Power converters, motor drive systems, and refrigeration cycle application equipment

Abstract

The power converter (200) connected to the rotary compressor includes a rectifier (3) that rectifies the first AC power supplied from the AC power source (1), a smoothing capacitor (5) connected to the output terminal of the rectifier (3), an inverter (30) connected to both ends of the smoothing capacitor (5) that generates a second AC power and outputs it to the motor (7) of the rotary compressor, and a control device (100) that controls the operation of the inverter (30). The control device (100) can suppress vane separation, which occurs when the vanes separate from the rolling piston in the rotary compressor, by reducing the rotational speed of the rolling piston according to the rotational position of the rolling piston of the rotary compressor, which is rotated by the motor (7).

Description

[Technical Field]

[0001] This disclosure relates to a power conversion device, a motor drive device, and equipment for use in refrigeration cycles, which convert AC power to a desired power. [Background technology]

[0002] Rotary compressors, which are compressors that compress refrigerants, generally use components called vanes and rolling pistons. During normal operation, the vanes move in contact with the rolling piston, but for some reason, vane separation can occur, where the vanes separate from the rolling piston. When vane separation occurs, a metallic collision sound is generated when the vanes re-contact the rolling piston, and this metallic collision sound has been a source of noise. To address this problem, Patent Document 1 discloses a technique to prevent vane separation by connecting the tip of the vane and a roller-side connecting part provided on the outside of the rolling piston (roller in Patent Document 1) with a connecting pin. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2001-73975 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the conventional technology described above requires a connecting pin in addition to the vanes and rolling piston, and also necessitates a roller-side connecting section on the outside of the rolling piston, resulting in a unique structure. Therefore, there was a problem in that it was difficult to manufacture compressors with such a structure using only existing manufacturing equipment.

[0005] This disclosure has been made in view of the above, and aims to provide a power conversion device capable of suppressing vane separation by controlling the operation of the compressor. [Means for solving the problem]

[0006] To solve the above-mentioned problems and achieve the objective, this disclosure provides a power conversion device connected to a rotary compressor. The power conversion device comprises a rectifier that rectifies a first AC power supplied from an AC power source, a capacitor connected to the output terminal of the rectifier, an inverter connected to both ends of the capacitor that generates a second AC power and outputs it to a motor of the rotary compressor, and a control device that controls the operation of the inverter. The control device reduces the rotational speed of the rolling piston of the rotary compressor, which is rotated by the motor, according to the rotational position of the rolling piston. and accelerate to return the rotational speed of the rolling piston. By doing so, vane separation suppression control is performed in the rotary compressor to suppress vane separation, which is the separation of the vanes from the rolling piston. [Effects of the Invention]

[0007] The power conversion device according to this disclosure has the effect of being able to suppress vane separation by controlling the operation of the compressor. [Brief explanation of the drawing]

[0008] [Figure 1] Block diagram showing an example configuration of a power conversion device according to Embodiment 1. [Figure 2] Block diagram showing an example of the configuration of the inverter included in the power conversion device according to Embodiment 1. [Figure 3] This figure shows an example of the configuration of a compressor connected to a power conversion device according to Embodiment 1. [Figure 4] This figure shows the vane separation that occurs in a compressor connected to a power conversion device according to Embodiment 1. [Figure 5] This figure shows the change in the speed of the rolling piston of the compressor connected to the power conversion device according to Embodiment 1. [Figure 6]Block diagram showing an example of the configuration of the control device included in the power conversion device according to Embodiment 1. [Figure 7] Block diagram showing an example of the configuration of the voltage command value calculation unit included in the control device of the power conversion device according to Embodiment 1. [Figure 8] Block diagram showing an example of the configuration of the vibration suppression control unit included in the voltage command value calculation unit according to Embodiment 1. [Figure 9] This figure shows the calculation contents of the vane separation suppression control unit included in the voltage command value calculation unit according to Embodiment 1. [Figure 10] This figure shows the relationship between the reduction rate and the noise standard ratio when the speed is reduced relative to the speed command in the power conversion device according to Embodiment 1. [Figure 11] This figure shows the relationship between the mechanical angular phase, which indicates the rotational position of the rolling piston controlled by the power conversion device according to Embodiment 1, and the load torque of the compressor. [Figure 12] This figure shows the calculation contents during vibration suppression control and coordinated control in the vane separation suppression control unit provided in the voltage command value calculation unit according to Embodiment 1. [Figure 13] This figure shows the relationship between the mechanical angular phase, which indicates the rotational position of the rolling piston, and the load torque of the compressor, as a result of the coordinated control of vane separation suppression control and vibration suppression control of the power converter according to Embodiment 1. [Figure 14] This figure shows examples of the δ-axis current compensation values ​​by the vibration suppression control unit and the δ-axis current compensation values ​​by the vane separation suppression control unit in the power converter according to Embodiment 1. [Figure 15] Flowchart showing the operation of the control device included in the power conversion device according to Embodiment 1 [Figure 16] This figure shows an example of a hardware configuration that realizes the control device included in the power conversion device according to Embodiment 1. [Figure 17] Block diagram showing an example of the configuration of the voltage command value calculation unit included in the control device of the power converter according to Embodiment 2. [Figure 18] A diagram showing an example configuration of a refrigeration cycle application device according to Embodiment 3. [Modes for carrying out the invention]

[0009] The power conversion device, motor drive device, and refrigeration cycle application equipment according to embodiments of this disclosure will be described in detail below with reference to the drawings.

[0010] Embodiment 1. Figure 1 is a block diagram showing an example configuration of a power converter 200 according to Embodiment 1. Figure 2 is a block diagram showing an example configuration of an inverter 30 provided in the power converter 200 according to Embodiment 1. The power converter 200 is connected to an AC power source 1 and a compressor 8. The power converter 200 converts a first AC power of power supply voltage Vs supplied from the AC power source 1 into a second AC power having a desired amplitude and phase, and supplies it to the compressor 8. The power converter 200 includes a reactor 2, a rectifier 3, a smoothing capacitor 5, an inverter 30, a bus voltage detection unit 10, a load current detection unit 40, a power supply current detection unit 50, and a control device 100. The power converter 200 and the motor 7 provided in the compressor 8 constitute a motor drive device 400.

[0011] The power supply current detection unit 50 is a detection unit that detects the power supply current Iin of the first AC power supplied from the AC power supply 1 to the power converter 200 and outputs the detected current value to the control device 100. The reactor 2 is connected between the AC power supply 1 and the rectifier unit 3. The rectifier unit 3 has a bridge circuit composed of rectifier elements 131 to 134 and rectifies and outputs the first AC power of the power supply voltage Vs supplied from the AC power supply 1. The rectifier unit 3 performs full-wave rectification.

