing through the converter 130, which is the power converter is, for example, the state quantity detection unit 501.
  • the current detector arranged on the path of the current flowing through the inverter 310, which is the power converter is, for example, the state quantity detection unit 504.
  • the waveform shape of the pulsed current waveform detected by the current detector is a waveform shape that includes surges, ringing, etc.
  • the waveform shape of the pulsed current waveform detected by the current detector changes due to the influence of surges, ringing, etc. in addition to the current that originally flows through the power converter, so that the power conversion device 1 can detect the current with high accuracy by performing current detection in an area that is not influenced by surges, ringing, etc.
  • the power conversion device 1 can detect current with high accuracy, it can appropriately control the switching of the switching elements of the converter 130 and the inverter 310 according to the detected current amount.
  • FIG. 17 is a diagram showing an example of a state quantity detection unit 504 that is a current detector using switching elements 311a to 311f and shunt resistors provided in the inverter 310 of the power conversion device 1 according to embodiment 1.
  • the assignment of reference symbols to each component is omitted, but the switching element 311a is indicated by Up, the switching element 311b is indicated by Un, the switching element 311c is indicated by Vp, the switching element 311d is indicated by Vn, the switching element 311e is indicated by Wp, and the switching element 311f is indicated by Wn.
  • the state quantity detection unit 504 that is a current detector using a shunt resistor is indicated by the resistor at the bottom left.
  • FIG. 18 is a diagram showing an example of a switching pattern of the switching elements of the inverter 310, which can be detected by the state quantity detection unit 504, which is a current detector using a shunt resistor, in the power conversion device 1 according to the first embodiment.
  • FIG. 18 is a diagram showing the on/off state of each switching element of the inverter 310 and the state of the command voltage vector in the inverter 310. In FIG. 18, the switching elements in the on state are indicated by circles.
  • FIG. 18(a) shows the state of the command voltage vector V1 where the switching elements Un, Vn, and Wp are on and the switching elements Up, Vp, and Wn are off.
  • FIG. 18(a) shows the state of the command voltage vector V1 where the switching elements Un, Vn, and Wp are on and the switching elements Up, Vp, and Wn are off.
  • FIG. 18(b) shows the state of the command voltage vector V2 where the switching elements Un, Vp, and Wn are on and the switching elements Up, Vn, and Wp are off.
  • FIG. 18(c) shows the state of the command voltage vector V3 where the switching elements Un, Vp, and Wp are on and the switching elements Up, Vn, and Wn are off.
  • Fig. 18(d) shows a state of a command voltage vector V4 where the switching elements Up, Vn, Wn are on and the switching elements Un, Vp, Wp are off.
  • Fig. 18(e) shows a state of a command voltage vector V5 where the switching elements Up, Vn, Wp are on and the switching elements Un, Vp, Wn are off.
  • Fig. 18(f) shows a state of a command voltage vector V6 where the switching elements Up, Vp, Wn are on and the switching elements Un, Vn, Wp are off.
  • the power conversion device 1 can detect currents in the states of the command voltage vectors V 1 to V 6 , although detectable phase currents change depending on the on/off state of each switching element of the inverter 310.
  • the state quantity detection unit 504 arranged on the N line of the power conversion device 1 can detect the current (-Iu) flowing through the switching element Un in the case of Fig. 18(c), can detect the current (-Iv) flowing through the switching element Vn in the case of Fig. 18(e), and can detect the current (-Iw) flowing through the switching element Wn in the case of Fig. 18(f).
  • the state quantity detection unit 504 can detect the current Iw flowing through the switching element Wp in the case of Fig. 18(a), can detect the current Iv flowing through the switching element Vp in the case of Fig. 18(b), and can detect the current Iu flowing through the switching element Up in the case of Fig. 18(d).
  • FIG. 19 is a diagram showing an example of a switching pattern of the switching elements of the inverter 310 in which the state quantity detection unit 504, which is a current detector using a shunt resistor in the power conversion device 1 according to the first embodiment, is unable to detect a current.
  • FIG. 19 is a diagram showing the on/off state of each switching element of the inverter 310 and the state of the command voltage vector. In FIG. 19, the switching elements in the on state are indicated by circles.
  • FIG. 19(a) shows a state of the command voltage vector V0 in which the switching elements Un, Vn, and Wn are on and the switching elements Up, Vp, and Wp are off.
  • FIG. 19 shows a state of the command voltage vector V0 in which the switching elements Un, Vn, and Wn are on and the switching elements Up, Vp, and Wp are off.
  • 19(b) shows a state of the command voltage vector V7 in which the switching elements Up, Vp, and Wp are on and the switching elements Un, Vn, and Wn are off. As shown in FIG. 19, the power conversion device 1 is unable to detect a current in the state of the command voltage vectors V0 and V7 .
  • FIG. 20 is a diagram showing an example of a control state when there is no phase in which current cannot be detected in the power conversion device 1 according to embodiment 1.
  • FIG. 21 is a diagram showing an example of a control state when there is a phase in which current cannot be detected in the power conversion device 1 according to embodiment 1.
  • FIG. 20 shows a state in which the currents of the U phase and W phase can be detected
  • FIG. 21 shows a state in which the current of the W phase can be detected but the current of the U phase cannot be detected.
  • FIG. 21 it appears that the current of the U phase can be detected, but if it is waited until the surges, ringing, etc. converge as described above, the time during which the current of the U phase can be detected becomes zero or is extremely short. In other words, for a certain switching element, current detection may not be possible if you wait until the surge, ringing, etc. subsides, depending on the timing when the switching of the next switching element begins.
  • FIG. 22 is a diagram showing an example of a region of a command voltage vector that cannot be used for motor control in the power conversion device 1 according to embodiment 1.
  • the region shown in FIG. 22 is the region of the command voltage vector that cannot be used for motor control.
  • the command voltage vector shown on the left side of FIG. 21 is included in the region shown in FIG. 22, and therefore there is a period in which the power conversion device 1 cannot detect current, resulting in a command voltage vector that cannot be used for motor control.
