Research On Position Signal Compensation Method For Permanent Magnet Synchronous Motor Based On Harmonic Decoupling Observer

Permanent magnet synchronous motors are widely used in various fields of life due to their small size,simple structure,easy maintenance,high torque inertia ratio,and high reliability.In the motor control system,it is very important to obtain the rotor position accurately,which is the important information reflecting the motor control performance.The rotor position of motor is usually measured by photoelectric encoder,rotary transformer and other sensors.Because of its precise resolution and strong anti-interference ability,rotary transformer is used in various occasions.However,due to non-ideal mechanical installation components,installation environment and other factors,the sensor failure,and even the breakdown of the control system and other serious consequences.Based on this,this topic proposes a new harmonic compensation structure,and the main work is as follows:(1)In order to obtain accurate position signals,firstly,the position signals of the permanent magnet synchronous motor are obtained from a resolver and transformed equivalently.When the fundamental frequency is known,an auxiliary filter is constructed to obtain the auxiliary function,and then the standard sinusoidal signal and harmonic interference are redefined.Finally,a harmonic decoupled observer is constructed to estimate the correlation vector to achieve compensation and extraction of the required signal.(2)A harmonic compensation method is designed for motor systems with unknown speed.A special auxiliary filter is constructed for the distorted position signal of permanent magnet synchronous motor,which decomposes and defines the standard sinusoidal signal and interference signal,and an extended observer is designed to estimate the unknown parameters related to the fundamental frequency.Finally,harmonic decoupled observer is used to compensate and extract standard sine signal and harmonic interference.(3)To improve the robustness of harmonic decoupling observers in noisy environments,a robust tracker was designed to filter the correlation vectors obtained from auxiliary filters.By using the auxiliary variables of the tracker,the noise content of the extended observer formed by it is greatly reduced,thereby improving the extraction accuracy of the motor standard angle signal and harmonic signal.Finally,the tracker was brought into the permanent magnet synchronous motor for simulation experiments to verify its effectiveness.