CN107911051B - Starting method and starting circuit of single-phase permanent magnet synchronous motor - Google Patents

Starting method and starting circuit of single-phase permanent magnet synchronous motor Download PDF

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Publication number
CN107911051B
CN107911051B CN201810009964.0A CN201810009964A CN107911051B CN 107911051 B CN107911051 B CN 107911051B CN 201810009964 A CN201810009964 A CN 201810009964A CN 107911051 B CN107911051 B CN 107911051B
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alternating current
motor
starting
circuit
chopping
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CN107911051A (en
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王奔
王伟华
王志双
薛利明
王艳涛
王薇薇
赵美丽
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Wuxi Haoli Pumps Industrial Co ltd
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Wuxi Haoli Pumps Industrial Co ltd
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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02PCONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/20Arrangements for starting

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Ac Motors In General (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)

Abstract

A starting method and a starting circuit of a single-phase permanent magnet synchronous motor relate to the technical field of motor starting, which converts symmetrical voltage supplied to a driven motor into asymmetrical alternating current transient voltage and then supplies the voltage to the motor, so that a magnetic field of the motor generates transient and asymmetrical to obtain larger starting torque, thereby effectively utilizing the inertia of a rotor to realize the starting of the single-phase synchronous motor.

Description

Starting method and starting circuit of single-phase permanent magnet synchronous motor
Technical Field
The invention relates to the technical field of motor starting, in particular to a starting method and a starting circuit of a single-phase permanent magnet synchronous motor.
Background
For a single-phase permanent magnet synchronous motor, initial starting is a difficult problem to solve when starting drive of the motor is achieved. Because it is a single-phase power source (i.e., mains supply) whose frequency is fixed and the magnetic field cannot form a phase angle, it is difficult to obtain an initial starting torque, so that the motor can only shake and is difficult to synchronize and operate under load.
In the past, the motor is started and operated conventionally by adopting a bridge arm type frequency converter, and the frequency converter can change the output frequency of the motor, so that the motor can control the output corresponding frequency according to the actual rotating speed of the motor, thereby achieving the aim of synchronization. But doing so greatly increases the overall cost and complexity of the synchronous motor. Therefore, the method is difficult to popularize and be adopted by customers in the application occasions with strict monomer cost requirements.
In view of the above, this single-phase permanent magnet synchronous motor adds some mechanical structure in the application to solve the difficult starting problem. The method is widely applied by existing single-phase permanent magnet synchronous motor water pump manufacturers, but the method has complex structure and low reliability, and because a starting gap is reserved between the rotor and the impeller, the rotor and the impeller collide to generate noise when the motor is in idle load.
In summary, it is important to realize a simple, reliable and low-cost driving circuit and method for a single-phase permanent magnet synchronous motor.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a starting method and a starting circuit of a single-phase permanent magnet synchronous motor, which can realize the starting of the single-phase permanent magnet synchronous motor under the condition of not changing the power frequency, and are quick and simple in starting and low in noise.
The aim of the invention is achieved by the following technical scheme:
provided is a starting method of a single-phase permanent magnet synchronous motor, comprising the following steps: the symmetrical alternating current is converted into asymmetrical alternating current and then is supplied to the motor.
Wherein the transition is cutting of an initial wave of alternating current.
Wherein, the cutting method is as follows: and judging the zero position of the alternating current, and chopping the alternating current at the zero position by starting delay time A, wherein the time A is not more than 2 milliseconds, and the alternating current is commercial power.
Wherein the chopping is regularly intermittent chopping.
Wherein the regular intermittent chopping is specifically that the time A is alternately performed.
Wherein the operating state of the motor is detected and the step of transitioning is performed when the motor is not synchronized.
The invention also provides a starting circuit of the single-phase permanent magnet synchronous motor, which comprises a conversion circuit for converting symmetrical alternating current into asymmetrical alternating current and then supplying the asymmetrical alternating current to the motor.
Wherein the conversion circuit includes a cutting circuit for cutting a start wave of the alternating current to form an asymmetric alternating current.
The cutting circuit comprises a synchronous voltage generating circuit for judging the zero position of alternating current, a chopping circuit and a microprocessor for controlling the chopping circuit to start chopping at the zero position of the alternating current by delay time A, wherein the time A is not more than 2 milliseconds, and the alternating current is commercial power.
The synchronous voltage generation circuit comprises a current-limiting voltage-reducing resistor and a first clamping diode, and alternating current sequentially enters the microprocessor after passing through the current-limiting voltage-reducing circuit and the clamping diode.
