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) performs vane separation suppression control in the rotary compressor, which suppresses vane separation, where the vanes separate from the rolling piston, by decelerating and accelerating 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 aforementioned 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 is If the rotational position of the rolling piston when the vane is in contact with the rolling piston of the rotary compressor and the tip of the vane is furthest from the rotation axis of the rolling piston is defined as 0° of the mechanical angular phase, then in the case of a single rotary compressor, control of the rotational speed of the rolling piston is completed when the mechanical angular phase of the rolling piston is within the range of 105° to 195°, and in the case of a twin rotary compressor, control of the rotational speed of the rolling piston is completed when the mechanical angular phase of the rolling piston is within the range of 122.5° to 167.5°, and further control of the rotational speed of the rolling piston is completed when the mechanical angular phase of the rolling piston is within the range of 302.5° to 347.5°. Reduce the rotational speed of the rolling piston. and acceleration 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 an example of a mechanical model of the vanes of a compressor connected to a 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] Flowchart showing the operation of the control device included in the power conversion device according to Embodiment 1 [Figure 12] 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 13] 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 14] 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 an example of a mechanical model of the vane 81 of a compressor 8 connected to a power converter 200 according to Embodiment 1. In Figure 5, the left side of the vane 81 is the intake side, and the right side of the vane 81 is the discharge side. In Figure 5, the spring force, inertial force, and back pressure are vane pressing forces acting in the direction of suppressing vane separation. The spring force is expressed as the spring constant of the vane spring 83 × the spring deformation of the vane spring 83. The inertial force is expressed as the mass of the vane 81 × the acceleration of the vane 81. The back pressure is expressed as the discharge pressure in the compressor 8 × the back surface area of ​​the vane 81. Also in Figure 5, the internal pressure and frictional force are vane separating forces acting in the direction of vane separation. The internal pressure is expressed as (compression chamber pressure of the compressor 8 + suction pressure of the compressor 8) × the tip area of ​​the vane 81. The frictional force is the frictional force between the vane 81 and the vane groove of the cylinder, and is expressed as reaction force × friction coefficient. In Figure 5, the differential pressure represents the difference between the pressure in the suction-side compression chamber and the pressure in the discharge-side compression chamber.

[0024] As shown in Figure 4(b), vane separation occurs, for example, when the vane pressing force decreases and a vane separation force is generated. In situations where vane separation occurs, the spring force is small because the vane spring 83 is fully extended, the inertial force is small because the acceleration of the vane 81 is small, and the back pressure is small because the discharge pressure is low and does not depend on the mechanical angular phase of the rolling piston 82. In addition, in situations where vane separation occurs, the wedge action is also less effective due to the low speed, making it difficult for an oil film to form. As a result, the coefficient of friction increases, the frictional force becomes large, and a vane separation force is generated regardless of the mechanical angular phase of the rolling piston 82. The wedge action is a condition in which, when the outlet (discharge) is narrower than the inlet (suction), the amount of fluid flowing in is greater than the amount of fluid flowing out, causing the fluids (oil) to push against each other, generating oil pressure inside and making it easier for an oil film to form.

[0025] When the mechanical angular phase of the rolling piston 82 is between 120° and 180°, the vane pressing force decreases, causing the vane separation force to become larger, resulting in vane separation. Approaches to prevent vane separation include increasing the vane pressing force and decreasing the vane separation force. Therefore, the control method of the motor 7 that achieves these effects will be described.

[0026] To suppress vane separation, we consider a control method for motor 7 that facilitates the formation of an oil film. Regarding the oil film, as mentioned in the explanation of the wedge action, we believe that generating oil pressure in a confined space is sufficient. • A longer time is better for generating pressure. Therefore, the speed of motor 7 is set to a low speed. When vane 81 is decelerating or stopped, the oil is less likely to move and the space becomes narrower, making it easier to generate pressure. Therefore, motor 7 is decelerated. If the speed of motor 7 is maintained near zero, the acceleration of motor 7 will also be near zero. The acceleration of vane 81 can also be brought close to zero.