  • the power conversion device 1 cannot use command voltage vectors in the region shown in FIG. 22 for motor control, but by reducing surges, ringing, etc. that occur in the shunt resistor, the region shown in FIG. 22 can be reduced, making it possible to achieve more accurate motor control.
  • FIG. 23 is a first diagram showing the relationship between the switching speed of the switching element and the current detection timing in the power conversion device 1 according to the first embodiment.
  • the upper part of FIG. 23(a) shows the state quantity indicating the operating state of the first switching element when the first switching element changes from non-conductive to conductive under the first drive condition
  • the lower part of FIG. 23(a) shows the detection value, i.e., the current value, detected by the state quantity detection unit, which is a current detector, when the first switching element changes from non-conductive to conductive under the first drive condition.
  • the upper part of FIG. 23(b) shows the state quantity indicating the operating state of the first switching element when the first switching element changes from non-conductive to conductive under the second drive condition
  • the detection value i.e., the current value
  • the state quantity detection unit which is a current detector
  • the state quantity indicating the operating state of the first switching element may be a voltage value or a current value detectable by the state quantity detection unit, a drive signal for driving the first switching element, or a command value used inside the control unit 400 to generate a drive signal.
  • the first switching element is any of the switching elements Up, Un, Vp, Vn, Wp, and Wn described above, that is, the switching elements 311a to 311f.
  • the first and second drive conditions indicate the difference in the switching speed of the first switching element, and here, the switching speed of the first switching element is faster under the first drive condition than under the second drive condition.
  • FIG. 23 shows the state in which the first switching element changes from non-conductive to conductive under the first and second drive conditions, but the case in which the first switching element changes from conductive to non-conductive under the first and second drive conditions can also be shown in a similar diagram.
  • the time until the state quantity indicating the conductive state of the first switching element reaches a specified threshold value when the first switching element changes from conductive to non-conductive or from non-conductive to conductive under the first drive condition is defined as a first time t1. Also, the time until the state quantity indicating the conductive state of the first switching element reaches a threshold value when the first switching element changes from conductive to non-conductive or from non-conductive to conductive under the second drive condition is defined as a second time t2.
  • the power conversion device 1 acquires the detection value of the current detector after the first time t1 has elapsed from the time that is the starting point of the first time t1 and after the specified third time t3 has elapsed. That is, when the first switching element is a switching element mounted on the inverter 310, the control unit 400 of the power conversion device 1 acquires the current value detected by the state quantity detection unit 504 after the first time t1 and the third time t3 have elapsed.
  • the power conversion device 1 acquires the detection value of the current detector after the second time t2 has elapsed from the time that is the starting point of the second time t2 and after the specified fourth time t4 has elapsed. That is, when the first switching element is a switching element mounted on the inverter 310, the control unit 400 of the power conversion device 1 acquires the current value detected by the state quantity detection unit 504 after the second time t2 and the fourth time t4 have elapsed. As shown in FIG. 23, the first time t1 is shorter than the second time t2, and the third time t3 is longer than the fourth time t4.
  • FIG. 24 is a second diagram showing the relationship between the switching speed of the switching element and the current detection timing in the power conversion device 1 according to the first embodiment.
  • the power conversion device 1 includes at least a first switching element and a second switching element as switching elements in the same power converter.
  • the upper part of FIG. 24(a) shows the state quantity indicating the operating state of the first switching element when the first switching element changes from non-conductive to conductive under the first driving condition
  • the middle part of FIG. 24(a) shows the state quantity indicating the operating state of the second switching element when the second switching element changes from non-conductive to conductive under the first driving condition
  • FIG. 24(a) shows the detection value, i.e., the current value, detected by the state quantity detection unit, which is a current detector, when the first switching element changes from non-conductive to conductive under the first driving condition.
  • the upper part of FIG. 24(b) shows the state quantity indicating the operating state of the first switching element when the first switching element changes from non-conductive to conductive under the second drive condition
  • the middle part of FIG. 24(b) shows the state quantity indicating the operating state of the second switching element when the second switching element changes from non-conductive to conductive under the second drive condition
  • the lower part of FIG. 24(b) shows the detection value, i.e., the current value, detected by the state quantity detection unit, which is a current detector, when the first switching element changes from non-conductive to conductive under the second drive condition.
  • the state quantity indicating the operating state of the first switching element and the second switching element only needs to indicate the operating state of the first switching element and the second switching element, and may be a voltage value or a current value detectable by the state quantity detection unit, a drive signal for driving the first switching element and the second switching element, or a command value used inside the control unit 400 to generate a drive signal.
  • the first switching element and the second switching element are any of the switching elements Up, Un, Vp, Vn, Wp, and Wn mentioned above, that is, switching elements 311a to 311f.
  • the first drive condition and the second drive condition indicate the difference in the switching speed of the first switching element, and here, it is assumed that the switching speed of the first switching element is faster under the first drive condition than under the second drive condition.
  • FIG. 24 shows the state in which the first switching element and the second switching element change from non-conductive to conductive under the first drive condition and the second drive condition
  • a similar diagram can also be used to show the case in which the first switching element and the second switching element change from conductive to non-conductive under the first drive condition and the second drive condition.
  • a fifth time t5 is a time until the state quantity indicating the conductive state of the first switching element reaches a specified threshold value when the first switching element changes from conductive to non-conductive or from non-conductive to conductive under the first drive condition.
  • a sixth time t6 is a time from when the first switching element changes from conductive to non-conductive or from non-conductive to conductive under the first drive condition until the second switching element starts to change from conductive to non-conductive or from non-conductive to conductive under the first drive condition.
  • a seventh time t7 is a time until the state quantity indicating the conductive state of the first switching element reaches a threshold value when the first switching element changes from conductive to non-conductive or from non-conductive to conductive under the second drive condition.
  • the time from when the first switching element changes from conductive to non-conductive or from non-conductive to conductive under the second drive condition to when the second switching element next starts to change from conductive to non-conductive or from non-conductive to conductive under the second drive condition is defined as an eighth time t8.
