A soft-switching hybrid BLDC drive using dc-dc converter

This paper presents a new low cost, highly efficient, reliable and compact motor drive topology for residential and commercial applications, such as building air-conditioning, appliances, etc. The drives consist of a three-phase permanent magnet brushless DC (BLDC) motor, a soft switching dc-dc converter and a three-phase inverter containing six silicon-controlled rectifiers (SCRs). A micro controller or a digital signal processor (DSP) will be used to control the overall system. The proposed system is fault tolerant doe to its current regulated nature, where it can even withstand a solid short-circuit at its output terminals. The drive is low cost with respect to the commercially used IGBT-based systems. Since all the switches used in the output three phase inverter are current commutated, and the dc-dc converter uses soft-switching techniques, this drive has much lower switching losses than the conventional PWM drive.