[0012] The smoothing capacitor 5 is connected to the output terminal of the rectifier 3 and is a smoothing element that smooths the power rectified by the rectifier 3. The smoothing capacitor 5 is, for example, a capacitor such as an electrolytic capacitor or a film capacitor. The smoothing capacitor 5 has a capacitance that smooths the power rectified by the rectifier 3, and the voltage generated in the smoothing capacitor 5 due to smoothing is not the full-wave rectified waveform shape of the AC power supply 1, but a waveform shape in which a voltage ripple corresponding to the frequency of the AC power supply 1 is superimposed on the DC component, and does not pulsate greatly. The frequency of this voltage ripple is twice the frequency of the power supply voltage Vs when the AC power supply 1 is single-phase, and the frequency of the sixth component is the main component when the AC power supply 1 is three-phase. When the power input from the AC power supply 1 and the power output from the inverter 30 do not change, the amplitude of this voltage ripple is determined by the capacitance of the smoothing capacitor 5. For example, the voltage ripple generated in the smoothing capacitor 5 pulsates within a range in which the maximum value is less than twice the minimum value.

[0013] The bus voltage detection unit 10 is a detection unit that detects the voltage across the smoothing capacitor 5, that is, the voltage between the DC buses 12a and 12b, as the bus voltage Vdc, and outputs the detected voltage value to the control device 100. The load current detection unit 40 is a detection unit that detects the load current Idc, which is the DC current flowing from the smoothing capacitor 5 into the inverter 30, and outputs the detected current value to the control device 100.

[0014] The inverter 30 is connected across the smoothing capacitor 5 and converts the power output from the rectifier 3 and the smoothing capacitor 5 into a second AC power having a desired amplitude and phase, i.e., generates a second AC power which is output to the motor 7 of the compressor 8. Specifically, the inverter 30 receives the bus voltage Vdc, generates a three-phase AC voltage with variable frequency and voltage value, and supplies it to the motor 7 via output lines 331 to 333. As shown in Figure 2, the inverter 30 comprises an inverter main circuit 310 and a drive circuit 350. The input terminals of the inverter main circuit 310 are connected to DC buses 12a and 12b. The inverter main circuit 310 comprises switching elements 311 to 316. Each of the switching elements 311 to 316 has a recirculating rectifier element 321 to 326 connected in antiparallel.

[0015] The drive circuit 350 generates drive signals Sr1 to Sr6 based on PWM (Pulse Width Modulation) signals Sm1 to Sm6 output from the control device 100. The drive circuit 350 controls the on / off state of switching elements 311 to 316 using the drive signals Sr1 to Sr6. As a result, the inverter 30 can supply a frequency-variable and voltage-variable three-phase AC voltage to the motor 7 via output lines 331 to 333.

[0016] The PWM signals Sm1 to Sm6 are signals with a magnitude of 0V to 5V, corresponding to the signal level of the logic circuit. The PWM signals Sm1 to Sm6 are reference signals with the ground potential of the control device 100 as their reference potential. On the other hand, the drive signals Sr1 to Sr6 are signals with a magnitude of -15V to +15V, corresponding to the voltage level required to control the switching elements 311 to 316. The drive signals Sr1 to Sr6 are reference signals with the potential of the negative terminal, i.e., the emitter terminal, of the corresponding switching element 311 to 316 as their reference potential.

[0017] The compressor 8 has a motor 7 for compression drive. The motor 7 drives a load element whose load torque fluctuates periodically. The motor 7 rotates according to the amplitude and phase of the second AC power supplied from the inverter 30 and performs compression. For example, if the compressor 8 is a sealed compressor used in air conditioners, the load torque of the compressor 8 can often be considered a constant torque load. Figure 1 shows the case where the motor windings of the motor 7 are Y-connected, but this is just an example and is not limited to this. The motor windings of the motor 7 may be Delta-connected, or they may be switchable between Y-connection and Delta-connection. In this embodiment, the compressor 8 is assumed to be a rotary compressor. The rotary compressor may be a single rotary compressor or a twin rotary compressor.

[0018] In the power converter 200, the arrangement of the components shown in Figure 1 is just one example, and the arrangement of the components is not limited to the example shown in Figure 1. For example, the reactor 2 may be placed after the rectifier 3. Also, the power converter 200 may include a boost unit, or the rectifier 3 may be given the function of a boost unit. In the following description, the bus voltage detection unit 10, the load current detection unit 40, and the power supply current detection unit 50 may be collectively referred to as the detection unit. Also, the voltage value detected by the bus voltage detection unit 10, the current value detected by the load current detection unit 40, and the current value detected by the power supply current detection unit 50 may be referred to as the detected value.

[0019] The control device 100 acquires the bus voltage Vdc from the bus voltage detection unit 10, the load current Idc from the load current detection unit 40, and the power supply current Iin from the power supply current detection unit 50. The control device 100 uses the detected values ​​from each detection unit to control the operation of the inverter main circuit 310, specifically the on / off switching of the switching elements 311 to 316 of the inverter main circuit 310. In this embodiment, the control device 100 controls the operation of the inverter 30 to suppress vane separation, where the vanes separate from the rolling piston, with respect to the vanes and rolling piston of the compressor 8, which is a rotary compressor, as will be described later. Note that the control device 100 does not need to use all the detected values ​​acquired from each detection unit, and may perform control using only some of the detected values.

[0020] Next, the characteristic operation of the control device 100 in this embodiment will be described. When the power converter 200 outputs a second AC power to the motor 7 of the compressor 8, the control device 100 performs constant current load control, which controls the operation of the inverter 30 so that the rotational speed of the motor 7 reaches a desired rotational speed. At this time, as described above, the control device 100 controls the operation of the inverter 30 so as to suppress vane separation, which is the separation of the vanes from the rolling piston in the compressor 8, which is a rotary compressor.

[0021] Figure 3 shows an example configuration of a compressor 8 connected to a power converter 200 according to Embodiment 1. Figure 4 shows the vane separation that occurs in the compressor 8 connected to the power converter 200 according to Embodiment 1. As shown in Figures 3 and 4, the compressor 8 comprises a vane 81, a rolling piston 82, and a vane spring 83. The vane 81, rolling piston 82, and vane spring 83 are similar to those found in a typical rotary compressor. Here, although not shown in the illustration, the rotational position of the rolling piston 82 when the tip of the vane 81 is furthest from the rotation axis of the rolling piston 82 while the vane 81 is in contact with the rolling piston 82 is defined as the mechanical angular phase 0°. Figure 4(a) shows the state where the mechanical angular phase of the rolling piston 82 is approximately 90°, Figure 4(b) shows the state where the mechanical angular phase of the rolling piston 82 is approximately 135°, and Figure 4(c) shows the state where the mechanical angular phase of the rolling piston 82 is approximately 180°. The mechanical angular phase of the rolling piston 82 at 0° is the position obtained by rotating the rolling piston 82 approximately 90° counterclockwise from the state shown in Figure 4(a).

