JP2006223097A - Permanent magnet motor, control method for permanent magnet motor, control device for permanent magnet motor, compressor, and refrigeration/air-conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a control device and a control method each capable of suppressing vibration and noise from a permanent magnet motor, and a compressor and a refrigeration/air conditioning device each mounted with the permanent magnet motor. <P>SOLUTION: In a variable speed motor using a permanent magnet which includes a stator having a plurality of phases of armature windings and a rotor mounted to a drive shaft, a PWM carrier frequency switching command circuit 20 connected to a speed control circuit 17 and an energization waveform switching command circuit 21 are provided, whereby a carrier frequency and a energization waveform can be switched in response to a motor rotational speed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a permanent magnet type motor used for driving a compressor of a refrigeration / air conditioner, for example, a control device thereof, a compressor equipped with a permanent magnet type motor, or a refrigeration / air conditioner.

  In recent years, for example, compressor motors of refrigerators and air conditioners are often used with permanent magnet motors that can easily control the rotation speed and are highly efficient. FIG. 18 shows a three-phase four-pole / 24-slot permanent magnet type motor used as a drive motor for a compressor for a conventional room air conditioner or refrigerator.

  In the figure, reference numeral 1 denotes a cylindrical stator core provided with 24 slots 2 extending in the axial direction on the inner peripheral surface, and a tooth portion 3 is formed between the slots 2. 4 is a winding inserted in each slot 2, and these windings 4 are formed by three phases of U phase, V phase, and W phase, and are distributed across the slots 2. This is a distributed winding type motor that is wound and Y-connected so as to form three-phase four-pole. Reference numeral 5 denotes a stator having a stator core 1 and a winding 4.

6 is a drive shaft having a rotor disposed on the axis of the stator 5 and supported by a bearing or the like so as to be rotatable with respect to the stator 5, 7 is a core portion of the rotor fixed to the drive shaft 6, 8 Is a plurality of permanent magnets fixed to the outer peripheral surface of the core portion 7 of the rotor, and these permanent magnets 8 are magnetized so that N-poles and S-poles alternate in the rotation direction. Reference numeral 9 denotes a rotor having a core portion 7 and permanent magnets 8, and a gap 10 is provided between the rotor 9 and the stator 5.
Recently, a magnet-embedded rotor in which a permanent magnet 8 is embedded in the core 7 is also used.

  Since the permanent magnet type motor configured as described above has a characteristic that the applied voltage and the rotational speed are in a substantially proportional relationship, the rotational speed is controlled by controlling the voltage applied to each phase of the motor. Can be done easily.

  Next, the drive circuit and drive principle of this motor will be described with reference to FIG. 19, FIG. 20, and FIG. FIG. 19 is a drive circuit diagram of a general motor often used for driving a motor, FIG. 20 is a diagram showing the order of switching of current to each phase of a conventional motor, and FIG. 21 is a conventional 120-degree rectangular wave energization It is the figure which showed the switching pattern in and the current waveform of each phase. The motor drive circuit includes a DC power supply unit 11, a main circuit unit 12, and a control circuit unit 13. The DC power supply unit 11 includes an electrolytic capacitor, a diode bridge circuit, and the like (not shown), converts AC power into DC power, and supplies the DC power to the main circuit unit 12. The main circuit unit 12 is composed of six switching elements Ua, Ub, Va, Vb, Wa, Wb and six free-wheeling diodes D1, D2,... D6, and each free-wheeling diode is in parallel with the switching elements. It is connected to the.

  Further, the switching elements Ua and Ub are connected in series to connect the arm part Uab, the switching elements Va and Vb are connected in series to connect the arm part Vab, and the switching elements Wa and Wb are connected in series. In total, three arms are formed. These arm portions Uab, Vab, and Wab are connected in parallel to form a three-phase bridge. In this main circuit portion, common nodes Uo, Vo, Wo of the switching elements of the three-phase arm portions Uab, Vab, Wab are connected to the corresponding motor terminal U, terminal V, terminal W, respectively. .

  The control circuit unit 13 includes an induced voltage detection unit 14, a rotor position calculation unit 15, a commutation control circuit unit 16, a speed control circuit unit 17, a PWM carrier frequency generation circuit 18, and a duty control unit 19. . Hereinafter, the operation principle of the control circuit unit 13 will be described.

First, the induced voltage of each phase generated by the rotational drive of the motor is detected by the induced voltage detector 14 connected to the output terminals U, V, W of the main circuit unit 12. The induced voltage is a counter electromotive force that is induced when the magnetic flux of the permanent magnet changes with the rotation of the rotor and interlinks with the winding of the stator. The number of motor turns is N, and the magnetic flux generated by the rotation of the rotor When the change is dF / dt, the induced voltage V can be expressed by equation (1) according to Faraday's law.
V = N · dF / dt (1)
That is, the induced voltage increases in proportion to the product of the number of turns of the motor and the time derivative of the magnetic flux generated by the permanent magnet. Therefore, since the induced voltage is proportional to the rotational speed, the rotational speed of the motor and the positional information of the rotor and the stator can be obtained by detecting the induced voltage.

  Next, based on the induced voltage waveform detected by the induced voltage detector 14, the rotor position calculator 15 calculates the rotor position. The rotor position can be detected by detecting the zero cross point (the point at which the induced voltage becomes 0V) of the induced voltage waveform detected by the induced voltage detector. From the equation (1), since the induced voltage V is proportional to the time derivative of the magnetic flux of the permanent magnet, the position where the change of the magnetic flux is the smallest, that is, the position where the magnetic pole center of the permanent magnet coincides with the magnetic pole center of the winding. Becomes the zero cross point of the induced voltage.

  Next, based on the rotor position information calculated by the rotor position calculation unit 15, the commutation control circuit unit 16 generates drive signals for the switching elements Ua, Ub, Uc, Va, Vb, and Vc of the main circuit unit 12. Then, each switching element of the main circuit unit 12 is driven and turned on / off.

On the other hand, the speed control circuit unit 17 connected in parallel with the rotor position calculation unit 15 receives the signal from the induced voltage detection unit 14 and calculates the rotation speed of the rotor so that the rotation speed of the rotor becomes equal to the command value. The voltage value is controlled. As a method for performing this voltage control, PWM (Pulse Width Modulate) is generally widely used.
In the PWM drive method, the speed control circuit unit 14 adjusts the ratio of the energization time in one cycle of the carrier (hereinafter referred to as the duty ratio) with respect to the constant carrier frequency generated by the PWM carrier frequency generation circuit 18. A control command is sent to the duty control unit 19. That is, when the detected rotational speed is lower than the rotational speed command value, the duty ratio is increased and the average voltage is increased. On the other hand, when the rotational speed is higher than the rotational speed command value, the average voltage is lowered by reducing the duty ratio. Thus, the rotational speed is controlled by changing the duty ratio.

  In this way, the control circuit unit 13 receives the position signal of the rotor 9 and performs ON / OFF control of each switching element of the main circuit unit 12 by the commutation control circuit unit 16 in synchronization therewith. FIG. 20 shows the order of switching of the current flowing through the windings of the respective phases connected in the three-phase Y connection. FIG. 21 corresponds to FIG. 20 and the switching timing of ON / OFF switching of each switching element and the terminals of each phase. The voltage and the current waveform which flows into each phase are shown.

  In FIG. 20, when the current in the direction flowing into the neutral point of the windings of the three-phase Y-connected windings is positive, the energization timing is divided into 6 steps, and S1, S2, S3, S4, and S5 shown below. The motor can be driven to rotate by repeatedly flowing the current in the order of S6. S1 from U phase to V phase, S2 from W phase to V phase, S3 from W phase to U phase, S4 from V phase to U phase, S5 from V phase to W phase, S6 from U phase The direction of current flow to the W phase is shown.

