Novel PWM technique without causing reversal DC-link current for brushless DC motor drives with bootstrap driver

For small power applications of brushless DC motor (BLDM) drives, the inverter consists of MOSFET and bootstrap driver. The speed of BLDM is controlled by the frequency and duty of the pulse-width modulation (PWM) technique, which is one of the key technologies for the development of BLDM drives. This paper presents a novel PWM technique for BLDM drives with bootstrap driver circuit. As compared with existing PWM techniques for BLDM drives the presented technique doesn´t cause any reversal DC-link current and thereby reducing the DC-link voltage fluctuation of the drives. Experimental results derived from an FPGA-based BLDM drives are presented to fully support the analysis and claim.