  • the power conversion device 1 acquires the detection value of the current detector after the fifth time t5 has elapsed from the time that is the starting point of the fifth time t5 and after the specified ninth time t9 has elapsed. That is, when the first switching element is a switching element mounted on the inverter 310, the control unit 400 of the power conversion device 1 acquires the current value detected by the state quantity detection unit 504 after the fifth time t5 and the ninth time t9 have elapsed.
  • the power conversion device 1 acquires the detection value of the current detector after the seventh time t7 has elapsed from the time that is the starting point of the seventh time t7 and after the specified tenth time t10 has elapsed. That is, when the first switching element is a switching element mounted on the inverter 310, the control unit 400 of the power conversion device 1 acquires the current value detected by the state quantity detection unit 504 after the seventh time t7 and the tenth time t10 have passed. As shown in FIG. 24, the sixth time t6 and the eighth time t8 are the same, or the error between the sixth time t6 and the eighth time t8 is within a prescribed tolerance range.
  • the prescribed tolerance range can be defined by a value according to the length of the sixth time t6, the eighth time t8, etc., such as a ratio, but is not limited thereto.
  • the ninth time t9 is shorter than the sixth time t6 and the eighth time t8, the tenth time t10 is shorter than the ninth time t9, and the seventh time t7 is longer than the fifth time t5.
  • the power conversion device 1 changes the waiting time until current detection according to the switching speed of the switching elements, so that it can accurately detect current, i.e., obtain the current value, even when control is performed in which the switching speed of the switching elements changes.
  • the power conversion device 1 takes into account the command values of each phase corresponding to each switching element, and when the period from when one switching element becomes conductive or non-conductive until another switching element becomes conductive or non-conductive is short, it can ensure time for current detection by slowing down the switching speed of a certain switching element to suppress the occurrence of surges, ringing, and the like.
  • FIG. 25 is a diagram showing an example of the switching state of a switching element and the voltage detected by a shunt resistor used in a current detector when the switching speed of the switching element is changed in the power conversion device 1 according to the first embodiment.
  • FIG. 25(a), FIG. 25(b), and FIG. 25(c) show the switching state of a certain switching element and the voltage detected by a shunt resistor when the switching state of a certain switching element changes.
  • the faster the switching state changes the faster the switching speed becomes, so as shown in FIG. 25, the switching speed of the switching element becomes faster from FIG. 25(a) to FIG. 25(c).
  • the shunt resistor voltage fluctuates due to the influence of surges, ringing, etc. immediately after switching of the switching element, and the fluctuation becomes larger as the switching speed becomes faster, i.e., from FIG. 25(a) to FIG. 25(c), and the time until convergence becomes longer.
  • FIG. 26 is a diagram showing the amplitude and convergence time of surges, ringing, etc. that occur when the switching elements of the power conversion device 1 according to embodiment 1 are switched.
  • the horizontal axis shows the switching speed of the switching elements
  • the vertical axis on the left shows the amplitude of surges, ringing, etc.
  • the vertical axis on the right shows the convergence time of surges, ringing, etc.
  • the graphs shown with circles show the amplitude of surges, ringing, etc.
  • the graphs shown with squares show the convergence time of surges, ringing, etc.
  • FIG. 27 is a diagram showing an example of the carrier frequency of the carrier signal used in the control of the inverter 310 of the power conversion device 1 according to the first embodiment.
  • the triangular wave shown in FIG. 27 is the carrier signal, and the carrier frequency of the carrier signal is f 1 as shown in FIG. 27.
  • the U-phase command value is a command value for driving the switching element corresponding to the U-phase of the motor 314
  • the V-phase command value is a command value for driving the switching element corresponding to the V-phase of the motor 31
  • the W-phase command value is a command value for driving the switching element corresponding to the W-phase of the motor 314.
  • the current detectable ratio Pn when a shunt resistor is used is defined by the following equation (1).
  • FIG. 28 is a diagram showing a state where a part of FIG. 27 is enlarged.
  • the U-phase command value, the V-phase command value, and the W-phase command value are actually sinusoidal as shown in FIG. 27, but are shown as straight lines because the horizontal axis is enlarged compared to FIG. 27.
  • the carrier signal is shown so that its magnitude changes for each clock period. As shown in FIG.
  • the pulse width from the timing when the command value of a certain first phase and the carrier signal cross each other to the timing when the command value of another second phase crosses each other is set as pulse width T1
  • the pulse width from the timing when the command value of the second phase and the carrier signal cross each other to the timing when the command value of yet another third phase crosses each other is set as pulse width T2 .
  • the current detectable ratio Pn changes depending on the length of the current detection wait time with respect to the carrier frequency of the carrier signal used in the control of the inverter 310.
  • FIG. 29 is a diagram showing an example of the relationship between the carrier frequency of the carrier signal used in the control of the inverter 310 in the power conversion device 1 according to the first embodiment and the current detectable ratio Pn calculated from the formula (1). From the example of FIG. 29, it can be seen that the shorter the current detection wait time is, that is, the slower the switching speed of the switching element is, the more to the right it shifts. Based on FIG. 29, the carrier frequency at which the current detectable ratio Pn is 0, that is, the current cannot be detected and motor control is impossible, is plotted as shown in FIG. 30.
  • FIG. 30 is a diagram showing an example of the relationship between the carrier frequency of the carrier signal used in the control of the inverter 310 in the power conversion device 1 according to the first embodiment and the maximum current detection wait time.
  • FIG. 30 is a diagram showing the maximum current detection wait time at each carrier frequency.
  • the power conversion device 1 if the current detection wait time is shorter than the maximum current detection wait time shown in FIG. 30, current detection is possible even at the corresponding carrier frequency, and motor control can be realized.
  • y -0.0008x + 8.413 as shown in FIG. 30, so the power conversion device 1 performs motor control with the current detection wait time that satisfies this linear approximation formula.
