Online gain scheduling of multi-resolution Wavelet-based controller for acoustic noise and vibration reduction in sensorless control of PM-synchronous motor at low speed

An online gain scheduling of the Wavelet-based controller coefficients is presented in this paper for the purpose of reducing noise and vibration resulting from a sensorless control of PM machines at low speeds. The Wavelet-based controller decomposes the whole frequency spectrum into several sub-bands. Each sub-band has a unique effect on the position and speed estimation error in the transient and steady state conditions. The high frequency bands mostly affect the noise and vibration of the system. In this study, parameters which belong to the wavelet-based controller are optimized with hardware in the loop in order to reduce the steady state errors and increase the estimation precision. For the optimization procedure, the GA (Genetic Algorithm) was implemented. The performance of the optimized controller was verified trough the simulation and laboratory experimentation.