Initial Motor Offset Angle Determination: Self-Calculation Approach with Enhanced Precision

This paper presents a novel algorithm for precisely determining the offset angle of a Permanent Magnet Synchronous Motor (PMSM) using an encoder as feedback. The proposed method involves running the motor at a predetermined speed with the assistance of a driver, initially set at a random offset angle. Once the motor reaches the desired speed, the power supply to the motor is interrupted, enabling it to decelerate (due to friction, drag, etc.), causing its speed to decrease until it comes to rest gradually. The offset angle of the motor is calibrated during the deceleration of the motor. To overcome challenges related to peak detection and excessive ripples (caused by power electronic components in the driver) in the back-EMF waveforms, wavelet denoising along with the running i<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> window method is employed. The effectiveness and merit of the proposed algorithm is validated through experimental results, demonstrating its superiority over conventional methods.