Power conversion devices, motor drives, and refrigeration cycle application equipment

Abstract

This power conversion device (100) is a device (100) for supplying output voltage to a load through output terminals (41, 42). The power conversion device is provided with: a rectifier circuit (20) that rectifies AC voltage and outputs the rectified voltage; a booster circuit (30) that supplies the output voltage between the output terminals (41, 42); a voltage detection unit (40) that outputs a voltage detection value (Vdc) indicating the output voltage; and a control unit (60). The booster circuit (30) includes: a reactor (31) connected to the rectifier circuit (20); a smoothing capacitor (33) that smooths the rectified voltage to generate the output voltage; and a switching element (32) that short-circuits the reactor (31). The control unit (60) controls a conduction period of the switching element (32) on the basis of the voltage detection value (Vdc) such that a first pulsation frequency which is a frequency of pulsation of the output voltage becomes higher than a second pulsation frequency which is a frequency of pulsation of the rectified voltage. This refrigeration cycle application apparatus includes the power conversion device (100).

Description

[Technical field]

[0001] The present disclosure relates to a power conversion device, a motor drive device, and a refrigeration cycle applied device. [Background technology]

[0002] There has been proposed a power conversion device that converts an AC voltage into a DC voltage and supplies the DC voltage as an output voltage from an output terminal to a load (see, for example, Patent Document 1). This power conversion device has a rectifier circuit and a boost chopper circuit. The boost chopper circuit has a reactor connected to the rectifier circuit, a smoothing capacitor for reducing pulsation of the output voltage, and a switching element for shorting the reactor. To further reduce pulsation of the output voltage, it is desirable to use a large-capacity smoothing capacitor, but in this case, the volume of the smoothing capacitor becomes large. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-65399 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above power conversion device, if the capacity of the smoothing capacitor is reduced, the pulsation of the output voltage becomes large, which results in the beat phenomenon being more likely to occur and also in the element breakdown of the inverter, which is the load, being more likely to occur.

[0005] An object of the present disclosure is to provide a power conversion device capable of reducing pulsation in output voltage, a motor drive device including the power conversion device, and a refrigeration cycle application device including the motor drive device. [Means for solving the problem]

[0006] The power conversion device of the present disclosure supplies an output voltage from an output terminal to a load. Power Conversion an inverter circuit for rectifying an AC voltage and outputting the rectified voltage; a boost circuit for supplying the output voltage between the output terminals; a voltage detection unit for detecting the output voltage and outputting a voltage detection value indicating the output voltage; and a control unit, wherein the boost circuit has a reactor connected to the rectifier circuit, a smoothing capacitor for smoothing the rectified voltage to generate the output voltage, and a switching element for shorting the reactor during a conduction period that is an on-state period, and the control unit controls the conduction period of the switching element based on the voltage detection value so that a first pulsation frequency that is a frequency of pulsation of the output voltage is higher than a second pulsation frequency that is a frequency of pulsation of the rectified voltage. At the same time, the conduction period when the voltage detection value is equal to or less than a predetermined threshold is controlled so that an average value of the voltage detection value approaches a predetermined target voltage, and the conduction period when the voltage detection value exceeds the threshold is controlled so as to be shorter than the conduction period when the voltage detection value is equal to or less than the threshold. .

[0007] A motor drive device according to the present disclosure includes the above-described power conversion device and an inverter that converts the output voltage into an AC voltage and supplies the AC voltage to a motor.

[0008] A refrigeration cycle applied device according to the present disclosure includes the above-mentioned motor drive device and a refrigeration cycle device having a motor driven by the motor drive device. Effect of the Invention

