JP2018165486A - Motor control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rotate two motors in a multi-cylinder compressor in which two rotary compression mechanism units such as a rotary compressor and two motors for driving these compression mechanism units are housed in one sealed case. Obtain a motor control device that suppresses vibration generated due to a deviation in the pulsation pattern of the shaft torque. SOLUTION: First and second permanent magnet synchronous motors each having a compression chamber and driving a compression mechanism unit are used in both motors in opposite directions at the same rotation speed and at rotation electric angles different from each other by about 180 °. A control means for driving the torque pulsation so that the phases are synchronized is provided. [Selection diagram] Fig. 1

Description

  Embodiments of the present invention relate to a motor control device for a compressor in which two compression mechanism units and two motors respectively driving these compression mechanism units are housed in one sealed case.

  2. Description of the Related Art A multi-cylinder type compressor in which two compression mechanism units and two motors that drive these compression mechanism units are accommodated in one sealed case is known.

JP 2011-254681 A

  In a rotary type compressor such as a rotary compressor, a gas to be compressed is sucked in, compressed, and discharged after one rotation. Along with this, pulsation occurs in the rotational shaft torque of the motor that drives the compressor. This pulsation causes compressor vibration and noise.

  In a multi-cylinder compressor in which two rotary type compression mechanisms and two motors that drive these compression mechanisms are housed in one sealed case, the two motors are operated independently, There is a difference between the pulsation pattern of the rotational shaft torque in the motor and the pulsation pattern of the rotational shaft torque in the other motor. This deviation may appear as a large vibration.

  The objective of embodiment of this invention is providing the motor control apparatus which can suppress the vibration of a compressor.

  According to a first aspect of the present invention, the first compression mechanism section including the compression chamber, the first motor that drives the first compression mechanism section, and the first compression mechanism section are arranged to face the first compression mechanism section. A second compression mechanism section having the same number of compression chambers and a second motor that drives the second compression mechanism section, and the rotational electrical angle of the motor and the rotational electrical angle of the first motor are approximately 180 degrees. If they are different, the phase of torque pulsation in the motor is synchronized with the phase of torque pulsation in the motor; and the first compression mechanism unit, the second compression mechanism unit, the first motor, and the second motor A compressor motor control device including a compressor case for housing the first motor and the second motor so that a phase of torque pulsation in the first motor and a phase of torque pulsation in the second motor are synchronized with each other. 2 motors in opposite directions And a control means for driving at the same speed in and substantially 180 ° different rotational electrical angle from each other.

The figure which shows the structure of the compressor and refrigeration cycle in connection with each embodiment. The figure which shows a response | compatibility with the rotor position (magnetic pole position) of each motor (6 pole motor) in connection with 1st Embodiment, and the rotation reference position of the roller of each compression mechanism part. The block diagram which shows the structure of each embodiment. The block diagram which shows the structure of the 1st position sensorless vector control part in 1st Embodiment. The block diagram which shows the structure of the 2nd position sensorless vector control part in 1st Embodiment. The figure which shows the electric current, rotational speed, rotational mechanical angle, and vibration displacement of one motor of the compressor concerning each embodiment. The figure which shows the rotating shaft torque and rotating electrical angle of each motor which concern on 1st Embodiment. The figure which shows the response | compatibility with the rotor position (magnetic pole position) of each motor (4 pole motor) in connection with 2nd Embodiment, and the rotation reference position of the roller of each compression mechanism part. It is a block diagram which shows the structure of the 1st position sensorless vector control part in 2nd Embodiment. It is a block diagram which shows the structure of the 2nd position sensorless vector control part in 2nd Embodiment. The figure which shows the rotating shaft torque and rotation electrical angle of each motor in connection with 2nd Embodiment.

[1] First embodiment
First, the configuration of the compressor and the refrigeration cycle according to this embodiment is shown in FIG. The compressor and the refrigeration cycle are mounted on, for example, an air conditioner or a heat source machine.

  In FIG. 1, the compressor 1 is covered with a compressor case, for example, a horizontally long sealed case 1a. A discharge pipe 2 is attached to the upper part of the sealed case 1a, and suction ports 3a, 3b, 3c, 3d are attached to the lower part of the sealed case 1a. One end of a condenser (heat radiator) 51 is connected to the discharge pipe 2 via a high-pressure side pipe, and one end of an evaporator (heat absorber) 53 is connected to the other end of the condenser 51 via an expansion valve 52. Has been. The other end of the evaporator 53 is connected to the suction ports 3a, 3b, 3c, and 3d via a low-pressure side pipe.

  In the sealed case 1a, a permanent magnet motor (first permanent magnet synchronous motor; brushless DC motor) 10 and a compression mechanism section (first compression mechanism section) 20 are provided on one side of the discharge pipe 2 as a boundary. And a permanent magnet synchronous motor (second permanent magnet synchronous motor; brushless DC motor) 30 and a compression mechanism section (second compression mechanism section) 40 are housed on the other side. Hereinafter, the permanent magnet synchronous motors 10 and 20 are abbreviated as motors 10 and 20, respectively. The compression mechanism sections 20 and 40 are disposed so that their excluded volumes are substantially equal to each other, and the respective rotation shafts (rotation shafts 13 and 33) are coaxial and face each other.