The switching timing of switching for realizing this current flow will be described with reference to FIG. In the figure, the horizontal axis is the electrical angle. The vertical axis indicates the energization timing of each switching element Ua, Ub, Va, Vb, Wa, Wb and current waveforms Iu, Iv, Iw flowing in the U phase, V phase, and W phase, respectively. The energization timing represents an ON state and an OFF state, and the current waveform is described in synchronization with the energization timing.
In the figure, first, in the first 60-degree section of the electrical angle indicated by S1, the switching element Ua and the switching element Vb are turned on, and the other switching elements are turned off. Thereby, an electric current can be sent between U-V of the round 1 shown by S1 of FIG. The voltage is controlled by PWM control in which a carrier of several kHz is superimposed on the switching element Ua of the arm unit Uab.

  Similarly, the switching elements Vb and Wa are turned on in S2, the switching elements Ub and Wa are turned on in S3, Ub and Va are turned on in S4, Va and Wb are turned on in S5, and Ua and Wb are turned on in S6. The ON / OFF of the switching element is sequentially switched every 60 degrees in electrical angle. In addition, the current flowing through the windings of each phase at this time is a rectangular waveform having a width of 120 degrees in electrical angle. Such an energization method is generally called 120-degree rectangular wave energization.

  In addition, since the switching elements Ua, Va, and Wa are duty controlled by turning the carrier ON / OFF by PWM control, the current increases when the carrier is ON, and the current decreases when the carrier is OFF. To do. This current fluctuation is called current ripple, and the current waveform is a waveform in which current ripple due to carrier ON / OFF fluctuation is superimposed. The amplitude of the current ripple is determined by a time constant of L / R where R is the winding resistance and L is the inductance of the winding. That is, the smaller the L / R, the sharper the current change, and the larger the current ripple when the carrier is on / off.

  As described above, by turning ON / OFF each switching element, a rotating magnetic field is generated by causing a current to flow through the stator windings according to the rotor position calculated by the rotor position calculation unit 15, and this rotating magnetic field is generated. The rotor 9 is rotationally driven by a magnetic attractive force and a repulsive force acting between the magnetic flux generated by the permanent magnet 7 and the permanent magnet 7.

  FIG. 22 is a diagram showing the frequency analysis results of the noise of the distributed winding type motor and the concentrated winding type motor, where the horizontal axis indicates the frequency and the vertical axis indicates the noise value. In the figure, when the distributed winding method and the concentrated winding method in which the winding is directly wound around the teeth portion 3 of the stator 5, the load with respect to the rated output is 40%, the rotation speed is 20%, and the PWM carrier frequency is 3 kHz. This is a result of frequency analysis of the noise value of the motor in the range of 0 to 10 kHz. In this figure, (a) is a measurement result of noise of the distributed winding specification, and (b) is a noise measurement result of the concentrated winding specification, with the horizontal axis representing the frequency and the vertical axis representing the noise value. From this result, comparing the two focusing on the frequency band near 3 kHz, it can be seen that the peak noise value near 3 kHz is larger when the concentrated winding is used than when the distributed winding is used. .

  Since the conventional permanent magnet type motor is configured as described above, it has a waveform in which a current ripple due to ON / OFF of a carrier is superimposed on a current waveform due to ON / OFF of the carrier by PWM control. This current ripple becomes a vibration source, causing vibrations of the stator and the rotor, and increasing high-frequency annoying noise. The vibration and noise associated with the PWM carrier are more prominent as the amplitude of the current ripple is larger. In particular, in a region where the rotational speed is relatively low, duty control is performed to increase the OFF time with respect to the PWM carrier ON time to lower the average voltage, so that the current drop during the OFF time increases and the current fluctuation increases. The current ripple was increased.

  In addition, in 120-degree rectangular wave energization, phase switching is performed every 60 degrees in electrical angle, so that a torque drop occurs at a period of 60 degrees in electrical angle, increasing torque fluctuation, that is, torque ripple. This torque ripple acts as an excitation force in the rotational direction, causing resonance of the drive shaft having the rotor, and increasing vibration and noise. In the case of a 24-slot 4-pole permanent magnet motor, torque ripple is generated at a cycle of 12 times per rotation of the motor, so that it becomes a low-frequency excitation source compared to the carrier frequency and the like. In the case of rotational driving, noise and vibration are caused by matching the resonance frequency of the drive shaft.

  Therefore, in order to reduce the current ripple, it is conceivable to increase the PWM carrier frequency over the entire rotation speed region and shorten the carrier OFF time. In this case, the carrier noise can be reduced, but the motor or compressor As the carrier frequency increases and the rotational speed of the motor increases, the leakage current generated in the inverter also increases the leakage current of the harmonic component of the inverter power supply. In particular, when applied to a compressor using a new HFC-based refrigerant that does not destroy the ozone layer, it must be used in combination with ester oil, polyglycol oil or the like having good compatibility. Compared to mineral oils used for CFC-based and HCFC-based refrigerants, the volume resistivity is low, so the leakage current increases, and it is a big challenge to reduce the leakage current and reduce the noise.

  In addition, when used in a compressor drive motor, torque ripple generated with the rotation of the motor serves as an excitation source, causing resonance of the drive shaft having the rotor, and the compressor piping via the compressor element section. And the phenomenon of increasing the vibration and noise of the muffler. For this reason, it has become necessary to take measures such as vibration and noise reduction with vibration-proofing materials, etc., increasing the cost of the compressor. Further, when used in a compressor motor of an air conditioner or a refrigerator, the compressor itself becomes a vibration source, resonates with the casing of the outdoor unit, and vibration and noise are amplified.

  In addition, in 120-degree rectangular wave energization, the current stored in the winding at the moment when the switching element is turned off at the time of phase switching passes through the free wheel diode connected in parallel with the switching element to return to the power supply unit. Circulation occurs. On the other hand, the non-energized section where the switching element is OFF during phase switching is the only section where the induced voltage can be detected. However, if the current circulation time is too long, it is induced in the reflux current due to the influence of the current circulation. The zero cross point of the current due to the voltage is interrupted, the zero cross point becomes difficult to understand, and the position of the rotor cannot be detected, and the motor has stepped out due to erroneous detection. This decrease in step-out has occurred at the time of high-speed rotation driving in which the circulation time relative to the rotation speed increases.

  When the rotor has a magnet-embedded structure, in addition to the Fleming's left-hand law that acts between the magnetic flux generated by the current flowing in the armature winding and the magnetic flux generated by the permanent magnet (magnet torque) Since an attractive force (reluctance torque) is generated by the action of magnetic flux generated by the current flowing in the iron part and the armature winding on the rotor surface, the reluctance torque is superimposed in addition to the magnet torque, Compared to this, torque ripple increased, causing even greater vibration and noise.

  In addition, when the concentrated winding method in which the winding is directly wound around the teeth portion 3 of the stator 5, the efficiency is better than that of the distributed winding specification, but the magnetomotive force distribution changes like a rectangular wave. Compared to a distributed winding having a sinusoidal magnetomotive force distribution, the torque ripple is further increased, and the peak associated with the ON / OFF of the PWM carrier. The sound was increasing.