[0009] According to the present disclosure, it is possible to reduce pulsation of the output voltage, and to make it difficult for the beat phenomenon to occur and for elements to be destroyed in the inverter, which is the load, to occur. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a configuration of a power conversion device according to a first embodiment. [Diagram 2] FIG. 4 is a block diagram showing a configuration of a control unit of a power conversion device of a comparative example. [Diagram 3] 10A and 10B are diagrams illustrating examples of operational waveforms of a power conversion device of a comparative example. [Figure 4]2 is a block diagram showing a configuration of a control unit of the power conversion device according to the first embodiment. FIG. [Diagram 5] 5 is a flowchart showing the operation of a control unit of the power conversion device according to the first embodiment. [Figure 6] 4 is a diagram showing an example of operational waveforms of the power conversion device according to the first embodiment. FIG. [Figure 7] 11 is a block diagram showing a configuration of a control unit of a power conversion device according to a second embodiment. FIG. [Figure 8] 10 is a flowchart showing the operation of a control unit of a power conversion device according to the second embodiment. [Figure 9] 11 is a diagram showing an example of operational waveforms of a power conversion device according to a second embodiment. FIG. [Figure 10] FIG. 11 is a diagram showing the configuration of a motor drive device and a refrigeration cycle applied device according to a third embodiment. [Figure 11] 5A and 5B are diagrams illustrating an example of operational waveforms of a motor drive device of a comparative example. [Figure 12] 13(A) and 13(B) are diagrams illustrating an example of operational waveforms of the motor drive device according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a power conversion device, a motor drive device, and a refrigeration cycle application device according to embodiments will be described with reference to the drawings. The following embodiments are merely examples, and the embodiments can be appropriately combined and each embodiment can be appropriately modified.

[0012] First Embodiment <composition> FIG. 1 is a diagram showing a configuration of a power conversion device 100 according to a first embodiment. The power conversion device 100 converts alternating current (AC) supplied from an alternating current power supply (i.e., an AC power supply) 10 into direct current (DC), and supplies the DC from output terminals 41, 42 to a load 50. The AC is, for example, a three-phase AC. In the first embodiment, an inverter is assumed as the load 50. However, the load 50 is not limited to an inverter. The inverter can drive a motor. Therefore, the power conversion device 100 and the inverter configure a motor drive device.

[0013] The power conversion device 100 has a rectifier circuit 20, a boost circuit (a boost chopper circuit in the example of FIG. 1) 30, a voltage detection unit 40, and a control unit 60. The rectifier circuit 20 rectifies the AC voltage supplied from the AC power source 10, and outputs the rectified voltage (i.e., the voltage before boosting). The boost circuit 30 supplies an output voltage (i.e., the voltage after boosting) between output terminals 41, 42. The voltage detection unit 40 is a detection circuit that detects the voltage between the output terminals 41, 42, and outputs a voltage detection value Vdc indicating the output voltage.

[0014] The boost circuit 30 includes a reactor 31 connected to the rectifier circuit 20, a smoothing capacitor 33 that smoothes the voltage rectified by the rectifier circuit 20 to generate an output voltage, a switching element 32 that shorts the reactor 31 during a conduction period that is an on-state period, and a diode 34 that serves as a backflow prevention element connected between the reactor 31 and the smoothing capacitor 33. The reactor 31 may be connected to either the input side or the output side of the rectifier circuit 20. The smoothing capacitor 33 and the switching element 32 are connected in parallel. The diode 34 prevents a backflow of current from the smoothing capacitor 33 to the AC power source 10.

[0015] The control unit 60 outputs a drive signal to the switching element 32 to control the switching element 32. The switching element 32 is on / off controlled. When the switching element 32 is on, it is in a conductive period, and when it is off, it is in a non-conductive period. The control unit 60 controls the conductive period, i.e., the on period, of the switching element 32 based on the voltage detection value Vdc so that a pulsation frequency (also referred to as a "first pulsation frequency"), which is the frequency of the pulsation of the output voltage (i.e., the voltage after boosting) between the output terminals 41 and 42, is higher than a pulsation frequency (also referred to as a "second pulsation frequency"), which is the frequency of the pulsation of the voltage rectified by the rectifier circuit 20 (i.e., the voltage before boosting).

[0016] The switching element 32 is a semiconductor switching element such as a power transistor, a power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or an IGBT (Insulated Gate Bipolar Transistor). A free wheeling diode (not shown) may be connected in parallel to the switching element 32 in order to suppress a surge voltage caused by switching. The free wheeling diode may be a parasitic diode of the switching element 32, which is a semiconductor switching element. The free wheeling diode may be a MOSFET. In this case, the MOSFET as the free wheeling diode is turned on at the timing of free wheeling. The material constituting the switching element 32 is not limited to silicon (Si). The switching element 32 may be a wide band gap semiconductor. The wide band gap semiconductor may be silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga 2 O 3 ) or diamond, it is possible to achieve low loss and high speed switching.