[0027] For the reasons stated above, in order to make it easier to form an oil film in order to suppress vane separation, it is considered best to decelerate the motor 7 and move it at a constant speed. Also, since it is necessary to increase the rotational speed command to the original speed after decelerating the motor 7, the motor 7 should be controlled to "decelerate → constant speed → accelerate". When performing the above control, i.e., vane separation suppression control, simultaneously with vibration suppression control, a control method such as decelerating the rolling piston 82 when the mechanical angular phase of the rolling piston 82 is between 105° and 120°, maintaining a constant speed when the mechanical angular phase of the rolling piston 82 is between 120° and 180°, and accelerating when the mechanical angular phase of the rolling piston 82 is between 180° and 195° is considered best.

[0028] Another control method for the motor 7 that facilitates the formation of an oil film to suppress vane separation is to accelerate and then decelerate the motor 7 so that the acceleration of the vane 81 becomes zero. However, in a control method that decelerates and then accelerates the motor 7, there is a limit to the amount by which the motor 7 can be decelerated. Therefore, by accelerating the motor 7 first and then decelerating it, it is possible to avoid limiting the amount of control that suppresses vane separation.

[0029] 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.

[0030] 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.

[0031] The inverter control unit 110 includes a current restoration unit 111, a three-phase to two-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 two-phase to three-phase conversion unit 117, and a PWM signal generation unit 118.

[0032] Based on the load current Idc detected by the load current detection unit 40, the current restoration unit 111 restores the phase currents iu, iv, iw flowing through the motor 7. The current restoration unit 111 samples the load current Idc detected by the load current detection unit 40 at a timing determined based on the PWM signals Sm1 to Sm6 generated by the PWM signal generation unit 118, thereby restoring the phase currents iu, iv, iw.

[0033] The three-phase to two-phase conversion unit 112 uses the electrical phase θe generated by the electrical phase calculation unit 116 described later to convert 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.

[0034] 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. * 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 equal to or greater than a specified value or maximum, that is, the current value is equal to or less than a specified value or minimum. Here, the γ-axis current command value generation unit 113 generates the γ-axis current command value Iγ based on the δ-axis current Iδ and the like. * 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 calculation is as shown, but is not limited to this. The γ-axis current command value generation unit 113 generates the γ-axis current Iγ and the frequency command value ωe * Based on these factors, the gamma-axis current command value Iγ * Similar effects can be obtained by seeking the same value. In addition, the γ-axis current command value generation unit 113 generates the γ-axis current command value Iγ by controlling the weakening of the magnetic flux, etc. * You may decide that.

[0035] The voltage command value calculation unit 115 calculates the frequency command value ωe obtained from the operation control unit 102. * The γ-axis current Iγ and δ-axis current Iδ obtained from the 3-phase 2-phase conversion unit 112, and the γ-axis current command value Iγ obtained from the γ-axis current command value generation unit 113. * Based on this, the γ-axis voltage command value Vγ * 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.

[0036] 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.

[0037] 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].

[0038] 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.

[0039] 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 provided 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, vibration suppression control unit 514, vane separation suppression control unit 515, a low-pass filter 518, and a selection unit 519.

[0040] 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.

[0041] 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.

[0042] The low-pass filter 518 performs low-pass filtering on the δ-axis current Iδ and outputs the δ-axis current Iδ_LPF. The selection unit 519 receives the δ-axis current command value Iδ, which is the output from the speed control unit 503. * Alternatively, the δ-axis current Iδ_LPF, which is the output from the low-pass filter 518, is selected and output. The selection unit 519, for example, selects and outputs the δ-axis current Iδ_LPF during vane separation suppression control.