The chopper circuit comprises a bidirectional thyristor, a first anode and a second anode of the bidirectional thyristor are respectively connected with a live wire of alternating current and a stator coil of the motor, and a control electrode of the bidirectional thyristor is connected with the microprocessor.
Wherein the microprocessor controls the chopper circuit to regularly and intermittently chop the alternating current.
Wherein the regular intermittent chopping is specifically that the time A is alternately performed.
Wherein, the motor operation state detection circuit is connected between the motor and the microprocessor.
The motor running state detection circuit comprises a step-down resistor and a second clamping diode, and the voltage output by the chopper circuit is connected to the microprocessor through the step-down resistor and the clamping diode in sequence.
The starting method and the starting circuit of the single-phase permanent magnet synchronous motor convert symmetrical alternating current into asymmetrical alternating current and then supply the asymmetrical alternating current to the motor, even if the voltage supplied to the driven motor is converted into asymmetrical alternating current transient voltage and then supplied to the motor, the magnetic field of the motor generates transient and asymmetrical to obtain larger starting torque, thereby effectively utilizing the inertia of a rotor to realize the starting of the single-phase synchronous motor.
Drawings
The invention will be further described with reference to the accompanying drawings, in which embodiments do not constitute any limitation of the invention, and other drawings can be obtained by one of ordinary skill in the art without inventive effort from the following drawings.
Fig. 1 is a circuit schematic of a starting circuit of a single-phase permanent magnet synchronous motor according to the present invention.
Fig. 2 is a waveform comparison chart of alternating current after chopping, chopping neutralization and chopping of a starting circuit of a single-phase permanent magnet synchronous motor of the present invention.
Fig. 3 is a waveform diagram showing the synchronized state of the motor operation state detection circuit output at the time of loading of the starting circuit of the single-phase permanent magnet synchronous motor according to the present invention.
Fig. 4 is a waveform diagram of the motor running state detection circuit output at the time of no load of the starting circuit of the single-phase permanent magnet synchronous motor according to the present invention.
Fig. 5 is a waveform diagram of the step-out (i.e., motor not rotated) output by the motor running state detection circuit at the time of loading of the starting circuit of the single-phase permanent magnet synchronous motor according to the present invention.
The figure comprises the following components:
the chopper circuit 1,
the motor operation state detection circuit 2,
a co-linear power supply circuit 3,
the synchronization signal generation circuit 4,
and an input voltage detection circuit 5.
Detailed Description
The invention will be further described with reference to the following examples.
The starting method of the single-phase permanent magnet synchronous motor of the embodiment comprises the following steps of: the symmetrical alternating current is converted into asymmetrical alternating current and then is supplied to the motor, and specifically, the initial wave of the alternating current is cut.
The cutting method comprises the following steps: judging the zero position of alternating current, and chopping the alternating current at the zero position by starting delay time A, wherein the time A is not more than 2 milliseconds, and the preferred method is to alternately carry out chopping by delaying 0.5 millisecond and chopping by delaying 2 milliseconds, and the alternating current is commercial power.
The motor can be supplied with the asymmetric alternating current when the motor is not synchronous by detecting the working state of the motor, namely the asymmetric alternating current is supplied to the motor for starting, and the motor is waited for starting, namely the working state of the motor is detected to be synchronous, the motor is switched to the symmetric alternating current for supplying power, so that the zero point position is not needed to be judged and the chopper is not needed. The asymmetric waveform can be used all the time to drive the motor to run, so that the heating value of the motor coil can be reduced. According to the method, the chopping angle can be properly adjusted according to the change of the power supply voltage, so that the voltage applied to the motor is not increased along with the increase of the input voltage, and the voltage on the motor is kept constant.
The method of the embodiment does not need to judge the position of the rotor of the single-phase permanent magnet synchronous motor, does not need directional excitation of unidirectional pulses, does not need to judge starting, and can realize normal starting and running without judging the position of the permanent magnet rotor.
In this embodiment, the above method is specifically realized by a starting circuit of a single-phase permanent magnet synchronous motor including a conversion circuit for converting a symmetrical alternating current into an asymmetrical alternating current and then supplying the same to the motor, the conversion circuit including a cutting circuit for cutting a start wave of the alternating current to form the asymmetrical alternating current.
Specifically, the cutting circuit includes a motor operation state detection circuit 2, a collinear power supply circuit 3, a synchronization signal generation circuit 4 for judging the zero position of the alternating current, an input voltage detection circuit 5, a chopper circuit 1, and a microprocessor IC1 for controlling the chopper circuit to start delaying time a for chopping at the zero position of the alternating current, wherein the time a is not more than 2 milliseconds. The microprocessor IC1 controls the chopper circuit to regularly and intermittently chop the alternating current, specifically, the time A is alternately performed, and the preferable method is to alternately perform chopping with a delay of 0.5 ms and chopping with a delay of 2 ms.
