JP5388089B2 - Motor control device and motor system - Google Patents

Description

  The present invention relates to a motor control device and a motor system, and more particularly, to a motor control device and a motor system that suppress motor turbulence.

  In single rotary compressors and reciprocating compressors that are widely used as compressors for products such as air conditioners and refrigerators, the load torque varies greatly depending on the timing of refrigerant suction and discharge during one rotation of the motor. There is a problem that the vibration of the motor increases due to uneven speed during one rotation.

  As an apparatus for suppressing such motor vibration, for example, Patent Document 1 discloses the following configuration. That is, this apparatus calculates the fluctuation of the load torque of the device during one rotation of the motor rotor based on the rotational position information during one rotation of the motor rotor. Based on this calculation result, at least one of the current and voltage supplied to the motor is controlled to make the load torque of the device and the output torque of the motor substantially equal. Thereby, the vibration which has arisen due to the difference between the motor output torque and the actual load torque pulsating during one rotation can be reduced.

  Patent Document 2 discloses the following configuration. That is, this device energizes each coil based on control data, a current sensor and a current amplifier that detect current, a mechanical angle determination unit that detects mechanical angle, a sine wave data generation unit that generates voltage data, and the control data. An inverter circuit, a torque storage unit corresponding to the mechanical angle and storing a first correction value, and a microcomputer for controlling the inverter circuit are provided. The microcomputer includes a detection unit that calculates a ratio between the integrated current values, a PI (Proportional Integral) calculation unit that calculates a second correction value so as to control the ratio calculated by the detection unit to a target ratio, And a PWM (Pulse Width Modulation) generator for calculating control data. In this way, by controlling the modulation rate or frequency of the motor based on the load torque fluctuation pattern measured in advance without using the rotor position sensor represented by the Hall IC (Integrated Circuit), the motor Suppresses vibration.

On the other hand, a turbulence phenomenon occurs due to mechanical resonance of the compressor. As a device that suppresses a turbulence phenomenon at a specific frequency, for example, Patent Document 3 discloses the following configuration. That is, in this apparatus, in a microcomputer that controls an inverter circuit that converts DC power into AC power, a phase difference between an AC voltage and an AC current is detected, and the detected AC voltage / current phase difference information and a target are detected. A duty reference value corresponding to an error from the phase difference information is calculated. Further, a vibration component of the alternating current is detected, and a correction amount for the rotational speed of the synchronous motor is calculated based on the vibration component. Based on the calculated duty reference value and sine wave data corresponding to the corrected rotation speed command value, a PWM waveform signal is created and output to the inverter circuit. In this way, the control system that does not use the rotor position sensor detects unexpected turbulence as a current fluctuation at a specific voltage phase, and adjusts the frequency (angular velocity) to the motor to suppress the fluctuation. Thus, the turbulence phenomenon can be suppressed.
JP-A-8-322275 JP 2004-274841 A JP 2006-115576 A

  However, when both the load torque fluctuation suppression control described in Patent Documents 1 and 2 and the turbulence suppression control described in Patent Document 3 exist in the same system, these controls interfere with each other, and the control operation is not effective. There arises a problem that it becomes stable and it becomes difficult to optimize the control gain.

  This is because the motor current waveform is generally greatly distorted by load torque fluctuation suppression control, so even when there is no turbulence phenomenon, the turbulence suppression control system erroneously detects turbulence and performs unnecessary control. It is.

  FIG. 25 is a diagram illustrating a state where load torque fluctuation suppression control and turbulence suppression control interfere with each other in a certain compressor 6-pole synchronous motor.

  In FIG. 25, a graph G21 shows the U-phase current waveform of the synchronous motor in the system that performs the turbulence control and optimizes the vibration suppression effect (vibration suppression performance) by the load torque fluctuation suppression control. A graph G22 shows a U-phase current waveform of the synchronous motor in a state where the turbulence control is stopped in the system shown by the graph G21.

  The magnitude of vibration indicated by the graph G21 is 124 μm, and the magnitude of vibration indicated by the graph G22 is 423 μm. From the graphs G21 and G22, it can be seen that when the turbulence control is stopped, the vibration suppression effect (damping performance) is affected, that is, the load torque fluctuation suppression control and the turbulence suppression control interfere with each other.

  Therefore, an object of the present invention is to provide a motor control device and a motor system capable of preventing the load torque fluctuation suppression control and the turbulence suppression control from interfering with each other and operating the motor stably. is there.

  In order to solve the above problems, a motor control device according to an aspect of the present invention is a motor control device for controlling a motor including a rotor and a coil, and detects a drive current flowing through the motor coil. The sensor includes a sensor, a mechanical angle determination unit that detects the mechanical angle of the rotor of the motor based on the detected drive current, and a switching element, and controls the on / off of the switching element based on the control data. An inverter circuit that controls energization of the motor, a torque storage unit that stores a plurality of torque correction amounts, and outputs a torque correction amount based on the detected mechanical angle, and stores a plurality of first rotation speed correction amounts, A frequency storage unit that outputs one of a plurality of first rotational speed correction amounts based on the detected mechanical angle, and a rotation based on the detected drive current A current vibration detection unit that detects current vibration occurring in a cycle longer than the mechanical angular cycle of the motor, a rotation speed correction amount calculation unit that generates a second rotation speed correction amount for canceling the detected current vibration, and a motor A sine wave data generating unit that corrects the rotation speed command value of the first rotation speed based on the first rotation speed correction amount and the second rotation speed correction amount, and generates sine wave data based on the corrected rotation speed; And a PWM creation unit that calculates a PWM signal as control data based on the data and the torque correction amount received from the torque storage unit.

  Preferably, the motor control device is further calculated by a phase difference calculation unit that calculates a phase difference between the motor drive voltage and the drive current based on the sine wave data and the detected drive current, and the phase difference calculation unit. And a PI calculation unit that calculates a PI control value based on the difference between the phase difference and the target value. The PWM creation unit is based on the sine wave data, the torque correction amount received from the torque storage unit, and the PI control value. The PWM signal is calculated as control data.

Preferably, the current vibration detection unit, based on the drive voltage of the motor obtained from the sine wave data phase to calculate the mechanical angle of the rotor, 1 calculated mechanical angle in mechanical angle cycle of the rotor or Measured the drive current when it coincides with multiple specific mechanical angles over multiple mechanical angle cycles, and calculated the average value of the measured data for a predetermined number of times up to the current measurement data for each drive current measurement A difference between the average value and the current measurement data is calculated as a current oscillation value.

  Preferably, the motor control device further includes a multiplier that multiplies the rotational speed command value of the motor, the first rotational speed correction amount, and the second rotational speed correction amount, and the sine wave data creation unit includes: Sine wave data having a frequency based on the multiplication result of the multiplier is created.

  In order to solve the above problems, a motor system according to an aspect of the present invention is based on a motor including a rotor and a coil, a current sensor that detects a drive current flowing through the coil of the motor, and a detected drive current. A mechanical angle determination unit that detects the mechanical angle of the rotor of the motor; a switching element; an inverter circuit that controls energization of the coil by controlling on / off of the switching element based on control data; A torque storage unit that stores the torque correction amount and outputs the torque correction amount based on the detected mechanical angle, stores a plurality of first rotational speed correction amounts, and stores a plurality of first rotation speeds based on the detected mechanical angle. Based on the frequency storage unit that outputs any one of the rotational speed correction amounts of 1 and the detected drive current, the cycle occurs longer than the mechanical angle cycle of the rotor. A current vibration detection unit for detecting a flow vibration, a rotation speed correction amount calculation unit for generating a second rotation speed correction amount for canceling the detected current vibration, and a motor rotation speed command value as a first rotation. A sine wave data generation unit that corrects based on the speed correction amount and the second rotation speed correction amount and generates sine wave data based on the corrected rotation speed, and torque correction received from the sine wave data and torque storage unit And a PWM creation unit that calculates a PWM signal as control data based on the quantity.