  • the power conversion device 1 if the carrier frequency of the carrier signal used in the switching control of the switching element is f 1 and the third time is t3, the first time t1 is adjusted to satisfy the formula t3 ⁇ ⁇ f 1 ⁇ (-0.0008) + 8.413 ⁇ ⁇ 10 -6 , that is, the switching speed of the switching element is adjusted. In this way, even if the switching speed of the switching element is increased, the power conversion device 1 keeps the current detection wait time, i.e., the third time t3, within a certain range or less, thereby enabling the power conversion device 1 to realize stable current detection in motor control.
  • the command values for each phase are the same as those used in a general power conversion device that controls a motor.
  • the basic pulse generating unit 410 and the waveform shape setting unit 420 of the control unit 400 may use the command values. That is, the power conversion device 1 includes a control unit 400 that controls the waveform shape of the switching waveform of the switching element according to the command value for each phase. In the power conversion device 1, the waveform shape of the switching waveform of the switching element is changed according to the magnitude of the command value. Since the control unit 400 knows the command value, the power conversion device 1 can suppress the occurrence of surges, ringing, and the like caused by switching of the switching element by slowing down the switching speed of the switching element when the command value is small, for example.
  • the power conversion device 1 in the power conversion device 1, at least one of the one or more power converters that perform power conversion, specifically the inverter 310, has at least three phases as output phases and at least one switching element for each phase.
  • the power conversion device 1 makes the waveform shape of the switching waveform of the switching element that changes secondly different from the waveform shape of the switching element that changes first and the waveform shape of the switching element that changes thirdly.
  • the power conversion device 1 slows down the switching speed of the switching elements only in the middle phase in the inverter 310, which is a three-phase inverter.
  • the inverter 310 has at least three output phases and at least one switching element for each phase, it is also applicable to cases where the inverter 310 is a four-phase inverter and has eight switching elements, for example.
  • FIG. 31 is a flowchart showing the operation of changing the waveform shape of the switching waveforms of the switching elements 311a to 311f in the power conversion device 1 according to the first embodiment.
  • the basic pulse generation unit 410 generates a basic pulse for driving the switching elements 311a to 311f of the inverter 310 based on the state quantities acquired from the state quantity detection units 501 to 505 (step S1).
  • the basic pulse generation unit 410 generates a basic pulse based on the state quantities acquired from the state quantity detection units 501 to 505, and determines the timing to turn on and off the switching elements 311a to 311f.
  • the basic pulse generation unit 410 outputs the generated basic pulse to the waveform shape setting unit 420.
  • the waveform shape setting unit 420 sets a waveform shape for changing the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 based on the basic pulse obtained from the basic pulse generating unit 410 and the state quantities obtained from the state quantity detecting units 501 to 505.
  • the waveform shape setting unit 420 sets the waveform shape of the switching waveform at the timing to turn on and turn off the switching elements 311a to 311f determined by the basic pulse generating unit 410 based on the state quantities obtained from the state quantity detecting units 501 to 505.
  • the waveform shape setting unit 420 outputs a control signal to the waveform shape changing unit 340 that can change the magnitude and output timing of the drive signal according to the set waveform shape, i.e., the set value of the waveform shape (step S2).
  • the waveform shape changing unit 340 changes the waveform shape of the gate current I G output to the switching elements 311a to 311f of the inverter 310, i.e., the waveform shape of the switching waveform of the switching elements 311a to 311f, based on the control signal obtained from the waveform shape setting unit 420 (step S3).
  • the waveform shape changing unit 340 outputs the gate current I G after the waveform shape change to the switching elements 311a to 311f of the inverter 310.
  • FIG. 32 is a diagram showing an example of a hardware configuration that realizes the control unit 400 included in the power conversion device 1 according to the first embodiment.
  • the control unit 400 is realized by a processor 91 and a memory 92.
  • the processor 91 is a CPU (Central Processing Unit, also known as a central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, processor, or DSP (Digital Signal Processor)) or a system LSI (Large Scale Integration).
  • Examples of memory 92 include non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), and EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory).
  • Memory 92 is not limited to these, and may also be a magnetic disk, optical disk, compact disk, mini disk, or DVD (Digital Versatile Disc).
  • the waveform shape setting unit 420 of the control unit 400 outputs a control signal for reflecting a set value when the switching waveform of the switching elements 311a to 311f is changed by the waveform shape changing unit 340 of the inverter 310, according to the state quantities detected by the state quantity detection units 501 to 505.
  • the waveform shape changing unit 340 of the inverter 310 changes the waveform shape of the switching waveform of the switching elements 311a to 311f by changing the gate current I G or gate voltage V G output to the switching elements 311a to 311f based on the control signal output from the waveform shape setting unit 420.
  • the power conversion device 1 can change the switching speed of the switching elements 311a to 311f while suppressing an increase in the circuit size.
  • the power conversion device 1 can realize a desired waveform shape for the switching waveforms of the switching elements 311a to 311f by finely adjusting the gate current I G or gate voltage V G output to the switching elements 311a to 311f in one switching period.
  • the power conversion device 1 when measuring the current flowing through the switching element, the power conversion device 1 appropriately changes the current detection wait time according to the switching speed of the switching element. This enables the power conversion device 1 to improve the current detection accuracy.
  • Embodiment 2 In the first embodiment, a case has been described in which the set value of the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 is changed in the power conversion device 1. In the second embodiment, a case has been described in which the set value of the waveform shape of the switching waveform of the switching element 136 of the converter 130 is changed in the power conversion device 1.
  • FIG. 33 is a diagram showing an example of the configuration of the power conversion device 1 according to the second embodiment.
  • the power conversion device 1 is connected to a commercial power source 110 and a motor 314.
  • the power conversion device 1 converts a first AC voltage of the power source voltage Vs supplied from the commercial power source 110, which is an AC power source, into a second AC voltage having a desired amplitude and phase, and supplies the second AC voltage to the motor 314.
  • the power conversion device 1 includes a state quantity detection unit 501, a converter 130, a capacitor 210, a state quantity detection unit 502, an inverter 310, a state quantity detection unit 503, a state quantity detection unit 504, a state quantity detection unit 505, and a control unit 400.