  The present invention has been made to solve the above-described problems, and reduces the amplitude of a current ripple accompanying switching of a PWM carrier to suppress vibration and noise. Further, it is intended to prevent vibration and noise from increasing due to the influence of current ripple in the low rotation speed region. It is another object of the present invention to suppress torque ripple during low-speed rotation in 120-degree rectangular wave energization, reduce circumferential excitation force associated with torque ripple, and reduce vibration and noise due to drive shaft resonance. In addition, it suppresses the vibration source that causes vibration and noise by transmitting it to the piping and muffler of the compressor, and suppresses vibration and noise without taking measures against sound insulation with vibration-proof materials. The aim is to get a chance.

  Moreover, the vibration force generated by driving the compressor is reduced to suppress noise generated from the outdoor unit of the air conditioner or the refrigerator. Another object of the present invention is to obtain a highly reliable drive system by eliminating erroneous detection of the rotor position during high-speed rotation. Another object of the present invention is to reduce the excitation force in the rotational direction and suppress the vibration and noise caused by the resonance of the drive shaft even when using an embedded magnet rotor that has a large torque ripple due to its structure.

  Further, even when a concentrated winding stator containing a large amount of higher-order magnetomotive force harmonics is used, a low-noise permanent magnet motor is obtained by reducing the excitation force associated with torque ripple and PWM carrier frequency. For the purpose. In addition, even for compressors that use ester oils or polyglycol oils that are compatible with HFC refrigerants but have low volumetric efficiency, the compressor noise has been reduced and leakage current has been reduced. An object is to obtain a permanent magnet type motor for driving a compressor. It is another object of the present invention to obtain a refrigeration / air conditioning apparatus with low vibration and low noise.

  A permanent magnet motor according to a first aspect of the present invention is a variable speed motor using a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft, and is connected to the armature winding. An inverter circuit composed of a plurality of drive switching elements, carrier frequency generation means for generating a switching frequency of the switching element group, and switching element groups sequentially switched according to the carrier frequency generated by the carrier frequency generation means A control means, a rotor position detection means for detecting the position of the rotor, and a rotation speed calculation means for calculating the rotation speed based on position information from the rotor position detection means. The carrier frequency generated by the carrier frequency generation means is changed corresponding to the obtained rotation speed.

  The permanent magnet motor according to the second aspect of the present invention comprises an energization waveform switching means for sending an energization waveform signal to the control means, and a detection means for detecting the rotational speed, and the rotational speed detected by the detection means is adjusted. Accordingly, the energization waveform generated by the energization waveform switching means is switched.

  A permanent magnet motor according to a third aspect of the present invention is a variable speed motor using a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft, and is connected to the armature winding. And a control means for sequentially switching the switching element group, a conduction waveform switching means for sending a conduction waveform signal to the control means, and a detection means for detecting the number of rotations. The energization waveform generated by the energization waveform switching means is switched according to the rotational speed detected by the means.

  In the permanent magnet motor according to the fourth aspect of the present invention, in the rotational speed region where the rotational speed detected by the detecting means substantially coincides with the resonance frequency of the drive shaft, the energization waveform is a sine wave energization, In the rotation speed region other than the above, the energization waveform is switched so that the energization waveform is equivalent to 120 degrees in the electrical angle and the energization waveform is a 120-degree rectangular wave energization having a rectangular wave shape.

  The permanent magnet motor according to the fifth aspect of the present invention is a partial sine wave in which a part of the energization waveform is a sine wave shape in a rotation speed region in which the rotation speed detected by the detection means substantially coincides with the resonance frequency of the drive shaft. The energization waveform is switched so that energization is performed by an amount equivalent to 120 degrees in electrical angle and the energization waveform is a 120-degree rectangular wave energization in which the energization waveform is rectangular.

  In the permanent magnet motor according to the sixth aspect of the present invention, in the rotational speed region where the rotational speed detected by the detecting means substantially coincides with the resonance frequency of the drive shaft, the electrical waveform is a rectangular wave shape with an electrical angle of 120 degrees or more. The energizing waveform is switched so that the energizing waveform is a rectangular wave shape of 120 ° rectangular wave energization corresponding to 120 ° in electrical angle in the other rotation speed region. is there.

  In the permanent magnet motor according to the seventh aspect of the present invention, when the rotational speed exceeds a predetermined value, the energization waveform is energized only in a range of less than 120 degrees where the energization waveform is less than 120 degrees in electrical angle. It is made to do.

  A permanent magnet motor according to an eighth aspect of the present invention uses a permanent magnet embedded rotor in which a permanent magnet is embedded in the rotor.

  A permanent magnet motor according to a ninth aspect of the present invention is the permanent magnet motor driven by the control device according to any one of claims 1 to 9, wherein a winding is wound for each tooth portion provided between the slots. The attached concentrated winding stator is used.

  A permanent magnet motor according to a tenth aspect of the present invention is the permanent magnet motor according to claim 9 applied to a compressor driving motor.

  A permanent magnet motor according to an eleventh aspect of the present invention is a refrigeration / air-conditioning apparatus constituting a refrigeration cycle, wherein a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft are used. Generated by a transmission motor, an inverter circuit composed of a plurality of drive switching elements connected to the armature winding, carrier frequency generation means for generating a switching frequency of the switching element group, and carrier frequency generation means Control means for sequentially switching the switching element group according to the carrier frequency, rotor position detecting means for detecting the position of the rotor, and rotation speed calculating means for calculating the rotation speed based on position information from the rotor position detecting means And a carrier frequency generated by the carrier frequency generating means corresponding to the rotational speed obtained by the rotational speed calculating means. It is obtained so as to control a permanent magnet motor to change the wave number.

  A permanent magnet motor according to a twelfth aspect of the present invention is a refrigeration / air-conditioning apparatus constituting a refrigeration cycle, wherein a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft are used. In a variable speed motor, a control means configured by a plurality of driving switching elements connected to an armature winding, sequentially switching a switching element group, an energization waveform switching means for sending an energization waveform signal to the control means, and a rotation speed And an energization generated by the energization waveform switching means in a rotation speed region in which the rotation speed detected by the detection means substantially coincides with the resonance frequency of the drive shaft having the rotor or the refrigeration / air conditioning apparatus. The permanent magnet type motor is controlled so as to switch the waveform.

  The permanent magnet motor according to the thirteenth aspect of the present invention is applied to a compressor constituting a refrigeration cycle.

  The permanent magnet motor according to the fourteenth aspect of the present invention uses an HFC refrigerant as a refrigerant circulating in the refrigeration cycle.

  A permanent magnet motor according to a fifteenth aspect of the present invention is a variable speed motor using a permanent magnet having a multi-phase armature winding and a rotor, and a plurality of driving switchings connected to the armature winding. A carrier frequency generation step for generating a switching frequency for sequentially switching the switching element group of the inverter circuit constituted by the elements; a switching element switching step for sequentially switching the switching element group according to the carrier frequency generated in the carrier frequency generation step; A rotor position detecting step for detecting the position of the rotor, and a rotation speed calculating step for calculating the rotation speed based on the position information obtained by the rotor position detecting step. Carrier generated by carrier frequency generation step according to the number of rotations It is obtained so as to change the frequency.

  A permanent magnet motor according to a sixteenth aspect of the present invention is a variable speed motor using a permanent magnet having a multi-phase armature winding and a rotor, and a plurality of driving switchings connected to the armature winding. An energization waveform switching step for sending a signal of an energization waveform to an inverter circuit composed of elements, and a rotation speed detection step for detecting the rotation speed, wherein the energization waveform is determined according to the rotation speed detected by the rotation speed detection step. The energization waveform generated by the switching step is switched.

