Permanent magnet synchronous motor static initial position estimation method and stator inductance identification method

Abstract

The invention provides a permanent magnet synchronous motor static initial position estimation method and a stator inductance identification method. A rated positive pulse voltage and a rated negative pulse voltage are sequentially injected into windings of an AB phase, a BC phase and a CA phase of a motor, response current values of the phases under the rated positive pulse voltage and the rated negative pulse voltage are recorded, and current response difference values delta Iab, delta Ibc and delta Ica of the AB phase, the BC phase and the CA phase under a three-phase static coordinate system are calculated; performing Clark transformation on the current response difference values of all phases to obtain current response difference values delta I alpha and delta I beta under the alpha-beta axis two-phase static coordinate system; and calculating the initial position theta of the rotor based on the delta I alpha and the delta I beta. And calculating the stator inductance of the permanent magnet synchronous motor based on the initial position of the rotor obtained through calculation. Through coordinate transformation and solution, the rotor position is directly obtained through current pulse response, an intermediate conversion link is omitted, data loss can be reduced, and data precision is guaranteed.

Description

technical field [0001] The invention relates to the technical field of motor control, and relates to a static initial position estimation method of a permanent magnet synchronous motor and a stator electrical identification method. Background technique [0002] Direct-drive permanent magnet wind turbines have stable performance and high economic benefits, and are widely used in major wind farms. However, due to factors such as the size of the unit, it is difficult to obtain sufficient installation space for components such as position sensors, so the sensorless control strategy has begun to become increasingly popular. It is increasingly used in the field of wind power. The sensorless control strategy of permanent magnet synchronous motor includes observer control, switching control, variable structure control and other control methods, and these methods need to realize accurate estimation of the initial rotor position. At the same time, the accurate identification of the i...

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Problems solved by technology

Such as the look-up table method, which uses the pre-obtained current response and rotor angle comparison table to obtain the rotor position. This method requires a large number of experiments in advance, and the operation is relatively complicated and the accuracy is not high; another example is the inductance matrix method, which is obtained through the transient current response. The inductance matrix, and then the rotor position is calculated by the inductance matrix. This method is complex to calculate, and due to sampling deviation, inductance matrix conversion, etc., it has high requirements for sampling and signal conditioning circuits.

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