Study on Noise Reduction of Variable Amplitude High Frequency Injection Based on Improved Model Reference

Aiming at the problem of sharp high-frequency noise caused by the fixed-amplitude pulsed vibration high-frequency injection, a noise reduction strategy of variable-amplitude pulsed vibration high-frequency injection is proposed with improved model reference. Specifically, the model reference adaptive system(MRAS) is used to identify the motor d- and q-axis inductance at first, according to the built-in permanent magnet synchronous motor model, and then the recursive least-squares(RLS) method with forgetting factor is further applied for forward prediction of identification results by the MRAS, so as to ultimately obtain more accurate and anti-interference results of inductance identification. Subsequently, the amplitude of injected voltage changes adaptively with the change of motor inductance, thereby realizing the reduction of additional high-frequency noise and high-frequency loss originated from the change of motor inductance due to the change of motor operation state. Finally, simulation and experiment are performed to verify the feasibility of the proposed method for reduction of high-frequency loss and high-frequency noise.