[0043] The addition unit 516 receives the δ-axis current command value Iδ output from the selection unit 519. * Alternatively, the delta-axis current Iδ_LPF and the delta-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. * The summation unit 516 outputs the sum of the two values. For example, during vane separation suppression control, the summation unit 516 calculates "δ-axis current Iδ_LPF + δ-axis current compensation value Iδ_trq * +δ axis current compensation value Iδ_VANE * It outputs "".

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062]

number

[0063] 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).

[0064]

number

[0065] The cosine function is minimized in equation (2) when given in equation (3) below.

[0066]

number

[0067] From the above, the torque of motor 7 is minimized in the case of equation (4) below.

[0068]

number

[0069] 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.

[0070] 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 For example, the phase required to position motor 7 at a mechanical angular phase of 105° is added, and the estimated mechanical angular phase of 105° is Theta Iδ_105 Obtain Theta Iδ_105 This is to position the rolling piston 82 at an estimated mechanical angle phase of 105°. Although not shown in the figure, the vane separation suppression control unit 515 controls the Theta to position the rolling piston 82 at a mechanical angle phase of 120°. Iδ_120 Theta to position the rolling piston 82 at a mechanical angular phase of 180° Iδ_180 , and Theta to position the rolling piston 82 at a mechanical angular phase of 195° Iδ_195 The same method can be used to obtain the same result. In addition, 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 To obtain.

[0071] The vane separation suppression control unit 515 controls the Theta Iδ_105 Theta Iδ_120 Theta Iδ_180 Theta Iδ_195 , and Theta Iδ_ωest_m Using Theta Iδ_ωest_m The deceleration occurs between 105° and 120°, ThetaIδ_ωest_m is a constant speed between 120° and 180°, Theta Iδ_ωest_m The δ-axis current compensation value Iδ_VANE for vane separation suppression control that accelerates between 180° and 195° * is output. At this time, the vane separation suppression control unit 515, Theta Iδ_ωest_m In the deceleration section where Theta is between 105° and 120°, the rotational speed of the motor 7 based on the speed command, that is, the rotational speed of the rolling piston 82, the δ-axis current compensation value Iδ_VANE for vane separation suppression control to reduce it by 30% or more * is output. The vane separation suppression control unit 515, Theta Iδ_ωest_m When outside the range of 105° to 195°, the δ-axis current compensation value Iδ_VANE for vane separation suppression control * is not output.

[0072] Here, the reason for reducing the rotational speed of the motor 7, that is, the rotational speed of the rolling piston 82 by 30% or more with respect to the speed command will be explained. FIG. 10 is a diagram showing the relationship between the reduction rate when reducing the speed with respect to the speed command and the noise standard ratio in the power conversion device 200 according to Embodiment 1. In FIG. 10, the horizontal axis represents the reduction rate with respect to the speed command, and the vertical axis represents the noise standard ratio. In FIG. 10, the noise targeted by the noise standard ratio is the metal collision sound generated when the vane 81 recontacts the rolling piston 82 after vane separation. As shown in FIG. 10, the power conversion device 200 can make the noise standard ratio 1 or less, that is, below the noise standard value, for the noise caused by the metal collision sound generated when the vane 81 recontacts the rolling piston 82 after vane separation, by reducing the rotational speed of the motor 7, that is, the rotational speed of the rolling piston 82 by 30% or more with respect to the speed command.

[0073] The reference phase Theta of the mechanical angular phase of the motor 7 Iδ_VANE is the minimum phase of the load torque of the compressor 8. Therefore, the vane separation suppression control unit 515, the reference phase Theta of the mechanical angular phase of the motor 7 Iδ_VANEBy adding a phase to set the mechanical angular phase of motor 7 to 105°, etc., vane separation suppression control is performed within a specified range using the mechanical angular phase of motor 7, which is 105°.