[0022] The rolling piston 82 is rotated by the motor 7. Normally, the vanes 81 are pressed against the rolling piston 82 by the vane springs 83, so they are in contact with the rolling piston 82, as shown in Figure 4(a). However, if for some reason the vanes 81 are unable to keep up with the rotational movement of the rolling piston 82, vane separation occurs, as shown in Figure 4(b). Subsequently, when the vanes 81 re-contact the rolling piston 82 at the position of the rolling piston 82 shown in Figure 4(c) due to the pressing force of the vane springs 83, a metallic collision sound is generated at the time of re-contact. This metallic collision sound becomes a source of noise. Therefore, in this embodiment, the control device 100 of the power converter 200 suppresses vane separation by controlling the operation of the compressor 8.

[0023] Figure 5 shows the change in speed of the rolling piston 82 of the compressor 8 connected to the power converter 200 according to Embodiment 1. In Figure 5, Figure 5(a) shows the settings of the X and Y axes, and the graph in Figure 5(b) shows the change in speed of the rolling piston 82 when the X and Y axes are set as shown in Figure 5(a). Here, the speed ratio when the speed of the rolling piston 82 is fastest in the positive direction is set to 1, and the speed ratio when the speed of the rolling piston 82 is fastest in the negative direction is set to -1. Regardless of the actual speed of the rolling piston 82, the speed ratio when the rolling piston 82 is rotating at a constant speed can be expressed as shown in Figure 5.

[0024] One possible cause of vane separation is that the rotational speed of the rolling piston 82 is too fast for the vane 81 to keep up with the movement of the rolling piston 82. In the example in Figure 5, the vane 81 moves in the Y direction in the compressor 8, so we focus on the Y-direction movement of the rolling piston 82. As shown in Figure 5, the rolling piston 82 moves away from the vane 81 when the Y-direction velocity Vy of the rolling piston 82 is in the positive range, that is, when the mechanical angular phase of the rolling piston 82 is in the range of 0° to 180°. Of these, the Y-direction velocity Vy of the rolling piston 82 is fastest when the mechanical angular phase of the rolling piston 82 is 90°, as shown in Figure 5(b). In other words, in the compressor 8, vane separation is likely to occur when the mechanical angular phase of the rolling piston 82 is near 90°. Therefore, the control device 100 of the power converter 200 suppresses the rotational speed of the rolling piston 82 when the mechanical angular phase of the rolling piston 82 is near 90°, i.e., it reduces the speed, thereby improving the tracking ability of the vanes 81 and suppressing vane separation.

[0025] The detailed configuration and operation of the control device 100 will now be described. Figure 6 is a block diagram showing an example configuration of the control device 100 included in the power converter 200 according to Embodiment 1. The control device 100 comprises an operation control unit 102 and an inverter control unit 110.

[0026] The operation control unit 102 acquires command information Qe from the refrigeration cycle application equipment. If the refrigeration cycle application equipment is an air conditioner, the command information Qe is information based on, for example, the temperature detected by a temperature sensor (not shown), information indicating the set temperature instructed by a remote control (not shown), information on the selection of the operating mode, and information on the start and end of operation. The operating mode is, for example, heating, cooling, dehumidification, etc. Based on the command information Qe, the operation control unit 102 generates a frequency command value ωe for generating a voltage command value, which is the command value of the voltage applied to the motor 7. * The operation control unit 102 generates the frequency command value ωe * Regarding this, the rotational angular velocity command value ωm is the command value for the rotational speed, i.e., the rotational velocity of motor 7. * This can be obtained by multiplying by the number of pole pairs Pm of the motor 7. Furthermore, the operation control unit 102 generates a stop signal St, which is a signal to stop the operation of the inverter 30, based on the command information Qe. The operation control unit 102 generates a frequency command value ωe * The voltage command value calculation unit 115 of the inverter control unit 110 outputs the signal, and the stop signal St is output to the PWM signal generation unit 118 of the inverter control unit 110.

[0027] The inverter control unit 110 includes a current restoration unit 111, a 3-phase to 2-phase conversion unit 112, a γ-axis current command value generation unit 113, a voltage command value calculation unit 115, an electrical phase calculation unit 116, a 2-phase to 3-phase conversion unit 117, and a PWM signal generation unit 118.

[0028] The current restoration unit 111 restores the phase currents iu, iv, and iw flowing through the motor 7 based on the load current Idc detected by the load current detection unit 40. The current restoration unit 111 can restore the phase currents iu, iv, and iw by sampling the load current Idc detected by the load current detection unit 40 at timings determined based on the PWM signals Sm1 to Sm6 generated by the PWM signal generation unit 118.

[0029] The three-phase to two-phase conversion unit 112 converts the phase currents iu, iv, iw restored by the current restoration unit 111 into the γ-axis current Iγ, which is the excitation current, and the δ-axis current Iδ, which is the torque current, that is, the current values in the rotating coordinate system of the γδ-axis, using the electrical phase θe generated by the electrical phase calculation unit 116 described later.

[0030] The γ-axis current command value generation unit 113 generates a γ-axis current command value Iγ in the rotating coordinate system of the γδ-axis. * Specifically, the γ-axis current command value generation unit 113 determines the optimal γ-axis current command value Iγ that maximizes the efficiency for driving the motor 7 based on the δ-axis current Iδ, the bus voltage Vdc, the γ-axis voltage command value Vγ * and the δ-axis voltage command value Vδ. * The γ-axis current command value generation unit 113 outputs a γ-axis current command value Iγ that results in a current phase βm such that the output torque of the motor 7 is greater than or equal to a specified value or maximum, that is, the current value is less than or equal to a specified value or minimum, based on the δ-axis current Iδ, the bus voltage Vdc, the γ-axis voltage command value Vγ * and the δ-axis voltage command value Vδ. * Here, the γ-axis current command value generation unit 113 obtains the γ-axis current command value Iγ based on the δ-axis current Iδ, etc., but this is just an example and is not limited to this. The γ-axis current command value generation unit 113 can obtain the same effect by obtaining the γ-axis current command value Iγ based on the γ-axis current Iγ, the frequency command value ωe * etc. Also, the γ-axis current command value generation unit 113 may determine the γ-axis current command value Iγ by flux weakening control or the like. * The voltage command value calculation unit 115 calculates the γ-axis voltage command value Vγ * and the δ-axis voltage command value Vδ * based on the frequency command value ωe obtained from the operation control unit 102, the γ-axis current Iγ and the δ-axis current Iδ obtained from the three-phase to two-phase conversion unit 112, and the γ-axis current command value Iγ obtained from the γ-axis current command value generation unit 113. * The voltage command value calculation unit 115 calculates the γ-axis voltage command value Vγ * and the δ-axis voltage command value Vδ

[0031] The voltage command value calculation unit 115 calculates the γ-axis voltage command value Vγ * and the δ-axis voltage command value Vδ * based on the frequency command value ωe obtained from the operation control unit 102, the γ-axis current Iγ and the δ-axis current Iδ obtained from the three-phase to two-phase conversion unit 112, and the γ-axis current command value Iγ obtained from the γ-axis current command value generation unit 113. * and the δ-axis voltage command value Vδ *It generates the following. Furthermore, the voltage command value calculation unit 115 calculates the γ-axis voltage command value Vγ * And the δ-axis voltage command value Vδ * Then, based on the γ-axis current Iγ and the δ-axis current Iδ, the frequency estimate ωest is calculated.