  • the power conversion device 1 and the motor 314 constitute a motor drive device 2.
  • the power conversion device 1 of the second embodiment shown in FIG. 33 is obtained by removing the waveform shape change unit 340 from the inverter 310 and adding a drive circuit 350 to the power conversion device 1 of the first embodiment shown in FIG. 1, and by removing the drive circuit 150 from the converter 130 and adding a waveform shape change unit 140 to the converter 130.
  • the power conversion device 1 of the second embodiment shown in FIG. 33 has changed the output destinations of the basic pulse generation unit 410 and the waveform shape setting unit 420 compared to the power conversion device 1 of the first embodiment shown in FIG. 1.
  • the basic pulse generation unit 410 outputs a basic pulse for controlling the operation of the switching element 136 of the converter 130 to the waveform shape setting unit 420, and outputs a basic pulse for controlling the operation of the switching elements 311a to 311f of the inverter 310 to the inverter 310.
  • the waveform shape setting unit 420 outputs a control signal for controlling the operation of the waveform shape change unit 140 to the waveform shape change unit 140.
  • the drive circuit 350 In the inverter 310, the drive circuit 350 generates a drive signal for actually driving the switching elements 311a to 311f based on the basic pulse generated by the basic pulse generating unit 410 of the control unit 400.
  • the waveform shape setting unit 420 sets the waveform shape of the switching waveform of the switching element 136 when the switching waveform of the switching element 136 is changed by the waveform shape changing unit 140 of the converter 130 according to the state quantities detected by the state quantity detection units 501 to 505, and outputs a control signal to reflect the set value indicating the set waveform shape.
  • the waveform shape setting unit 420 controls the magnitude of the drive signal that the waveform shape changing unit 140 of the converter 130 outputs to the switching element 136 to actually drive the switching element 136, and the timing of outputting the drive signal.
  • the waveform shape setting unit 420 outputs a control signal for controlling the operation of the waveform shape changing unit 140 to the waveform shape changing unit 140.
  • the waveform shape modification unit 140 can change the waveform shape of the switching waveform of the switching element 136 without physically switching the gate resistor or the like.
  • the waveform shape modification unit 140 can output two or more waveform shapes as the waveform shape of the switching waveform of the switching element 136.
  • the waveform shape modification unit 140 is included in the converter 130, which is a power converter including the switching element 136.
  • the configuration of the waveform shape modification unit 140 is the same as the configuration of the waveform shape modification unit 340 of the first embodiment shown in FIG. 12. That is, the waveform shape modification unit 140 and the switching element 136 are configured by one digital gate driver module.
  • the waveform shape modification unit 140 may adjust the gate voltage V G to be output to the switching element 136 as the drive signal, instead of the gate current I G to be output to the switching element 136.
  • the waveform shape modification unit 140 can divide at least one of the turn-on period and the turn-off period of the switching element 136 into two or more periods based on the control signal output from the waveform shape setting unit 420, and can change the amplitude of the gate current I G or the gate voltage V G for the switching element 136 to a different magnitude in each divided period based on the control signal output from the waveform shape setting unit 420.
  • the waveform shape modification unit 140 includes a plurality of transistors, and can change the amplitude of the gate current I G or the gate voltage V G by changing the number of transistors to be operated based on the control signal output from the waveform shape setting unit 420.
  • the power conversion device 1 can change the waveform shape of the switching waveform of the switching element 136 of the converter 130 by the waveform shape setting unit 420 and the waveform shape modification unit 140 by performing the same operation as in the first embodiment.
  • the power conversion device 1 can adjust the noise and loss generated in the switching element 136 by changing the setting value of the waveform shape of the switching waveform of the switching element 136 mounted on the converter 130.
  • the waveform shape change unit 140 changes the switching waveform of the switching element 136 according to a state quantity correlated with either the current flowing through the converter 130, the current flowing from the commercial power source 110, or the second DC voltage, based on the control signal.
  • the power conversion device 1 can suppress an increase in noise and loss generated in the switching element 136 by changing the waveform shape of the switching waveform of the switching element 136.
  • the power conversion device 1 operates to suppress losses generated in the switching element 136 under light loads and to suppress losses generated in the switching element 136 under heavy loads, thereby contributing to improvement of the APF (Annual Performance Factor) and VE (Value Engineering) by reducing noise countermeasure costs.
  • APF Annual Performance Factor
  • VE Value Engineering
  • the waveform shape setting unit 420 of the control unit 400 outputs a control signal for reflecting a set value when the switching waveform of the switching element 136 is changed by the waveform shape changing unit 140 of the converter 130, according to the state quantities detected by the state quantity detection units 501 to 505.
  • the waveform shape changing unit 140 of the converter 130 changes the waveform shape of the switching waveform of the switching element 136 by changing the gate current I G or the gate voltage V G output to the switching element 136 based on the control signal output from the waveform shape setting unit 420.
  • the waveform shape changing unit 140 can change the waveform shape of the switching waveform of the switching element 136 in the same way that the waveform shape changing unit 340 of the first embodiment changes the waveform shape of the switching waveform of the switching element 311a. This allows the power conversion device 1 to change the switching speed of the switching element 136 while suppressing an increase in the circuit size.
  • the power conversion device 1 can realize a desired waveform shape for the switching waveform of the switching element 136 by finely adjusting the gate current I G or gate voltage V G output to the switching element 136 in one switching period.
  • the configuration of the converter 130 for which the waveform shape of the switching element is changed is not limited to the example in FIG. 33.
  • the configuration of the converter 130 for which the waveform shape of the switching element is changed can also be applied to the configurations of the converter 130 shown in FIG. 2 to FIG. 6.
  • the waveform shape change unit 140 changes the waveform shape of the switching waveform of the switching elements 136a and 136b in the example of FIG. 2, changes the waveform shape of the switching waveform of the switching elements 136b and 136d in the example of FIG. 3, changes the waveform shape of the switching waveform of the switching elements 136a to 136d in the example of FIG. 4, changes the waveform shape of the switching waveform of the switching elements 136a and 136b in the example of FIG. 5, and changes the waveform shape of the switching waveform of the switching element 136 in the example of FIG. 6.