As shown in fig. 1, the operating principle of the starting circuit of the present embodiment is:
(1) Collinear power supply circuit 3: the capacitor consists of a resistor R4, a resistor R3, a capacitor C2, a capacitor C3, a resistor R5, a diode D3 and a diode D4. The 220V alternating current is rectified by the diode D3, reduced in voltage by the resistor R3 and the resistor R4 and stabilized by the diode D4, and then 5V direct current voltage relative to direct current ground is formed, so that the bidirectional thyristor T1 and the microprocessor IC1 are powered.
(2) The synchronization signal generation circuit 4: the synchronous signal is shown in the TB waveform in fig. 2 to 5, after the current is limited and reduced by the current limiting and voltage reducing resistors R7 and R6, a 5-volt square wave signal with the same phase as the input alternating current is obtained by clamping through the first clamping diodes D5 and D6, and the signal is supplied to the microprocessor IC1 through the point B to serve as a reference for judging the power supply signal.
(3) Motor operation state detection circuit 2: m is a permanent magnet synchronous motor, T1 is a bidirectional thyristor, a step-down resistor R2, a diode D1, a diode D2 (namely a second clamping diode) and a capacitor C1 form a motor state detection circuit together, and the motor state detection circuit is connected to a microprocessor IC1 through an A point. By detecting the waveform at the point a, the operation state of the motor can be judged. The negative pole of diode D1 and the positive pole of diode D2 are connected with step-down resistor R2 to form the clamping circuit, which can obtain the back electromotive force signal output of larger volt value signal, is favorable for judging the state of the motor by the singlechip, and the state of the motor comprises synchronization, step-out (i.e. not synchronization) and locked rotation (i.e. the motor cannot rotate), etc., see the waveform diagrams of fig. 3 to 5, the waveform diagram of fig. 3 is the waveform of the motor synchronization under load, the waveform of the motor synchronization under no load, the waveform of fig. 4 is the waveform of the motor cannot rotate under load, the waveform MT touches the LE line, and the waveform MT represents that the motor cannot rotate.
(4) Chopper circuit 1: the high-voltage power supply comprises a bidirectional thyristor T1, wherein a first anode and a second anode of the bidirectional thyristor T1 are respectively connected with a live wire of alternating current and a stator coil of a permanent magnet synchronous motor M, and a control electrode of the bidirectional thyristor T1 is connected to a microprocessor IC1 through a resistor R1 (namely a T point). The microprocessor IC1 judges the running state of the motor according to the waveform of the point A, if the motor is in a step-out state, the microprocessor ICA judges the zero position of the 5 volt square wave through the 5 volt square wave transmitted by the point B, when the zero position is encountered, the zero position is delayed by 0.5 millisecond, the bidirectional thyristor T1 is controlled to conduct through the point T to carry out small-angle chopping on alternating current, after a plurality of small-angle chopping, the small-angle chopping is delayed by 2 milliseconds again to carry out large-angle chopping, and the steps are sequentially and alternately carried out until the motor is synchronous, see the waveform diagram of fig. 2.
Of course, the large-angle chopping may be performed first, and then the small-angle chopping may be performed, so long as a regular waveform is formed.
(5) The starting circuit in this embodiment further includes an input voltage detection circuit 5: the alternating current is reduced by the voltage reducing resistors R9 and R10, rectified by the rectifying diodes D7 and D8, and then divided by the resistor R11 to obtain the relative voltage value of the input voltage, the relative voltage value is sent to the microprocessor IC1 through the point C to judge the corresponding value of the current voltage supplied to the motor for the microprocessor IC1, and if the current voltage is too high, the microprocessor IC1 regulates the current voltage to be proper voltage to avoid burning the motor due to the too high voltage.
The method and the circuit for starting the single-phase permanent magnet synchronous motor convert symmetrical alternating current into asymmetrical alternating current through chopping and then supply the asymmetrical alternating current to the motor, so that the voltage supplied to a driven motor is converted into asymmetrical alternating current transient voltage and then is supplied to the converting circuit of the motor, the magnetic field of the motor generates transient and asymmetrical to obtain larger starting torque, the inertia of a rotor is effectively utilized, the starting of the single-phase permanent magnet synchronous motor is realized, the method for changing the driving torque by controlling the chopping angle (namely delay time A or phase shift) is utilized, the dead zone appears artificially at a specific position of a driving signal, the controlled dead zone can reduce synchronous repulsive force, the inertia of the rotor can be increased by the two methods, the starting of the single-phase permanent magnet synchronous motor can be effectively utilized, the starting of the single-phase permanent magnet synchronous motor can be realized under the condition that the power frequency is not changed, and the noise is low when the single-phase permanent magnet synchronous motor is started.
The method and the circuit can be used for starting the electric appliances with load characteristics, such as fans driven by single-phase permanent magnet synchronous motors, washing machine drainage pumps and the like, with load.
Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention.