  As described above, the control device for a permanent magnet type motor according to claim 1 of the present invention is a variable speed motor using a stator having a plurality of phases of armature windings and a permanent magnet having a rotor on a drive shaft. , An inverter circuit composed of a plurality of drive switching elements connected to the armature winding, carrier frequency generation means for generating a switching frequency of the switching element group, and carrier frequency generated by the carrier frequency generation means Control means for sequentially switching the switching element group, rotor position detection means for detecting the position of the rotor, rotation speed calculation means for calculating the rotation speed based on position information by the rotor position detection means, The carrier frequency generated by the carrier frequency generating means is changed in accordance with the rotational speed obtained by the rotational speed calculating means. As a result, it is possible to operate at the optimum carrier frequency according to the motor speed, reduce the current ripple caused by the carrier, and reduce vibration and noise even when used in the low speed range. .

  The control device for a permanent magnet type motor according to the invention of claim 2 comprises an energization waveform switching means for sending an energization waveform signal to the control means, and a detection means for detecting the rotational speed, and the rotation detected by the detection means. Since the energization waveform generated by the energization waveform switching means is switched according to the number, it is possible to reduce the torque ripple at the time of phase switching due to resonance of the drive shaft, and to reduce vibration and noise. it can.

  The permanent magnet type motor control device according to claim 3 is connected to the armature winding in a variable speed motor using a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft. A control means comprising a plurality of drive switching elements and sequentially switching the switching element group, an energization waveform switching means for sending an energization waveform signal to the control means, and a detection means for detecting the rotational speed. Since the energization waveform generated by the energization waveform switching means is switched according to the rotation speed detected by, even if used in a low rotation speed region where the rotation speed substantially matches the resonance frequency of the drive shaft, The excitation force of the motor generated by resonance can be reduced, and a permanent magnet motor with low vibration and low noise can be obtained.

  According to a fourth aspect of the present invention, there is provided a control apparatus for a permanent magnet motor, wherein the energization waveform is a sine wave energization in a rotation speed region in which the rotation speed detected by the detecting means substantially coincides with the resonance frequency of the drive shaft. In the rotation speed range other than, the current is switched by the amount equivalent to 120 degrees in electrical angle, and the current waveform is switched so that the current waveform is a 120-degree rectangular wave with a rectangular wave shape. Therefore, torque ripple during phase switching can be reduced. A permanent magnet motor with low vibration and noise can be obtained.

  The control apparatus for a permanent magnet type motor according to claim 5 is a partial sine wave in which a part of the energization waveform has a sine wave shape in a rotation speed region where the rotation speed detected by the detection means substantially coincides with the resonance frequency of the drive shaft. Energization was performed, and in other rotation speed regions, the current was switched by an amount equivalent to 120 degrees in electrical angle, and the energization waveform was switched to a 120-degree rectangular wave with a rectangular waveform. Ripple can be reduced, and an inexpensive permanent magnet motor with low vibration and low noise can be obtained.

  According to a sixth aspect of the present invention, there is provided a control apparatus for a permanent magnet type motor, wherein an electric angle of 120 degrees or more is applied in a rotational speed region where the rotational speed detected by the detecting means substantially coincides with the resonance frequency of the drive shaft, and the energization waveform is rectangular. The energizing waveform is switched so that the energizing waveform is a rectangular wave-shaped 120 degree rectangular wave energizing by an amount equivalent to 120 degrees in the electrical angle in the other rotation speed region. Therefore, torque ripple at the time of phase switching can be reduced, and a low-vibration, low-noise permanent magnet motor can be obtained.

  In the control device for the permanent magnet type motor according to the invention of claim 7, when the rotational speed exceeds a predetermined value, the energization waveform is energized only in a range of less than 120 degrees energizing less than 120 degrees in electrical angle. Since the energization is less than that, the rotor position can be reliably detected, and a highly reliable motor and control method can be realized.

  Since the permanent magnet type motor control device according to the invention of claim 8 uses the permanent magnet embedded rotor in which the permanent magnet is embedded in the rotor, in addition to the magnet torque in accordance with Fleming's left-hand rule, the reluctance The component of the large torque ripple with the superimposed torque can be greatly reduced, and a control method for the permanent magnet motor with low vibration and low noise can be obtained.

  A permanent magnet motor according to a ninth aspect of the present invention is the permanent magnet motor driven by the control device according to any one of the first to ninth aspects, wherein a winding is wound around each tooth portion provided between the slots. In addition, since the concentrated winding stator is used, a torque ripple component caused by higher-order magnetomotive force harmonics can be suppressed, and an efficient permanent magnet motor with low vibration and low noise can be obtained.

  Since the compressor according to the invention of claim 10 uses the permanent magnet type motor of claim 9, the vibration of the drive shaft is not transmitted to the piping of the compressor and causes resonance, and the vibration isolator Therefore, it is possible to reduce the number of parts for countermeasures against resonance of piping, and to obtain an inexpensive, low vibration, low noise compressor.

  The refrigeration / air conditioning apparatus according to the invention of claim 11 is a refrigeration / air conditioning apparatus constituting a refrigeration cycle, wherein a variable speed using a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft. An inverter circuit composed of a plurality of drive switching elements connected to a motor, armature windings, carrier frequency generation means for generating a switching frequency of the switching element group, and carrier generated by the carrier frequency generation means Control means for sequentially switching the switching element group according to frequency, rotor position detection means for detecting the position of the rotor, and rotation speed calculation means for calculating the rotation speed based on position information from the rotor position detection means; The carrier frequency generated by the carrier frequency generating means corresponding to the rotational speed obtained by the rotational speed calculating means Since so as to control a permanent magnet motor to change the vibration of be used in a low speed range device, it is possible to obtain a refrigerating air-conditioning apparatus capable of reducing noise.

  A refrigeration / air conditioning apparatus according to a twelfth aspect of the present invention is a refrigeration / air conditioning apparatus constituting a refrigeration cycle, wherein a variable speed using a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft. In the motor, a control means constituted by a plurality of drive switching elements connected to the armature winding, sequentially switching the switching element group, an energization waveform switching means for sending an energization waveform signal to the control means, and a rotation speed And an energization waveform generated by the energization waveform switching means in a rotation speed region in which the rotation speed detected by the detection means substantially coincides with a resonance frequency of a drive shaft having a rotor or a refrigeration / air conditioning apparatus. Since the permanent magnet type motor is controlled so as to switch the rotation speed, the rotational speed is substantially the same as the resonance frequency of the drive shaft and the resonance frequency of the device. Cheap in the low speed range, to reduce the exciting force generated from the resonance, it is possible to obtain a low noise refrigerating and air conditioning apparatus with low vibration.

  Since the refrigeration / air-conditioning according to the invention of claim 13 is applied to the compressor constituting the refrigeration cycle, the vibration source generated from the compressor can be reduced, and the vibration is transmitted to an apparatus such as an outdoor unit. And a refrigeration / air-conditioning apparatus with low vibration and low noise can be obtained.

  In the refrigeration / air conditioning apparatus according to the fourteenth aspect of the present invention, since the HFC refrigerant is used as the refrigerant circulating in the refrigeration cycle, it is possible to obtain a highly reliable refrigeration / air conditioning apparatus that can reduce leakage current even at high speed operation. it can.

  According to a fifteenth aspect of the present invention, there is provided a control method for a permanent magnet type motor in a variable speed motor using a permanent magnet having a multi-phase armature winding and a rotor, and a plurality of drives connected to the armature winding. Carrier frequency generation step for generating a switching frequency for sequentially switching the switching element group of the inverter circuit composed of switching elements for switching, and a switching element switching step for sequentially switching the switching element group according to the carrier frequency generated in the carrier frequency generation step A rotor position detecting step for detecting the position of the rotor, and a rotational speed calculating step for calculating the rotational speed based on the position information obtained by the rotor position detecting step. It is generated by the carrier frequency generation step according to the obtained rotation speed. Since to change the carrier frequency, according to the rotation speed of the motor, will be able to operate at the optimum carrier frequency, it reduces the current ripple due to carrier, vibration, noise can be suppressed.