[0017] The control unit 60 controls the output voltage supplied from the output terminals 41 and 42 to the load 50 by controlling the on / off of the switching element 32. For example, the control unit 60 adjusts the on / off time of the switching element 32 (i.e., adjusts the duty) using proportional-integral (PI) control or the like so that the average value Vav of the voltage detection value Vdc of the voltage detection unit 40 becomes the target voltage Vta. For example, pulse width modulation (PWM) control may be used for the on / off control. The control unit 60 can be configured as a discrete system of a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and a microcomputer. For example, the control unit 60 may be a control circuit configured as an electric circuit such as an analog circuit or a digital circuit.

[0018] <assignment> The problem to be solved by the first embodiment will be described. Fig. 2 is a block diagram showing the configuration of a control unit 60a of a power conversion device of a comparative example. The power conversion device of Fig. 2 differs from the power conversion device 100 of Fig. 1 in the configuration of the control unit 60a. Fig. 3 is a diagram showing an example of an operating waveform of the power conversion device of the comparative example.

[0019] In the comparative example of FIG. 2, the control unit 60a has an average calculation unit 61 that calculates an average value Vav of the voltage detection value Vdc, and a PI control unit 62 that performs PI control based on the difference between the average value Vav and the target voltage Vta. For example, a capacitor having a capacitance of about several hundred μF is used as the smoothing capacitor 33, and as shown in FIG. 3, the duty of the switching element 32 (that is, the ratio of the on-time of the switching element 32 to one control period, also called "PWM duty") is PI controlled so that the average value Vav of the voltage detection value Vdc of the voltage detection unit 40 becomes the target voltage Vta. In this case, a large amplitude pulsation occurs in the terminal voltage of the smoothing capacitor 33 (that is, the output voltage between the output terminals 41 and 42), as shown as a waveform after boosting. The pulsation frequency, which is the frequency of the pulsation of the terminal voltage of the smoothing capacitor 33, is n times (n is a positive integer) the frequency of the AC voltage input to the rectifier circuit 20. n is 2 when the AC voltage is single-phase, and 6 when it is three-phase. Although the average terminal voltage Vav of the smoothing capacitor 33 is boosted, the pulsation is large, causing a beat phenomenon. In addition, the voltage peak value (for example, the portion surrounded by the dashed circle in the upper waveform of FIG. 3) becomes excessively large, which may exceed the withstand voltage of the inverter and cause damage to the elements that constitute the inverter.

[0020] In order to solve such a problem, in the first embodiment, the control unit 60 controls the conduction period (i.e., the on-period) of the switching element 32 based on the voltage detection value Vdc so that a first pulsation frequency, which is the frequency of the pulsation of the terminal voltage of the smoothing capacitor 33 (i.e., the output voltage between the output terminals 41 and 42), is higher than a second pulsation frequency, which is the frequency of the pulsation of the voltage before boosting by the boost circuit 30 (i.e., the voltage rectified by the rectifier circuit 20). This reduces the peak value of the terminal voltage of the smoothing capacitor 33.

[0021] <Operation> 4 is a block diagram showing a configuration of a control unit 60 of the power conversion device 100 according to the first embodiment. In the first embodiment, the control unit 60 has a PI control unit 62 that adjusts a duty (duty during PI control) so that an average value Vav of the voltage detection value Vdc of the voltage detection unit 40 becomes a predetermined target voltage Vta, and a duty command switching unit 63 that outputs either the output of the PI control unit 62 or a predetermined duty (fixed duty). This fixed duty is also called a "low duty" or a "first duty".

[0022] Fig. 5 is a flowchart showing the operation of the control unit 60 of the power conversion device 100 according to the first embodiment. As shown in Fig. 5, the control unit 60 compares the voltage detection value Vdc of the voltage detection unit 40 with a predetermined threshold value Vth (for example, a target voltage ta or an average value Vav of the voltage detection value Vdc) (step S11). Note that the voltage detection value Vdc of the voltage detection unit 40 may be subjected to filtering processing in software or hardware to remove noise during detection.