Claims (7)

1. A starting method of a single-phase permanent magnet synchronous motor is characterized in that: the method comprises the following steps of: converting symmetrical alternating current into asymmetrical alternating current and then supplying the asymmetrical alternating current to the motor; the transition step is used for enabling the motor to obtain starting torque;
the converting symmetrical alternating current into asymmetrical alternating current includes: judging the zero position of the alternating current, and chopping the alternating current at the zero position by starting delay time A;
the method further comprises the steps of:
detecting a start-up state of the motor, the converting step being performed when the motor is not started up to supply an alternating current asymmetric to the motor;
switching to symmetrical alternating current to supply power to the motor when the starting state of the motor is detected to be synchronous after the transition step is executed;
the time A is 0.5 ms or 2 ms;
the chopping includes performing small-angle chopping on the alternating current at a zero position for a delay time of 0.5 ms, and performing large-angle chopping on the alternating current at a zero position for a delay time of 2 ms, and sequentially and alternately performing the small-angle chopping and the large-angle chopping until the motor is synchronous.
2. A method of starting a single phase permanent magnet synchronous motor as defined in claim 1, wherein: the alternating current is commercial power.
3. A starting circuit of a single-phase permanent magnet synchronous motor is characterized in that: the motor comprises a conversion circuit for converting symmetrical alternating current into asymmetrical alternating current and then supplying the asymmetrical alternating current to the motor;
the conversion circuit comprises a cutting circuit for cutting a start wave of alternating current to form asymmetric alternating current;
the cutting circuit comprises a synchronous voltage generating circuit for judging the zero position of the alternating current, a chopping circuit and a microprocessor for controlling the chopping circuit to start to delay a time A for chopping at the zero position of the alternating current, wherein the time A is 0.5 millisecond or 2 milliseconds;
the chopping comprises the steps of carrying out small-angle chopping on the alternating current at a zero position for 0.5 millisecond of delay time, carrying out large-angle chopping on the alternating current at a zero position for 2 millisecond of delay time, and sequentially and alternately carrying out the small-angle chopping and the large-angle chopping until the motors are synchronous;
and a motor running state detection circuit connected between the motor and the microprocessor.
4. A starting circuit for a single-phase permanent magnet synchronous motor according to claim 3, wherein: the alternating current is commercial power.
5. A starting circuit for a single-phase permanent magnet synchronous motor according to claim 3, wherein: the synchronous voltage generation circuit comprises a current-limiting voltage-reducing resistor and a first clamping diode, and alternating current sequentially enters the microprocessor after passing through the current-limiting voltage-reducing resistor and the first clamping diode.
6. A starting circuit for a single-phase permanent magnet synchronous motor according to claim 3, wherein: the chopper circuit comprises a bidirectional thyristor, a first anode and a second anode of the bidirectional thyristor are respectively connected with a live wire of alternating current and a stator coil of the motor, and a control electrode of the bidirectional thyristor is connected with the microprocessor.
7. A starting circuit for a single-phase permanent magnet synchronous motor according to claim 3, wherein: the motor running state detection circuit comprises a step-down resistor and a second clamping diode, and the voltage output by the chopper circuit is connected to the microprocessor through the step-down resistor and the second clamping diode in sequence.
CN201810009964.0A 2018-01-05 2018-01-05 Starting method and starting circuit of single-phase permanent magnet synchronous motor Active CN107911051B (en)