  According to a sixteenth aspect of the present invention, there is provided a control method for a permanent magnet type motor in a variable speed motor using a permanent magnet having a plurality of phases of armature windings and a rotor, and a plurality of drives connected to the armature windings. An energization waveform switching step for sending an energization waveform signal to an inverter circuit constituted by a switching element for use, and a rotation speed detection step for detecting the rotation speed, according to the rotation speed detected by the rotation speed detection step, Since the energization waveform generated by the energization waveform switching step is switched, it is possible to suppress the resonance of the drive shaft having the rotor accompanying the increase in the torque ripple in the low rotation speed region that substantially matches the resonance frequency of the drive shaft. The vibration and noise of the permanent magnet type motor can be suppressed.

Embodiment 1 FIG.
Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a control device and a control method of a permanent magnet type motor according to Embodiment 1 of the present invention, and FIG. 2 is a permanent magnet type motor using distributed windings that are rotationally driven by the control device of FIG. FIG.

  In the figure, reference numeral 1 denotes a cylindrical stator core provided with 24 slots 2 extending in the axial direction on the inner peripheral surface, and a tooth portion 3 is formed between the slots 2. Reference numerals 4 denote windings inserted into the respective slots 2, and these windings 4 are formed by three phases of U phase, V phase, and W phase, and are distributed windings across the slots 2. Are Y-connected so as to form a three-phase four-pole. Reference numeral 5 denotes a stator having a stator core 1 and a winding 4.

  6 is a drive shaft having a rotor disposed on the axis of the stator 5 and supported by a bearing or the like so as to be rotatable with respect to the stator 5; 7 is a core portion of the rotor fixed to the drive shaft 6; Reference numeral 8 denotes a plurality of permanent magnets fixed to the outer peripheral surface of the core portion 7, and these permanent magnets 8 are magnetized so that N poles and S poles are alternated. Reference numeral 9 denotes a rotor having a core portion 7 and permanent magnets 8, and a gap 10 is provided between the rotor 9 and the stator 5.

  Next, the drive circuit and operation of the present embodiment will be described with reference to FIG. In the figure, 11 is a DC power supply unit, 12 is a main circuit unit, and 13 is a control circuit unit. The DC power supply unit 11 includes an electrolytic capacitor, a diode bridge circuit, and the like (not shown), converts AC power into DC power, and supplies the DC power to the main circuit unit 12. The main circuit unit 12 is composed of six switching elements Ua, Ub, Va, Vb, Wa, Wb and six free-wheeling diodes D1, D2,... D6, and each free-wheeling diode is in parallel with the switching elements. It is connected to the.

  Further, the switching elements Ua and Ub are connected in series to connect the arm part Uab, the switching elements Va and Vb are connected in series to connect the arm part Vab, and the switching elements Wa and Wb are connected in series. In total, three arms are formed. These arm portions Uab, Vab, and Wab are connected in parallel to form a three-phase bridge. In this main circuit portion, common nodes Uo, Vo, Wo of the switching elements of the three-phase arm portions Uab, Vab, Wab are connected to the corresponding terminal U, terminal V, and terminal W of the motor.

  The control circuit unit 13 includes an induced voltage detection unit 14, a rotor position calculation unit 15, a commutation control circuit unit 16, a speed control circuit unit 17, a PWM carrier frequency generation circuit unit 18, a duty control unit 19, and a PWM carrier frequency switching. A command unit 20 and an energization waveform switching command unit 21 are included. Hereinafter, the operation principle of the control circuit unit 13 will be described.

  First, the induced voltage of each phase generated by the rotational drive of the motor is detected by the induced voltage detector 14 connected to the output terminals U, V, W of the main circuit unit 12. Based on the induced voltage waveform detected by the induced voltage detector 14, the rotor position calculator 15 calculates the rotor position from the zero cross point of the induced voltage. Next, based on the rotor position information calculated by the rotor position calculation unit 15, the commutation control circuit unit 16 generates ON / OFF signals of the switching elements Ua, Ub, Va, Vb, Wa, Wb of the main circuit unit 12. The switching element provided in the main circuit 12 is driven.

  On the other hand, the speed control circuit unit 17 connected in parallel with the rotor position calculation unit 15 receives the signal from the induced voltage detection unit 14 and calculates the rotation speed of the motor so that the rotation speed of the motor becomes equal to the command value. In addition, the voltage value is controlled by PWM (pulse width modulation) control.

  Further, upon receiving the rotational speed information of the speed control circuit 17, the PWM carrier frequency switching command circuit unit 20 changes the current fluctuation due to the current increase at the ON time and the current decrease at the OFF time in the duty control of the PWM carrier, that is, current ripple. The appropriate carrier frequency is selected in order to reduce the amplitude of noise and suppress vibration and noise. The carrier frequency selection can be easily extracted by experimentally obtaining the optimum carrier frequency characteristic with respect to the rotational speed in advance and storing it in a database in the PWM carrier frequency switching circuit.

  FIG. 4 is a diagram illustrating an example of a carrier frequency control pattern representing the present embodiment. In the figure, the horizontal axis represents the rotational speed and the vertical axis represents the carrier frequency. From the figure, the carrier frequency is set large in the relatively low rotational speed region, and the carrier frequency is set small in the other rotational speed regions.

Therefore, since the carrier frequency is increased in a relatively low rotational speed region, the energization OFF time in one cycle is shortened, current drop can be reduced, and vibration and noise due to current ripple can be reduced. As a result, the 3 kHz noise peak in FIG. 22 can be reduced. FIG. 17 is a diagram showing the relationship between frequency and noise when applied to a 1 KW class room air conditioner. In the figure, (a) shows the case where the carrier frequency is 5 kHz and the rotation speed 30S ⁻¹ , and (b) shows the case where the carrier frequency is 3 kHz and the rotation speed 30S ⁻¹ , and shows the measurement results under the same load conditions. In the figure, the horizontal axis represents frequency and the vertical axis represents noise value. It can be seen from FIG. 5B that a noise peak appears in the vicinity of 3 kHz when the carrier frequency is 3 kHz. When the carrier frequency is changed to 5 kHz ((a) in the figure) under the same conditions, it can be seen that the peak value of noise in the vicinity of 3 kHz decreases and the peak appears in the vicinity of 5 kHz.

  However, the peak value of 5 kHz is small and does not cause a problem. This is because by changing the carrier frequency from 3 kHz to 5 kHz, the OFF time in one cycle of the carrier is shortened and the current ripple is reduced, so that the peak appears but the peak value is small and does not cause a problem. . Therefore, it is shown that the influence on the noise and vibration of the apparatus is reduced through the drive shaft due to the influence of the current ripple by changing the carrier frequency to 5 kHz. In addition, the leakage current increases as the carrier frequency increases, but in this embodiment, the carrier frequency is reduced except in the low rotation speed region where it easily resonates with the drive shaft. A motor can be obtained.

