Hybrid motor control application with moving average based low-pass filter and high-pass filter

A moving average low-pass filter and a counter moving average high-pass filter are discussed and their empirical cutoff frequencies are determined. Compared to conventional infinite-impulse response filter, the moving average based filter is more suitable in motor application control. A fixed depth method with fixed sampling interval is proposed to make the moving average algorithm be consistent with motor electrical speed variation. Different control effect can be obtained, depending on the behavior of alternate component signal in the control loop. Average speed control and current harmonic reduction control are performed. The similarity between counter moving average high-pass filter and repetitive control is also proposed and verified. Simulation and experiment validate the effectiveness of the proposed method.