  Preferably, the motor system further includes a phase difference calculation unit that calculates a phase difference between the drive voltage and the drive current of the motor based on the sine wave data and the detected drive current, and a level calculated by the phase difference calculation unit. A PI calculation unit that calculates a PI control value based on the difference between the phase difference and the target value, and the PWM creation unit, based on the sine wave data, the torque correction amount received from the torque storage unit, and the PI control value, The PWM signal is calculated as control data.

  According to the present invention, it is possible to prevent the load torque fluctuation suppression control and the turbulence suppression control from interfering with each other, and to drive the motor stably.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

FIG. 1 is a diagram showing a configuration of a motor system according to an embodiment of the present invention.
Referring to FIG. 1, motor system 201 includes an IPM (Interior Permanent Magnet) motor 51 and a synchronous motor control device 101. Synchronous motor control device 101 is connected to IPM motor 51, inverter circuit 52 that drives IPM motor 51, converter circuit 53 that is connected to inverter circuit 52, converts AC power to DC power, and supplies the converter circuit. 53, an AC power supply 54 for supplying AC power, and a winding current flowing in a specific phase (U phase in FIG. 1) among the winding terminals U, V, W of the IPM motor 51 are detected. A current sensor 55 that outputs a signal, a current amplifier 56 that is connected to the current sensor 55, performs a predetermined amount of amplification and offset addition on the signal output from the current sensor 55, and outputs a winding current signal; And a microcomputer 57 connected to an amplifier 56.

  The IPM motor 51 is controlled by so-called forced excitation drive, unlike the method of controlling the speed by detecting a counter electromotive voltage pulse or the like. Forced excitation drive refers to a drive method in which the rotational speed of the motor is determined by the frequency of a sine wave voltage composed of a PWM (Pulse Width Modulation) wave that energizes the motor winding. The waveform of the current that drives the IPM motor 51 is not particularly specified, but the waveform is such that a winding current that matches the magnetic flux distribution of the rotor can be obtained. In the present embodiment, the IPM motor 51 is driven using a sine wave that can reduce vibration and noise by supplying a current because the change is smooth.

  The IPM motor 51 is a kind of synchronous motor, and is an embedded magnet type brushless motor in which a permanent magnet is embedded in a rotor. In the present embodiment, IPM motor 51 is a three-phase four-pole brushless motor. As a result, the framing torque generated by the magnet magnetic flux and the winding current at the time of driving and the reluctance torque utilizing the change in the inductance of the motor winding depending on the rotor shape are synthesized. As a result, since the IPM motor can obtain a larger torque than other synchronous motors, the efficiency of the motor can be increased. The framing torque and the reluctance torque are functions of the relative positions of the rotor and the stator, respectively. In order to maximize the sum of the framing torque and the reluctance torque, it is necessary to energize the motor winding when the relative position between the rotor and the stator is appropriate.

  A single rotary type compressor (not shown) is connected to the IPM motor 51 as a load. The single rotary type compressor is a compressor that compresses a refrigerant in a refrigerator (not shown) or air in an air conditioner (not shown). With reference to FIG. 2, the load torque characteristics of the single rotary compressor and the scroll compressor will be described. The feature of the single rotary type compressor is that the structure is simple and the manufacturing cost is low, but the load torque fluctuation is very large. The single rotary type compressor sequentially repeats the cycle of refrigerant suction, compression, and discharge during one rotation of the motor. Immediately before the discharge, the refrigerant is compressed, so the load torque increases. Immediately after the discharge, the refrigerant is removed and the load torque becomes small. As a result, the load torque varies according to the mechanical angle of the rotor. A scroll compressor that continuously sucks, compresses, and discharges refrigerant does not cause such load torque fluctuations.

  Inverter circuit 52 includes a plurality of switching elements. By controlling on / off of the switching element, energization of the plurality of motor windings in the IPM motor 51 is controlled.

  The current sensor 55 may be a current transformer, but in the present embodiment, it is a so-called current sensor composed of a winding and a Hall element.

  The microcomputer 57 includes a detection unit 60, a phase difference storage unit 61, an adder 62, a PI (Proportion Integral) calculation unit 63, a setting unit 65, a sine wave storage unit 66, and a sine wave data creation unit 67. A PWM creation unit 68, a mechanical angle determination unit 70, a torque storage unit 72, a first multiplier 75, a frequency storage unit 80, a second multiplier 85, a current vibration detection unit 81, and a rotation speed. A correction amount calculation unit 82.

  The detection unit 60 calculates phase difference information. The phase difference storage unit 61 stores a target value of phase difference information. The adder 62 calculates error data representing an error between the target value of the phase difference information and the phase difference information output from the detection unit 60, and outputs the error data to the PI calculation unit 63. PI calculation unit 63 calculates proportional data (P) and integral data (I) based on the error data received from adder 62, and outputs a PI control signal that is the basis of the PWM waveform signal to first multiplier 75. To do.

  The setting unit 65 sets a command value for the rotational speed of the IPM motor 51. The sine wave storage unit 66 stores a data string in which a sine wave appears when continuously plotted on a graph. The sine wave data creation unit 67 outputs the sine wave data stored in the sine wave storage unit 66 corresponding to each phase of the motor winding terminals U, V, and W to the PWM creation unit 68 and also uses a U-phase motor. Information indicating the phase of the drive voltage is output to the detection unit 60. The sine wave data is read from the data string stored in the sine wave storage unit 66 at intervals determined according to the rotational speed of the IPM motor 51. The sine wave data is data for specifying a standard setting of the voltage and phase of each phase of the motor winding terminals U, V, and W. When the rotational speed of the IPM motor 51 is increased, this interval is increased. When the rotational speed of the IPM motor 51 is decreased, this interval is reduced. That is, the motor rotation speed is determined by the PWM carrier frequency and this interval, excluding the structural one of the IPM motor 51. When data is read for each phase of the winding from the sine wave storage unit 66, the difference in the order of the read data corresponds to the phase difference between the phases. For example, in the case of three phases, the difference in the order of the data of each phase corresponds to a deviation of 120 ° in electrical angle. Information representing the phase of the driving voltage of the U-phase motor is created based on the U-phase sine wave data. The detection unit 60 may be configured to calculate the phase of the drive voltage of the U-phase motor based on the U-phase sine wave data output from the sine wave data creation unit 67.

  The PWM generator 68 includes a so-called PWM waveform generator. In the present embodiment, the PWM creation unit 68 outputs a PWM waveform signal based on a result obtained by multiplying sine wave data for each phase and a duty reference value described later.

  Mechanical angle determination unit 70 detects the mechanical angle of the rotor from the pulsation data representing the pulsation during one rotation of IPM motor 51 at the winding current, and outputs rotor information representing the mechanical angle of the rotor to torque storage unit 72.