  5 and 6 show another example of the carrier frequency control pattern. 5 and 6 are diagrams showing carrier frequency control patterns of the present embodiment. In the figure, the horizontal axis represents the rotational speed and the vertical axis represents the carrier frequency. FIG. 5 shows an example in which the carrier frequency in the low rotational speed region is increased and kept constant, and the carrier frequency is linearly reduced in accordance with other high speed rotational regions. FIG. 6 shows the carrier frequency in the low rotational speed region. This is an example in which the carrier frequency is increased stepwise as the number of rotations increases. Each of the control patterns shown in FIGS. 5 and 6 can prevent resonance when the rotational speed and the carrier frequency coincide.

  Thus, by increasing the carrier frequency while keeping the duty ratio constant, one cycle is shortened, the number of times the carrier is turned ON / OFF is increased, and the OFF time can be shortened. For example, by doubling the carrier frequency from 6 kHz to 12 kHz at the same rotation speed, the OFF time can be shortened by half and the current ripple can be reduced. FIG. 7 is a diagram showing a switching pattern and a current waveform of each phase in 120-degree rectangular wave energization when the carrier frequency is doubled with respect to FIG.

  In the figure, the horizontal axis represents the electrical angle. When the electrical angle is 2 poles, it represents one rotation at 360 degrees, and when it is 4 poles, it represents one rotation at 720 degrees. The vertical axis indicates the energization timing of each switching element Ua, Ub, Va, Vb, Wa, Wb, the terminal voltage in each of the U phase, V phase, and W phase, and the current waveform Iu that flows in each of the U phase, V phase, and W phase. Iv and Iw are shown. The energization timing represents an ON state and an OFF state, and the terminal voltage and current waveform are described in synchronization with the energization timing. From this figure, it can be seen that by doubling the carrier frequency, the current drop due to the energization OFF can be reduced, and the current ripple accompanying the ON / OFF of the PWM carrier can be greatly reduced.

  The reduction of the current ripple works more effectively in the region where the duty ratio is small with respect to the PWM carrier ON time, that is, in the region where the average voltage is small and the rotation speed is low and the load torque is small. Conversely, in a region where the rotational speed is high and the load torque is large, it is necessary to increase the average voltage by PWM control. Therefore, the duty ratio is increased and the OFF time is shortened with respect to the carrier ON time. In addition, current ripple can be suppressed.

  In addition, compressors that use HFC-based refrigerants are compatible with high-speed rotation regions where ester oil or polyglycol oil, which has good compatibility but low volume resistivity and high leakage current, is used. However, in the rotational speed region other than the rotational speed region that resonates with the drive shaft and the equipment to be mounted, if the PWM carrier frequency is reduced, the harmonic component of the inverter power supply leaks and the leakage current is reduced. Not only can the increase be prevented, but also the peak sound accompanying the PWM carrier frequency can be reduced.

  The energization waveform switching command circuit unit 21 connected in parallel with the PWM carrier frequency switching command circuit unit 20 receives the signal from the speed control circuit unit 17, calculates the rotational speed of the motor, and switches the phase of each switching element. The appropriate energization waveform is selected to reduce the torque ripple associated with the vibration and suppress vibration and noise, and the waveform signal is sent to the commutation control circuit unit 16. As with the PWM carrier frequency switching command circuit unit 20, the selection of the energization waveform is performed by experimentally deriving the optimum characteristics of the energization waveform with respect to the rotational speed in advance and storing it in the energization waveform switching command circuit unit 21 as a database. Therefore, it can be easily extracted.

  In order to suppress the torque ripple, it is necessary to suppress a drop in the torque ripple at the time of phase switching. For this reason, in this embodiment, the energization waveform is switched. 8, FIG. 9 and FIG. 10 are examples of energization waveforms for reducing torque ripple, in which the horizontal axis represents the electrical angle and the vertical axis represents the current value flowing in each phase. FIG. 8 is a diagram showing a current waveform of a sine wave energization in which the current waveform is a sine wave waveform. FIG. 9 is a graph showing a current value of approximately 15 degrees before and after the zero cross point with respect to the sine wave waveform current of FIG. FIG. 10 is a diagram showing a current waveform of partial sine wave energization with a partial sine wave waveform as shown in FIG. It is the figure which expressed the electric current waveform of the overlap energization which suppressed the fall of the torque at the time of phase switching by expanding the generation | occurrence | production area | region and making it overlap with the generated torque of another phase.

  The torque ripple suppression effect decreases in the order of sine wave energization, partial sine wave energization, overlap energization, 120 degree rectangular wave energization, but the cost is 120 degree rectangular wave energization, overlap energization, partial sine wave energization, sine Since the frequency increases in the order of wave energization, an effective effect can be obtained by properly using each device in accordance with the rotation speed, load conditions, and required performance (vibration, noise). FIG. 11 is a diagram showing the relationship between the load torque characteristic with respect to the rotational speed and the energization waveform as the operation range of the compression drive motor mounted on the room air conditioner. In the figure, the horizontal axis represents the rotational speed, and the vertical axis represents the load torque. As shown in the figure, in the relatively low rotation speed region where the resonance frequency of the drive shaft and equipment is likely to match, the above-described overlap energization, partial sine wave energization, and sine wave energization are used, and then an inexpensive 120-degree rectangular wave energization is performed. Switch to.

Rotational speed of the motor when the compressor for example room air conditioner, since it is variable speed controlled over a wide range and 60min ^-1 ~8000min ^-1, will be hit the resonant frequency of the drive shaft in either frequency band Therefore, it is very difficult to avoid resonance with the drive shaft by the conventional 120-degree rectangular wave energization. In particular, in the case of a compressor motor, when the axial resonance of the rotor is several hundred Hz and the period of the torque ripple is this motor (three-phase four-pole six-slot), if f is a frequency, 12f (12 times in one rotation) And occurs at the low-speed rotation range, and the resonance frequency of the drive shaft is encountered.

  For this reason, in the low-speed rotation region that resonates with the drive shaft, the energization waveform switching command circuit unit 21 suppresses torque ripple that becomes an excitation source that increases resonance with the drive shaft. By enabling switching to sine wave energization or overlap energization, a permanent magnet motor with low vibration and low noise can be obtained while avoiding resonance with the drive shaft.

  In addition, when the motor operating with 120-degree rectangular wave energization reaches a preset speed at which the recirculation time becomes longer and the zero cross point of the induced voltage is buried in the circulating current, the set speed has been exceeded. Is detected by the speed control circuit unit 17. When it is detected that the speed control circuit unit 17 has exceeded the set rotational speed, the energization waveform switching command circuit unit 21 receives the signal from the speed command circuit unit 17 and, as shown in FIG. An energization waveform switching command is sent to the commutation control circuit 16 so that the rectangular wave energization of less than 120 degrees is made smaller. FIG. 12 is a diagram showing a current waveform of energization less than 120 degrees, where the horizontal axis represents the electrical angle and the vertical axis represents the current value of each phase, and the energization sections of each phase are less than 120 degrees that do not overlap. The current waveform of rectangular wave energization is shown.

  By switching to rectangular wave energization of less than 120 degrees, the zero cross point of the induced voltage is not buried by the influence of the circulating current, and the rotor position can be reliably detected, and a highly reliable permanent magnet motor And a control device can be obtained. In the present embodiment, the sensorless permanent magnet type motor that detects the position of the rotor by the induced voltage detection unit 14 has been described. However, the sensorless need not be separately provided, and an encoder may be attached to the rotor shaft, or a Hall element may be attached to the stator. A similar effect can be obtained by using a permanent magnet motor with a sensor attached to the motor.