[0023] When the voltage detection value is equal to or lower than the threshold Vth (NO in step S11), the control unit 60 switches the duty command switching unit 63 in Fig. 4 to the contact A side to perform PI control (step S13). When the voltage detection value is higher than the threshold Vth (YES in step S11), the control unit 60 switches the duty command switching unit 63 in Fig. 4 to the contact B side to control the switching element 32 with a fixed duty (step S13). The fixed duty is a value smaller than the duty of the PI control.

[0024] Fig. 6 is a diagram showing an example of an operation waveform of the power conversion device 100 according to the first embodiment. Fig. 6 shows an operation waveform in the case where 0 is set as a fixed duty and the target voltage Vta is set to the threshold value Vth. As shown in Fig. 6, by setting the duty to 0 when the average value Vav of the voltage detection value Vdc exceeds the threshold value Vth, it is possible to make the first pulsation frequency of the pulsation of the terminal voltage of the smoothing capacitor 33 (i.e., the output voltage) higher than the second pulsation frequency of the pulsation of the voltage before boosting, and to reduce the voltage peak value.

[0025] In the first embodiment, since the average value Vav of the terminal voltage of the smoothing capacitor 33 is controlled to become the target voltage Vta, the average value of the terminal voltage of the smoothing capacitor 33 may be used as the threshold value Vth.

[0026] <effect> According to the first embodiment, when an inverter and a motor are used as the load 50 of the power conversion device 100, the operating range of the motor can be expanded, and even when overmodulation control is performed, beat is suppressed, thereby making it possible to reduce vibration and noise of the motor. In addition, since voltage peaks can be reduced, overvoltage failures of equipment can be prevented.

[0027] Second Embodiment The power conversion device according to the second embodiment differs from the power conversion device 100 according to the first embodiment in the configuration and operation of a control unit. The control unit of the power conversion device according to the second embodiment performs PI control on the conduction period of the switching element 32 so as to bring the voltage detection value Vdc close to a predetermined target voltage Ta, and controls the gain Gb of the PI control when the voltage detection value Vdc exceeds a threshold value Vth to be larger than the gain Ga of the PI control when the voltage detection value Vdc is equal to or smaller than the threshold value Vth.

[0028] 7 is a block diagram showing a configuration of a control unit 60b of a power conversion device according to the second embodiment. The control unit 60b has a gain switching unit 64, a PI control unit 65, and an upper / lower limit unit 66. However, it is possible to not provide the upper / lower limit unit 66. The gain switching unit 64 switches the control gain used for the PI control of the PI control unit 65 to either a predetermined gain Ga or Gb based on a comparison result between the voltage detection value Vdc and the threshold value Vth. Here, Gb>Ga. The threshold value Vth may be set to a value equal to, for example, the target voltage Vta or the average value Vav of the voltage detection value Vdc.

[0029] Furthermore, since switching the control gain may cause the integral result in the PI control unit 65 to change abruptly, the integral value is saved (i.e., temporarily saved) and restored. Furthermore, in order to prevent the output of the PI control unit 65 from becoming too large or too small, it is desirable to provide an upper and lower limit unit 66. When the upper and lower limit unit 66 is provided, it is desirable to perform an anti-windup operation to prevent unnecessary integration from being performed when the output of the PI control unit 65 reaches the upper limit value or the lower limit value set in the upper and lower limit unit 66. One example of the anti-windup operation is an operation to stop the integral operation.

[0030] 8 is a flowchart showing the operation of the control unit 60b of the power conversion device according to embodiment 2. The control unit 60b compares the voltage detection value Vdc of the voltage detection unit 40 with a preset threshold value Vth (step S21).

[0031] If the voltage detection value Vdc is equal to or less than the threshold Vth (NO in step S21), the control unit 60b compares the previous voltage detection value Vdc1 with the threshold Vth (step S24). If the previous voltage detection value Vdc1 is equal to or less than the threshold Vth (NO in step S24), the control unit 60b sets the control gain used in the PI control unit 65 to the gain Ga (step S27). If the previous voltage detection value Vdc1 is greater than the threshold Vth (YES in step S24), the control unit 60b sets the integral value temporarily stored as the integral value of the PI control (step S25), and sets the control gain used in the PI control unit 65 to the gain Ga (step S26).

