An adaptive approach for online fine tuning of current PI controllers in washing machines

Washing machines are becoming more and more complex devices in terms of both drives and motor control as the computational power of microprocessors increase and their costs fall. In the recent years PMSM drives started to govern the drive usage percentage simply as a result of their high performance in the appliance industry too. Because of the speed and load characteristics of washing process, certain modifications should be applied to the used control method without increasing the need of the computational power of the microprocessor. This paper proposes an online tuning method for tuning the proportional and integral terms of current controllers used to control the direct and quadrature axes currents in Field Oriented Control (FOC) of PMSM which is used to drive the washing machine. The tuning is based on Nelder-Mead optimization algorithm and experimental results are given.