[0032] The electrical phase calculation unit 116 calculates the electrical phase θe by integrating the frequency estimate ωest obtained from the voltage command value calculation unit 115.

[0033] The two-phase to three-phase conversion unit 117 receives the γ-axis voltage command value Vγ from the voltage command value calculation unit 115. * and the δ-axis voltage command value Vδ * In other words, the voltage command value in the two-phase coordinate system is converted to the three-phase voltage command value Vu, which is the output voltage command value in the three-phase coordinate system, using the electrical phase θe obtained from the electrical phase calculation unit 116. * ,Vv * VW * Convert to [the desired result].

[0034] The PWM signal generation unit 118 receives the 3-phase voltage command value Vu from the 2-phase to 3-phase conversion unit 117. * ,Vv * VW * Based on the stop signal St obtained from the operation control unit 102, PWM signals Sm1 to Sm6 are generated. The PWM signal generation unit 118 can also stop the motor 7 by not outputting PWM signals Sm1 to Sm6 based on the stop signal St.

[0035] The configuration and operation of the voltage command value calculation unit 115 will be described in detail. Figure 7 is a block diagram showing an example of the configuration of the voltage command value calculation unit 115 included in the control device 100 of the power converter 200 according to Embodiment 1. The voltage command value calculation unit 115 includes a frequency estimation unit 501, addition / subtraction units 502, 504, 505, 509, 513, a speed control unit 503, a γ-axis current control unit 506, a δ-axis current control unit 507, multiplication units 508, 510, 512, addition units 511, 516, a vibration suppression control unit 514, and a vane separation suppression control unit 515.

[0036] The frequency estimation unit 501 uses the γ-axis current Iγ, the δ-axis current Iδ, and the γ-axis voltage command value Vγ. * And the δ-axis voltage command value Vδ * Based on this, the frequency of the voltage supplied to the motor 7 is estimated and output as the frequency estimate value ωest. Note that the frequency estimate value ωest output from the frequency estimation unit 501 to the outside of the voltage command value calculation unit 115 in Figure 7 is the same frequency estimate value ωest output from the voltage command value calculation unit 115 to the electrical phase calculation unit 116 in Figure 6. The addition / subtraction unit 502 calculates the frequency command value ωe * Subtracting the frequency estimate ωest from this gives the frequency command value ωe * Output the frequency deviation del_ω between the estimated frequency ωest and the output.

[0037] The speed control unit 503 determines the δ-axis current command value Iδ based on the frequency deviation del_ω. * The following is calculated and output: δ-axis current command value Iδ * This is the command value of the delta-axis current Iδ for which the frequency deviation del_ω is zero, i.e., the frequency command value ωe * This is the command value for the delta-axis current Iδ to match the frequency estimate ωest. The speed control unit 503 is, for example, a proportional-integral (PI) controller, but is not limited to this.

[0038] The adder 516 receives the δ-axis current command value Iδ output from the speed control unit 503. * The δ-axis current compensation value Iδ_trq output from the vibration suppression control unit 514. * And the δ-axis current compensation value Iδ_VANE output from the vane separation suppression control unit 515. * Add and output.

[0039] The addition / subtraction unit 504 calculates the γ-axis current command value Iγ * Subtract the γ-axis current Iγ from the γ-axis current command value Iγ. * The deviation between the γ-axis current Iγ is output. The γ-axis current control unit 506 is composed of, for example, a PI controller, and the γ-axis current command value Iγ * The γ-axis current control unit 506 operates to converge the deviation between the first γ-axis voltage command value Vγfb to zero.* Outputs.

[0040] The addition / subtraction unit 505 subtracts the delta-axis current Iδ from the output of the addition unit 516 and outputs the deviation between the output of the addition unit 516 and the delta-axis current Iδ. The delta-axis current control unit 507 is configured, for example, as a PI controller and operates to converge the deviation between the output of the addition unit 516 and the delta-axis current Iδ to zero. The delta-axis current control unit 507 receives the first delta-axis voltage command value Vδfb * Outputs.

[0041] The multiplier 508 multiplies the output of the adder 516 by the delta-axis inductance Lδ of the motor 7 and the frequency estimate ωest to obtain the first gamma-axis voltage command value Vγfb * Compensation value Vγff * The addition / subtraction unit 509 calculates and outputs the first γ-axis voltage command value Vγfb. * Compensation value Vγff * Subtracting this, the first γ-axis voltage command value Vγfb * and compensation value Vγff * The deviation from (Vγfb * -Vγff * The second γ-axis voltage command value, which is the γ-axis voltage command value Vγ from the voltage command value calculation unit 115, is obtained from the voltage command value calculation unit 115. * Output as follows.

[0042] The multiplication unit 510 calculates the γ-axis current command value Iγ * The output is multiplied by the γ-axis inductance Lγ of the motor 7 and output. The adder 511 adds the magnetic flux linkage vector φf of the motor 7 to the output from the multiplier 510. The multiplier 512 multiplies the output from the adder 511 by the frequency estimate ωest and outputs the first δ-axis voltage command value Vδfb * Compensation value Vδff * The addition / subtraction unit 513 calculates and outputs the first δ-axis voltage command value Vδfb. * Compensation value Vδff * Subtracting this, the first delta-axis voltage command value Vδfb * and compensation value Vδff * The deviation from (Vδfb * -Vδff *The second δ-axis voltage command value, which is the δ-axis voltage command value Vδ from the voltage command value calculation unit 115, is obtained from the voltage command value calculation unit 115. * Output as follows.

[0043] The configuration of the vibration suppression control unit 514 will now be described. Figure 8 is a block diagram showing an example configuration of the vibration suppression control unit 514 included in the voltage command value calculation unit 115 according to Embodiment 1. The vibration suppression control unit 514 includes a calculation unit 550, a cosine calculation unit 551, a sine calculation unit 552, multiplication units 553, 554, low-pass filters 555, 556, addition and subtraction units 557, 558, frequency control units 559, 560, multiplication units 561, 562, and an addition unit 563.

[0044] The calculation unit 550 calculates the mechanical angular phase θmn, which indicates the rotational position of the motor 7, by integrating the frequency estimate ωest and dividing by the pole-to-pole number Pm. The cosine calculation unit 551 calculates the cosine cosθmn based on the mechanical angular phase θmn. The sine calculation unit 552 calculates the sine sinθmn based on the mechanical angular phase θmn.