  The motor 10 has a cylindrical stator 11 disposed in contact with the inner peripheral surface of the sealed case 1a, a rotor (first rotor) 12 accommodated inside the stator 11, and rotatably supports the rotor 12. 6 includes a rotation shaft (first rotation shaft; also referred to as a shaft) 13, phase windings Lu, Lv, and Lw described later are mounted on the stator 11, and six permanent magnets 12 a to 12 f are embedded in the rotor 12. It is a pole motor. The rotation shaft 13 extends toward the compression mechanism unit 20 and passes through the center of the compression mechanism unit 20. The compression mechanism 20 includes a compression chamber (first compression chamber: cylinder) 21a communicating with the suction port 3a, a compression chamber (first compression chamber) 21b communicating with the suction port 3b, and a rotation shaft in the compression chambers 21a and 21b. 13 is a so-called two-cylinder rotary compressor having cranks 14a and 14b provided in an eccentric state 13 and rollers (first rollers) 22a and 22b mounted on the outer peripheral surfaces of the cranks 14a and 14b. By rotating eccentrically 22b, the gas refrigerant in the compression chambers 21a, 21b is compressed and discharged into the sealed case 1a. The discharged gas refrigerant flows to the condenser 51 through the discharge pipe 2.

  The motor 30 has a cylindrical stator 31 disposed in contact with the inner peripheral surface of the sealed case 1a, a rotor (second rotor) 32 accommodated inside the stator 31, and rotatably supports the rotor 32. This is a 6-pole motor that includes a rotation shaft (second rotation shaft) 33, phase windings Lu, Lv, and Lw described later are mounted on the stator 31, and six permanent magnets 32 a to 32 f are embedded in the rotor 32. . The rotation shaft 33 extends toward the compression mechanism 40 and passes through the center of the compression mechanism 40. The compression mechanism section 40 includes a compression chamber (second compression chamber) 41a that communicates with the suction port 3a, a compression chamber (second compression chamber; cylinder) 41b that communicates with the suction port 3b, and a rotation shaft in the compression chambers 41a and 41b. 33 is a so-called two-cylinder rotary compressor having cranks 34a and 34b provided in an eccentric state at 33 and rollers (second rollers) 42a and 42b mounted on the outer peripheral surfaces of the cranks 34a and 34b. By rotating eccentrically 42b, the gas refrigerant in the compression chambers 41a and 41b is compressed and discharged into the sealed case 1a. The discharged gas refrigerant flows to the condenser 51 through the discharge pipe 2.

  The excluded volumes of the compression chambers 21a and 21b of the compression mechanism unit 20 are the same as the excluded volumes of the compression chambers 41a and 41b of the compression mechanism unit 40, respectively. The number of compression chambers 21a, 21b (referred to as the number of compression chambers) is an even number “2”, and the number of compression chambers 41a, 41b (referred to as the number of compression chambers) is also an even number “2”. Further, the number of pole pairs (= number of poles / 2) of the motor 10 that is a 6-pole motor is an odd number “3”, and the number of pole pairs of the motor 30 that is also a 6-pole motor is an odd number “3”.

  The rotor 12 of the motor 10 is fixed to the rotating shaft 13 by press-fitting and, similarly, the rotor 32 of the motor 30 is fixed to the rotating shaft 33 by press-fitting and fixing. During this fixing, the rotational positions (rotor positions; also referred to as magnetic pole positions) of the rotors 12 and 32 of the motors 12 and 32 are the cranks 14a and 14b and 34a and 34b on the rotating shafts 13 and 33, that is, the rollers 22a and 22b. And 42a and 42b are aligned to be the same. As an optimal embodiment, the set of the motor 10 and the compression mechanism unit 20 and the set of the motor 30 and the compression mechanism unit 40 are exactly the same, and the two compressor rear portions 20 and 40 are assembled into the sealed case 1a. All of the motors 10 and 30 and the compression mechanism units 20 and 40 are arranged by arranging the rotation shafts 13 and 33 in the sealed case 1a so that the compression mechanism units 20 and 40 face each other. These parts can be shared, and productivity is improved.

  Correspondence between the rotation position of the rotor 12 in the motor 10 and the rotation reference position of the rollers 22a and 22b in the compression mechanism section 20, and the rotation position (rotor position; also referred to as magnetic pole position) of the rotor 32 in the motor 30 and compression. FIG. 2 shows the correspondence relationship between the rotation reference positions of the rollers 42a and 42b in the mechanism unit 40.

  The rollers 22a and 22b of the compression mechanism unit 20 are arranged in contrast to each other at a position 180 ° different from the rotation mechanical angle Q1 of the rotation shaft 13. As shown in FIG. 2, a state where the roller 22a is at the lowest point and the roller 22b is at the highest point is referred to as a rotation reference position of the rollers 22a and 22b. The rollers 42a and 42b of the compression mechanism unit 40 are also arranged at positions different from each other by 180 ° when viewed from the rotating mechanical angle Q2 of the rotating shaft 33. As shown in FIG. 2, a state where the roller 42a is at the lowest point and the roller 42b is at the highest point is referred to as a rotation reference position of the rollers 42a and 42b.

  When the rollers 22a and 22b of the compression mechanism unit 20 are at the rotation reference position, the magnetic pole position of the rotor 12 of the motor 10 is such that the magnetic pole S is at the highest point and the magnetic pole N is at the lowest point, as shown in FIG. When the rollers 42a and 42b of the compression mechanism 40 are at the rotation reference position, the magnetic pole position of the rotor 32 of the motor 30 is also such that the magnetic pole S is at the highest point and the magnetic pole N is at the lowest point, as shown in FIG. That is, the correspondence relationship between the rotation reference positions of the rollers 22a and 22b and the magnetic pole position of the rotor 12 in the compression mechanism unit 20 is the correspondence relationship between the rotation reference position of the rollers 42a and 42b and the magnetic pole position of the rotor 32 in the compression mechanism unit 40. Is the same.