[0074] Figure 11 is a flowchart illustrating 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 a rotational position that reduces the rotational speed of the motor 7, i.e., the rotational speed of the rolling piston 82, relative to the speed command (step S2). If the rotational position of the rolling piston 82 is not a rotational position that reduces the rotational speed of the rolling piston 82 relative to the speed command (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 a rotational position that reduces the rotational speed of the rolling piston 82 relative to the speed command (step S2: Yes), the control device 100 performs vane separation suppression control to reduce the rotational speed of the rolling piston 82 relative to the speed command (step S3).

[0075] The control device 100 waits for a specified period of time (step S4) and determines whether the rotational position of the rolling piston 82 is a rotational position that keeps the rotational speed of the rolling piston 82 constant (step S5). If the rotational position of the rolling piston 82 is not a rotational position that keeps the rotational speed of the rolling piston 82 constant (step S5: No), the control device 100 returns to step S3. If the rotational position of the rolling piston 82 is a rotational position that keeps the rotational speed of the rolling piston 82 constant (step S5: Yes), the control device 100 performs vane separation suppression control to keep the rotational speed of the rolling piston 82 constant (step S6).

[0076] The control device 100 waits for a specified period (step S7) and determines whether the rotational position of the rolling piston 82 is a rotational position that accelerates the rotational speed of the rolling piston 82 relative to the speed command (step S8). If the rotational position of the rolling piston 82 is not a rotational position that accelerates the rotational speed of the rolling piston 82 relative to the speed command (step S8: No), the control device 100 returns to step S6. If the rotational position of the rolling piston 82 is a rotational position that accelerates the rotational speed of the rolling piston 82 relative to the speed command (step S8: Yes), the control device 100 performs vane separation suppression control to accelerate the rotational speed of the rolling piston 82 relative to the speed command (step S9).

[0077] The control device 100 waits for a specified period (step S10) and determines whether the rotational position of the rolling piston 82 is the rotational position that terminates the vane separation suppression control (step S11). If the rotational position of the rolling piston 82 is not the rotational position that terminates the vane separation suppression control (step S11: No), the control device 100 returns to step S9. If the rotational position of the rolling piston 82 is the rotational position that terminates the vane separation suppression control (step S11: Yes), the control device 100 determines whether the operation of the power converter 200 has finished (step S12). If the operation of the power converter 200 has not finished (step S12: No), the control device 100 returns to step S1. If the operation of the power converter 200 has finished (step S12: Yes), the control device 100 terminates the operations shown in this flowchart.

[0078] Furthermore, as described above, the control device 100 may first accelerate the rotational speed of the rolling piston 82 and then decelerate it. Also, when the control device 100 first accelerates the rotational speed of the rolling piston 82 and then decelerates it, it may provide a section between the acceleration and deceleration in which the rotational speed is kept constant.

[0079] Thus, in the power conversion device 200, the control device 100 performs vane separation suppression control to suppress vane separation, where the vanes 81 separate from the rolling piston 82 in the rotary compressor 8, which is a compressor rotated by the motor 7, by decelerating and accelerating the rotational speed of the rolling piston 82 according to the rotational position of the rolling piston 82. For example, if the rotary compressor 8 is a single rotary compressor, the control device 100 performs control to decelerate and accelerate the rotational speed of the rolling piston 82 at least once during one mechanical angle cycle of the rolling piston 82. If the rotary compressor 8 is a twin rotary compressor, the control device 100 performs control to decelerate and accelerate the rotational speed of the rolling piston 82 at least twice during one mechanical angle cycle of the rolling piston 82. In this case, as control to decelerate the rotational speed of the rolling piston 82, the control device 100 performs control to decelerate by 30% or more compared to the rotational speed of the rolling piston 82 indicated by the speed command. The control device 100 performs a control to accelerate the rotational speed of the rolling piston 82, accelerating it by 30% or more relative to the rotational speed of the rolling piston 82 indicated by the speed command.

