Permanent magnet synchronous motor initial position identification method and device

Abstract

The invention discloses a permanent magnet synchronous motor initial position identification method and device. The permanent magnet synchronous motor initial position identification method comprisesthe following steps that first I / f open-loop operates and pulls a permanent magnet synchronous motor rotor to a zero point, then 100, 010 and 001 voltage vectors are injected into the motor, and a UVWthree-phase current is sampled through AD; and a current position of the rotor is calculated according to the three-phase current, if the current position is near the zero point, the identification is successful and the motor enters a normal operation state, and the purpose of injecting the voltage vectors is to further confirm whether the rotor position is at the zero point or not. And therefore, the permanent magnet synchronous motor initial position identification method can accurately identify the initial position of the rotor, ensures the smooth start and normal operation of the permanent magnet synchronous motor, avoids the problems of getting out of control and galloping during the start and overflowing and overloading during operation, and improves the reliability of an alternating current servo drive system.

Description

technical field [0001] The invention relates to the technical field of servo drive control, and more specifically, to a method and device for identifying an initial position of a permanent magnet synchronous motor. Background technique [0002] The permanent magnet synchronous motor has the advantages of small size, high power density and high reliability, and has a relatively high proportion in today's AC servo control system. Servo systems for permanent magnet synchronous motors are mostly closed-loop control systems, and position sensors need to be installed to obtain real-time position information and speed information of the rotor. However, in some practical applications, position sensors cannot be installed due to environmental influences. Therefore, sometimes the position sensor is installed outside the motor, such as on the machine shaft, but due to a certain mechanical transmission ratio, the motor rotor angle and the output of the position sensor are not in a one-t...

AI Technical Summary

Problems solved by technology

The closed-loop vector control of the permanent magnet synchronous motor must first determine the initial position of the motor rotor. The accuracy of the determination of the initial rotor position is related to whether the motor can run normally. If the initial position of the rotor is detected incorrectly, the motor will run out of control, endangering the personal safety of the operator Even if there is a certain error in the initial position of the rotor, the output torque of the motor will be reduced, which will affect the operating efficiency of the motor. The motor will heat up seriously, and the driver will alarm for overcurrent or overload.

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