[0045] The multiplication unit 553 multiplies the frequency estimate ωest by the cosine cosθmn to calculate the cosine component ωest·cosθmn of the frequency estimate ωest. The multiplication unit 554 multiplies the frequency estimate ωest by the sine sinθmn to calculate the sine component ωest·sinθmn of the frequency estimate ωest. The cosine component ωest·cosθmn and the sine component ωest·sinθmn calculated by the multiplication units 553 and 554 include not only the pulsating component with frequency ωmn, but also pulsating components with frequencies higher than ωmn, i.e., harmonic components.

[0046] The low-pass filters 555 and 556 are first-order lag filters with a transfer function of 1 / (1+s·Tf). Tf is the time constant, and is set to remove pulsating components with frequencies higher than frequency ωmn. Note that "removal" includes cases where a portion of the pulsating components are attenuated, i.e., reduced. The time constant Tf is set by the operation control unit 102 based on the speed command, and the operation control unit 102 may notify the low-pass filters 555 and 556 of this, or the low-pass filters 555 and 556 may retain this information. The first-order lag filters are just one example of low-pass filters 555 and 556; moving average filters or other types may also be used, and the type of filter is not limited as long as it can remove the high-frequency pulsating components.

[0047] The low-pass filter 555 performs low-pass filtering on the cosine component ωest·cosθmn to remove pulsating components with frequencies higher than ωmn, and outputs the low-frequency component ωestcos. The low-frequency component ωestcos is the DC flow rate representing the cosine component with frequency ωmn among the pulsating components of the frequency estimate ωest.

[0048] The low-pass filter 556 performs low-pass filtering on the sinusoidal component ωest·sinθmn to remove pulsating components with frequencies higher than ωmn, and outputs the low-frequency component ωestsin. The low-frequency component ωestsin is the DC flow that represents the sinusoidal component with frequency ωmn among the pulsating components of the frequency estimate ωest.

[0049] The addition / subtraction unit 557 calculates the difference (ωestcos-0) between the low-frequency component ωestcos output from the low-pass filter 555 and 0. The addition / subtraction unit 558 calculates the difference (ωestsin-0) between the low-frequency component ωestsin output from the low-pass filter 556 and 0.

[0050] The frequency control unit 559 performs a proportional-integral operation on the difference (ωestcos-0) calculated by the addition-subtraction unit 557 to calculate the cosine component Iδtrqcos of the current command value that brings the difference (ωestcos-0) closer to zero. By generating the cosine component Iδtrqcos in this way, the frequency control unit 559 performs control to make the low-frequency component ωestcos equal to 0.

[0051] The frequency control unit 560 performs a proportional-integral operation on the difference (ωestsin-0) calculated by the addition-subtraction unit 558 to calculate the sinusoidal component Iδtrqsin of the current command value that brings the difference (ωestsin-0) closer to zero. By generating the sinusoidal component Iδtrqsin in this way, the frequency control unit 560 performs control to make the low-frequency component ωestsin equal to 0.

[0052] The multiplier unit 561 multiplies the cosine component Iδtrqcos output from the frequency control unit 559 by the cosine cosθmn to generate Iδtrqcos·cosθmn. Iδtrqcos·cosθmn is an AC component with frequency n·ωest.

[0053] The multiplier unit 562 multiplies the sinusoidal component Iδtrqsin output from the frequency control unit 560 by the sine sinθmn to generate Iδtrqsin·sinθmn. Iδtrqsin·sinθmn is an AC component with frequency n·ωest.

[0054] The summer 563 calculates the sum of the AC component Iδtrqcos·cosθmn output from the multiplier 561 and the AC component Iδtrqsin·sinθmn output from the multiplier 562. The vibration suppression control unit 514 uses the sum obtained by the summer 563 to calculate the δ-axis current compensation value Iδ_trq for vibration suppression control. * Output as follows.

[0055] The vane separation suppression control unit 515 uses the frequency estimate value ωest obtained from the frequency estimation unit 501 and the reference phase Theta of the mechanical angular phase of the motor 7. Iδ_VANEBased on this, the δ-axis current compensation value Iδ_VANE for vane separation suppression control. * The vane separation suppression control unit 515 calculates and outputs the reference phase Theta of the mechanical angular phase of the motor 7. Iδ_VANE You may estimate this yourself, or you may use estimations from other configurations; the method of acquisition is not restricted.

[0056] For example, the vibration suppression control unit 514 controls the reference phase of the mechanical angular phase of the motor 7 for the vane separation suppression control unit 515. Iδ_VANE The δ-axis current command value Iδ in the control device 100 may be estimated. * This can be expressed as shown in equation (1) below.

[0057]

number

[0058] In equation (1), although not shown in Figure 7, Iδdc is the δ-axis current command value Iδ, which is the output from the speed control unit 503. * This is based on the following equation, where the AC component Iδtrqcos·cosθmn is the output from the multiplier 561 shown in Figure 8, and the AC component Iδtrqsin·sinθmn is the output from the multiplier 562 shown in Figure 8. Equation (1) can be transformed into the following equation (2).

[0059]

number

[0060] The cosine function is minimized in equation (2) when given in equation (3) below.

[0061]

number

[0062] From the above, the torque of motor 7 is minimized in the case of equation (4) below.

[0063]

number

[0064] By using the mechanical angular phase θmn obtained in equation (4), the vibration suppression control unit 514 determines the reference phase Theta of the mechanical angular phase of the motor 7. Iδ_VANE =θmn × 180 / π(°) can be estimated.

[0065] Figure 9 shows the calculation contents of the vane separation suppression control unit 515 included in the voltage command value calculation unit 115 according to Embodiment 1. The vane separation suppression control unit 515 calculates the reference phase Theta of the mechanical angular phase of the motor 7 obtained from the vibration suppression control unit 514. Iδ_VANE In contrast, the phase required to position motor 7 at a mechanical angular phase of 90° is added, and the estimated mechanical angular phase of 90° is Theta Iδ_90 Obtain Theta Iδ_90 This is to position the rolling piston 82 at an estimated mechanical angular phase of 90°. Furthermore, the vane separation suppression control unit 515 converts the frequency estimate ωest obtained from the frequency estimation unit 501 into mechanical angular velocity, integrates it to convert it into mechanical angular phase, and applies a phase limiter to obtain the current estimated mechanical angular phase, Theta. Iδ_ωest_m The vane separation suppression control unit 515 obtains the Theta Iδ_90 and Theta Iδ_ωest_m Using Theta Iδ_ωest_m Theta Iδ_90 Within a range of ±20°, i.e., Theta Iδ_ωest_m Iδ_VANE is a δ-axis current compensation value for vane separation suppression control used to reduce the rotational speed of the motor 7, i.e., the rotational speed of the rolling piston 82, based on the speed command, by 30% or more when the range is between 70° and 110°. * It outputs the vane separation suppression control unit 515. Iδ_ωest_m Outside the range of 70° to 110°, the δ-axis current compensation value Iδ_VANE for vane separation suppression control is used. * It does not output.

