PWM ZCS DC Motor Drive and DC Power Supply

Abstract

Following the extension and increase in capacity of power electronic elements, many convertors with special applications have been designed. Convertors such as rectifiers, AC and DC power supplies, AC and DC drivers and so on. At present, optimization of these convertors, decreasing loss and bringing down the electromagnetic interference are desired. In this paper, a DC to DC convertor for controlling the speed  of DC motor is designed and  one prototype is presented in which switching losses is close to zero and it has a very low electromagnetic interference. In this convertor, the switches  turn on and turn off approximately with zero current. The speed of motor is controlled by PWM.  This plan includes advantages of  PWM and resonant convertors.The disadvantages, such as ;  high switching losses and changing switching  frequency  for controlling output were removed. As switching frequency has a direct relation with switching losses, when losses decreased, it is possible to increase the frequency, then volume and weight of passive filter elements can be decreased. Besides, by decreasing the losses ,  the need of  heatsink , which is  the heavy and voluminous elements of convertors, can be removed.