  In the compression mechanism section 20, the suction of the gas to be compressed, the compression, and the discharge after the compression are performed during one rotation of each of the rollers 22a and 22b, and accordingly, a pulsation is generated in the rotation shaft torque T1 of the motor 10. The compression mechanism 40 also sucks the gas to be compressed, compresses it, and discharges it after it is rotated during one rotation of each of the rollers 42a, 42b. As a result, pulsation occurs in the rotation shaft torque T2 of the motor 30. In each compression mechanism section 20, 40, the rollers 22a, 22b and 42a, 42b are arranged at positions shifted by 180 ° in the rotational mechanical angle, so that they are generated in the rotational shaft torques T1, T2 of the motors 10, 30. The pulsation also occurs with a rotation mechanical angle of 180 ° as a cycle.

  The pulsations of the rotation shaft torques T1 and T2 occur when the rotational electrical angles θest1 and θest2 of the motors 10 and 30 are substantially completely synchronized (θest1 = θest2) and when they are different from each other by approximately 180 ° (θest1 = θest2 ± 180 °). The phases of each other are synchronized. Since the rotation directions of the motors 10 and 30 are rotating in opposite directions, the directions of the rotation shaft torques T1 and T2 are reversed, and the torque applied to the sealed case 1a is a combination thereof. Therefore, torque pulsation (also referred to as torque fluctuation) applied to the sealed case 1a that causes vibration is in a state where the rotational electrical angles θest1 and θest2 of the motors 10 and 30 are almost completely synchronized (θest1 = θest2) or substantially 180 ° with respect to each other. In different states (θest1 = θest2 ± 180 °), the greatest cancellation is achieved and extremely low vibrations can be achieved. When the compression chambers 21a, 21b, 41a, 41b have the same volume in each compression mechanism 20, 40, the torque pulsation applied to the sealed case 1a can be set to “0” to substantially eliminate vibration. It becomes.

Next, the configuration of the motor control device of the present embodiment is shown in FIG.
A converter 61 is connected to the AC power supply 60, and an inverter 62 is connected to the output terminal of the converter 61. Converter 61 converts the voltage of AC power supply 60 into a DC voltage. Inverter 62 converts the output voltage of converter 61 into a three-phase AC voltage having a predetermined frequency by switching. The motor 10 is operated by the output voltage of the inverter 62. A current sensor 63 that detects a current flowing through each phase winding of the motor 10 is disposed in the energization line between the inverter 62 and the motor 10. The output signal of the current sensor 63 is sent to the controller 70.

  A converter 64 is connected to AC power supply 60, and an inverter 65 is connected to the output terminal of converter 64. Converter 64 converts the voltage of AC power supply 60 into a DC voltage. Inverter 65 converts the output voltage of converter 64 into a three-phase AC voltage having a predetermined frequency by switching. The motor 30 is operated by the output voltage of the inverter 65. A current sensor 66 that detects a current flowing through each phase winding of the motor 30 is disposed on the energization line between the inverter 65 and the motor 30. The output signal of the current sensor 66 is sent to the controller 70.

  The controller 70 includes a position sensorless vector control unit (first position sensorless vector control unit) 71, a position sensorless vector control unit (second position sensorless vector control unit) 72, and a main control unit 73. The main control unit 73 sets the number of motors 10 and 30 to be operated and the target rotational speed ωref according to the air conditioning load of the refrigeration cycle (such as the difference between the room temperature and the set temperature), and the setting contents are position sensorless vector control. Commands the units 71 and 72.

  The position sensorless vector control units 71 and 72 control switching of the inverters 62 and 65 in accordance with a command from the main control unit 73. As a main function, the motors 10 and 30 are operated simultaneously with the motors 10 and 30. Includes control means for driving the motors 10 and 30 in opposite directions and at the same rotational speed to control the rotational electrical angles θest1 and θest2 of the motors 10 and 30. Specifically, this control means drives the motors 10 and 30 in the opposite directions and at the same target rotational speed ωref while driving the motors 10 and 30 simultaneously, while rotating the motor 10 and the rotation electrical angle θest1. Among the plurality of rotation shaft torques T1 generated when the rotation angle is 0 °, the rotation electric angle θest1 = 0 ° corresponding to the specific rotation shaft torque T1 and the plurality of rotations generated when the rotation electric angle θest2 of the motor 30 is 180 ° The rotational speed of the motor 30 is adjusted so that the rotational electrical angle θest2 = 180 ° corresponding to the specific rotational shaft torque T2 in the shaft torque T2 is synchronized.

[Configuration of Position Sensorless Vector Control Unit 71]
As shown in FIG. 4, the position sensorless vector control unit 71 includes a current detection unit 81, a speed estimation calculation unit 82, an integration unit 83, a subtraction unit 85, a speed control unit 86, a calculation unit 87, subtraction units 88, 89, 90, current control units 91 and 92, a PWM signal generation unit 93, a speed fluctuation detection unit 94, and an Iq correction unit 95.

  The current detector 81 detects a current (referred to as a motor current) flowing through the winding of the motor 10 via the current sensor 63, and based on this detected current and a rotational electrical angle θest1 described later, the field on the rotor shaft in the motor 10 is detected. A field component current (also referred to as a d-axis current) Id1 and a torque component current (also referred to as a q-axis current) Iq1 converted into a magnetic axis (d-axis) coordinate and a torque axis (q-axis) coordinate are detected. The speed estimation calculation unit 82 estimates the rotation speed ωest1 of the motor 10 by calculation using the field component current Id1 and the torque component current Iq1 in the motor current detected by the current detection unit 81. The integrator 83 integrates the estimated rotational speed ωest1 of the speed estimation calculator 82 to detect the rotational electrical angle θest1 that is the rotational position of the rotor 12 in the motor 10. The rotational electrical angle θest1 is supplied to the current detector 81 and the PWM signal generator 93.