[0066] Here, we will explain why the rotational speed of the motor 7, i.e., the rotational speed of the rolling piston 82, is reduced by 30% or more relative to the speed command. Figure 10 is a diagram showing the relationship between the reduction rate and the noise standard ratio when the speed is reduced relative to the speed command in the power converter 200 according to Embodiment 1. In Figure 10, the horizontal axis shows the reduction rate relative to the speed command, and the vertical axis shows the noise standard ratio. In Figure 10, the noise subject to the noise standard ratio is the metallic collision sound that occurs when the vane 81 re-contacts the rolling piston 82 after the vane separates. As shown in Figure 10, the power converter 200 reduces the rotational speed of the motor 7, i.e., the rotational speed of the rolling piston 82, by 30% or more relative to the speed command, thereby making the noise standard ratio for the metallic collision sound that occurs when the vane 81 re-contacts the rolling piston 82 after the vane separates 1 or less, i.e., below the noise standard value.

[0067] The reference phase of the mechanical angular phase of motor 7: Theta Iδ_VANE This is the minimum phase of the load torque of the compressor 8. Therefore, the vane separation suppression control unit 515 sets the reference phase Theta of the mechanical angle phase of the motor 7. Iδ_VANE Using the motor 7's mechanical angular phase of 90°, which is obtained by adding a phase to make the motor 7's mechanical angular phase 90°, the δ-axis current command value Iδ is set within the specified range, in the example above, from 70° to 110°. * Vane separation suppression control is performed to reduce the Theta Iδ_90 The ±20° range is just an example, and the vane separation suppression control unit 515 may change the range as appropriate depending on the actual conditions under which vane separation occurs.

[0068] FIG. 11 is a diagram showing the relationship between the mechanical angular phase indicating the rotational position of the rolling piston 82 by the control of the power conversion device 200 according to Embodiment 1 and the load torque of the compressor 8. In FIG. 11, the horizontal axis indicates the mechanical angular phase indicating the rotational position of the rolling piston 82, and the vertical axis indicates the load torque of the compressor 8. Also, in FIG. 11, the solid line indicates the load torque of the compressor 8, and the dotted line indicates the ideal value of the output torque from the power conversion device 200. The above-described equations (1) to (4) are for obtaining the phase when the output torque of the dotted line shown in FIG. 11 becomes the minimum value, and the phase when it becomes the minimum value is the reference phase Theta Iδ_VANE becomes. Also, in the vane separation suppression control unit 515, the phase added to set the motor 7 at the position of the mechanical angular phase of 90° with respect to the reference phase Theta Iδ_VANE is the phase of the width between the dotted line of Theta Iδ_VANE shown in FIG. 11 and the dotted line of 90°. The vane separation suppression control unit 515 performs vane separation suppression control in the range of the mechanical angular phase of 70° to 110° shown in FIG. 11 in the above-described example.

[0069] FIG. 12 is a diagram showing the calculation content during cooperative control with vibration suppression control in the vane separation suppression control unit 515 included in the voltage command value calculation unit 115 according to Embodiment 1. The calculation content in the left part in FIG. 12 is the same as the calculation content in the left part of FIG. 9 described above. When the compressor 8 is a single rotary compressor during cooperative control with vibration suppression control, the vane separation suppression control unit 515 controls so as to fall within 90° of the mechanical angular phase from deceleration to acceleration with respect to the rotational speed of the motor 7, that is, the rotational speed of the rolling piston 82, in order to prevent control interference. In the example of FIG. 12, when Theta Iδ_ωest_m is in the range of 45° to 135°, the vane separation suppression control unit 515 outputs the δ-axis current compensation value Iδ_VANE * for vane separation suppression control to reduce the rotational speed of the motor 7 based on the speed command, that is, the rotational speed of the rolling piston 82, by 30% or more.

[0070] Also, when the compressor 8 is a twin rotary compressor during vibration suppression control and coordinated control, the vane separation suppression control unit 515 performs control so that it falls within a mechanical angular phase of 45° or less from deceleration to acceleration with respect to the rotational speed of the motor 7, that is, the rotational speed of the rolling piston 82, in order to prevent control interference. In the example of FIG. 12, the vane separation suppression control unit 515 is Theta Iδ_ωest_m When is in the range of 67.5° to 112.5°, the δ-axis current compensation value Iδ_VANE for vane separation suppression control for reducing the rotational speed of the motor 7 based on the speed command, that is, the rotational speed of the rolling piston 82, by 30% or more * is output. The timing of performing the vane separation suppression control is not limited even when the vane separation suppression control unit 515 performs coordinated control with the vibration suppression control. However, the period from deceleration to acceleration, that is, the period during which the vane separation suppression control is performed, is within a mechanical angular phase range of 90° when the compressor 8 is a single rotary compressor, and within a mechanical angular phase range of 45° when the compressor 8 is a twin rotary compressor.

[0071] FIG. 13 is a diagram showing the relationship between the mechanical angular phase indicating the rotational position of the rolling piston 82 and the load torque of the compressor 8 by the coordinated control of the vane separation suppression control and the vibration suppression control of the power conversion device 200 according to Embodiment 1. The viewing method of the figure is the same as in the case of FIG. 11 described above. In FIG. 13, an example of the case where the compressor 8 is a single rotary compressor is shown, and the description is omitted when the compressor 8 is a twin rotary compressor.

[0072] FIG. 14 is a diagram showing an example of the δ-axis current compensation value Iδ_trq by the vibration suppression control unit 514 and the δ-axis current compensation value Iδ_VANE by the vane separation suppression control unit 515 in the power conversion device 200 according to Embodiment 1. In FIG. 14, the solid line indicates the δ-axis current compensation value Iδ_trq * and the dotted line indicates the δ-axis current compensation value Iδ_VANE by the vane separation suppression control unit 515 * . The vane separation suppression control unit 515 is based on the period of the δ-axis current compensation value Iδ_trq * which is the command value of the vibration suppression control, and the δ-axis current compensation value Iδ_VANE * which is the command value of the vane separation suppression control. * which is the command value of the vibration suppression control, and the δ-axis current compensation value Iδ_VANE which is the command value of the vane separation suppression control* By doubling the period, control interference between vibration suppression control and vane separation suppression control can be avoided. In the example in Figure 14, the δ-axis current compensation value Iδ_trq * If the mechanical angular frequency is the mechanical 1f component, then the δ-axis current compensation value Iδ_VANE * The mechanical angular frequency is defined as the mechanical 2f component.