  • the power conversion device 1 since the waveform shape of the switching waveform of the switching element of the converter 130 can be changed, when the state quantity detection unit 501 detects the current, the power conversion device 1 can appropriately change the current detection wait time according to the switching speed of the switching element of the converter 130. This allows the power conversion device 1 to improve the current detection accuracy, similar to the case of changing the switching speed of the switching element of the inverter 310 in embodiment 1.
  • the configuration of converter 130 can also be applied to the configurations of converter 130 shown in Figures 2 to 6, so when the power conversion device 1 is configured to have a switching element for each input phase of the converter, it is equipped with a control unit 400 that controls the waveform shape of the switching waveform of the switching element according to the command value for each phase. In the power conversion device 1, the waveform shape of the switching waveform of the switching element is changed according to the magnitude of the command value.
  • the power conversion device 1 when the commercial power source 110 is a three-phase AC power source, in the power conversion device 1, at least one of the one or more power converters that perform power conversion, specifically the converter 130, has at least three phases as input phases and is provided with at least one switching element for each phase.
  • the power conversion device 1 makes the waveform shape of the switching waveform of the switching element that changes second to different from the waveform shapes of the switching waveform of the switching element that changes first and the switching element that changes third.
  • the power conversion device 1 slows down the switching speed of the switching elements only in the intermediate phase.
  • Embodiment 3 In the first embodiment, a case has been described in which a set value of the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 is changed in the power conversion device 1. In the second embodiment, a case has been described in which a set value of the waveform shape of the switching waveform of the switching element 136 of the converter 130 is changed in the power conversion device 1. In the third embodiment, a case will be described in which a set value of the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 is changed and a set value of the waveform shape of the switching waveform of the switching element 136 of the converter 130 is changed in the power conversion device 1.
  • FIG. 34 is a diagram showing an example of the configuration of the power conversion device 1 according to the third embodiment.
  • the power conversion device 1 is connected to a commercial power source 110 and a motor 314.
  • the power conversion device 1 converts a first AC voltage of the power source voltage Vs supplied from the commercial power source 110, which is an AC power source, into a second AC voltage having a desired amplitude and phase, and supplies the second AC voltage to the motor 314.
  • the power conversion device 1 includes a state quantity detection unit 501, a converter 130, a capacitor 210, a state quantity detection unit 502, an inverter 310, a state quantity detection unit 503, a state quantity detection unit 504, a state quantity detection unit 505, and a control unit 400.
  • the power conversion device 1 and the motor 314 constitute a motor drive device 2.
  • the power conversion device 1 of the third embodiment shown in FIG. 34 is obtained by removing the drive circuit 150 from the converter 130 and adding a waveform shape change unit 140 to the power conversion device 1 of the first embodiment shown in FIG. 1.
  • the power conversion device 1 of the third embodiment shown in FIG. 34 has changed the output destinations of the basic pulse generation unit 410 and the waveform shape setting unit 420 compared to the power conversion device 1 of the first embodiment shown in FIG. 1.
  • the basic pulse generation unit 410 outputs a basic pulse for controlling the operation of the switching elements 311a to 311f of the inverter 310 to the waveform shape setting unit 420, and outputs a basic pulse for controlling the operation of the switching element 136 of the converter 130 to the waveform shape setting unit 420.
  • the waveform shape setting unit 420 outputs a control signal for controlling the operation of the waveform shape change unit 340 to the waveform shape change unit 340, and outputs a control signal for controlling the operation of the waveform shape change unit 140 to the waveform shape change unit 140.
  • the waveform shape setting unit 420 performs the operation described in embodiment 1 as well as the operation described in embodiment 2.
  • the waveform shape changing unit 340 performs the same operation as that described in embodiment 1, and the waveform shape changing unit 140 performs the same operation as that described in embodiment 2.
  • the power conversion device 1 can change the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 by performing the same operation as in embodiment 1 using the waveform shape setting unit 420 and the waveform shape changing unit 340.
  • the power conversion device 1 can change the waveform shape of the switching waveform of the switching element 136 of the converter 130 by performing the same operation as in embodiment 2 using the waveform shape setting unit 420 and the waveform shape changing unit 140.
  • the power conversion device 1 can reduce the noise caused by the inverter 310 by the waveform shape change unit 340 slowing down the switching speed of the switching elements 311a to 311f mounted on the inverter 310, but this increases the loss in the inverter 310.
  • the power conversion device 1 can adjust the waveform shape change unit 140 to speed up the switching speed of the switching element 136 mounted on the converter 130, thereby improving the total loss of the power conversion device 1.
  • the power conversion device 1 can easily achieve the effect of improving loss by speeding up the switching speed of the switching element 136 of the converter 130, which has a high carrier frequency.
  • the power conversion device 1 optimizes the total noise and loss as the power conversion device 1 by taking into account the noise and loss generated by the switching element 136 of the converter 130 and the noise and loss generated by the switching elements 311a to 311f of the inverter 310, thereby contributing to improved APF and VE by reducing noise countermeasure costs.
  • the power conversion device 1 is equipped with a switching element in at least one of the converter 130 and the inverter 310, and the setting value of the waveform shape of the switching waveform of the switching element is changed, thereby making it possible to adjust the noise and loss generated in the switching element.
  • the waveform shape change unit 340 changes the switching waveform of the switching elements 311a to 311f according to a state quantity correlated with the second DC voltage based on a control signal.
  • the waveform shape change unit 140 changes the switching waveform of the switching element 136 according to a state quantity correlated with either the current flowing through the converter 130, the current flowing from the commercial power source 110, or the second DC voltage based on a control signal.
  • the power conversion device 1 can suppress an increase in noise and loss generated by the switching elements 311a to 311f, the switching element 136, etc., by changing the waveform shape of the switching waveform of the switching elements 311a to 311f, the switching element 136, etc., even under conditions where the bus voltage Vdc is large.