  The torque storage unit 72 includes a memory (not shown) and a circuit (not shown) that selects and outputs an appropriate one from information stored in the memory. The torque storage unit 72 stores in advance a torque correction amount for each state corresponding to the mechanical angle of the rotor, and outputs a torque correction amount according to the rotational speed of the rotor and the rotor information to the first multiplier 75. The state refers to a state in which one rotation of the rotor is divided into predetermined ranges such as an electrical angle of 60 ° (= mechanical angle of 30 °). The range of the state can be specified based on the arrangement of the stator of the IPM motor 51. With reference to FIG. 3, the torque correction amount data in the present embodiment will be described. In the present embodiment, since the motor torque is controlled by the PWM duty, the torque correction amount stored in the torque storage unit 72 represents the correction amount of the PWM duty. Since the torque pattern suitable for reducing the vibration varies depending on the rotation speed and the load torque, the torque storage unit 72 corresponds to the rotation speed and the load torque (only the rotation speed in the present embodiment) divided into a plurality of sections. A plurality of torque patterns are stored. When the torque storage unit 72 outputs a torque pattern corresponding to the rotation speed, the control performance is improved. The torque pattern has 12 states from 0th state to 11th state divided into 12 which is the product of the number of phases and the number of poles. However, the inverter drive voltage phases of the S state and the (S + 6) state (S: integer of 0 to 5) are the same. FIG. 4 shows the relationship between the mechanical angle and the electrical angle in each state in the case of a three-phase four-pole brushless motor. The method for detecting the rotational speed of the rotor by the torque storage unit 72 is not particularly limited, but in the present embodiment, based on the temporal change in the mechanical angle of the rotor of the IPM motor 51 detected by the mechanical angle determination unit 70. Rotation speed shall be detected.

  The first multiplier 75 multiplies the PI control signal output from the PI calculation unit 63 and the torque correction amount of the state corresponding to the mechanical angle of the rotor output from the torque storage unit 72, and calculates the duty reference value. Output to the PWM creation unit 68. The duty reference value that is finally output to the PWM generator 68 is calculated according to the equation (1) using the torque correction amount of FIG.

Duty reference value = torque correction amount × PI control signal (1)
The reason why the duty reference value is calculated by multiplying the PI control signal by the torque correction amount will be described with reference to FIGS. FIG. 5 is a diagram showing characteristics of motor efficiency, phase difference information, and motor drive voltage. FIG. 5A shows a case where the load torque of the single rotary compressor is small, and FIG. 5B shows a case where the load torque is large. In order to drive the motor with high efficiency without causing the motor to step out, the energization timing to the rotor needs to be controlled to an appropriate value based on the relative position between the rotor and the stator. In order to control the energization timing to an appropriate value, the microcomputer 57 needs to control the phase difference information to an appropriate value. An appropriate value in this embodiment refers to a value included in the phase difference range shown in FIG. If the phase difference information is too small, the IPM motor 51 cannot output the motor generated torque that drives the load torque. As a result, motor step-out occurs. For example, assuming that the phase difference information in FIG. 5A and the phase difference information in FIG. 5B have the same value, when the load torque is small, the IPM motor 51 is driven with high efficiency, but the load torque is large. Causes motor step-out. This is because the value of the phase difference information is not included in the phase difference range.

  FIG. 6 is a diagram showing the relationship between the phase difference information and the motor drive voltage in the present embodiment. Since it is known that there is a linear relationship between the drive voltage and the phase difference information, the phase difference information is expressed as phase difference information = K (1) × drive voltage + K (2) (K (1), K ( 2) can be expressed by the equation of correlation coefficient). The correlation coefficients K (1) and K (2) vary depending on conditions such as load torque. According to FIG. 6, when the value of the phase difference information is constant, the driving voltage V (2) becomes larger than V (1) when the load torque is large. On the basis of this, when an appropriate value is output as the drive voltage, the microcomputer 57 can control the phase difference information to an appropriate value. In order to output an appropriate value as the drive voltage, the microcomputer 57 needs to determine the value of the drive voltage based on the load torque. The value of the drive voltage is determined by the duty reference value. This is the reason why the duty reference value is calculated by multiplying the PI control signal by the torque correction amount.

  The frequency storage unit 80 includes a memory (not shown) and a circuit (not shown) that selects and outputs an appropriate one from information stored in the memory. Of the drive frequency correction amount for correcting the frequency of the drive voltage stored in advance, the frequency storage unit 80 outputs the rotor information output from the mechanical angle determination unit 70 and the rate of change (rotation speed) per unit time of the rotor information. Is output to the second multiplier 85. The drive frequency correction amount stored in the frequency storage unit 80 will be described with reference to FIG. The average value of the drive frequency correction amount is set to be “1”. This is because the average value of the frequency of the drive voltage per predetermined cycle, which is determined from the target value of the rotation speed of the motor, is made constant. The plurality of correction amount patterns corresponding to the rotation speeds divided into the plurality of regions are stored because the correction amount patterns suitable for high-efficiency operation and the like vary depending on the rotation speed and the load torque. The control performance is improved by the frequency storage unit 80 outputting the drive frequency correction amount corresponding to the rotational speed. However, immediately after the start of the motor, the frequency storage unit 80 does not output the drive frequency correction amount. Since the differential pressure between the condensing pressure and the evaporation pressure of the compressor is small, the load fluctuation during rotation of the IPM motor 51 connected to the single rotary compressor is also reduced. As a result, the IPM motor 51 needs to correct the driving frequency. Because it does not.

  The current vibration detection unit 81 calculates the U-phase mechanical angle of the IPM motor 51 based on the information indicating the phase of the drive voltage of the U-phase motor received from the sine wave data creation unit 67. Then, the current vibration detection unit 81 detects current vibration generated in a cycle of one mechanical angle or more based on the U-phase current value of the IPM motor 51 received from the current amplifier 56 and the calculated mechanical angle. .

FIG. 8 is a diagram illustrating an example of a waveform of a U-phase current and current sample timing.
Referring to FIG. 8, first, current vibration detection unit 81 calculates the mechanical angle of the drive voltage of the U-phase motor.

  In the present embodiment, since the IPM motor 51 is a three-phase four-pole brushless motor, one cycle of the mechanical angle is two electrical angular cycles of the drive voltage of the U-phase motor.

  Therefore, the current vibration detection unit 81 is the first period of the electrical angular period and the timing at which the phase of the U-phase motor drive voltage is cleared from 360 degrees to 0 degrees, that is, the electrical angular period of 2 at zero crossing. It is determined that the cycle has been switched. Further, the current vibration detection unit 81 determines that the switching has been performed in the first period of the electrical angular period at the next zero-cross timing in the second period of the electrical angular period. Thereafter, these determinations are repeated.

  Then, the current vibration detection unit 81 calculates the mechanical angle of the driving voltage of the U-phase motor, that is, the U-phase mechanical angle of the IPM motor 51 in the first period of the electrical angle cycle by the following equation.

Mechanical angle of drive voltage of U-phase motor = phase of drive voltage of U-phase motor / 2
Further, the current vibration detection unit 81 calculates the mechanical angle of the drive voltage of the U-phase motor in the second period of the electrical angle period by the following formula.

Mechanical angle of driving voltage of U-phase motor = 180 degrees + phase of driving voltage of U-phase motor / 2
The current vibration detection unit 81 compares the calculated mechanical angle of the drive voltage of the current U-phase motor with a specific mechanical angle set in advance (60 degrees in the present embodiment), thereby obtaining the FIG. As shown by the arrows, the absolute value of the U-phase current is detected at the same timing in each mechanical angular period.

  Next, the current vibration detection unit 81 calculates an average value of the detected current absolute value (hereinafter referred to as I60).