[0073] Figure 15 is a flowchart showing the operation of the control device 100 included in the power converter 200 according to Embodiment 1. In the power converter 200, the control device 100 waits for a specified period (step S1) and determines whether the rotational position of the rolling piston 82 is within a specified range including a mechanical angular phase of 90° (step S2). If the rotational position of the rolling piston 82 is not within a specified range including a mechanical angular phase of 90° (step S2: No), the control device 100 returns to step S1. That is, the control device 100 performs the operation of step S2 at a cycle of a specified period. If the rotational position of the rolling piston 82 is within a specified range including a mechanical angular phase of 90° (step S2: Yes), the control device 100 performs vane separation suppression control (step S3). The control device 100 determines whether the operation of the power converter 200 has finished (step S4). If the operation of the power converter 200 has not finished (step S4: No), the control device 100 returns to step S1. When the operation of the power converter 200 is completed (step S4: Yes), the control device 100 terminates the operations shown in this flowchart.

[0074] Thus, in the power conversion device 200, the control device 100 performs vane separation suppression control in the rotary compressor 8, which is the compressor 8, by reducing the rotational speed of the rolling piston 82 according to the rotational position of the rolling piston 82, which is the rotary compressor 8, which is rotated by the motor 7, thereby suppressing vane separation, where the vanes 81 separate from the rolling piston 82 in the rotary compressor 8. For example, if the rotary compressor 8 is a single rotary compressor, the control device 100 performs control to reduce and accelerate the rotational speed of the rolling piston 82 at least twice during one mechanical angular phase cycle of the rolling piston 82. If the rotary compressor 8 is a twin rotary compressor, the control device 100 performs control to reduce and accelerate the rotational speed of the rolling piston 82 at least four times during one mechanical angular phase cycle of the rolling piston 82. In this case, as control to reduce the rotational speed of the rolling piston 82, the control device 100 performs control to reduce the rotational speed of the rolling piston 82 by 30% or more relative to the rotational speed of the rolling piston 82 indicated by the speed command.

[0075] Furthermore, if the rotary compressor 8 is a single rotary compressor, the control device 100 completes the control to decelerate and accelerate the rotational speed of the rolling piston 82 within a range of 90°±45° for the mechanical angular phase of the rolling piston 82. If the rotary compressor 8 is a twin rotary compressor, the control device 100 completes the control to decelerate and accelerate the rotational speed of the rolling piston 82 within a range of 90°±22.5° for the mechanical angular phase of the rolling piston 82, and further completes the control to decelerate and accelerate the rotational speed of the rolling piston 82 within a range of 270°±22.5° for the mechanical angular phase of the rolling piston 82.

[0076] Furthermore, the control device 100 can also perform vibration suppression control to suppress vibrations of the motor 7 by compensating the output torque of the motor 7 to match the load torque of the rotary compressor 8. In this case, the control device 100 uses different frequency bands as the mechanical angular frequency based on the rotational speed of the rolling piston 82 for the vane separation suppression control and the vibration suppression control. Specifically, the control device 100 makes the frequency component used for vane separation suppression control larger than the frequency component used for vibration suppression control.

[0077] When the control device 100 performs vane separation suppression control, if the compressor 8 is a single rotary compressor, the frequency components generated when the phase current from the power converter 200 to the motor 7 is Fourier transformed will have, excluding the fundamental wave component which is a multiple of the electrical angular frequency of the motor 7, the first and second components which are the mechanical angular frequency of the rolling piston 82 as the higher frequency components. Similarly, when the control device 100 performs vane separation suppression control, if the compressor 8 is a twin rotary compressor, the frequency components generated when the phase current is Fourier transformed will have, excluding the fundamental wave component which is a multiple of the electrical angular frequency of the motor 7, the second and fourth components which are the mechanical angular frequency of the rolling piston 82 as the higher frequency components.

[0078] Next, the hardware configuration of the control device 100 provided in the power converter 200 will be described. Figure 16 is a diagram showing an example of the hardware configuration that realizes the control device 100 provided in the power converter 200 according to Embodiment 1. The control device 100 is realized by a processor 91 and a memory 92.

[0079] The processor 91 is a CPU (Central Processing Unit, also known as a 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 (Electrically Erasable Programmable Read Only Memory). However, memory 92 is not limited to these and may also be a magnetic disk, optical disk, compact disk, minidisc, or DVD (Digital Versatile Disc).

[0080] As described above, according to this embodiment, in the power converter 200, the control device 100 performs vane separation suppression control such that the rotational speed of the rolling piston 82 is reduced within a defined range in which the rotational position of the rolling piston 82 includes a mechanical angular phase of 90°. As a result, the power converter 200 can suppress vane separation by controlling the operation of the compressor 8.

[0081] Embodiment 2. In Embodiment 1, the control device 100 controls the δ-axis current command value Iδ by vane separation suppression control by the vane separation suppression control unit 515. * The case in which the value is changed was explained. In Embodiment 2, the control device 100 controls the frequency command value ωe by vane separation suppression control by the vane separation suppression control unit 515. * This section explains how to change [the value].

[0082] In Embodiment 2, the configuration of the power converter 200 is the same as that of the power converter 200 in Embodiment 1 shown in Figure 1. Also, in Embodiment 2, the configuration of the control device 100 is the same as that of the control device 100 in Embodiment 1 shown in Figure 6. Figure 17 is a block diagram showing an example of the configuration of the voltage command value calculation unit 115 provided in the control device 100 of the power converter 200 according to Embodiment 2. In Embodiment 2, the voltage command value calculation unit 115 is modified from the voltage command value calculation unit 115 shown in Figure 7 by adding an adder 517.

[0083] In Embodiment 2, the vane separation suppression control unit 515 of the voltage command value calculation unit 115 provides the δ-axis current compensation value Iδ_VANE for vane separation suppression control to the addition unit 516. * Instead of outputting the frequency command compensation value ω_VANE for vane separation suppression control to the summing unit 517. * The following is output. While a detailed explanation is omitted, the vane separation suppression control unit 515 performs calculations similar to those in Figure 9 or Figure 12, and outputs the δ-axis current compensation value Iδ_VANE for vane separation suppression control. * Instead, the frequency command compensation value ω_VANE for vane separation suppression control. * Outputs.

[0084] Thus, the control device 100, as vane separation suppression control, uses a δ-axis current command, i.e., a δ-axis current command value Iδ, as in Embodiment 1. * The speed command, i.e., the frequency command value ωe, may be changed, or as in Embodiment 2, the speed command may be changed. * This can be changed. Even in this case, the power converter 200 can obtain the same effect as in Embodiment 1.