  • the power conversion device 1 can also control one of the waveform shape modification units 140, 340 to change the waveform shape of the switching waveform of the switching element at a certain timing, while the other does not change the waveform shape of the switching waveform of the switching element.
  • the switching elements for which the waveform shape modification units 140, 340 of the power conversion device 1 change the switching waveform are one or more switching elements included in at least one of the one or more power converters that perform power conversion in the power conversion device 1.
  • the waveform shape setting unit 420 of the control unit 400 outputs a control signal for reflecting a set value when the switching waveform of the switching elements 311a to 311f is changed by the waveform shape changing unit 340 of the inverter 310 in accordance with the state quantities detected by the state quantity detection units 501 to 505, and outputs a control signal for reflecting a set value when the switching waveform of the switching element 136 is changed by the waveform shape changing unit 140 of the converter 130.
  • the waveform shape changing unit 340 of the inverter 310 changes the waveform shape of the switching waveform of the switching elements 311a to 311f by changing the gate current I G or gate voltage V G output to the switching elements 311a to 311f based on the control signal output from the waveform shape setting unit 420. Furthermore, the waveform shape changing unit 140 of the converter 130 changes the gate current I G or gate voltage V G output to the switching element 136 based on the control signal output from the waveform shape setting unit 420, thereby changing the waveform shape of the switching waveform of the switching element 136. This allows the power conversion device 1 to change the switching speed of the switching elements 311a to 311f and the switching element 136 while suppressing an increase in circuit size.
  • the power conversion device 1 can realize a desired waveform shape for the switching waveform of the switching elements 311a to 311f and the switching element 136 by finely adjusting the gate current I G or gate voltage V G output to the switching elements 311a to 311f and the switching element 136 in one switching period.
  • the waveform shape of the switching waveform of the switching elements 311a to 311f of the inverter 310 is changeable, and the waveform shape of the switching waveform of the switching element 136 of the converter 130 is changeable. Therefore, when detecting a current with the state quantity detection unit 504, the power conversion device 1 can appropriately change the current detection wait time according to the switching speed of the switching elements 311a to 311f of the inverter 310, and when detecting a current with the state quantity detection unit 501, can appropriately change the current detection wait time according to the switching speed of the switching element 136 of the converter 130. This allows the power conversion device 1 to obtain the same effects as those of the first and second embodiments.
  • the power conversion device 1 includes a control unit 400 having the functions described in the first and second embodiments.
  • the waveform shape of the switching waveform of the switching element is changed according to the magnitude of the command value.
  • At least one of the one or more power converters that perform power conversion has at least three phases as input phases or output phases, and at least one switching element for each phase.
  • the power conversion device 1 makes the waveform shape of the switching waveform of the switching element that changes second, for the switching element that changes first, the switching element that changes second, and the switching element that changes third, different from the waveform shapes of the switching waveform of the switching element that changes first and the switching element that changes third.
  • Embodiment 4 a case will be described in which the waveform shape setting section 420 and the waveform shape modification sections 140 and 340 transmit and receive control signals via a signal transmitting and receiving section.
  • the power conversion device 1 shown in FIG. 35 is a diagram showing an example of the configuration of the power conversion device 1 according to the fourth embodiment.
  • the power conversion device 1 shown in FIG. 35 is obtained by adding signal transmission/reception units 141, 341, and 421 to the power conversion device 1 according to the third embodiment shown in FIG. 34.
  • the signal transmission/reception unit 141 is arranged in the converter 130.
  • the signal transmission/reception unit 341 is arranged in the inverter 310.
  • the signal transmission/reception unit 421 is arranged in the control unit 400.
  • the signal transmission/reception unit 421 acquires a control signal output from the waveform shape setting unit 420, transmits a control signal for controlling the operation of the waveform shape modification unit 140 to the signal transmission/reception unit 141 arranged in the converter 130, and transmits a control signal for controlling the operation of the waveform shape modification unit 340 to the signal transmission/reception unit 341 arranged in the inverter 310.
  • the signal transmission/reception unit 141 outputs the control signal received from the signal transmission/reception unit 421 arranged in the control unit 400 to the waveform shape modification unit 140.
  • the signal transmission/reception unit 341 outputs the control signal received from the signal transmission/reception unit 421 arranged in the control unit 400 to the waveform shape modification unit 340.
  • the operation of the waveform shape modification units 140 and 340 that receive the control signal is as described above.
  • the signal transmission/reception unit 141 can transmit a control signal acquired from the waveform shape modification unit 140 to the signal transmission/reception unit 421.
  • the control signal for the waveform shape setting unit 420 generated by the waveform shape modification unit 140 is, for example, a signal indicating whether the waveform shape modification unit 140, the switching element 136, etc. are operating normally, but is not limited to this.
  • the signal transmission/reception unit 421 outputs the control signal received from the signal transmission/reception unit 141 to the waveform shape setting unit 420.
  • the signal transmission/reception unit 341 can transmit a control signal acquired from the waveform shape modification unit 340 to the signal transmission/reception unit 421.
  • the control signal for the waveform shape setting unit 420 generated by the waveform shape modification unit 340 is, for example, a signal indicating whether the waveform shape modification unit 340, the switching elements 311a to 311f, etc. are operating normally, but is not limited to this.
  • the signal transmission/reception unit 421 outputs the control signal received from the signal transmission/reception unit 341 to the waveform shape setting unit 420.
  • the signal transmission/reception unit 141 may not have the function of transmitting a signal.
  • the signal transmission/reception unit 341 may not have the function of transmitting a signal. If no signal is transmitted from the signal transmission/reception units 141, 341, the signal transmission/reception unit 421 may not have the function of receiving a signal.
  • the waveform shape setting unit 420 and the waveform shape modification unit 140 can also exchange control signals via the signal transmission/reception units 421 and 141.
  • the waveform shape setting unit 420 and the waveform shape modification unit 340 can also exchange control signals via the signal transmission/reception units 421 and 341.