  The subtracting unit 85 obtains a speed deviation between the target rotational speed ωref and the estimated rotational speed ωest1 by subtracting the estimated rotational speed ωest1 from the target rotational speed ωref set by the main control unit 73. The speed control unit 86 calculates a target value Iqref1 of the torque component current Iq1 by calculating a proportional / integral control (PI control) on the speed deviation obtained by the subtracting unit 85. The calculation unit 87 obtains the target value Idref1 of the field component current Id1 from the target value Iqref1 of the torque component current Iq1. The subtracting unit 88 obtains a deviation ΔId1 between the target value Idref1 and the field component current Id1 by subtracting the field component current Id1 from the target value Idref1. The subtraction unit 89 subtracts the torque component current correction value Iqx1 supplied from the Iq correction unit 95 from the target value Iqref1 of the torque component current Iq1, thereby obtaining a correction target value Iqref1 ′. The subtraction unit 90 subtracts the torque component current Iq1 from the correction target value Iqref1 ′ to obtain a deviation ΔIq1 between the correction target value Iqref1 ′ and the torque component current Iq1.

  The current control unit 91 obtains the field component voltage Vd1 converted into the d-axis coordinate on the rotor shaft in the motor 10 by proportional / integral control (PI control) calculation of the deviation ΔId1. The current control unit 92 obtains a torque component voltage Vq1 converted into q-axis coordinates on the rotor shaft in the motor 10 by proportional / integral control (PI control) calculation of the deviation ΔIq1. The PWM signal generator 93 generates a switching pulse width modulation signal (referred to as a PWM signal) for the inverter 62 in accordance with the field component voltage Vd1, the torque component voltage Vq1, and the rotational electrical angle θest1. By this PWM signal, each switching element of the inverter 62 is turned on / off, and drive voltages Vu, Vv, Vw for the phase windings Lu, Lv, Lw of the motor 10 are output from the inverter 62.

  The speed fluctuation detection unit 94 detects a fluctuation in the estimated rotational speed ωest1 as a vibration component of the compression mechanism unit 20. An example of the fluctuation of the estimated rotational speed ωest1 is shown in FIG. The vibration displacement of the rotating shaft 13 appears as the fluctuation of the estimated rotational speed ωest1. The Iq correction unit 95 obtains a torque component current correction value Iqx1 for reducing the “variation of the estimated rotational speed ωest1” detected by the speed variation detection unit 94. The torque component current correction value Iqx1 is supplied to the subtraction unit 89. The rotational electrical angle θest1 detected by the integration unit 83 and the torque component current Iq1 detected by the current detection unit 81 are supplied to the position sensorless vector control unit 72. In addition, when synchronizing the torque pulsation of the two compression mechanism parts 20 and 40 to eliminate the influence of the torque pulsation, it is necessary to reduce the “variation of the estimated rotational speed ωest1” of the individual compression mechanism parts 20 and 40. Therefore, if the two compression mechanism units 20 and 40 are always operated, the processing of this part is unnecessary or the torque component current correction value Iqx1 = 0 may be set. On the other hand, if only one of the compression mechanisms 20 and 40 can be operated, it is necessary to reduce the “variation in the estimated rotational speed ωest1”, so the torque component current correction value Iqx1 is necessary. Become.

[Configuration of Position Sensorless Vector Control Unit 72]
As shown in FIG. 5, the position sensorless / vector control unit 72 includes the same current detection unit 81, speed estimation calculation unit 82, integration unit 83, subtraction unit 85, speed control unit 86, calculation as the position sensorless / vector control unit 71. Unit 87, subtraction units 88, 89, 90, current control units 91, 92, PWM signal generation unit 93, speed fluctuation detection unit 94, Iq correction unit 95, and synchronization control not included in position sensorless vector control unit 71 Part 96 is included.

  The position sensorless vector control unit 72 is different from the position sensorless vector control unit 71 in that it includes a synchronization control unit 96, a field component current Id2, a torque component current Iq2, an estimated rotational speed ωest2, a rotational electrical angle θest2, The target value Idref2, the target value Iqref2, the deviation ΔId2, the torque component current correction value Iqx2, the corrected target value Iqref2 ′, the deviation ΔIq2, the field component voltage Vd2, the torque component voltage Vq2, and the like are handled as control elements.

  The synchronous control unit 96 receives the rotational electrical angle θest2 detected by the integrating unit 83 in the position sensorless vector control unit 72 and the torque component current Iq2 detected by the current detection unit 81, and the position sensorless vector. The rotating electrical angle θest1 and the torque component current Iq1 supplied from the controller 71 are input.

  The synchronization control unit 96 adjusts the rotation speed of the motor 30 so that the fluctuation of the rotation shaft torque T1 of the motor 10 and the fluctuation of the rotation shaft torque T2 of the motor 30 are synchronized. More specifically, the rotational electrical angle θest1 = 0 ° corresponding to a specific (for example, minimum) rotational shaft torque T1 among the plurality of rotational shaft torques T1 generated when the rotational electrical angle θest1 of the motor 10 is 0 °, and The motor 30 is synchronized with the rotation electrical angle θest2 = 180 ° corresponding to a specific (for example, minimum) rotation shaft torque T2 among the plurality of rotation shaft torques T2 generated when the rotation electrical angle θest2 of the motor 30 is 180 °. A speed correction value Δω for adjusting the rotation speed of 30 is output.

Here, FIG. 7 shows the rotational shaft torque T1 and the rotational electrical angles θest1 and θest2 of the motors 10 and 30 which are 6-pole motors having the number of pole pairs “3”.
The rotating mechanical angle Q1 = 360 ° (one rotation) of the motor 10 corresponds to three cycles of the rotating electrical angle θest1, and a pulsation pattern of two cycles of the rotating shaft torque T1 exists within the three cycles of the rotating electrical angle θest1. To do. Looking at the correspondence between the rotational electrical angle θest1 and the pulsation pattern of the rotational shaft torque T1, three values T1a, T1b, T1c (different in magnitude) are obtained as the rotational shaft torque T1 generated when the rotational electrical angle θest1 is 0 °. T1a <T1b <T1c).