[0080] Furthermore, if the rotary compressor 8 is a single rotary compressor, the control device 100 completes control of the rotational speed of the rolling piston 82 when the mechanical angular phase of the rolling piston 82 is within the range of 105° to 195°. If the rotary compressor 8 is a twin rotary compressor, the control device 100 completes control of the rotational speed of the rolling piston 82 when the mechanical angular phase of the rolling piston 82 is within the range of 122.5° to 167.5°, and further completes control of the rotational speed of the rolling piston 82 when the mechanical angular phase of the rolling piston 82 is within the range of 302.5° to 347.5°.

[0081] Furthermore, as vane separation suppression control, the control device 100 controls the vane pressing force in the direction in which the vane 81 is pressed against the rolling piston 82 to be greater than the vane separation force in the direction in which the vane 81 is separated from the rolling piston 82. For example, the control device 100 reduces the frictional force included in the vane separation force by making it easier to generate an oil film between the vane 81 and the rolling piston 82. Specifically, the control device 100 reduces the rotational speed of the rolling piston 82 to a speed lower than the rotational speed of the rolling piston 82 indicated by the speed command, rotates the rolling piston 82 at a constant rotational speed after deceleration for a specified period, and then accelerates the rotational speed of the rolling piston 82 back to the rotational speed of the rolling piston 82 indicated by the speed command. Alternatively, the control device 100 accelerates the rotational speed of the rolling piston 82 to a speed lower than the rotational speed of the rolling piston 82 indicated by the speed command, and then decelerates the rotational speed of the rolling piston 82 back to the rotational speed of the rolling piston 82 indicated by the speed command. Alternatively, the control device 100 accelerates the rotational speed of the rolling piston 82 to a speed higher than the rotational speed of the rolling piston 82 indicated by the speed command, rotates the rolling piston 82 at a constant speed after acceleration for a specified period, and then decelerates the rotational speed of the rolling piston 82 back to the rotational speed of the rolling piston 82 indicated by the speed command.

[0082] 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.

[0083] 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.

[0084] Next, the hardware configuration of the control device 100 included in the power converter 200 will be described. Figure 12 is a diagram showing an example of the hardware configuration that realizes the control device 100 included in the power converter 200 according to Embodiment 1. The control device 100 is realized by a processor 91 and a memory 92.

[0085] 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).

[0086] As described above, according to this embodiment, in the power conversion device 200, the control device 100 performs vane separation suppression control to accelerate and decelerate the rotational speed of the rolling piston 82 so that the vane pressing force is greater than the vane separation force. As a result, the power conversion device 200 can suppress vane separation by controlling the operation of the compressor 8.

[0087] Embodiment 2. In Embodiment 1, the case where the control device 100 changes the δ-axis current command value Iδ by the vane separation suppression control by the vane separation suppression control unit 515 * has been described. In Embodiment 2, the case where the control device 100 changes the frequency command value ωe * by the vane separation suppression control by the vane separation suppression control unit 5 will be described.

[0088] In Embodiment 2, the configuration of the power conversion device 200 is the same as the configuration of the power conversion device 200 in Embodiment 1 shown in FIG. 1. Also, in Embodiment 2, the configuration of the control device 100 is the same as the configuration of the control device 100 in Embodiment 1 shown in FIG. 6. FIG. 13 is a block diagram showing a configuration example of the voltage command value calculation unit 115 included in the control device 100 of the power conversion device 200 according to Embodiment 2. In Embodiment 2, the voltage command value calculation unit 115 is obtained by deleting the low-pass filter 518 and the selection unit 519 from the voltage command value calculation unit 115 shown in FIG. 7 and adding an addition unit 517.

[0089] In Embodiment 2, the vane separation suppression control unit 515 of the voltage command value calculation unit 115 does not output the δ-axis current compensation value Iδ_VANE for vane separation suppression control to the addition unit 516, but outputs the frequency command compensation value ω_VANE for vane separation suppression control to the addition unit 517. * Although detailed description is omitted, the vane separation suppression control unit 515 performs the same calculation as in FIG. 9 and outputs the δ-axis current compensation value Iδ_VANE for vane separation suppression control as an output. * *Instead, the frequency command compensation value ω_VANE for vane separation suppression control. * Outputs.

