JP2005184885A - Drive controller of motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To readily realize regulation of a current ratio of two phase winding currents Im, Ia, while retaining a phase difference of 90°, as it is, by regulating the phase of a voltage waveform Vc applied to the common terminal of two-phase windings, to realize generating of an optimum rotary magnetic field, in response to the specification state of the motor, and to provide high efficiency and low noise. <P>SOLUTION: The drive controller of the motor 4, having the two-phase stator windings (a main winding 4a and an auxiliary winding 4b) freely regulates the voltage phase of the voltage waveform Va of the auxiliary winding 4b, the voltage phase, the voltage wave high value of the voltage waveform Vc of a common terminal 5c of the two-phase windings, and the voltage phase high value with the voltage waveform Vm of the main winding 4a as a reference, by an inverter circuit 3 having six elements. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a drive control device for a motor having a two-phase stator winding, and uses an inverter to change the rotation speed of a compressor equipped with a single-phase induction motor in a refrigeration system such as a refrigerator. The refrigeration capacity can be varied.

  In a refrigeration system such as a refrigerator, a single-phase induction motor has been widely used as a compressor that is the heart of the refrigeration system. In general, a single-phase induction motor has a two-phase winding of a main winding and an auxiliary winding to increase its efficiency, and is driven by a driving capacitor.

  However, in this method, since the rotational speed of the motor is always constant, a large amount of refrigeration capacity is obtained when the refrigeration load is small, and therefore, this method is very wasteful.

  In order to efficiently operate this type of single-phase induction motor, it is necessary to maintain the phase difference between the current Im flowing through the main winding and the current Ia flowing through the auxiliary winding at 90 degrees. However, the conventional operating capacitor Cr has a problem that the efficiency is high in a certain range of the load of the single-phase induction motor, but the efficiency is not high in other load ranges.

  Furthermore, various troubles occur due to the operation capacitor for the phase advance. For example, when the frequency is lowered, the phase advance capacitor is saturated, so that almost no current flows through the motor auxiliary winding, and when the frequency is increased, the phase advance capacitor generates heat. An inverter control system that changes the power supply frequency over a wide range could not be applied to a single-phase induction motor.

  As a control device for an inverter that drives a two-phase induction motor without a phase advance capacitor, PWM (Pulse Width Modulation) control allows the drive voltage, current direction, and frequency to be varied. There are four switching elements, and eight switching elements in total.

  Also, recent two-phase motor drive control devices are configured with six switching elements (see, for example, Patent Document 1) or configured with four switching elements (for example, see Patent Document 2). Has been proposed.

  The conventional motor drive control apparatus will be described below with reference to the drawings.

  FIG. 8 shows an example in which a conventional motor drive control device is applied to a compressor used in a refrigeration system such as a refrigerator.

  In FIG. 8, 10 is a commercial power source, and in the case of a general Japanese home, a single-phase alternating current of 100 V 50 Hz or 60 Hz is generally used.

  Reference numeral 11 denotes a rectifier circuit that converts the AC voltage of the commercial power supply 10 into a DC voltage. The rectifier circuit 11 is a voltage doubler rectifier circuit, and obtains DC280V from AC100V.

  The rectifier circuit 11 is a bridge connection of four rectifier diodes 11a to 11d. The positive terminal of the electrolytic capacitor 11e is connected to the connection point between the rectifier diode 11a and the rectifier diode 11c that are bridge-connected, and the negative terminal of the electrolytic capacitor 11f is connected to the connection point between the rectifier diode 11b and the rectifier diode 11d that are bridge-connected. Connected.

  Further, the negative terminal of the electrolytic capacitor 11e and the positive terminal of the electrolytic capacitor 11f are directly connected, and are connected to the connection point between the rectifier diode 11c and the rectifier diode 11d. By connecting in this way, among the AC input of the commercial power supply 10, the electrolytic capacitor 11e is charged in the positive half cycle, and the electrolytic capacitor 11f is charged in the negative half cycle. By rectifying in this way, DC 280V rectified with a double voltage is generated between the negative terminal of the electrolytic capacitor 11f and the positive terminal of the electrolytic capacitor.

  Reference numeral 12 denotes an inverter circuit which converts the DC voltage output rectified by the rectifier circuit 11 into a two-phase AC having an arbitrary frequency and an arbitrary voltage.