  Similarly, the rotation mechanical angle Q2 = 360 ° (one rotation) of the motor 30 corresponds to three cycles of the rotation electrical angle θest2 of the motor 30, and the rotation shaft torque T2 of the motor 30 falls within the three cycles of the rotation electrical angle θest2. There are two cycles of pulsation patterns. Looking at the correspondence between the rotational electrical angle θest2 and the pulsation pattern of the rotational shaft torque T2, three values T2a, T2b, T2c (different in magnitude) are obtained as rotational shaft torque T2 generated when the rotational electrical angle θest2 is 180 ° ( T2a <T2b <T2c).

  Even if the motors 10 and 30 operate at the same rotational speed (target rotational speed ωref), the rotational electrical angles θest1 and θest2 proceed independently of each other, so that the pulsation phase of the rotational shaft torque T1 in the motor 10 and the motor 30 The phase of the pulsation of the rotation shaft torque T2 does not always match. The difference between the pulsation phase of the rotation shaft torque T1 and the pulsation phase of the rotation shaft torque T2 appears as vibration of the sealed case 1a.

  In order to suppress this vibration, the synchronization controller 96 sets the rotational electrical angle θest1 corresponding to the minimum rotational shaft torque T1a among the rotational shaft torques T1a, T1b, T1c generated when the rotational electrical angle θest1 of the motor 10 is 0 °. The rotational electrical angle θest2 = 180 ° corresponding to the smallest rotational shaft torque T2a among the rotational shaft torques T2a, T2b, T2c generated when the rotational electrical angle θest2 of the motor 30 is 180 ° is synchronized with 0 °. The speed correction value Δω with respect to the rotational speed of the motor 30 is output. The speed correction value Δω may be a predetermined constant value, or may be a value proportional to the difference between the rotational electrical angle θest1 = 0 ° and the rotational electrical angle θest2 = 180 ° that are the synchronization targets. The synchronization controller 96 periodically repeats the speed correction value Δω until the rotational electrical angle θest1 = 0 ° corresponding to the rotational shaft torque T1a and the rotational electrical angle θest2 = 180 ° corresponding to the rotational shaft torque T2a are synchronized. When the synchronization is realized, the output of the speed correction value Δω is terminated (Δω = 0).

  The speed correction value Δω output from the synchronization control unit 96 is supplied to the speed control unit 86. The speed control unit 86 calculates the target value Iqref2 of the torque component current Iq2 by performing proportional / integral control (PI control) operation on the speed deviation obtained by the subtracting unit 85, which is the same as that of the first embodiment. The target value Iqref2 is corrected according to the speed correction value Δω supplied from the synchronization control unit 96. The corrected target value Iqref2 is supplied to the calculation unit 87. The calculating unit 87 obtains the target value Idref2 of the field component current Id2 from the corrected target value Iqref2.

  Thus, the target values Idref2, Iqref2 taking into account the speed correction value Δω for adjusting the rotational speed of the motor 30 are supplied to the subtracting units 88, 89. The subtracting unit 88 obtains a deviation ΔId2 between the target value Idref2 and the field component current Id2 by subtracting the field component current Id2 from the target value Idref2. The subtracting unit 89 subtracts the torque component current correction value Iqx2 supplied from the Iq correction unit 95 from the target value Iqref2, thereby obtaining a corrected target value Iqref2 ′. The corrected target value Iqref2 ′ is supplied to the subtracting unit 90. The subtracting unit 90 obtains a deviation ΔIq2 between the corrected target value Iqref2 ′ and the torque component current Iq2 by subtracting the torque component current Iq2 from the corrected target value Iqref2 ′.

  The deviation ΔId2 obtained by the subtraction unit 88 is supplied to the current control unit 91, and the deviation ΔIq2 obtained by the subtraction unit 90 is supplied to the current control unit 92. The current control unit 91 obtains a field component voltage Vd2 converted into d-axis coordinates on the rotor shaft in the motor 30 by calculating proportional / integral control (PI control) of the deviation ΔId2. The current control unit 92 obtains the torque component voltage Vq2 converted into the q-axis coordinate on the rotor shaft in the motor 30 by the proportional / integral control (PI control) calculation of the deviation ΔIq2. The field component voltage Vd2 and the torque component voltage Vq2 obtained by the current control units 91 and 92 are supplied to the PWM signal generation unit 93. The PWM signal generator 93 generates a switching pulse width modulation signal (referred to as a PWM signal) for the inverter 62 in accordance with the field component voltage Vd2, the torque component voltage Vq2, and the rotational electrical angle θest2. By this PWM signal, each switching element of the inverter 62 is turned on / off, and drive voltages Vu, Vv, Vw for the phase windings Lu, Lv, Lw of the motor 30 are output from the inverter 62.

  With the above configuration, the speed of the motor 30 is adjusted according to the speed correction value Δω, and the rotational electrical angle θest2 = 180 ° of the motor 30 approaches the rotational electrical angle θest1 = 0 ° of the motor 10. At this time, the rotational speed of the motor 10 is maintained at the target rotational speed ωref. When the rotational electrical angle θest2 = 180 ° of the motor 30 coincides with the rotational electrical angle θest1 = 0 ° of the motor 10, that is, the pulsation phase of the rotational shaft torque T1 and the pulsation phase of the rotational shaft torque T2 in the motor 30 , The speed adjustment for the motor 30 ends. With the completion of this speed adjustment, the rotational speeds of the motors 10 and 30 both become the target rotational speed ωref, and this state is maintained and the operation is continued.

