Optimal energy saving for variable speed single phase induction motor drives

The object of this paper is to maximize the energy saving of the permanent split capacitor single phase induction motor (PSCSPIM). The proposed technique ensures that, the motor drives the load at the reference speed with maximum efficiency regardless the load torque. Therefore, the proposed energy saving (ES) controller minimizes the motor power consumption for the consumers. In the proposed ES controller, the frequency of the drive and the auxiliary winding capacitor values are controlled according to the reference speed values regardless the load torque. The motor voltage is controlled using a proportional integral (PI) controller to eliminate the error between the reference speed and actual motor speed at the demanded load torque. The steady and dynamic performances of the motor are presented with MATLAB/ Simulink package. The optimal values of the drive frequency, auxiliary capacitor and PI gains have been attained using the water cycle algorithm (WCA) as one of new metaheuristic optimization techniques. The results of WCA are confirmed by using other well known optimization technique of particle swarm optimization (PSO). To show the feasibility of the proposed method, it has been applied for fan and compressor loads. The paper presented a comparison between the drive performance with a fixed capacitor and classical V/f control method and with the proposed ES controller with an electronically controlled capacitor to achieve maximum efficiency operation at the demanded load.