[0085] Embodiment 3. Figure 18 shows an example configuration of a refrigeration cycle application device 900 according to Embodiment 3. The refrigeration cycle application device 900 according to Embodiment 3 includes the power converter 200 described in Embodiment 1. The refrigeration cycle application device 900 according to Embodiment 3 can be applied to products equipped with a refrigeration cycle, such as air conditioners, refrigerators, freezers, and heat pump water heaters. In Figure 18, components having the same functions as those in Embodiment 1 are denoted by the same reference numerals as in Embodiment 1.

[0086] The refrigeration cycle equipment 900 includes a compressor 8 with a built-in motor 7 as in Embodiment 1, a four-way valve 902, an indoor heat exchanger 906, an expansion valve 908, and an outdoor heat exchanger 910, all of which are connected via refrigerant piping 912.

[0087] Inside the compressor 8 are a compression mechanism 904 for compressing the refrigerant and a motor 7 for operating the compression mechanism 904.

[0088] The refrigeration cycle equipment 900 can operate in heating or cooling mode by switching the four-way valve 902. The compression mechanism 904 is driven by a motor 7 that is controlled by variable speed control.

[0089] During heating operation, as indicated by the solid arrows, the refrigerant is pressurized by the compression mechanism 904 and sent out, then returns to the compression mechanism 904 after passing through the four-way valve 902, indoor heat exchanger 906, expansion valve 908, outdoor heat exchanger 910 and the four-way valve 902.

[0090] During cooling operation, as indicated by the dashed arrows, the refrigerant is pressurized by the compression mechanism 904 and sent out, then returns to the compression mechanism 904 after passing 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.

[0091] During heating operation, 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. During cooling operation, 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 and causes it to expand.

[0092] The configurations shown in the above embodiments are merely examples, and it is possible to combine them with other known technologies, combine different embodiments, and omit or modify parts of the configuration without departing from the gist of the invention. [Explanation of Symbols]

[0093] 1 AC power supply, 2 Reactor, 3 Rectifier, 5 Smoothing capacitor, 7 Motor, 8 Compressor, 10 Bus voltage detection unit, 12a, 12b DC bus, 30 Inverter, 40 Load current detection unit, 50 Power supply current detection unit, 81 Vane, 82 Rolling piston, 83 Vane spring, 91 Processor, 92 Memory, 100 Control device, 102 Operation control unit, 110 Inverter control unit, 111 Current restoration unit, 112 3-phase 2-phase conversion unit, 113 γ-axis current command value generation unit, 115 Voltage command value calculation unit, 116 Electrical phase calculation unit, 117 2-phase 3-phase conversion unit, 118 PWM signal generation unit, 131~134, 321~326 Rectifier element, 200 Power converter, 310 Inverter main circuit, 311~316 Switching element, 331~333 Output line, 350 Drive circuit, 400 Motor drive device, 501 Frequency estimation unit, 502, 504, 505, 509, 513, 557, 558 Addition / subtraction unit, 503 Speed ​​control unit, 506 γ-axis current control unit, 507 δ-axis current control unit, 508, 510, 512, 553, 554, 561, 562 Multiplication unit, 511, 516, 517 Addition unit, 514 Vibration suppression control unit, 515 Vane separation suppression control unit, 550 Calculation unit, 551 Cosine calculation unit, 552 Sine calculation unit, 555, 556 Low-pass filter, 559, 560 Frequency control unit, 563 Addition unit, 900 Refrigeration cycle application equipment, 902 Four-way valve, 904 Compression mechanism, 906 Indoor heat exchanger, 908 Expansion valve, 910 outdoor heat exchanger, 912 refrigerant piping.

Claims

1. A power conversion device connected to a rotary compressor, A rectifier unit that rectifies the first AC power supplied from the AC power source, A capacitor connected to the output terminal of the rectifier section, An inverter connected to both ends of the capacitor generates a second AC power and outputs it to the motor of the rotary compressor, A control device for controlling the operation of the inverter, Equipped with, The control device performs vane separation suppression control in the rotary compressor by reducing the rotational speed of the rolling piston and accelerating it to return to its original speed, in accordance with the rotational position of the rolling piston of the rotary compressor which is rotated by the motor, thereby suppressing vane separation, where the vanes separate from the rolling piston. Power converter.

2. The control device is If the rotary compressor is a single rotary compressor, control is performed to decelerate the rotational speed of the rolling piston and accelerate it back up at least twice during one mechanical angular phase cycle of the rolling piston. If the rotary compressor is a twin rotary compressor, control is performed to decelerate the rotational speed of the rolling piston and accelerate it back up at least four times during one mechanical angular phase cycle of the rolling piston. The power conversion device according to claim 1.

3. The control device performs a control to reduce the rotational speed of the rolling piston by 30% or more relative to the rotational speed of the rolling piston indicated by the speed command. The power conversion device according to claim 1.

4. The control device, when the vane is in contact with the rolling piston, and the tip of the vane is furthest from the rotation axis of the rolling piston, sets the rotational position of the rolling piston to a mechanical angular phase of 0°. If the rotary compressor is a single rotary compressor, control is completed to decelerate the rotational speed of the rolling piston and accelerate it back up within a range of 90° ± 45° of the mechanical angular phase of the rolling piston. If the rotary compressor is a twin rotary compressor, control is completed to decelerate the rotational speed of the rolling piston and accelerate it back up within a range of 90° ± 22.5° for the mechanical angular phase of the rolling piston, and further control is completed to decelerate the rotational speed of the rolling piston and accelerate it back up within a range of 270° ± 22.5° for the mechanical angular phase of the rolling piston. The power conversion device according to claim 1.

5. The control device further performs vibration suppression control to suppress vibrations of the motor by compensating the output torque of the motor to match the load torque of the rotary compressor. The power conversion device according to claim 1.

6. The control device uses different frequency bands as the mechanical angular frequency based on the rotational speed of the rolling piston for the vane separation suppression control and the vibration suppression control. The power conversion device according to claim 5.

7. The control device makes the frequency component used for the vane separation suppression control greater than the frequency component used for the vibration suppression control. The power conversion device according to claim 6.

8. In the case where the rotary compressor is a single rotary compressor, when the phase current from the power converter to the motor is Fourier transformed, the frequency components generated are, excluding the fundamental wave component which is a multiple of the motor's electrical angular frequency, the first and second components which are the mechanical angular frequency of the rolling piston, which are the higher frequency components. In the case of the rotary compressor being a twin rotary compressor, when the phase current is Fourier transformed, the frequency components generated, excluding the fundamental wave component which is a multiple of the motor's electrical angular frequency, have as high-frequency components the 2x and 4x components which are multiples of the rolling piston's mechanical angular frequency. The power conversion device according to claim 1.

9. The control device, as vane separation suppression control, changes the δ-axis current command or changes the speed command. The power conversion device according to claim 1.

10. A motor drive device comprising a power conversion device according to any one of claims 1 to 9.

11. A refrigeration cycle application device comprising a power conversion device according to any one of claims 1 to 9.

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