  As described above, when the number of compression chambers of the compression mechanisms 20 and 40 is an even number “2” and the number of pole pairs of the motors 10 and 30 is an odd number “3”, the rotational electrical angle θest1 and the rotational electrical angle θest2 are 180. By rotating the motors 10 and 30 under different anti-phase conditions and adjusting the rotational speed of the motor 30 so that the rotational electrical angle θest1 = 0 ° and the rotational electrical angle θest2 = 180 ° are synchronized, the rotational axis The phase of the pulsation of the torque T1 and the phase of the pulsation of the rotation shaft torque T2 in the motor 30 can be made to coincide with each other, so that the vibration of the sealed case 1a can be suppressed. Since the vibration of the sealed case 1a can be suppressed, noise can be reduced, and so-called pipe stress generated at the connecting portion between the compressor 1 and the refrigerant pipe can be suppressed within a specified value.

  Further, since the motors 10 and 30 are driven under a reverse phase condition in which the rotating electrical angle θest1 and the rotating electrical angle θest2 are different by 180 °, the neutral point voltage Vn1 of the motor 10 and the neutral point voltage Vn2 of the motor 30 shown in FIG. Are offset (Vn1 + Vn2 = 0). Thereby, EMI (Electro Magnetic Interference) noise and leakage current can be suppressed.

  In order to make the phase of the pulsation of the rotational shaft torque T1 of the motor 10 and the phase of the pulsation of the rotational shaft torque T2 of the motor 30 coincide, the rotational electrical angle θest1 of the motor 10 and the rotational electrical angle θest2 of the motor 30 are matched. But it is possible. However, in this case, since the motors 10 and 30 are driven under the same phase condition, the neutral point voltage Vn1 of the motor 10 and the neutral point voltage Vn2 of the motor 30 are not canceled out, and EMI noise and leakage current are reduced. There is no effect.

  Moreover, in the said embodiment, although it was set as the structure which adjusts the rotational speed of the motor 30 among the rotational speeds of the motors 10 and 30, it is good also as a structure which adjusts the rotational speed of the motor 10 not only to it. Or it is good also as a structure which adjusts both the rotational speeds of the motors 10 and 30. In short, at least one of the rotational speeds of the motors 10 and 30 may be adjusted.

  In the above embodiment, the rotational electrical angle θest1 = 0 ° corresponding to the rotational shaft torque T1a and the rotational electrical angle θest2 = 180 ° corresponding to the rotational shaft torque T2a are synchronized, but the rotational shaft torque T1b is synchronized with the rotational shaft torque T1b. The corresponding rotating electrical angle θest1 = 0 ° and the rotating electrical angle θest2 = 180 ° corresponding to the rotating shaft torque T2b may be synchronized, or the rotating electrical angle θest1 = 0 ° corresponding to the rotating shaft torque T1c and the rotating shaft The rotating electrical angle θest2 = 180 ° corresponding to the torque T2c may be synchronized.

[2] Second embodiment
A second embodiment will be described.
Correspondence relationship between the magnetic pole position of the rotor 12 in the motor 10 and the rotation reference position of the rollers 22a and 22b in the compression mechanism section 20, and the rotation reference position of the magnetic pole position of the rotor 32 in the motor 30 and the rollers 42a and 42b in the compression mechanism section 40 FIG. 8 shows the corresponding relationship.

  The motor 10 is a four-pole motor in which four permanent magnets 12a to 12d are embedded in the rotor 12, and therefore the number of pole pairs is an even number “2”. The motor 30 is also a four-pole motor formed by embedding four permanent magnets 32a to 32d in the rotor 32. Therefore, the number of pole pairs is an even number “2”. The number of compression chambers of each of the compression mechanisms 20 and 40 is an even number “2” as in the first embodiment.

  As shown in FIG. 8, when the rollers 22a and 22b of the compression mechanism section 20 are at the rotation reference position, the magnetic pole position of the rotor 12 of the motor 10 is such that the magnetic pole S is at the highest point and the magnetic pole N is at the lowest point. On the other hand, when the rollers 42a and 42b of the compression mechanism 40 are at the rotation reference position, the magnetic pole N of the rotor 32 of the motor 30 is at the uppermost point and the magnetic pole S is at the lowermost point. That is, the magnetic pole position of the rotor 12 with respect to the rotation reference position of the rollers 22a and 22b in the compression mechanism section 20 is equal to the number of pole pairs “2” with respect to the magnetic pole position of the rotor 32 with respect to the rotation reference position of the rollers 42a and 42b in the compression mechanism section 40. The rotation mechanical angle corresponding to “= 180 ° / number of pole pairs”, that is, 90 ° differs.

  The magnetic pole positions of the rotors 12 and 32 are appropriately selected by changing the polarity of each permanent magnet by supplying a large exciting current for magnetization to the phase windings Lu, Lv, and Lw of the motors 10 and 30. Is possible.

  The position sensorless vector control units 71 and 72, as main functions, drive the motors 10 and 30 in the opposite directions and at the same rotational speed during the simultaneous operation of the motors 10 and 30, respectively. Control means for adjusting the angles θest1 and θest2 are included. Specifically, the control means drives the motors 10 and 30 in the opposite directions and at the same target rotational speed ωref while simultaneously driving the motors 10 and 30, while rotating the motors 10 and 30. The rotational speed of the motor 30 is adjusted so that the angle θest1 and the rotational electrical angle θest2 of the motor 30 are synchronized with each other with a value shifted by 180 °.

  In order to realize this control, the position sensorless vector control unit 71 has the configuration shown in FIG. 9, and the position sensorless vector control unit 72 has the configuration shown in FIG. That is, the rotational electrical angle θest1 detected by the integration unit 83 of the position sensorless vector control unit 71 is input to the synchronization control unit 96 of the position sensorless vector control unit 72 and the integration unit of the position sensorless vector control unit 72. The rotational electrical angle θest2 detected at 83 is input to the synchronization control unit 96.