  The inverter circuit 12 bridges the switching elements 12a to 12d. In this embodiment, an FET is used as a switching element. Each switching element 12a to 12d includes a high-speed diode in parallel in the reverse current direction. The built-in high-speed diode functions to flow a circulating current when the switching elements 12a to 12d are turned off.

  A compressor 13 circulates the refrigerant in the refrigeration system. The compressor 13 includes a compression element and a two-phase induction motor 14 in a hermetically sealed container. The rotational motion generated by the two-phase induction motor 14 is transmitted as a reciprocating motion to the compression element via a shaft having a crank, and converted into a compression work by the piston reciprocating in the cylinder.

  The induction motor 14 includes a stator (not shown) having a main winding and an auxiliary winding, and having a two-phase winding 15 with one terminal serving as a common terminal, and a cage rotor 16.

  Reference numeral 17 denotes voltage pattern selection means, which selects an optimum voltage pattern set in advance according to the set frequency set by the frequency setting means 18. According to the selected voltage pattern, the voltage applied to the main winding is set by the main winding voltage setting means 19, the voltage applied to the auxiliary winding is set by the auxiliary winding voltage setting means 20, and the phase setting means 21 is set. To set the phase difference between the main winding voltage (or current) and the auxiliary winding voltage (or current).

  Reference numeral 22 denotes a waveform generating means, which receives the parameters set by the frequency setting means 18, the main winding voltage setting means 20, the auxiliary winding voltage setting means 20, and the phase setting means 21, and switches the inverter circuit 12 corresponding thereto. An on / off signal is generated for the elements 12a to 12d. Here, a signal is generated so as to obtain a desired output waveform by PWM (pulse width modulation) control.

  Reference numeral 23 denotes drive means for turning on / off the switching elements 3 a to 3 d of the inverter circuit 3 in accordance with an on / off signal generated from the waveform generating means 22.

  Reference numeral 24 denotes a current sensor that detects a current (ie, motor current) flowing between the common terminal of the two-phase winding 15 of the induction motor 14 and the middle point of the voltage doubler rectifier circuit 11. Use a current transformer or DC current sensor.

  Reference numeral 25 denotes state detection means, which receives the output of the current sensor 24, the output voltage (DC voltage) of the voltage doubler rectifier circuit 11 and the like as input, and the operation state (load state) of the compressor 13 and the input voltage of the commercial power source 1 Detect status and so on.

  26 is a correction means, which corrects the main winding voltage, the auxiliary winding voltage and the phase according to the state detected by the state detection means 25, respectively, and the main winding voltage setting means 19, the auxiliary winding voltage setting means 20, A signal is sent to the phase setting means 21 or the like, and the parameters are changed so as to be in an optimum state.

  Here, the motor current and the DC voltage are to detect the state, but may of course be protected. For example, when the motor current increases, it is in an overload state, and a decrease or increase in input voltage can be detected by a DC voltage. However, since the short circuit between the upper and lower arms of the inverter cannot be detected only by these detections, it is necessary to detect the DC bus current using a separate shunt resistor or the like.

  The basic operation of the control device of the refrigeration system configured as shown in FIG. 8 will be described with reference to FIG. FIG. 9 is a timing chart of the control device of the conventional refrigeration system.

  In FIG. 9, the upper four timing charts show on / off timings of the switching elements 12 a to 12 d of the inverter circuit 12.

  Here, it is assumed that the winding connected to the switching elements 12a and 12b is a main winding, and the winding connected to the switching elements 12c and 12d is an auxiliary winding. The lower two timing charts in FIG. 9 are a main winding current Im and an auxiliary winding current Ia, respectively. The horizontal axis indicates the phase where one cycle of the output waveform is 360 degrees.

  The switching element 12a is chopping between 90 degrees and 270 degrees in phase, and the pulse width is controlled so that the pulse width (that is, area) of the PWM control approaches a sine wave. The pulse width is narrow in the vicinity of 90 degrees and 270 degrees, and is turned on / off so as to be maximum near 180 degrees. The output voltage can be controlled by adjusting the pulse width. The switching element 12b performs PWM control in a section where the switching element 12a is at rest, that is, between 270 degrees and 90 degrees.

  Further, the switching element 12c performs switching advanced by a phase difference φ (90 degrees in FIG. 9) from the switching element 12a, and performs PWM control in a section from 0 degrees to 180 degrees. Further, the switching element 12d performs PWM control in a section where the switching element 12c is at rest, that is, between 180 degrees and 360 degrees.