  For example, the current vibration detection unit 81 calculates an average value for the past four times by a cycling buffer method. Specifically, the current vibration detection unit 81 stores the detected I60 from the oldest value in the order of I60 [3], I60 [2], I60 [1], I60 [0]. At the next detection timing, the value of I60 [2] is set in I60 [3], the value of I60 [1] is set in I60 [2], the value of I60 [0] is set in I60 [1], and I60 [0]. ], The latest I60 values are sequentially stored, so that the latest data for the past four times are always updated, and the average value of the data for the past four times is calculated.

  Then, the current vibration detection unit 81 calculates a difference between the calculated average value and the latest I60 as a current vibration value.

  FIG. 9 is a diagram showing an example of a vibration waveform of the U-phase current detected in the motor system according to the embodiment of the present invention.

  Referring to FIG. 9, it can be seen that the current vibration detection unit 81 detects only current vibration having a period longer than the mechanical angular period by the calculation method as described above.

FIG. 10 is a diagram illustrating another example of the waveform of the U-phase current and the current sample timing.
Referring to FIG. 10, current vibration detection unit 81 measures U-phase currents at a plurality of mechanical angles in one mechanical angle period at a plurality of mechanical angle periods, and detects current vibration based on the measurement results. It may be a configuration. In FIG. 10, the current vibration detection unit 81 measures currents in two phases in one mechanical angular period, for example, 60 degrees and 285 degrees.

  The current vibration detection unit 81 compares the calculated mechanical angle of the driving voltage of the current U-phase motor with a specific mechanical angle (60 degrees and 285 degrees in this case) set in advance, as shown in FIG. The absolute value of the U-phase current is detected at the same timing in each mechanical angular period as shown in FIG.

  Next, an average value of current absolute value I60 at a mechanical angle of 60 degrees and an average value of current absolute value at a mechanical angle of 285 degrees (hereinafter referred to as I285) are calculated. The calculation method of the average value is the same as that described above. Then, the current vibration detection unit 81 calculates the difference between the calculated average value of I60 and I285 and the latest I60 and I285 as the current vibration value.

  FIG. 11 is a diagram showing another example of the vibration waveform of the U-phase current detected in the motor system according to the embodiment of the present invention.

  Referring to FIG. 11, by the calculation method as described above, current vibration detection unit 81 detects current vibration more accurately and at a higher speed than a configuration that measures the current of one mechanical angle in one mechanical angle period. Responsiveness can be improved.

  The rotational speed correction amount calculation unit 82 calculates a turbulence correction amount for canceling the current vibration by multiplying the current vibration value received from the current vibration detection unit 81 by an appropriate gain.

  The second multiplier 85 multiplies the output value from the setting unit 65, the drive frequency correction amount from the frequency storage unit 80, and the turbulence correction amount from the rotation speed correction amount calculation unit 82, and causes the sine wave data creation unit 67 to Information indicating the phase of the voltage is output.

  The microcomputer 57 is realized by computer hardware and software executed by a control unit (not shown). Generally, such software is stored and distributed in a recording medium such as an FD (Flexible Disk) or a CD-ROM (Compact Disk-Read Only Memory), and is read by an input unit (not shown) as the recording medium. The control unit executes software read into the input unit.

  Referring to FIGS. 12 and 13, the program executed by microcomputer 57 has the following control structure with respect to control of IPM motor 51.

  In step (hereinafter, step is abbreviated as S) 100, detection unit 60 detects the command value for the rotational speed of IPM motor 51 set by setting unit 65. This rotational speed command value is detected via a sine wave data creation unit 67. In S102, detection unit 60 determines whether or not the command value for the rotational speed of IPM motor 51 has increased to the rotational speed determined at the time of design on the assumption that the differential pressure between the condensation pressure and the evaporation pressure of the compressor has increased. Judging. The IPM motor 51 rotates at the rotation speed set by the setting unit 65. The rotation speed initially set by the setting unit 65 is smaller than the final rotation speed. This is for rotating the IPM motor 51 stably. After the IPM motor 51 starts rotating, the setting unit 65 gradually increases the rotational speed command value. If it is determined that the rotational speed has been increased to the speed determined at the time of design (YES in S102), the process proceeds to S104. If not (NO in S102), the process proceeds to S100. In S104, the detection unit 60 temporarily sets the state by an arbitrary method, and temporarily sets the winding current value IP (4) of the fourth state and the winding current value IP (10) of the tenth state. taking measurement.

  In S106, detection unit 60 determines whether or not the difference between winding current values IP (4) and IP (10) is greater than or equal to a threshold value determined in advance according to the motor rotation speed. This is because when the difference in the winding current values to be compared is small, the detection error of the winding current value becomes large, and therefore there is a high possibility that the determination of the mechanical angle of the rotor is wrong. If it is determined that the threshold value is exceeded (YES in S106), the process proceeds to S108. If not (NO in S106), the process proceeds to S104.

  In S108, detection unit 60 measures the winding current value and determines whether or not winding current value IP (4) is larger than IP (10). If it is determined that winding current value IP (4) is larger than IP (10) (YES in S108), the process proceeds to S110. If not (NO in S108), the process proceeds to S112.

  In S110, detection unit 60 adds “1” to the value of the internal first register (not shown) and sets the value of the internal second register (not shown) to “0”. In S112, PWM creation unit 68 adds “1” to the value of the internal second register and sets the value of the internal first register to “0”.

  In S114, the detection unit 60 determines whether the value of either the first register or the second register is equal to or greater than a predetermined value such as “3” as a result of the processes of S108 to S112 being repeated several times. Judge whether or not. If it is determined that the value is equal to or greater than the predetermined value (YES in S114), the process proceeds to S116. If not (NO in S114), the process proceeds to S118.

  In S116, detection unit 60 determines that the current state setting is a normal setting. In S118, detection unit 60 shifts the setting of the state by a mechanical angle of 180 ° so that the mechanical angle of the rotor corresponding to the tenth state is the fourth state, thereby setting the normal state.

  In S120, detection unit 60 sets sampling timing TS based on the information output from sine wave data creation unit 67. In addition, each variable such as the number of samplings N is initialized. In the present embodiment, the sampling timing TS is set so that the phase of the motor drive voltage is a constant and symmetric timing centered on 90 °. This is to facilitate control design such as setting of the target phase difference. The phase period will be described with reference to FIG. The phase at which the motor drive voltage reaches a peak is 90 °. In this case, the first phase period θ (0) is a period in which the phase of the motor driving voltage is 0 ° to 90 °. The second phase period θ (1) is a period in which the phase of the motor drive voltage is 90 ° to 180 °. In the present embodiment, the width of the phase period is 90 °, but other values may be used and are not particularly limited.

  In S122, detection unit 60 waits for sampling timing based on the count cycle of the built-in timer. In S <b> 124, detection unit 60 measures the U-phase current value of IPM motor 51 using current sensor 55 via current amplifier 56.

  In S126, detection unit 60 adds “1” to the value of sampling count N. In S128, detection unit 60 determines whether or not the current phase period is θ (0) based on the value of sampling count N. If it is determined that the current phase period is θ (0) (YES in S128), the process proceeds to S130. If not (NO in S128), the process proceeds to S134.

  In S130, detection unit 60 determines whether sampling number N is equal to or greater than a predetermined value (three times in the present embodiment). If it is determined that sampling number N is equal to or greater than a predetermined value (YES in S130), the process proceeds to S132. If not (NO in S130), the process proceeds to S124.

  In S132, the detection unit 60 integrates the current sampling data on the assumption that the sampling in the phase period θ (0) is completed, and the motor current signal area S (0) (= I (0) + I (1) + I (2)).

