Starting method and starting circuit for single-phase permanent magnet synchronous motor

Abstract

The invention provides a starting method and a starting circuit for a single-phase permanent magnet synchronous motor and relates to the technical field of motor starting. A symmetrical voltage supplied to a driven motor is converted into an asymmetrical alternating current transient voltage and then is supplied to the motor, so that a magnetic field of the motor produces transition and asymmetry,larger starting torque is obtained, inertia of a rotor is effectively utilized, and starting of a unidirectional synchronous motor is realized. By utilizing the starting method provided by the invention, the single-phase permanent magnet synchronous motor can be started without changing frequency of a power supply and judging power supply polarity of the power supply, and the starting method andthe starting circuit can be applied to load-carrying starting of load characteristic electric appliances such as a fan driven by the single-phase permanent magnet synchronous motor and a drainage pumpof a washing machine.

Description

technical field [0001] 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 technique [0002] For single-phase permanent magnet synchronous motors, the initial start-up is a difficult problem to solve when realizing the start-up drive of the motor. Because it is a single-phase power supply (that is, mains power), its frequency is fixed, and the magnetic field cannot form a phase angle, so it is difficult to obtain the initial starting torque, so under the condition of load, the motor can only vibrate, and it is difficult to synchronize and run. [0003] In the past, the startup and operation of this kind of motor was usually driven by a bridge-arm type inverter, because the inverter can change its output frequency, so that it can control the output corresponding frequency according to the actual speed of the motor to achieve the purpose of sy...

AI Technical Summary

Problems solved by technology

That is, an inertial mechanism that starts zero load is needed. When the motor obtains the initial torque, the load can be applied to the motor rotor, thereby driving the motor to rotate and do work. This method is widely used by existing single-phase permanent magnet synchronous motor water pump manufacturers application, but this method has complex structure and low reliability. Since there is a starting gap between the rotor and the impeller, the impact of the rotor and the impeller at no load produces noise.

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