  The synchronization control unit 96 outputs a speed correction value Δω for the rotational speed of the motor 30 so that the rotational electrical angle θest1 of the motor 10 and the rotational electrical angle θest2 of the motor 30 are synchronized at a position shifted by 180 °.

Here, FIG. 11 shows the rotation shaft torque T1 and the rotation electrical angles θest1 and θest2 of the motors 10 and 30 which are 4-pole motors having the number of pole pairs “2”.
The rotating mechanical angle Q1 = 360 ° (one rotation) of the motor 10 corresponds to two cycles of the rotating electrical angle θest1, and a pulsation pattern of two cycles of the rotating shaft torque T1 exists within the two cycles of the rotating electrical angle θest1. To do. Looking at the correspondence between the rotational electrical angle θest1 and the pulsation pattern of the rotational shaft torque T1, the rotational shaft torque T1 is minimized when the rotational electrical angle θest1 is 0 °.

  On the other hand, in the motor 30, the magnetizing position is varied by the rotational mechanical angle “= 180 ° / number of pole pairs”, that is, 90 °, and therefore the rotational shaft torque T 2 is minimized because the rotational electrical angle θest 2 is 180 °. At the time.

  Even if the motors 10 and 30 operate at the same rotational speed (target rotational speed ωref), the rotational electrical angles θest1 and θest2 proceed independently of each other, so that the pulsation phase of the rotational shaft torque T1 in the motor 10 and the motor 30 The phase of the pulsation of the rotation shaft torque T2 does not always match. The phase difference between the pulsation of the rotation shaft torque T1 and the pulsation of the rotation shaft torque T2 appears as vibration of the sealed case 1a. As described above, in order to minimize the phase difference between the pulsation of the rotational shaft torque T1 and the pulsation of the rotational shaft torque T2, the phase difference (deviation) between the rotational electrical angle θest1 of the motor 10 and the rotational electrical angle θest2 of the motor 30. Can be set to 180 °.

  Therefore, the synchronization control unit 96 outputs a speed correction value Δω for adjusting the rotational speed of the motor 30 so that the rotational electrical angle θest1 of the motor 10 and the rotational electrical angle θest2 of the motor 30 are synchronized with a 180 ° deviation. To do. The speed correction value Δω may be a predetermined constant value, or may be a value proportional to the difference between the rotational electrical angle θest1 = 0 ° and the rotational electrical angle θest2 = 180 ° that are the synchronization targets. The synchronization control unit 96 periodically outputs the speed correction value Δω until the rotation electrical angle θest1 = 0 ° and the rotation electrical angle θest2 = 180 ° are synchronized, and outputs the speed correction value Δω when synchronization is realized. Is terminated (Δω = 0). Thereafter, the operation is continued in a state where the rotating electrical angle θest1 = 0 ° and the rotating electrical angle θest2 = 180 ° are synchronized. Since the rotating electrical angles θest1 and θest2 of the two motors 10 and 30 are synchronized, the speeds of both motors are the same.

Other configurations are the same as those of the first embodiment.
With the above configuration, the speed of the motor 30 is adjusted according to the speed correction value Δω, and the rotational electrical angle θest2 = 0 ° of the motor 30 approaches the rotational electrical angle θest1 = 180 ° of the motor 10. At this time, the rotational speed of the motor 10 is maintained at the target rotational speed ωref. When the rotational electrical angle θest2 = 0 ° of the motor 30 coincides with the rotational electrical angle θest1 = 180 ° of the motor 10, that is, the pulsation phase of the rotational shaft torque T1 and the pulsation phase of the rotational shaft torque T2 in the motor 30 , The speed adjustment for the motor 30 ends. As the speed adjustment ends, the rotational speeds of the motors 10 and 30 both become the target rotational speed ωref. Thereafter, the operation is continued in a state where the rotating electrical angle θest1 = 0 ° and the rotating electrical angle θest2 = 180 ° are synchronized.

  Thus, when the number of compression chambers of the compression mechanisms 20 and 40 is an even number “2” and the number of pole pairs of the motors 10 and 30 is an even number “2”, the rotational electrical angle θest1 = 0 ° and the rotational electrical angle θest2 By adjusting the rotation speed of the motor 30 so as to synchronize with 180 °, the phase of the pulsation of the rotation shaft torque T1 and the phase of the pulsation of the rotation shaft torque T2 in the motor 30 can be made to coincide with each other. The vibration of the case 1a can be suppressed. Since the vibration of the sealed case 1a can be suppressed, noise can be reduced, and so-called pipe stress generated at the connecting portion between the compressor 1 and the refrigerant pipe can be suppressed within a specified value. In addition, since the rotating electrical angles θest1 and θest2 are only shifted by 180 ° and synchronized without considering the rotating mechanical angles Q1 and Q2, the torque pulsation is adjusted so that the torque pulsations in each phase match as in the first embodiment. It is not necessary to match the phases while detecting, and the control burden on the position sensorless vector control units 71 and 72 can be reduced.

  Further, since the motors 10 and 30 are driven under a reverse phase condition in which the rotating electrical angle θest1 and the rotating electrical angle θest2 are different by 180 °, the neutral point voltage Vn1 of the motor 10 and the neutral point voltage Vn2 of the motor 30 are canceled out. (Vn1 + Vn2 = 0). Thereby, EMI noise and leakage current can be suppressed.

  In the present embodiment, the magnetic pole position of the rotor 12 with respect to the rotation reference position of the rollers 22a and 22b in the compression mechanism section 20 is the same as the magnetic pole position of the rotor 32 with respect to the rotation reference position of the rollers 42a and 42b in the compression mechanism section 40. The rotating machine angle corresponding to the number of pole pairs “2” was changed by “= 180 ° / number of pole pairs”, that is, 90 °. When this is not performed, that is, when the magnetization position is the same, in order to make the phase of the pulsation of the rotation shaft torque T1 of the motor 10 coincide with the phase of the pulsation of the rotation shaft torque T2 of the motor 30, The rotational electrical angle θest1 and the rotational electrical angle θest2 of the motor 30 are made to coincide (θest1 = θest2). However, in this case, the motors 10 and 30 are driven under in-phase conditions, and the neutral point voltage Vn1 of the motor 10 and the neutral point voltage Vn2 of the motor 30 are not canceled out. This reduction effect cannot be obtained.