Embodiment 2. FIG.
In the first embodiment of the present invention, a permanent magnet type motor having a surface magnet arrangement type structure in which the permanent magnet 6 is arranged on the surface of the rotor of the permanent magnet type motor has been described as an example. For example, FIG. As shown in FIG. 6, the present invention can also be applied to a structure in which a permanent magnet is embedded in the rotor. 13 is a cross-sectional view of a rotor having a D-shaped permanent magnet embedded structure in which D-shaped permanent magnets are arranged so that the arc side faces the drive axis direction, and FIG. 14 is a V-shape in which eight rectangular magnets are arranged in a V-shape. FIG. 15 is a sectional view of a rotor having a permanent magnet embedded structure in which four rectangular parallelepiped permanent magnets are arranged in a mouth shape.

  In the figure, 66, 76, 86 are drive shafts, 67, 77, 87 are core parts of the rotor, 68, 78, 88 are permanent magnets, and 69, 79, 89 are rotors. Operation and drive control are the same as in the first embodiment. Unlike the magnet surface arrangement type rotor, the embedded magnet type rotor as shown in FIGS. 13, 14, and 15 is a framing generated by the action of the magnetic flux generated by the current flowing through the armature winding and the magnetic flux generated by the permanent magnet. In addition to the torque that follows the left hand rule (magnet torque), the magnetic flux generated by the current flowing in the armature winding, and the shape of the iron part where the magnet is embedded and the part where it is not embedded change as a result of embedding. The force (reluctance torque) that attracts the iron part of the rotor surface due to the rotor acts and the torque ripple increases as compared with the magnet surface arrangement type rotor. Therefore, the load shown in FIG. By switching to a sinusoidal drive that can reduce torque ripple by the energization waveform switching circuit unit 21 in the region, compared to a magnet surface arrangement type rotor, The rotor shaft resonance caused by Rukurippuru can be greatly reduced, the noise can be suppressed.

Embodiment 3 FIG.
In the third embodiment, instead of the distributed winding stator shown in the first embodiment, a concentrated winding stator in which a winding is directly wound around each magnetic pole tooth shown in FIG. The case where it applies to is demonstrated. FIG. 3 is a cross-sectional view of a permanent magnet type motor using concentrated windings, and 51 is a cylindrical stator core having six slots 52 extending in the axial direction on the inner peripheral surface. The teeth part 53 is formed in the. Reference numerals 54 denote windings inserted into the slots 52, respectively. These windings 54 are formed by three phases of U phase, V phase, and W phase, and are directly wound around the slots 52. The wire specifications are Y-connected to form three-phase four-pole. Reference numeral 55 denotes a stator having a stator core 51 and a winding 54.

  56 is a drive shaft having a rotor disposed on the axis of the stator 55 and supported by a bearing or the like so as to be rotatable with respect to the stator 55; 57 is a core portion of the rotor fixed to the drive shaft 56; Reference numeral 58 denotes a plurality of permanent magnets fixed to the outer peripheral surface of the core portion 57, and these permanent magnets 58 are magnetized so that N poles and S poles are alternated. Reference numeral 59 denotes a rotor having a core portion 57 and permanent magnets 58, and a gap 60 is provided between the rotor 59 and the stator 55. The drive circuit and operation are the same as those in the first embodiment.

  When concentrated windings are used for the stator, the magnetomotive force distribution created on the stator side changes in a rectangular wave, so there are many higher-order harmonic components compared to a distributed winding type stator that changes sinusoidally. Contains. Therefore, a permanent magnet type motor using concentrated winding is inevitably a motor having a large torque ripple as compared with a permanent magnet type motor using a distributed winding stator. Therefore, for the permanent magnet type motor using the concentrated winding stator, the torque ripple is suppressed by the energization waveform switching command circuit unit 21 in the low load and low rotation region by using the method shown in the first embodiment of the present invention. By switching to the sine wave drive that can be performed, the resonance of the drive shaft having the rotor accompanying the torque ripple can be greatly reduced, and noise can be suppressed.

  3 shows the structure of 6 slots and 4 poles, it can be applied to all combinations in which the rotor can be rotationally driven, such as 3N slots 2N poles and 3N slots 4N poles, where N is an integer of 1 or more. Needless to say.

Embodiment 4 FIG.
FIG. 16 is a diagram showing a configuration when the permanent magnet motor shown in the first to third embodiments is applied to a compressor used in a refrigeration / air conditioning apparatus such as a room air conditioner or a refrigerator.

  In the figure, reference numeral 22 denotes a compressor housing, which has a drive shaft 6 having a rotor 9 and a stator 5 therein. The stator 5 is fixed to the compressor housing 22 by shrink fitting or the like, and a rotor 9 is inserted into the stator 3 with a gap 10 of about 0.5 to 1 mm inside. The drive shaft is held in a rotatable state. Further, a suction pipe 25 for sucking the refrigerant into the compressor element section 24 and a discharge pipe 23 for discharging the compressed refrigerant are connected to the casing 22 of the compressor.

  Therefore, when resonance occurs in the drive shaft 6, it is transmitted to the compressor element 24 and is transmitted to the compressor casing 22, the suction pipe 25, and the discharge pipe 23, causing vibration and noise of the compressor. Furthermore, the vibration and noise of the compressor vibrate the outdoor unit and the indoor unit on which the compressor of the refrigeration / air conditioner is mounted, generating noise. However, if the permanent magnet motor and its control method described in the first to third embodiments are applied to the compressor of the refrigeration / air-conditioning apparatus, the vibration of the drive shaft 6 having the rotor causes the compressor and compressor to vibrate. Transmission to the suction pipe 25 and the discharge pipe 23 does not cause resonance, and vibration and noise can be reduced. Moreover, parts for measures against resonance of piping such as vibration-proof materials can be reduced, and a low-cost, low-vibration, low-noise compressor and refrigeration / air-conditioning apparatus can be obtained.

It is a block diagram which shows the control apparatus and control method of a permanent magnet type motor by Embodiment 1 of this invention. It is sectional drawing of the permanent magnet type motor using the distributed winding by Embodiment 1 of this invention. It is sectional drawing of the permanent magnet type motor using the concentrated winding by Embodiment 3 of this invention. It is a figure which shows the control pattern of the carrier frequency of the permanent magnet type motor by Embodiment 1 of this invention. It is a figure which shows the control pattern of the carrier frequency of the permanent magnet type motor by Embodiment 1 of this invention. It is a figure which shows the control pattern of the carrier frequency of the permanent magnet type motor by Embodiment 1 of this invention. It is the figure which showed the switching pattern in 120 degree | times rectangular wave energization by Embodiment 1 of this invention, the terminal voltage of each phase, and the current waveform of each phase. It is a figure showing the current waveform of sine wave energization by Embodiment 1 of the present invention. It is a figure showing the current waveform of the partial sine wave energization by Embodiment 1 of the present invention. It is a figure showing the electric current waveform of the overlap energization by Embodiment 1 of this invention. It is the figure which showed the relationship between the characteristic of the load torque with respect to the rotation speed by the Embodiment 1 of this invention, and an energization waveform. It is the figure which showed the current waveform of the electricity supply less than 120 degree | times by Embodiment 1 of this invention. It is rotor sectional drawing of the D-shaped permanent magnet embedding structure by Embodiment 2 of this invention. It is rotor sectional drawing of the V-shaped permanent magnet embedding structure by Embodiment 2 of this invention. It is rotor sectional drawing of the mouth shape permanent magnet embedding structure by Embodiment 2 of this invention. It is a figure which shows the structure at the time of applying the permanent magnet type motor by Embodiment 3 of this invention to a compressor. It is a figure showing the relationship between the frequency and noise at the time of applying the permanent magnet type motor by Embodiment 1 of this invention to a room air conditioner. It is sectional drawing of the permanent magnet type | mold motor of the 3 phase 4 pole 24 slot used as a drive motor of the conventional compressor. It is a drive circuit diagram of a conventional motor. It is the figure which showed the order in which the electric current to each phase of the conventional motor switches. It is the figure which showed the switching pattern in the conventional 120 degree | times rectangular wave energization, the terminal voltage of each phase, and the current waveform of each phase. It is a figure which shows the frequency analysis result of the noise of the motor of a distributed winding system and the motor of a concentrated winding system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Stator core, 2 slots, 3 teeth part, 4 windings, 5 stator, 6 Drive shaft, 7 Rotor core part, 8 Permanent magnet, 9 Rotor, 10 Air | gap, 11 DC power supply part, 12 Main circuit part, 13 Control circuit Unit, 14 induced voltage detection unit, 15 rotor position calculation unit, 16 commutation control circuit unit, 17 speed control circuit unit, 18 PWM carrier frequency generation circuit unit, 19 duty control unit, 20 PWM carrier frequency switching command circuit unit, 21 Energization waveform switching command circuit unit, 22 Compressor housing, 23 Discharge piping, 24 Compressor element unit, 25 Suction piping, 55 Stator, 56 Drive shaft, 57 Rotor core, 59 Rotor, 60 Air gap, 66 Drive shaft 67 Rotor core, 68 Permanent magnet, 69 Rotor, 76 Drive shaft, 77 Rotor core, 78 Permanent magnet, 79 Data, 86 drive shaft, 87 core part of rotor, 88 permanent magnet, 89 rotor.