  The current Im of the main winding of the induction motor 14 has a sinusoidal waveform that crosses zero at 90 degrees and 270 degrees, but in reality, it has a waveform including harmonics of the carrier frequency component of PWM control. On the other hand, the auxiliary winding current Ia has a waveform whose phase is advanced by φ (90 degrees in this example) from the main winding current Im.

  FIG. 10 is a characteristic diagram showing the relationship between voltage and motor efficiency in the conventional form.

  In FIG. 10, characteristic 27 shows the motor efficiency when the voltage at frequency F4 and load torque T4 is changed. When the voltage is high, the iron loss increases due to magnetic flux saturation and the efficiency is lowered. Conversely, when the voltage is low, the current increases and the copper loss increases and the efficiency is lowered. V4 exists.

Characteristic 28 shows the motor efficiency when the voltage at frequency F5 and load torque T5 is changed. Similar to the characteristic 27, there is an optimum voltage value V5. Here, when frequency F4 <frequency F5, as described above, an optimum voltage is obtained as load torque T4 <load torque T5.
JP-A-5-344750 JP 2001-309692 A

  However, the above-described conventional configuration is based on voltage doubler rectification, and when full voltage rectification is used, there is a drawback that current does not flow and does not operate. Also, in regions with high voltage such as overseas, the voltage doubler rectification method has disadvantages such as a large circuit and high cost when considering the withstand voltage of electrical components.

  In recent years, an IPM (Intelligent Power Module) containing six switching elements has been provided at a low cost, but there has been a problem that it cannot be easily used with the four-element type.

  The present invention solves such problems.

  In order to solve the above conventional problems, the present invention provides an inverter circuit in which a motor having a two-phase stator winding of a first winding and a second winding, a rectifier circuit, and six switching elements are bridge-connected. And the stator winding of each phase of the motor and the common terminal of the two-phase stator winding are connected to the output terminal of the inverter circuit, and the inverter circuit feeds a substantially sinusoidal current to the stator winding. And can be driven by a full-wave rectification method.

  The motor drive control device of the present invention can be driven by a full-wave rectification method.

  A first aspect of the present invention is a motor having a two-phase stator winding of a first winding and a second winding, a rectifier circuit, an inverter circuit in which six switching elements are bridge-connected, and a motor The stator winding of each phase and the common terminal of the two-phase stator winding are connected to the output terminal of the inverter circuit, and the inverter circuit performs PWM control to pass a substantially sine wave current through the stator winding It can be driven by a full-wave rectification method.

  According to a second aspect of the present invention, in the first aspect of the present invention, the voltage phases of the voltage waveform Vm output from the inverter circuit to the first winding and the voltage waveform Va output from the second winding are expressed as follows. Since it can be freely adjusted, as a result, the phase and current value of the current Im flowing through the first winding and the current Ia flowing through the second winding can be freely set.

  The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the voltage phase applied to the first winding and the second winding is shifted by approximately 180 degrees. Regardless of the voltage phase applied to the common terminal of the two-phase stator winding, the voltage phase difference applied between the first terminal, the second winding, and the common terminal of each winding can be fixed at 90 degrees. An optimal phase difference can be obtained with a two-phase induction motor that is electrically shifted by 90 degrees.

  The invention according to claim 4 is characterized in that, in the invention according to any one of claims 1 to 3, the voltage phase applied to the common terminal of the two-phase stator winding can be freely set. Thus, the voltage ratio can be freely set while the voltage phase difference applied to the first winding and the second winding is fixed at 90 degrees.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the voltage phase applied to the common terminal of the two-phase stator winding is the first winding and the first winding. It is located between the voltage phases of the two windings, and the voltage ratio can be set freely with the voltage phase difference applied to the first and second windings fixed at 90 degrees. The optimum voltage ratio and rotating magnetic field can be set accordingly.

  According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the voltage phase applied to the common terminal of the two-phase stator winding is changed when the motor is started. As a feature, the starting torque can be set optimally.

  The invention according to claim 7 is the invention according to any one of claims 1 to 5, wherein the voltage phase applied to the common terminal of the two-phase stator winding is changed according to the rotational speed of the motor. The motor can suppress heat generation and can rotate at high speed.