[0032] When the voltage detection value Vdc is greater than the threshold value Vth (YES in step S21), the control unit 60b temporarily stores the integral value of the PI control (step S22) and sets the control gain used in the PI control unit 65 to gain Gb (Gb>Ga) (step S27).

[0033] Fig. 9 is a diagram showing an example of an operation waveform of the power conversion device according to the second embodiment. In the second embodiment, the control unit 60b performs PI control on the conduction period of the switching element 32 so as to bring the voltage detection value Vdc close to the target voltage Vta, and controls the gain Gb of the PI control when the voltage detection value Vdc exceeds the threshold value Vth to be larger than the gain Ga of the PI control when the voltage detection value Vdc is equal to or smaller than the threshold value Vth. Therefore, as shown in Fig. 9, it is possible to reduce pulsation of the output voltage of the output terminals 41 and 42 (i.e., the voltage after boosting by the boost circuit 30).

[0034] Third Embodiment Fig. 10 is a diagram showing the configurations of a motor drive device 300 and a refrigeration cycle application device 400 according to the third embodiment. The motor drive device 300 has a power conversion device 100 and an inverter 51 as a load. The refrigeration cycle application device 400 has the motor drive device 300 and a refrigeration cycle device 200. The refrigeration cycle application device 400 is, for example, an air conditioner, a refrigerator, etc. As the power conversion device 100, the power conversion device according to the first or second embodiment can be used.

[0035] The refrigeration cycle device 200 includes a compressor 201, a four-way valve 202, an internal heat exchanger 203, an expansion mechanism 204, a heat exchanger 205, and refrigerant piping 206 that sequentially connects these components. Inside the compressor 201, a compression mechanism 207 that compresses the refrigerant and a motor 208 that operates the compression mechanism 207 are provided. The motor 208 is driven by an inverter 51 that is connected to the power conversion device 100 as a load.

[0036] 11(A) and (B) are diagrams showing examples of operation waveforms of a motor drive device of a comparative example. In the motor drive device of the comparative example, unlike the control unit 60 or 60b of the first or second embodiment, the control unit 60a (shown in FIG. 2) does not execute a process of controlling the conduction period of the switching element 32 so that the first pulsation frequency of the output terminal is higher than the second pulsation frequency of the rectified voltage. As shown in FIG. 11(A), in the motor drive device of the comparative example, a low-frequency beat is superimposed on the current flowing through the motor 208 due to the influence of the pulsation of the terminal voltage of the smoothing capacitor 33, which may cause deterioration of vibration and noise. At this time, the pulsation frequency of the terminal voltage of the smoothing capacitor 33 is n times the frequency of the AC voltage input to the rectifier circuit 20. Here, n is 2 when the AC voltage is single-phase and 6 when it is three-phase.

[0037] 12(A) and (B) are diagrams showing examples of operational waveforms of the motor drive device 300 according to the third embodiment. In the third embodiment, the control unit (i.e., the control unit 60 or 60b) controls the conduction period of the switching element 32 based on the voltage detection value Vdc so that the first pulsation frequency of the output voltage (for example, the pulsation frequency of the pulsation shown in FIG. 12(B)) is higher than the second pulsation frequency which is the pulsation frequency of the rectified voltage. In other words, in the motor drive device 300 according to the third embodiment, the pulsation frequency of the terminal voltage of the smoothing capacitor 33 can be increased.

[0038] For example, when the power converter 100 according to the first embodiment is used as the power converter of the motor drive device 300, the pulsation frequency is approximately twice as high as that of the comparative example shown in FIG. 3, as shown as a boosted voltage in FIG. 6. FIG. 12(A) shows an operation waveform when the pulsation frequency of the terminal voltage of the smoothing capacitor 33 is approximately twice as high as that of the comparative example shown in FIG. 11(B), as shown in FIG. 12(B). It can be seen from FIG. 12(A) that the low-frequency beat can be reduced by increasing the pulsation frequency. This makes it possible to reduce the vibration and noise of the device.

