Permanent magnet synchronous motor sensorless control method based on pulse high-frequency injection

Abstract

The invention discloses a permanent magnet synchronous motor sensorless control method with pulse high-frequency injection, and belongs to the motor control field. The high-frequency signal generatorgenerates a high-frequency voltage signal and injects the high-frequency voltage signal into an estimated d-axis coordinate system. The stator winding currents ia, ib and ic are sampled by the currentsensor and transformed into a coordinate system rotating synchronously with the estimated position to obtain d-q-axis currents id and iq; According to the obtained iq, the position error informationis extracted by using the moving average filter, and the rotor position estimation value is calculated. Based on the obtained id, the magnitude of the current is calculated using the moving average filter, and the polarity of the rotor magnetic pole is determined. This method can realize the position identification at zero speed and low speed. The bandpass filter and low pass filter are omitted inthe signal processing process, and the stability and dynamic and static performance of the system are improved. The sliding average filter is easy to realize digitally and only needs to complete thewindow length design, thus simplifying the signal processing process.

Description

technical field [0001] The invention relates to a position sensorless control algorithm of a permanent magnet synchronous motor, belonging to the field of motor control. Background technique [0002] Permanent magnet synchronous motors have the advantages of high power density, high efficiency and low noise, and are widely used in electric vehicles, wind power and servo fields. The control methods of the motor drive system mainly include vector control and direct torque control, but both need to obtain the position information of the rotor accurately. Position can be detected using an optical encoder or a resolver, but mechanical sensors increase system cost and risk of failure. Therefore, the research of position sensorless algorithm is of great significance. [0003] At present, the sensorless operation methods of permanent magnet synchronous motors are mainly divided into methods based on motor back EMF and methods based on motor saliency. In the medium and high speed ...

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Problems solved by technology

[0008] The technical problem to be solved by the present invention is to provide a permanent magnet synchronous motor based on pulse vibration high-frequency injection for the problems of poor dynamic and static performance and complex signal processing in the zero-speed and low-speed position identification of permanent magnet synchronous motors The position sensorless control method injects pulsed high-frequency voltage signals into the motor, samples the stator winding current, and estimates the position and speed of the motor rotor from the high-frequency current response

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