[0090] 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.

[0091] Embodiment 3. Figure 14 shows an example configuration of the 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 14, components having the same functions as those in Embodiment 1 are denoted by the same reference numerals as in Embodiment 1.

[0092] 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.

[0093] Inside the compressor 8 are a compression mechanism 904 for compressing the refrigerant and a motor 7 for operating the compression mechanism 904.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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]

[0099] 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, 518, 555, 556 Low-pass filter, 519 Selection unit, 550 Calculation unit, 551 Cosine calculation unit, 552 Sine calculation unit, 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 decelerating and accelerating the rotation speed of the rolling piston, thereby suppressing vane separation, where the vane separates from the rolling piston, in the rotary compressor. This control device assumes that the rotational position of the rolling piston when the tip of the vane is furthest from the rotation axis of the rolling piston while the vane is in contact with the rolling piston of the rotary compressor is 0° in mechanical angular phase. If the rotary compressor is a single rotary compressor, it completes control of the rotational speed of the rolling piston when the mechanical angular phase of the rolling piston is within the range of 105° to 195°. If the rotary compressor is a twin rotary compressor, it completes control of the rotational speed of the rolling piston when the mechanical angular phase of the rolling piston is within the range of 122.5° to 167.5°. Furthermore, it completes control of the rotational speed of the rolling piston when the mechanical angular phase of the rolling piston is within the range of 302.5° to 347.5°. 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 to its original speed at least once during one cycle of the mechanical angle of the rolling piston, or to accelerate the rotational speed of the rolling piston and decelerate it back to its original speed. If the rotary compressor is a twin rotary compressor, the control is performed to decelerate the rotational speed of the rolling piston and accelerate it back up, or to accelerate the rotational speed of the rolling piston and decelerate it back up, at least twice during one cycle of the mechanical angle of the rolling piston. The power conversion device according to claim 1.

3. The control device performs the following control actions: to reduce the rotational speed of the rolling piston, it performs a control that reduces 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; to accelerate the rotational speed of the rolling piston back up, it performs a control that accelerates 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; or to accelerate the rotational speed of the rolling piston, it performs a control that accelerates 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; and to decelerate the rotational speed of the rolling piston back up, it performs a control that reduces 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, as vane separation suppression control, controls the vane pressing force in the direction in which the vane is pressed against the rolling piston to be greater than the vane separation force in the direction in which the vane separates from the rolling piston. The power conversion device according to claim 1.

5. The control device reduces the frictional force included in the vane separation force by making it easier to generate an oil film between the vane and the rolling piston. The power conversion device according to claim 4.

6. The control device reduces the rotational speed of the rolling piston to a speed lower than the rotational speed of the rolling piston indicated by the speed command, rotates the rolling piston at a constant speed after reduction for a specified period, and then accelerates the rotational speed of the rolling piston back to the rotational speed of the rolling piston indicated by the speed command. The power conversion device according to claim 4.

7. The control device accelerates the rotational speed of the rolling piston to a speed greater than the rotational speed of the rolling piston indicated by the speed command, and decelerates the rotational speed of the rolling piston to return it to the rotational speed of the rolling piston indicated by the speed command. The power conversion device according to claim 4.

8. The control device accelerates the rotational speed of the rolling piston to a speed higher than the rotational speed of the rolling piston indicated by the speed command, rotates the rolling piston at a constant speed after acceleration for a specified period, and then decelerates the rotational speed of the rolling piston to return it to the rotational speed of the rolling piston indicated by the speed command. The power conversion device according to claim 4.

9. 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.

10. 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 9.

11. 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 10.

12. 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.

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

14. A motor drive device comprising a power conversion device according to any one of claims 1 to 13.

15. A refrigeration cycle application device comprising a power conversion device according to any one of claims 1 to 13.

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