  In S134, detection unit 60 determines whether sampling number N is equal to or greater than a predetermined value (six times in the case of the present embodiment). If it is determined that sampling number N is equal to or greater than a predetermined value (YES in S134), the process proceeds to S136. If not (NO in S134), the process proceeds to S124.

  In S136, assuming that sampling in phase period θ (1) has been completed, detection unit 60 integrates current sampling data, and motor current signal area S (1) (= I (3) + I (4) + I (5)).

  In S138, detection unit 60 determines whether or not calculation of motor current signal areas S (0) and S (1) has been completed. If it is determined that the calculation has been completed (YES in S138), the process proceeds to S140. If not (NO in S138), the process proceeds to S124.

  In S140, detection unit 60 calculates the ratio (S (0) / S (1)) of motor current signal areas S (0) and S (1) to obtain phase difference information, which is output to adder 62. . At S142, mechanical angle determination unit 70 reads pulsation data representing pulsation during rotation of IPM motor 51 in the U phase of IPM motor 51 using current sensor 55 via current amplifier 56.

  In S144, mechanical angle determination unit 70 detects the mechanical angle of the rotor based on the pulsation data, and outputs rotor information representing the mechanical angle of the rotor to torque storage unit 72. In S 146, torque storage unit 72 outputs a torque correction amount corresponding to the rotational speed of the rotor and the rotor information to first multiplier 75. The rotor mechanical angle is detected, for example, in the case of a 4-pole brushless motor, the electrical angle of the rotor is 360 ° when the mechanical angle is 180 ° and 360 °, and the rotor position cannot be clearly detected. Because.

  With reference to FIG. 15, a method for determining the mechanical angle of the rotor in the three-phase four-pole brushless motor will be described. FIG. 15 is a diagram illustrating a relationship among a state during one rotation, load torque, and winding current (for one phase). Since there are three strokes (inhalation, compression, and discharge) during one rotation, the load torque varies greatly. As the refrigerant is compressed from the suction state, the load torque increases rapidly, and when the discharge valve opens and the refrigerant is discharged, the load torque decreases. Due to the influence of the load torque fluctuation, the winding current value also fluctuates like IP (1), IP (4), IP (7), IP (10) in FIG. From this phenomenon, the mechanical angle determination unit 70 determines the mechanical angle of the rotor on the basis of the relationship between the magnitude of the winding current value of the state determined in advance through experiments or the like and the mechanical angle of the rotor. If the difference between the winding current values to be compared is small, the possibility of an error in the determination increases. Therefore, the mechanical angle determination unit 70 determines that the combination of the winding current values to be compared has the same inverter drive voltage phase. The combination having the largest difference in the section. In the present embodiment, the difference between the winding current value IP (4) in the fourth state and the winding current value IP (10) in the tenth state is the largest, so the mechanical angle determination unit 70 is in the fourth state. And the tenth state.

  A method for determining the mechanical angle of the rotor in a three-phase six-pole brushless motor will be described with reference to FIGS. 16 and 17. FIG. 16 is a diagram showing the relationship among the state during one rotation of the rotor of the three-phase six-pole brushless motor, the load torque, and the winding current (for one phase). FIG. 17 is a diagram showing the relationship between the mechanical angle and the electrical angle in each state in the case of a three-phase six-pole brushless motor. As shown in FIG. 17, in the case of a three-phase six-pole brushless motor, the torque pattern has 18 states from the 0th state to the 17th state divided into 18 which is the product of the number of phases and the number of poles. However, the inverter drive voltage phases of the S state, the (S + 6) state, and the (S + 12) state (S: integer of 0 to 5) are the same.

  As in the case of the 4-pole brushless motor, the load torque varies greatly in the 6-pole brushless motor. As the refrigerant is compressed from the suction state, the load torque increases rapidly, and when the discharge valve opens and the refrigerant is discharged, the load torque decreases. Under the influence of the load torque fluctuation, the winding current value also fluctuates like IP (1), IP (4), IP (7), IP (10), IP (13), IP (16) in FIG. . Using this phenomenon, the mechanical angle determination unit 70 compares the magnitudes of these winding current values to determine the mechanical angle of the rotor. In this case, the mechanical angle determination unit 70 compares the sizes of the first state, the seventh state, and the thirteenth state. For example, the mechanical angle determination unit 70 temporarily sets the state and measures the current values of the windings in the first state, the seventh state, and the thirteenth state. When the current value of the winding is measured, the mechanical angle determination unit 70 determines the minimum state by comparing the measured current value of the winding. When the seventh state is the minimum, the mechanical angle determination unit 70 maintains the definition of the current state. When the first state is the minimum, the mechanical angle determination unit 70 shifts the setting of the state by a mechanical angle of 120 ° so that the current first state becomes the seventh state. When the thirteenth state is the minimum, the mechanical angle determination unit 70 shifts the mechanical angle by 240 ° so that the current thirteenth state 13 becomes the seventh state. Thereby, since the correspondence between the mechanical angle of the rotor and the phase of the torque pattern can be taken, torque control is permitted and torque control is performed, and correction of the drive frequency is permitted, and the drive frequency is controlled.

  In S <b> 148, the adder 62 obtains the difference between the phase difference information obtained by the detection unit 60 and the target value of the phase difference information outputted by the phase difference storage unit 61 as error data, and outputs it to the PI calculation unit 63.

  In S150, PI calculation unit 63 calculates proportional data (P) and integral data (I) based on the error data output from adder 62, and supplies PI control value including these data to first multiplier 75. Output. In S 152, first multiplier 75 multiplies the PI control value and the torque correction amount output from torque storage unit 72, and outputs the duty reference value to PWM creation unit 68.

  In S 154, setting unit 65 outputs the set value of the rotational speed of IPM motor 51 to second multiplier 85. In S 156, the frequency storage unit 80 outputs a drive frequency correction amount corresponding to the rotor state and the rotation speed to the second multiplier 85.

  In S157, the current vibration detection unit 81 detects current vibration generated at a cycle of one mechanical angle or more based on the U-phase current value of the IPM motor 51 received from the current amplifier 56 and the calculated mechanical angle. To detect. Then, the rotational speed correction amount calculation unit 82 outputs a turbulence correction amount based on the current vibration value received from the current vibration detection unit 81.

  In S158, the second multiplier 85 corrects the frequency of the drive voltage in each state based on the drive frequency correction amount output from the frequency storage unit 80 and the turbulence correction amount output from the rotation speed correction amount calculation unit 82. . Then, the second multiplier 85 creates phase data representing the voltage phase based on the corrected frequency of the drive voltage and outputs it to the sine wave data creation unit 67. In the present embodiment, the second multiplier 85 calculates the phase data as shown in Expression (2) using the drive frequency correction amount of FIG.

Phase data = drive frequency correction amount × disturbance correction amount × command value of rotational speed of IPM motor 51 (2)
In S160, sine wave data creation unit 67 outputs sine wave data to PWM creation unit 68 based on the phase data and the sine wave data, and from the U-phase sine wave data, the drive voltage of the U-phase motor is calculated. Information representing the phase is output to the detector 60. Although the sine wave data may be created by calculation, in the present embodiment, sine wave data corresponding to each phase of the motor winding terminals U, V, and W is read from the sine wave storage unit 66.

  In S162, the PWM creation unit 68 multiplies the sine wave data and the duty reference value, and outputs a PWM waveform signal, which is a motor drive voltage, to each drive element of the inverter circuit 52 to the inverter circuit 52 for each phase.