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CN107911051B true CN107911051B (en) 2024-02-23

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5481171A (en) * 1994-02-07 1996-01-02 James River Corporation Of Virginia Method and apparatus for symmetrical current starting of polyphase induction motors
JPH08191593A (en) * 1995-01-09 1996-07-23 Hitachi Ltd Electric motor control device and electric vacuum cleaner using the control device
US6239563B1 (en) * 1997-01-21 2001-05-29 Wunnibald Kunz Electronic starting and operating control system for a single-phase synchronous motor with a permanent magnetic rotor, also in case of failure
JP2004336851A (en) * 2003-05-01 2004-11-25 Nidec Shibaura Corp Drive unit for single-phase ac synchronous motor
JP2008029115A (en) * 2006-07-21 2008-02-07 Japan Servo Co Ltd Single-phase position sensorless permanent magnet motor controller
CN201409107Y (en) * 2009-03-12 2010-02-17 敬石桥 AC motor control circuit and AC synchronous water pump
CN202301063U (en) * 2011-06-30 2012-07-04 深圳市钜泰泵业有限公司 Directional-operating alternating current permanent magnet synchronous water pump
CN207664901U (en) * 2018-01-05 2018-07-27 无锡好力泵业有限公司 A kind of start-up circuit of single-phase permanent-magnet synchronous motor

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2911735B1 (en) * 2007-01-23 2009-04-10 Leroy Somer Moteurs METHOD FOR SUPPLYING A SINGLE PHASE ELECTRIC MOTOR AND FEEDING SYSTEM FOR IMPLEMENTING SUCH A METHOD

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5481171A (en) * 1994-02-07 1996-01-02 James River Corporation Of Virginia Method and apparatus for symmetrical current starting of polyphase induction motors
JPH08191593A (en) * 1995-01-09 1996-07-23 Hitachi Ltd Electric motor control device and electric vacuum cleaner using the control device
US6239563B1 (en) * 1997-01-21 2001-05-29 Wunnibald Kunz Electronic starting and operating control system for a single-phase synchronous motor with a permanent magnetic rotor, also in case of failure
JP2004336851A (en) * 2003-05-01 2004-11-25 Nidec Shibaura Corp Drive unit for single-phase ac synchronous motor
JP2008029115A (en) * 2006-07-21 2008-02-07 Japan Servo Co Ltd Single-phase position sensorless permanent magnet motor controller
CN201409107Y (en) * 2009-03-12 2010-02-17 敬石桥 AC motor control circuit and AC synchronous water pump
CN202301063U (en) * 2011-06-30 2012-07-04 深圳市钜泰泵业有限公司 Directional-operating alternating current permanent magnet synchronous water pump
CN207664901U (en) * 2018-01-05 2018-07-27 无锡好力泵业有限公司 A kind of start-up circuit of single-phase permanent-magnet synchronous motor

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