A low-cost BLDC motor drive using buck-boost converter for residential and commercial applications

This paper presents a novel 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, an AC-DC converter and a three-phase inverter containing six silicon-controlled rectifiers (SCRs). A microcontroller or a digital signal processor (DSP) is used to control the overall system. The proposed system is fault tolerant due to its current regulated nature, where it can even withstand a solid short circuit at its output terminals. Our analysis shows about 30% cost reduction in the proposed BLDC motor drives with respect to the commercially used IGBT-based system. Since all the switches used in the output three-phase inverter are current commutated, this drive has much lower switching losses than the conventional PWM drive.