[0039] As described above, in the motor drive device 300 according to the third embodiment, the power conversion device according to the first or second embodiment is used to reduce the pulsation of the voltage applied to the inverter 51, and therefore it is possible to reduce low-frequency beat. As a result, in the refrigeration cycle applied equipment 400 including the motor drive device 300, it is possible to achieve low vibration and low noise. [Explanation of symbols]

[0040] 10 AC power source, 20 rectifier circuit, 30 boost circuit, 31 reactor, 32 switching element, 33 smoothing capacitor, 34 diode (backflow prevention element), 40 voltage detection unit (detection circuit), 50 load, 51 inverter, 60, 60b control unit (control circuit), 61 average value calculation unit, 62 PI control unit, 63 duty command switching unit, 64 gain switching unit, 65 PI control unit, 66 upper and lower limit unit, 100 power conversion device, 200 refrigeration cycle device, 201 compressor, 202 four-way valve, 203 internal heat exchanger, 204 expansion mechanism, 205 heat exchanger, 206 refrigerant piping, 207 compression mechanism, 208 motor, 300 motor drive device, 400 Refrigeration cycle application equipment.

Claims

1. A power conversion device that supplies an output voltage from an output terminal to a load, a rectifier circuit that rectifies an AC voltage and outputs the rectified voltage; a boost circuit for supplying the output voltage between the output terminals; a voltage detection unit that detects the output voltage and outputs a voltage detection value that indicates the output voltage; A control unit; having The boost circuit includes: A reactor connected to the rectifier circuit; a smoothing capacitor that smoothes the rectified voltage to generate the output voltage; a switching element that shorts the reactor during a conduction period, which is a period during which the switching element is in an on state; having the control unit controls the conduction period of the switching element based on the voltage detection value so that a first pulsation frequency, which is a frequency of pulsation of the output voltage, is higher than a second pulsation frequency, which is a frequency of pulsation of the rectified voltage; controlling the conduction period when the voltage detection value is equal to or lower than a predetermined threshold value so that an average value of the voltage detection value approaches a predetermined target voltage; A power conversion device that controls the conduction period when the detected voltage value exceeds the threshold value so as to be shorter than the conduction period when the detected voltage value is equal to or lower than the threshold value.

2. The control unit is When the voltage detection value is equal to or less than a predetermined threshold value, a duty of the switching element is controlled so that an average value of the voltage detection value approaches the target voltage; When the voltage detection value exceeds the threshold value, a control is performed using a predetermined first duty that is lower than the duty so that the average value of the voltage detection value approaches the target voltage. The power conversion device according to claim 1 .

3. The first duty is 0. The power conversion device according to claim 2 .

4. The threshold value is equal to the average value of the target voltage or the detected voltage value. The power conversion device according to claim 1 .

5. A power conversion device that supplies an output voltage from an output terminal to a load, a rectifier circuit that rectifies an AC voltage and outputs the rectified voltage; a boost circuit for supplying the output voltage between the output terminals; a voltage detection unit that detects the output voltage and outputs a voltage detection value that indicates the output voltage; A control unit; having The boost circuit includes: A reactor connected to the rectifier circuit; a smoothing capacitor that smoothes the rectified voltage to generate the output voltage; a switching element that shorts the reactor during a conduction period, which is a period during which the switching element is in an on state; having the control unit controls the conduction period of the switching element based on the voltage detection value so that a first pulsation frequency, which is a frequency of pulsation of the output voltage, is higher than a second pulsation frequency, which is a frequency of pulsation of the rectified voltage; performing PI control on the conduction period so that the voltage detection value approaches a predetermined target voltage; A power conversion device that controls a gain of the PI control when the voltage detection value exceeds a predetermined threshold value so that the gain of the PI control is larger than the gain of the PI control when the voltage detection value is equal to or smaller than the threshold value.

6. The control unit has an upper and lower limit unit that limits a duty for commanding the switching element for the conduction period to a value equal to or greater than a predetermined lower limit value and equal to or less than a predetermined upper limit value. The power conversion device according to claim 5 .

7. The threshold value is equal to the average value of the target voltage or the detected voltage value. The power conversion device according to claim 5 or 6.

8. The power conversion device according to any one of claims 1 to 7, an inverter that converts the output voltage into an AC voltage and supplies the AC voltage to a motor; A motor drive device comprising:

9. The motor drive device according to claim 8 , a refrigeration cycle device having a motor driven by the motor drive device; Refrigeration cycle application equipment equipped with

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