Claims (16)

In a variable speed motor using a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft, an inverter constituted by a plurality of drive switching elements connected to the armature winding A circuit, carrier frequency generating means for generating a switching frequency of the switching element group, control means for sequentially switching the switching element group according to the carrier frequency generated by the carrier frequency generating means, and detecting the position of the rotor And a rotation speed calculation means for calculating the rotation speed based on position information from the rotor position detection means, corresponding to the rotation speed obtained by the rotation speed calculation means. And changing the carrier frequency generated by the carrier frequency generating means. Other control devices. An energization waveform switching means for sending an energization waveform signal to the control means; and a detection means for detecting the number of rotations. The energization generated by the energization waveform switching means according to the number of rotations detected by the detection means. 2. The permanent magnet type motor control device according to claim 1, wherein the waveform is switched. In a variable speed motor using a stator having a plurality of phases of armature windings and a permanent magnet having a rotor on a drive shaft, the variable speed motor includes a plurality of driving switching elements connected to the armature windings. A control means for sequentially switching the element group, an energization waveform switching means for sending an energization waveform signal to the control means, and a detection means for detecting the rotation speed, according to the rotation speed detected by the detection means, A control apparatus for a permanent magnet type motor, wherein the energization waveform generated by the energization waveform switching means is switched. In the rotational speed region where the rotational speed detected by the detecting means substantially coincides with the resonance frequency of the drive shaft, the energization waveform is a sine wave energization having a sine wave shape, and in other rotational speed regions, the electrical angle is equivalent to 120 degrees. 4. The control apparatus for a permanent magnet motor according to claim 3, wherein the energization waveform is switched so that the energization waveform is a 120-degree rectangular wave energization having a rectangular wave shape. In the rotational speed region where the rotational speed detected by the detecting means substantially coincides with the resonance frequency of the drive shaft, partial sine wave energization in which a part of the energization waveform has a sine wave shape is used. 4. The control apparatus for a permanent magnet type motor according to claim 3, wherein the energization waveform is switched so that the energization is performed by an amount corresponding to a degree and the energization waveform is a 120-degree rectangular wave energization having a rectangular wave shape. In the rotational speed region where the rotational speed detected by the detecting means substantially coincides with the resonance frequency of the drive shaft, an electrical angle of 120 degrees or more is applied, and an energized waveform is an overlapping rectangular wave, and the other rotational speeds. 4. The control apparatus for a permanent magnet motor according to claim 3, wherein the energization waveform is switched in such a way that the energization is equivalent to 120 degrees in the electrical angle and the energization waveform is a 120-degree rectangular wave energization having a rectangular wave shape. . When the rotation speed exceeds a predetermined value, the energization waveform is less than 120 degrees with an electrical angle of less than 120 degrees, and the energization waveform is a rectangular wave with less than 120 degrees energization with a rectangular wave shape. The control device for a permanent magnet type motor according to claim 3. 8. A permanent magnet type motor driven by the control device according to claim 1, wherein a permanent magnet embedded rotor having a permanent magnet embedded therein is used. motor. 9. A permanent magnet motor driven by the control device according to claim 1, wherein a concentrated winding stator in which a winding is wound for each tooth portion provided between the slots is used. Magnet type motor. 10. A compressor in which the permanent magnet motor according to claim 8 is applied to a drive motor. In a refrigeration / air-conditioning apparatus constituting a refrigeration cycle, a variable speed motor using a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft, and a plurality connected to the armature winding An inverter circuit composed of a plurality of driving switching elements, carrier frequency generation means for generating a switching frequency of the switching element group, and switching the switching element group in accordance with the carrier frequency generated by the carrier frequency generation means A control means; a rotor position detection means for detecting the position of the rotor; and a rotation speed calculation means for calculating a rotation speed based on position information from the rotor position detection means. The carrier frequency generated by the carrier frequency generator is changed according to the rotation speed obtained by the calculator. Refrigeration and air-conditioning system and controls a permanent magnet type motor as. In a refrigeration / air-conditioning apparatus constituting a refrigeration cycle, in a variable speed motor using a stator having a multi-phase armature winding and a permanent magnet having a rotor on a drive shaft, a plurality connected to the armature winding A control means configured to sequentially switch the switching element group configured by a plurality of driving switching elements, an energization waveform switching means for sending an energization waveform signal to the control means, and a detection means for detecting the number of rotations, Permanent magnet type so that the energization waveform generated by the energization waveform switching means is switched in the rotation speed region where the rotation speed detected by the detection means substantially coincides with the drive shaft having the rotor or the resonance frequency of the refrigeration / air conditioning apparatus. A refrigeration / air-conditioning apparatus characterized by controlling a motor. The refrigeration / air conditioning apparatus according to claim 11 or 12, wherein the refrigeration / air conditioning apparatus is applied to a compressor constituting a refrigeration cycle. 14. The refrigeration / air-conditioning apparatus according to claim 11, wherein an HFC-based refrigerant is used as the refrigerant circulating in the refrigeration cycle. In a variable speed motor using a permanent magnet having a multi-phase armature winding and a rotor, the switching element group of the inverter circuit configured by a plurality of driving switching elements connected to the armature winding A carrier frequency generating step for generating a switching frequency for sequentially switching, a switching element switching step for sequentially switching the switching element group according to the carrier frequency generated in the carrier frequency generating step, and a rotor for detecting the position of the rotor A position detection step, and a rotation speed calculation step for calculating a rotation speed based on the position information obtained by the rotor position detection step, and depending on the rotation speed obtained by the rotation speed calculation step, Change the carrier frequency generated by the carrier frequency generation step Control method of a permanent magnet motor, characterized in that the so that. In a variable speed motor using a multi-phase armature winding and a permanent magnet having a rotor, an energization waveform signal is applied to an inverter circuit composed of a plurality of driving switching elements connected to the armature winding. An energization waveform switching step to be transmitted; and a rotation speed detection step for detecting the rotation speed, wherein the energization waveform generated by the energization waveform switching step is switched according to the rotation speed detected by the rotation speed detection step. A control method for a permanent magnet motor, characterized in that

Images