  The invention according to claim 8 is the invention according to any one of claims 1 to 5, wherein the impedance Zm of the first winding, the number of turns Nm, and the applied voltage Vm are set, and the impedance Za of the second winding is set. Nm · (Vm−Vc) / Zm = Na · (Va−Vc) / Za when winding Na is applied voltage Va and voltage applied to the common terminal of the two-phase stator winding is Vc. The voltage phase to be applied to the common terminal of the two-phase stator winding is set so that a circular magnetic field can be generated between the first winding and the second winding, and the efficiency Can drive with low noise.

  The invention according to claim 9 is the induction motor for a single phase power source according to any one of claims 1 to 8, wherein the motor has a first winding and a second winding. The single-phase induction motor can be suitably driven.

  The invention according to claim 10 is the invention according to any one of claims 1 to 9, wherein the motor drives the compressor. For a system using a compressor such as a refrigeration system. The compressor can be driven optimally.

  Embodiments of a motor drive control apparatus according to the present invention will be described below with reference to the drawings. In addition, about the same structure as the past, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

(Embodiment 1)
FIG. 1 is a circuit diagram of a motor drive control apparatus according to Embodiment 1 of the present invention.

  In FIG. 1, reference numeral 1 denotes a commercial power source, and a single-phase alternating current of 100 V 50 Hz or 60 Hz is generally used in a general Japanese home. Moreover, a single-phase alternating current of 200 V or more may be used for business use or overseas.

  Reference numeral 2 denotes a rectifier circuit that converts the AC voltage of the commercial power source 1 into a DC voltage. The rectifier circuit 2 is a full-voltage rectifier circuit and converts it to DC140V at AC100V. The rectifier circuit bridges four rectifier diodes 2a to 2d. Moreover, it is smoothed by the electric field capacitors 2e and 2f.

  Reference numeral 3 denotes an inverter circuit which receives the DC voltage output rectified by the rectifier circuit 2 and converts it into a three-phase AC having an arbitrary voltage and an arbitrary frequency. The inverter 3 bridge-connects the switching elements 3a to 3f. In this embodiment, an FET is used as a switching element. Each switching element 3a to 3f includes a high-speed diode in parallel in the reverse current direction. The built-in high-speed diode functions to flow a reflux current when the switching elements 3a to 3f are turned off.

  Reference numeral 4 denotes a two-phase induction motor, which drives a compressor used in the refrigeration system. The induction motor 4 has a main winding 4a and an auxiliary winding 4b, and a stator (not shown) having a two-phase winding in which one terminal of each winding serves as a common terminal; It consists of a cage rotor (not shown). The main winding 4a and the auxiliary winding 4b are arranged at mechanical positions that are 90 degrees out of phase.

  The induction motor 4 has a main winding terminal 5a, an auxiliary winding terminal 5b, and a common terminal 5c for each winding. The terminals 5a to 5c of the induction motor 4 are connected to the output terminals 6a, 6b and 6c of the inverter circuit 3, respectively.

  Reference numeral 7 denotes output voltage setting means, which sets an optimum voltage value set in advance according to the set frequency set by the frequency setting means 8. The output voltage setting means 7 sets the voltage output from the inverter circuit 3. Here, the voltage Vm applied to the main winding 4a, the voltage Va applied to the auxiliary winding 4b, and the voltage Vc applied to the common terminal can be set individually. The output voltages Vm, Va, Vc of the inverter circuit 3 are based on the potential at the common connection point on the negative side of the switching elements 3b, 3d, 3f.

  Reference numeral 9 denotes voltage phase setting means, which can freely set the phase of the voltage output to the terminals 6a, 6b, 6c of each phase.

  Reference numeral 10 denotes a waveform generating means, which receives parameters set by the frequency setting means 8, the output voltage setting means 7, and the voltage phase setting means 9 and inputs on / off signals for the switching elements 3a to 3f of the inverter circuit 3 corresponding thereto. Create. Here, a signal is generated so as to obtain a desired output waveform by PWM (Pulse Width Modulation) control.

  FIG. 2 is a timing chart of the motor drive control apparatus according to the first embodiment of the present invention. In FIG. 2, the upper three timing charts show on / off timings of the switching elements 3 a to 3 f of the inverter 3. Here, the main winding terminal 5a is connected to the output terminal 6a of the switching elements 3a and 3b, the auxiliary winding terminal 5b and the switching element 3e are connected to the output terminal 6b of the switching elements 3c and 3d. , 3f is connected to a common terminal 5c.