  In addition, in this 2nd Embodiment, it was set as the structure which adjusts the rotational speed of the motor 30 among the rotational speeds of the motors 10 and 30, but it is good also as a structure which adjusts the rotational speed of the motor 10 not only to it. Or it is good also as a structure which adjusts both the rotational speeds of the motors 10 and 30. In short, at least one of the rotational speeds of the motors 10 and 30 may be adjusted.

  In addition, the rotational electrical angle θest1 = 0 ° and the rotational electrical angle θest2 = 180 ° are synchronized, but the point is that they may be synchronized with a value shifted from each other by 180 °. For example, the rotational electrical angle θest1 = 180 ° may be synchronized with the rotational electrical angle θest2 = 0 °.

  As described above, the case where the compression mechanism units 20 and 40 are each a two-cylinder type having two compression chambers has been described as an example. However, in the second embodiment, the compression mechanism units 20 and 40 each have one compression chamber. The same can be applied to the case of the single cylinder type.

[3] Modification
In each of the above-described embodiments, the case where the compression mechanism units 20 and 40 are each a two-cylinder type having two compression chambers has been described as an example.

  In each embodiment, an operation is performed in which the rotational electrical angles θest1 and θest2 are shifted by 180 °. Optimum vibration reduction is possible at this deviation angle. However, if the fluctuation range is about ± 25 °, that is, if the deviation angle is from 165 ° to 205 °, a large vibration suppression effect can be obtained. Therefore, it may be set within this range, that is, within a range of about 180 °. Similarly, the effect of suppressing the EMI noise and the leakage current is optimal in an operation in which the rotational electrical angles θest1 and θest2 are shifted from each other by 180 °. It is possible to exert an inhibitory effect.

  The above-described embodiments and modifications are presented as examples, and are not intended to limit the scope of the invention. The novel embodiments and modifications can be implemented in various other forms, and various omissions, rewrites, and changes can be made without departing from the spirit of the invention. In these embodiments and modifications, the scope of the invention is included in the gist, and is included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Compressor, 1a ... Sealing case, 10, 30 ... Permanent magnet synchronous motor, 12, 32 ... Rotor, 13, 33 ... Rotating shaft, 20, 40 ... Compression mechanism part, 22a, 22b ... Roller, 61, 64 ... Converter, 62, 65 ... Inverter, 70 ... Controller, 71, 72 ... Position sensorless vector control unit, 73 ... Main control unit, 96 ... Synchronization control unit

Claims (7)

A first compression mechanism having a compression chamber;
A first motor that drives the first compression mechanism;
A second compression mechanism portion arranged in a state facing the first compression mechanism portion, and having the same number of compression chambers as the first compression mechanism portion;
A second motor for driving the second compression mechanism, and when the rotational electrical angle of the motor and the rotational electrical angle of the first motor differ by approximately 180 °, the phase of torque pulsation in the motor and the first The phase of torque pulsation in the motor is synchronized;
A compressor case that houses the first compression mechanism, the second compression mechanism, the first motor, and the second motor;
A compressor motor control device comprising:
The first and second permanent magnet synchronous motors have the same rotational speed in opposite directions and are substantially 180 ° different from each other so that the phase of torque pulsation in the first motor and the phase of torque pulsation in the second motor are synchronized. Control means driven by rotating electrical angle,
A motor control device comprising: The compressor case is a cylindrical sealed case,
The first compression mechanism and the first motor are accommodated on one side along the axial direction of the sealed case,
The second compression mechanism and the second motor are accommodated on the other side along the axial direction of the sealed case,
The motor control device according to claim 1. The number of compression chambers of the first and second compression mechanisms is an even number,
The first and second motors are permanent magnet synchronous motors, respectively, and the number of pole pairs of the first and second motors is an odd number, respectively.
The correspondence between the rotation reference position of the roller in the first compression mechanism section and the magnetic pole position of the rotor in the first motor is as follows: the rotation reference position of the roller in the second compression mechanism section and the magnetic pole position of the rotor in the second motor Is the same as
The control means drives the first and second motors to have the same target rotational speed in opposite directions, and generates a plurality of rotational shaft torques generated when the rotational electric angle of the first motor is 0 °. Among them, a rotating electrical angle 180 corresponding to a specific rotating shaft torque among a plurality of rotating shaft torques generated when the rotating electrical angle 0 ° corresponding to a specific rotating shaft torque and the rotating electric angle of the second motor is 180 °. Adjusting at least one of the rotational speeds of the first and second motors so as to be synchronized with °.
The motor control device according to claim 1, wherein the motor control device is provided.   The motor control device according to claim 3, wherein each of the first and second motors is a six-pole motor. The first and second motors are permanent magnet synchronous motors, respectively, and the number of pole pairs of the first and second motors is an even number,
The magnetic pole position of the rotor in the first motor when the roller in the first compression mechanism is at the rotation reference position is the position of the rotor in the second motor when the roller in the second compression mechanism is at the rotation reference position. The rotating machine angle corresponding to the number of pole pairs differs from the magnetic pole position by “= 180 ° / number of pole pairs”.
The motor control device according to claim 1, wherein the motor control device is provided.   The motor control device according to claim 5, wherein each of the first and second motors is a four-pole motor.   The motor control device according to any one of claims 1 to 6, wherein the number of compression chambers of the first and second compression mechanism sections is "2", respectively.

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