  In S164, PWM creation unit 68 determines whether or not the torque pattern or the frequency correction pattern has been switched. If it is determined that the torque pattern or the frequency correction pattern has been switched (YES in S164), the process proceeds to S166. If not (NO in S164), the process proceeds to S120.

  In S166, the PWM creation unit 68 waits until a predetermined time elapses as necessary to stabilize the rotation of the motor. The predetermined time is T (1) which is a predetermined time necessary for the motor rotation to be stable after switching the torque pattern, etc., and is necessary for the motor rotation to be stable after the motor target rotation speed is changed. Let T (2) be a predetermined time.

  In S168, PWM creation unit 68 estimates the rotational speed of IPM motor 51 based on the sine wave data. In S170, PWM creation unit 68 determines whether or not the estimated value of the rotational speed is equal to or higher than a predetermined rotational speed that is determined in advance as it is not necessary to correct the drive frequency. If it is determined that the rotation speed is equal to or higher than the predetermined rotation speed (YES in S168), the process is terminated. If not (NO in S168), the process proceeds to S122. This determination is made because, in the case of a single rotary compressor, when the rotational speed of the IPM motor 51 is increased, the load fluctuation during the rotation of the IPM motor 51 is reduced, and the rotational speed fluctuation is accordingly reduced.

  The operation of the motor system 201 based on the structure and flowchart as described above will be described.

  The detection unit 60 detects a command value for the rotational speed of the IPM motor 51 (S100), and the rotational speed of the IPM motor 51 is determined in advance as a difference between the condensation pressure and the evaporation pressure of the compressor increases. Wait until the speed increases (S102).

  When it is determined that the rotational speed has increased to a predetermined rotational speed, the detection unit 60 sets the state once and arbitrarily, and temporarily sets the winding current value IP (4) of the fourth state and the winding of the tenth state. The current value IP (10) is measured (S104). When the winding current value is measured, the detection unit 60 waits until the difference between the measured winding current values exceeds a predetermined threshold value according to the motor rotation speed (S106). If it is determined that the threshold value has been exceeded, the detection unit 60 measures the winding current value and compares the winding current values IP (4) and IP (10) with each other (S108). When the measurement and comparison of the winding current value are repeated several times (S108 to S114), the detection unit 60 formally determines the state setting (S116, S118). Thus, since the correspondence between the mechanical angle of the rotor and the phase of the torque pattern can be taken, the torque is controlled and the drive frequency is controlled.

  The detection unit 60 sets the sampling timing TS based on the information output from the sine wave data creation unit 67. In addition, the detection unit 60 initializes each variable such as the number of samplings N (S120). When the sampling timing TS is set and each variable is initialized, the detection unit 60 calculates phase difference information.

  A method for calculating phase difference information will be described with reference to FIG. The detection unit 60 waits for predetermined sampling timings SP (0) to SP (5) such that the sampling timings in both phase periods are symmetric in the two phase periods based on the motor drive voltage (S122). When the timing comes, the detection unit 60 measures the U-phase current value of the IPM motor 51 (S124). When the current value is measured, the detection unit 60 integrates the winding current values I (0) to I (2) in each phase period, and accumulates the motor current signal area S (0) (= I (0) + I ( 1) + I (2)) is calculated (S126 to S132). When the motor current signal area S (0) is calculated, the detection unit 60 again measures the U-phase current value of the IPM motor 51, and the motor current signal area S (1) ( = I (3) + I (4) + I (5)) is calculated (S122 to S136). When motor current signal areas S (0) and S (1) are calculated (YES in S138), detection unit 60 calculates the ratio (S (0) / S (1)) of the respective values and adds them. The data is output to the device 62 (S140). This calculation result is phase difference information. In the present embodiment, the phase difference information is controlled to be a predetermined value. In the case of FIG. 14, the detection unit 60 performs A / D sampling at a timing that is symmetric in two phase periods. Therefore, when the phase difference between the voltage and the current is 0 ° as shown in FIG. 14, S (0) = S (1). As a result, the phase difference information is “1”. This means that the phase difference information may be controlled to be “1” in order to control at a phase difference of 0 °.

  When the phase difference information is output, the mechanical angle determination unit 70 reads pulsation data representing pulsation during rotation of the IPM motor 51 in the U phase of the IPM motor 51 (S142). When the pulsation data is read, the mechanical angle determination unit 70 detects the mechanical angle of the rotor based on the pulsation data, and outputs rotor information representing the mechanical angle of the rotor to the torque storage unit 72 (S144). When the rotor information is output, the torque storage unit 72 outputs a torque correction amount corresponding to the rotational speed of the rotor and the rotor information to the first multiplier 75 (S146).

  When the torque correction amount is output, the adder 62 obtains the difference between the phase difference information and the target value of the phase difference information output from the phase difference storage unit 61 as error data, and outputs it to the PI calculation unit 63. The adder 62 outputs the target value of the phase difference information and the phase difference information output from the detection unit 60 to the PI calculation unit 63 (S148). When the phase difference information or the like is output, the PI calculation unit 63 calculates proportional data (P) and integral data (I) based on the error data output from the adder 62, and sets the PI control value to the first multiplier 75. (S150). When the PI control value is output, the first multiplier 75 multiplies the PI control value by the torque correction amount output from the torque storage unit 72, and outputs the duty reference value to the PWM creation unit 68 (S152).

  The vibration of the single rotary compressor does not disappear completely even if the torque is controlled as described above, and some vibration remains. The fluctuation of the motor angular speed is also smaller than when the torque is not controlled, but it remains to some extent, so the drive frequency for forced excitation is changed to the fluctuation of the motor angular speed in order to control the energization timing to the stator to an appropriate value. Correct accordingly. As a result, the frequency of the driving power of the IPM motor 51 is increased or decreased according to the correction amount pattern, and energization is performed according to the fluctuation of the rotation speed. Since energization is performed according to fluctuations in the rotational speed, the microcomputer 57 can prevent the IPM motor 51 from stepping out and can be operated with high efficiency.

  When the duty reference value is output, the setting unit 65 outputs the setting value of the rotational speed of the IPM motor 51 to the second multiplier 85 (S154). When the set value is output, the frequency storage unit 80 outputs a drive frequency correction amount corresponding to the rotor state and the rotation speed to the second multiplier 85 (S156). Based on the U-phase current value of the IPM motor 51 received from the current amplifier 56 and the calculated mechanical angle, the current vibration detection unit 81 detects current vibration that occurs at a cycle of one mechanical angle or more. Then, the rotational speed correction amount calculation unit 82 outputs a turbulence correction amount based on the current vibration value received from the current vibration detection unit 81 (S157). When the drive frequency correction amount and the irregularity correction amount are output, the second multiplier 85 corrects the frequency of the drive voltage in each state based on the output drive frequency correction amount and the irregularity correction amount. Then, the second multiplier 85 creates phase data representing the voltage phase based on the corrected frequency of the drive voltage and outputs the phase data to the sine wave data creation unit 67 (S158).

  The reason why the phase data is multiplied by the correction amount will be described with reference to FIG. FIG. 18 shows phase difference information-efficiency characteristics parameterized by dividing the load torque fluctuation of the single rotary compressor when the load torque is large and when the load torque is small. Here, it should be noted that even if the motor drive voltage is the same, the phase difference information also changes when the load torque changes. For example, in FIG. 18, when the motor is driven with the motor drive voltage VJ, the motor is driven with different phase difference information when the load torque is large and small. This is because a large motor drive voltage is required when the load torque is large. If this is applied to the single rotary type compressor described above, it means that it is difficult to follow a sudden and large load torque fluctuation synchronized with one rotation of the motor by controlling the phase difference. If it becomes difficult to control and follow the phase difference, the motor drive voltage cannot be controlled or changed.