  The switching elements 3a, 3b, 3c, 3d, 3e, 3f connected up and down repeat the chopping of the inversion operation in the whole period, and the pulse width is set so that the pulse width (that is, area) of the PWM control is close to a sine wave. I have control. Looking at the switching element 3a, the pulse width is narrow when the phase is around 0 degrees, and is turned on / off so as to be maximum around 180 degrees. The output voltage can be controlled by adjusting the pulse width.

  The switching element 3b performs the reversal operation of the switching element 3a (off when one is on, and on when the other is off). In this case, the pulse width is thick, and the pulse width is turned on / off so as to be the minimum around 180 degrees. Further, since the switching elements 3a and 3b, the switching elements 3c and 3d, and the switching elements 3e and 3f that are connected to the upper and lower sides are alternately chopped in the upper and lower directions, dead current is prevented in order to prevent vertical through current due to operation delay of the switching elements. A time (period in which both are off) is provided.

  Further, in the present embodiment, the switching element 3b performs switching with a phase difference φ (180 degrees in FIG. 2) delayed from the switching element 3a, and similarly performs PWM control over the entire interval. Further, the switching element 3d performs the inversion operation of the switching element 3c.

  The switching element 3e is delayed from the switching element 3a in this embodiment by a phase difference ψ (135 degrees in this embodiment). The switching elements 3e and 3f perform PW control and inversion operation as described above.

  The ratio (namely, pulse width / carrier cycle) of the PWM control pulse width (on interval) in the carrier cycle (chopping repetition cycle) is called duty, and the duty is 50% in OV output.

  The current Im of the main winding of the induction motor has a sinusoidal waveform, but actually has a waveform including harmonics of the carrier frequency component of PWM control. The current Ia of the auxiliary winding has a waveform whose phase is advanced by θ (90 degrees in this embodiment) from the current Im of the main winding.

  Actually, the current Im of the main winding has a waveform slightly delayed from the phase voltage (Vm−Vc) of the main winding due to the power factor and impedance. Similarly, the current Ia flowing through the auxiliary winding has a delayed waveform with respect to the phase voltage (Va−Vc) of the auxiliary winding.

  3 to 7 show the phase voltage (Vm−Vc) of the main winding and the phase of the auxiliary winding when the phase ψ of the output voltage Vc to the common terminal 5c of the two-phase winding of the inverter circuit 3 is changed. The waveform of voltage (Va-Vc) is shown. For convenience, the voltage is shown as a sinusoidal waveform.

  3 shows the case where the applied voltage Vc to the common terminal is in phase with the main winding applied voltage Vm, that is, when the phase ψ = 0 degrees, FIG. 4 shows ψ = 45 degrees, FIG. 5 shows ψ = 90 degrees, 6 is when ψ = 135 degrees, and FIG. 7 is when ψ = 180 degrees.

  As described above, from FIG. 3, the phase voltage (Vm−Vc) of the main winding and the phase voltage (Va−Vc) of the auxiliary winding can be changed only by changing the phase ψ of the output voltage Vc applied to the common terminal. It can be seen that the voltage ratio can be changed.

  Therefore, it can be seen that the ratio of the winding currents of the main winding and the auxiliary winding can be changed while the current phase θ (90 degrees) flowing through the main winding 4a and the auxiliary winding 4b is kept constant. Therefore, in the case of a two-phase induction motor, if the number of turns of the main winding is Nm and the number of turns of the auxiliary winding is Na, the relationship between the main winding current Im and the auxiliary winding current Ia is Nm · Im = Na · Ia In this case, a circular magnetic field is formed and the motor can be driven efficiently. Further, the phase ψ of the voltage Vc applied to the common terminal may be determined so that the phase angle between Im and Ia is maintained at 90 degrees so as to satisfy this relational expression.

  In the present embodiment, the phase difference between the output voltages of the inverter circuit of the main winding and the auxiliary winding is set to 180 degrees, but the current waveform has a delay due to impedance. Further, the phase difference between the currents of the main winding and the auxiliary winding may be slightly deviated from the ideal value of 90 degrees due to the difference in impedance. In that case, the current phase difference can be set to 90 degrees by adjusting the phase of the output voltage waveform of Vm or Va and by adjusting the output voltage Vm and Va peak values.

  Also, if the current phase shift becomes large due to the number of rotations or load, adjust the phase of the output voltage waveform of Vm or Va to correct, and adjust the output voltage Vm, Va peak value The current phase can be corrected to 90 degrees.