  • the power conversion device 1 of embodiment 3 shown in FIG. 34 has been used as an example for explanation, this is not limiting, and the signal transmission/reception unit can also be applied to the power conversion device 1 of embodiment 1 and embodiment 2.
  • signal transmission/reception units 341, 421 can be added, and control signals can be transmitted and received between the waveform shape setting unit 420 and the waveform shape changing unit 340 via the signal transmission/reception units 421, 341.
  • signal transmission/reception units 141, 421 can be added, and control signals can be transmitted and received between the waveform shape setting unit 420 and the waveform shape changing unit 140 via the signal transmission/reception units 421, 141.
  • Fig. 36 is a diagram showing a configuration example of a refrigeration cycle-applied device 900 according to embodiment 5.
  • the refrigeration cycle-applied device 900 according to embodiment 5 includes the power conversion device 1 described in embodiment 1.
  • the refrigeration cycle-applied device 900 according to embodiment 5 can also include the power conversion device 1 described in embodiments 2 to 4.
  • the refrigeration cycle-applied device 900 according to embodiment 5 can be applied to products equipped with a refrigeration cycle, such as air conditioners, refrigerators, freezers, and heat pump water heaters.
  • components having the same functions as those in embodiment 1 are denoted by the same reference numerals as those in embodiment 1.
  • the refrigeration cycle application device 900 includes a compressor 315 incorporating the motor 314 in the first embodiment, a four-way valve 902, an indoor heat exchanger 906, an expansion valve 908, and an outdoor heat exchanger 910, which are attached via a refrigerant pipe 912.
  • a compression mechanism 904 that compresses the refrigerant, and a motor 314 that operates the compression mechanism 904.
  • the refrigeration cycle device 900 can perform heating or cooling operation by switching the four-way valve 902.
  • the compression mechanism 904 is driven by a variable speed controlled motor 314.
  • the refrigerant is pressurized by the compression mechanism 904 and sent out, passes through the four-way valve 902, the indoor heat exchanger 906, the expansion valve 908, the outdoor heat exchanger 910, and the four-way valve 902, and returns to the compression mechanism 904.
  • the refrigerant is pressurized by the compression mechanism 904 and sent out, passes through the four-way valve 902, the outdoor heat exchanger 910, the expansion valve 908, the indoor heat exchanger 906, and the four-way valve 902, and returns to the compression mechanism 904.
  • the indoor heat exchanger 906 acts as a condenser to release heat, and the outdoor heat exchanger 910 acts as an evaporator to absorb heat.
  • the outdoor heat exchanger 910 acts as a condenser to release heat, and the indoor heat exchanger 906 acts as an evaporator to absorb heat.
  • the expansion valve 908 reduces the pressure of the refrigerant to expand it.
  • the refrigeration cycle-applied device 900 can reduce the noise generated by the switching elements 311a to 311f, etc., by slowing down the switching speed of the switching elements 311a to 311f, etc.
  • the refrigeration cycle-applied device 900 can reduce the loss generated by the switching elements 311a to 311f, etc., by speeding up the switching speed of the switching elements 311a to 311f, etc.
  • the digital gate driver module which is composed of the waveform shape changing unit 340 and the switching elements 311a to 311f included in the inverter 310, generates a large surge voltage and a lot of electromagnetic noise when the switching speed is fast.
  • the refrigeration cycle application device 900 uses a flammable refrigerant, there is a possibility that the refrigerant may burn due to discharge caused by electromagnetic noise when the refrigerant leaks. Therefore, the refrigeration cycle application device 900 sets the switching speed of the digital gate driver module provided in the power conversion device 1 according to the flammability of the refrigerant used in the refrigeration cycle application device 900.
  • the refrigeration cycle application device 900 slows down the switching speed of the digital gate driver module provided in the power conversion device 1 the higher the flammability of the refrigerant used in the refrigeration cycle application device 900.
  • the refrigeration cycle application device 900 can reduce the surge voltage by slowing down the switching speed of the digital gate driver module, and can prevent combustion even if the refrigerant leaks from the refrigeration cycle application device 900 by suppressing the occurrence of discharge caused by electromagnetic noise.
  • the refrigerant used in the refrigeration cycle application equipment 900 is, for example, any one of R1234yf, R1234ze(E), R1243zf, HFO1123, HFO1132(E), R1132a, CF3I, and R290, or a mixed refrigerant containing at least two of the aforementioned refrigerants.
  • 1 Power conversion device 2 Motor drive device, 91 Processor, 92 Memory, 110 Commercial power source, 130 Converter, 131-134, 131a-134a Rectifier element, 135, 135a, 135b Reactor, 136, 136a-136d, 311a-311f Switching element, 137, 137a-137d, 312a-312f Freewheel diode, 138, 138a, 138b Diode, 140, 340 Waveform shape change unit, 141, 341 , 421 signal transmission/reception unit, 150, 350 drive circuit, 161 rectification unit, 162 boost unit, 163 rectification boost unit, 210 capacitor, 310 inverter, 314 motor, 315 compressor, 400 control unit, 410 basic pulse generation unit, 420 waveform shape setting unit, 501-505 state quantity detection unit, 900 refrigeration cycle applicable device, 902 four-way valve, 904 compression mechanism, 906 indoor heat exchanger, 908 expansion valve, 910 outdoor heat exchanger, 912 refrigerant

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012200042A (ja) * 2011-03-18 2012-10-18 Mitsubishi Electric Corp インバータ制御装置及び冷凍空調装置
JP7325632B2 (ja) * 2020-06-01 2023-08-14 三菱電機株式会社 パワー半導体素子の駆動制御装置、及び、パワーモジュール

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012200042A (ja) * 2011-03-18 2012-10-18 Mitsubishi Electric Corp インバータ制御装置及び冷凍空調装置
JP7325632B2 (ja) * 2020-06-01 2023-08-14 三菱電機株式会社 パワー半導体素子の駆動制御装置、及び、パワーモジュール

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