Modeling and design of fuzzy speed controller for constant frequency zero current switched converter fed DC servo motor for battery operated vehicles

A new method of speed control of DC motors using pulse width modulation (PWM) based quasi-resonant (QR) zero current switching (ZCS) DC to DC converters is proposed. This control minimizes the switching losses, eliminates electromagnetic interference (EMI), and improves efficiency and commutation capability of the motor. The speed control is achieved by controlling the free wheeling period of the resonant inductor of the quasi-resonant converter (QRC). A half wave (HW) constant frequency (CF) ZCS converter exhibits a nonlinear relationship between its ON time and average output voltage. Hence, a fuzzy speed controller is designed to get better performance under load conditions. The software package PSPICE A/D is used for simulation