  When the phase data is output, the sine wave data creation unit 67 outputs the sine wave data to the PWM creation unit 68 based on the phase data and the sine wave data. The sine wave data creation unit 67 outputs sine wave data and outputs information representing the phase of the driving voltage of the U-phase motor from the U-phase sine wave data to the detection unit 60 (S160).

  When the sine wave data or the like is output, the PWM generator 68 multiplies the sine wave data by the duty reference value, and inverts the PWM waveform signal that is the motor drive voltage to each drive element of the inverter circuit 52 for each phase. The data is output to the circuit 52 (S162). As a result, current is applied to the motor windings via the inverter circuit 52, so that the IPM motor 51 is driven. As a result, the output torque of the IPM motor 51 is increased or decreased according to the torque pattern, and torque control according to the load torque is performed. Therefore, the microcomputer 57 prevents motor step-out and changes in the rotational speed of the IPM motor 51. Can be suppressed.

  When the PWM waveform signal is output, PWM creation unit 68 determines the magnitude of the drive voltage (the duty width of the PWM duty) until the torque pattern or the frequency correction pattern is switched (NO in S164). The magnitude of the drive voltage is determined by a phase difference control feedback loop for controlling the winding current phase difference with respect to the motor drive voltage (output duty) to be constant (S120 to S162). When determining the magnitude of the drive voltage, the rotational speed of the IPM motor 51 is determined by sine wave data output at a desired frequency. As a result, the IPM motor 51 is driven and controlled with a desired phase difference and a desired rotation speed.

  When the torque pattern or the frequency correction pattern is switched (YES in S164), PWM creation unit 68 waits until a predetermined time elapses to stabilize the motor rotation (S166). The predetermined time is T (1) which is a predetermined time necessary for the motor rotation to be stable after switching the torque pattern, etc., and is necessary for the motor rotation to be stable after the motor target rotation speed is changed. Let T (2) be a predetermined time. When the predetermined time has elapsed, PWM creation unit 68 estimates the rotational speed of IPM motor 51 based on the sine wave data (S168), and ends the process when the rotational speed exceeds a predetermined rotational speed (YES in S168). . This determination is made because, in the case of a single rotary compressor, when the rotational speed of the IPM motor 51 is increased, the load fluctuation during the rotation of the IPM motor 51 is reduced, and the rotational speed fluctuation is accordingly reduced.

  Referring to FIGS. 19 and 20, the relationship among load torque, motor drive voltage (for one phase), and angular velocity when a single rotary compressor motor having a large load fluctuation during one rotation is driven is shown. FIG. 19 shows the case of the conventional example, and FIG. 20 shows the case where the torque control of the present embodiment is performed. In the conventional example, the fluctuation of the angular velocity is large, and the vibration of the compressor is also large. In the case of this embodiment, the duty reference value is corrected by the torque pattern, and the motor drive voltage is corrected, so that the winding current is corrected to generate a motor torque that matches the load torque. Thereby, the angular velocity fluctuation is reduced, and the compressor vibration is also reduced.

  With reference to FIG. 21 and FIG. 22, the relationship between the load torque, motor drive voltage (for one phase), and phase difference information when a single rotary compressor motor having a large load fluctuation during one rotation is driven will be described. . FIG. 21 shows a conventional example. FIG. 22 shows a case where the frequency of the driving power is corrected in the present embodiment. In the case of the conventional example shown in FIG. 21, the fluctuation of the phase difference information is large, and as a result, the phase difference information moves away from the high efficiency point, resulting in an inefficient operation. In the worst case, the phase difference information fluctuates beyond the above-described phase difference range, and step-out occurs. In the case of the present embodiment shown in FIG. 22, the microcomputer 57 always controls the phase difference information to the high efficiency point by correcting the phase data according to the load fluctuation during the rotation of the IPM motor 51 by the correction amount pattern. It becomes possible.

  As described above, the drive device according to the present embodiment controls the drive voltage according to the torque pattern stored in the storage unit in advance. Since the drive voltage is controlled according to the torque pattern, the phase of the current remains in a controllable range. Since the phase of the current is kept within the controllable range, it is possible to drive a load having a sudden and large load torque fluctuation such as a single rotary compressor without causing motor step-out. Furthermore, since the mechanical angle of the rotor is not detected from the induced current of the coil but based on the peak of the winding current, control by 180 ° energization is possible. In addition, since the rotational speed is also corrected, it is possible to prevent the phase difference information from being affected by fluctuations in the rotational speed. As a result, it is possible to provide a control device that can apply control by 180 ° energization that is low noise, low vibration, and high efficiency to a wider range of fields.

  In S154, the setting unit 65 may start the drive frequency correction after the fluctuation amount of the phase difference information becomes equal to or larger than a first fluctuation amount that is arbitrarily determined.

  In S154, the setting unit 65 may immediately perform the processes of S157 and S158 when the fluctuation amount of the phase difference information is equal to or less than the arbitrarily determined second fluctuation amount.

  Furthermore, the winding current values to be compared may be states in which the mechanical angle of the rotor is 180 degrees apart in the case of a 4-pole brushless motor.

  In addition, in the case of a three-phase six-pole brushless motor, the winding current values to be compared may be states in which the phases of the motor driving voltages are equal.

  FIG. 23 is a diagram showing a state where a turbulence phenomenon occurs in a certain compressor 6-pole synchronous motor. In FIG. 23, a graph G1 indicates a U-phase current.

  As can be seen from the graph G1, in the U-phase current, a pulsation, that is, a turbulence phenomenon corresponding to one cycle occurs in the motor two rotations, that is, the cycle of the motor current that is a cycle of the load torque fluctuation peculiar to the compressor.

  FIG. 24 is a diagram showing U-phase current waveforms before and after the start of current vibration suppression control in the motor system according to the embodiment of the present invention. In FIG. 24, a graph G11 indicates the U-phase current. Graph G12 shows the current waveform after filtering the motor current oscillation of one mechanical angle or less with respect to the U-phase current shown in graph G11. S indicates the start timing of the current vibration suppression control by the current vibration detection unit 81 and the rotation speed correction amount calculation unit 82.

