Permanent magnet synchronous motor low-speed domain rotor position identification method

Abstract

The invention discloses a permanent magnet synchronous motor low-speed domain rotor position identification method, so as to solve the problems that the traditional pulse signal injection method usesmultiple filters, the hysteresis effects are superimposed, the dynamic performance of the system is reduced, and the position estimation error is increased. A new low-speed position sensorless controlstrategy is proposed. In particular, on the basis of injection of a high-frequency pulse square wave voltage signal to a two-phase stationary coordinate system, through a generalized second-order integrator (SOGI), current in a beta axis is subjected to signal separation and amplitude demodulation, two paths of orthogonal signals including rotor position information are obtained, and through heterodyne and a rotor position observer, the rotor position information is extracted, and no filter is used during the whole signal demodulation process. The dynamic performance of the control system andthe accuracy of the rotor position estimation are effectively improved.

Description

technical field [0001] The invention relates to the field of permanent magnet synchronous motor control, in particular to a position sensorless rotor position identification method in the low speed field of permanent magnet synchronous motors. Background technique [0002] Permanent magnet synchronous motors are widely used in wind power generation, electric vehicles, aerospace and other fields due to their advantages of high power density, high efficiency and low noise. In order to achieve high-performance vector control, it is necessary to obtain accurate rotor position information. The rotor position can be accurately obtained by installing a high-resolution mechanical sensor, but it increases the size of the motor and hardware cost, and cannot be used in some special occasions. Therefore, it is of great significance to study the position sensorless control technology with high reliability and high precision to replace the mechanical sensor. [0003] For the control of t...

AI Technical Summary

Problems solved by technology

However, the traditional high-frequency signal injection methods, that is, the rotating voltage injection method and the pulse vibration voltage injection method, both need to use one or more filters in the process of current loop and signal demodulation, and the use of filters will bring different degrees of damage. Amplitude attenuation and phase lag will not only reduce the bandwidth of the current loop, affect the dynamic performance of the system, but also increase the position estimation error

In addition, the traditional pulse vibration signal injection method injects high-frequency voltage signals into the estimated d-axis, which has the advantages of simple algorithm and small torque ripple. However, the traditional rotating signal injection method injects high-frequency voltage signals into the two-phase stationary coordinate system, which has good stability, but the signal demodulation process is complicated, and multiple filters use to degrade the dynamic performance of the system

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