  Therefore, at the time of low rotation at start-up, the phase difference of the output voltage may be set to 180 degrees, and the phase may be adjusted according to the increase in the rotation speed.

  Although the rectifier circuit is a full-voltage rectifier circuit, a voltage doubler rectifier circuit is formed by connecting a connection point between the negative terminal of the electric field capacitor 2e and the positive terminal of the electric field capacitor 2f and a connection point between the rectifier diodes 2c and 2d. Also good.

  Since the motor drive control device of the present invention can be driven by a full-wave rectification method, it can be applied to control of a compressor equipped with a single-phase induction motor in a refrigeration system such as a refrigerator.

The figure which shows the drive control apparatus of the motor of one embodiment of this invention Timing chart of motor drive control device of same embodiment Characteristic chart showing output voltage waveform of inverter circuit when phase difference ψ = 0 degree in motor drive control device of same embodiment Characteristic diagram showing output voltage waveform of inverter circuit when phase difference ψ = 45 degrees in motor drive control device of same embodiment Characteristic diagram showing output voltage waveform of inverter circuit when phase difference ψ = 90 degrees in motor drive control device of same embodiment Characteristic diagram showing output voltage waveform of inverter circuit when phase difference ψ = 135 degrees in motor drive control device of same embodiment Characteristic diagram showing output voltage waveform of inverter circuit when phase difference ψ = 180 degrees in motor drive control device of same embodiment The figure which shows the motor drive control apparatus of the conventional form Timing chart of conventional motor drive control device Characteristic diagram showing the relationship between voltage and motor efficiency in conventional form

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Rectifier circuit 3 Inverter circuit 3a-3f Switching element 4 Two-phase induction motor 4a Main winding 4b Auxiliary winding 5c Common terminal 7 Output voltage generation means 8 Frequency setting means 9 Waveform generation means

Claims (10)

A motor having a two-phase stator winding of a first winding and a second winding, a rectifier circuit, an inverter circuit in which six switching elements are bridge-connected, a stator winding of each phase of the motor, A common terminal of the two-phase stator winding is connected to an output terminal of the inverter circuit, and the inverter circuit performs a PWM control for causing a substantially sinusoidal current to flow through the stator winding; and the motor A motor drive control device comprising frequency setting means for determining a frequency to be applied to the motor. Based on the voltage waveform Vm output from the inverter circuit to the first winding, the voltage phase of the voltage waveform Va output to the second winding and output to the common terminal of the two-phase stator winding A voltage phase setting means capable of freely adjusting each voltage phase of the voltage waveform Vc and an output voltage setting means capable of freely adjusting the peak values of the voltage waveforms Vm, Va, Vc are provided. Item 2. A motor drive control device according to Item 1. The voltage phase of the voltage waveform Vm output to the first winding from the inverter circuit and the voltage waveform Va output to the second winding are shifted by approximately 180 degrees. Item 3. A motor drive control device according to Item 2. The voltage waveform Vc output from the inverter circuit to the common terminal of the two-phase stator winding is the voltage waveform Vm applied to the first winding or the voltage waveform Va applied to the second winding. 4. The motor drive control device according to claim 1, wherein the voltage phase can be set freely. 5. The voltage phase of the voltage waveform Vc output from the inverter circuit to the common terminal of the two-phase stator winding is the voltage waveform Vm output from the inverter circuit to the first winding and the second winding, respectively. 5. The motor drive control device according to claim 1, wherein the motor drive control device is located between the voltage phases of Vc. 6. The motor according to claim 1, wherein the voltage phase of the voltage waveform Vc applied to the common terminal of the two-phase stator winding is changed when the motor is started. 6. Drive control device. 6. The motor according to claim 1, wherein a voltage phase of a voltage waveform Vc applied to a common terminal of the two-phase stator winding is changed according to a rotation speed of the motor. Drive control device. When the impedance Zm of the first winding, the number of turns Nm, the phase voltage Vmc of the first winding and the impedance Za of the second winding, the winding Na, and the phase voltage Vac of the second winding, Nm · Vmc 6. The voltage phase of the voltage waveform Vc applied to the common terminal of the two-phase stator winding is set so that / Zm = Na · Vac / Za. The motor drive control apparatus as described in any one of Claims. The motor drive control device according to any one of claims 1 to 8, wherein the motor is an induction motor for a single-phase power source having a first winding and a second winding. The motor drive control apparatus according to any one of claims 1 to 9, wherein the motor drives a compressor.

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