  In the motor system according to the embodiment of the present invention, when a turbulence phenomenon occurs at a cycle of one rotation period or more of the motor, which is a cycle of load torque fluctuation unique to the compressor, only the periodic fluctuation peculiar to the turbulence phenomenon is detected As described above, motor current oscillations that are less than one motor rotation cycle, that is, less than one mechanical angle cycle, are filtered. Then, the filtered motor current is fed back to correct the motor drive frequency, thereby canceling the motor current oscillation. By correcting the motor drive frequency, it is possible to suppress the turbulence phenomenon without interfering with the load torque fluctuation suppression control that operates at one rotation period of the motor. Therefore, the load torque fluctuation suppression control and the turbulence suppression control interfere with each other. Thus, the synchronous motor can be stably operated.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is an overall configuration diagram of a drive device according to an embodiment of the present invention. It is a figure showing the load torque characteristic of the single rotary type compressor and scroll type compressor which concern on embodiment of this invention. It is a figure explaining the example of the data of the torque correction amount which concerns on embodiment of this invention. It is a figure which shows the relationship between the mechanical angle and electric angle of each state in the case of the 3 phase 4 pole brushless motor in embodiment of this invention. It is a figure which shows the characteristic of motor efficiency, phase difference information, and a motor drive voltage based on embodiment of this invention. It is a figure showing the relationship between the phase difference information which concerns on embodiment of this invention, and the drive voltage of a motor. It is a figure explaining the corrected amount which the frequency memory | storage part which concerns on embodiment of this invention memorize | stores. It is a figure which shows an example of the waveform of U phase electric current, and an electric current sample timing. It is a figure which shows an example of the vibration waveform of the U-phase current detected in the motor system which concerns on embodiment of this invention. It is a figure which shows the other example of the waveform of U phase electric current, and an electric current sample timing. It is a figure which shows the other example of the vibration waveform of the U-phase current detected in the motor system which concerns on embodiment of this invention. It is a 1st flowchart which shows the procedure of control of the drive process of the IPM motor 51 which concerns on embodiment of this invention. It is a 2nd flowchart which shows the procedure of control of the drive process of the IPM motor 51 which concerns on embodiment of this invention. It is a conceptual diagram showing the phase period which concerns on embodiment of this invention. It is a figure which shows the relationship between the state in 1 rotation of the rotor of the 3 phase 4 pole brushless motor which concerns on embodiment of this invention, load torque, and the winding current for 1 phase. It is a figure which shows the relationship between the state in 1 rotation of the rotor of the 3 phase 6 pole brushless motor which concerns on embodiment of this invention, load torque, and the winding current for 1 phase. It is a figure which shows the relationship between the mechanical angle and electric angle of each state in the case of the 3 phase 6 pole brushless motor in embodiment of this invention. It is a figure showing the phase difference information-efficiency characteristic of the single rotary type compressor concerning an embodiment of the invention. It is a figure which shows the relationship between the load torque of the single rotary type | mold compressor motor with a large load fluctuation | variation during 1 rotation, the motor drive voltage for one phase, and angular velocity at the time of performing the torque control which concerns on a prior art example. The figure which shows the relationship between the load torque of the single rotary type | mold compressor motor with a large load fluctuation | variation in 1 rotation, the motor drive voltage for one phase, and angular velocity at the time of performing torque control which concerns on embodiment of this invention. is there. It is a figure which shows the relationship between the load torque of the single rotary compressor motor with a large load fluctuation | variation during 1 rotation, the motor drive voltage for 1 phase, and phase difference information at the time of performing torque control which concerns on a prior art example. FIG. 5 shows the relationship between the load torque of a single rotary compressor motor having a large load fluctuation during one rotation, the motor driving voltage for one phase, and phase difference information when torque control according to the embodiment of the present invention is performed. FIG. It is a figure which shows a mode that the turbulence phenomenon has arisen in a certain 6-pole synchronous motor for compressors. In the motor system which concerns on embodiment of this invention, it is a figure which shows the U-phase current waveform before and after the start of current vibration suppression control. It is a figure which shows the state which load torque fluctuation suppression control and disorder | damage | failure suppression control mutually interfere in a certain 6-pole synchronous motor for compressors.

Explanation of symbols

  51 IPM motor, 52 inverter circuit, 53 converter circuit, 54 AC power supply, 55 current sensor, 56 current amplifier, 57 microcomputer, 60 detection unit, 61 phase difference storage unit, 62 adder, 63 PI operation unit, 65 setting unit , 66 sine wave storage unit, 67 sine wave data generation unit, 68 PWM generation unit, 70 mechanical angle determination unit, 72 torque storage unit, 75 first multiplier, 80 frequency storage unit, 81 current vibration detection unit, 82 rotational speed Correction amount calculation unit, 85 second multiplier, 101 synchronous motor control device, 201 motor system.

Claims (6)

A motor control device for controlling a motor including a rotor and a coil,
A current sensor for detecting a drive current flowing through the motor coil;
A mechanical angle determination unit that detects a mechanical angle of the rotor of the motor based on the detected drive current;
An inverter circuit that includes a switching element and controls energization of the coil by controlling on / off of the switching element based on control data;
A torque storage unit that stores a plurality of torque correction amounts and outputs the torque correction amount based on the detected mechanical angle;
A frequency storage unit that stores a plurality of first rotation speed correction amounts, and outputs any one of the plurality of first rotation speed correction amounts based on the detected mechanical angle;
Based on the detected drive current, a current vibration detection unit that detects current vibration generated in a cycle longer than the mechanical angle cycle of the rotor;
A rotational speed correction amount calculation unit for generating a second rotational speed correction amount for canceling the detected current oscillation;
Sine wave data creation for correcting the rotational speed command value of the motor based on the first rotational speed correction amount and the second rotational speed correction amount and creating sine wave data based on the corrected rotational speed And
A motor control device comprising: a PWM creation unit that calculates a PWM (Pulse Width Modulation) signal as the control data based on the sine wave data and the torque correction amount received from the torque storage unit. The motor control device further includes:
A phase difference calculation unit that calculates a phase difference between the drive voltage and the drive current of the motor based on the sine wave data and the detected drive current;
A PI calculation unit that calculates a PI (Proportional Integral) control value based on a difference between the phase difference calculated by the phase difference calculation unit and a target value;
The motor control device according to claim 1, wherein the PWM creation unit calculates a PWM signal as the control data based on the sine wave data, the torque correction amount received from the torque storage unit, and the PI control value. The current oscillation detection section,
Based on the phase of the drive voltage of the motor obtained from the previous SL sine wave data to calculate the mechanical angle of the rotor,
Measuring the drive current when the calculated mechanical angle matches one or more specific mechanical angles in the mechanical angle period of the rotor over a plurality of the mechanical angle periods;
For each measurement of the drive current, an average value of a predetermined number of measurement data up to the current measurement data is calculated, and a difference between the calculated average value and the current measurement data is calculated as a current oscillation value. the motor control device according to claim 1. The motor control device further includes:
A multiplier for multiplying the rotational speed command value of the motor, the first rotational speed correction amount, and the second rotational speed correction amount;
The motor control device according to claim 1, wherein the sine wave data creating unit creates the sine wave data having a frequency based on a multiplication result of the multiplier. A motor including a rotor and a coil;
A current sensor for detecting a drive current flowing through the motor coil;
A mechanical angle determination unit that detects a mechanical angle of the rotor of the motor based on the detected drive current;
An inverter circuit that includes a switching element and controls energization of the coil by controlling on / off of the switching element based on control data;
A torque storage unit that stores a plurality of torque correction amounts and outputs the torque correction amount based on the detected mechanical angle;
A frequency storage unit that stores a plurality of first rotation speed correction amounts, and outputs any one of the plurality of first rotation speed correction amounts based on the detected mechanical angle;
Based on the detected drive current, a current vibration detection unit that detects current vibration generated in a cycle longer than the mechanical angle cycle of the rotor;
A rotational speed correction amount calculation unit for generating a second rotational speed correction amount for canceling the detected current oscillation;
Sine wave data creation for correcting the rotational speed command value of the motor based on the first rotational speed correction amount and the second rotational speed correction amount and creating sine wave data based on the corrected rotational speed And
A motor system comprising: a PWM creation unit that calculates a PWM signal as the control data based on the sine wave data and the torque correction amount received from the torque storage unit. The motor system further includes:
A phase difference calculation unit that calculates a phase difference between the drive voltage and the drive current of the motor based on the sine wave data and the detected drive current;
A PI calculation unit that calculates a PI control value based on a difference between the phase difference calculated by the phase difference calculation unit and a target value;
The motor system according to claim 5 , wherein the PWM creation unit calculates a PWM signal as the control data based on the sine wave data, the torque correction amount received from the torque storage unit, and the PI control value.

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