Novel loss reduction pulsewidth modulation technique for brushless dc motor drives fed by MOSFET inverter

It is well known that small power brushless dc motor (BLDCM) drives, which are fed by metal oxide semiconductor field effect transistors (MOSFET) inverters, have been widely applied to the information technology industry, especially for fan and spindle applications [1]-[3]. For small power applications of BLDCM drives, due to the use of battery or/and limited space for heat dissipation, reduction of power consumption is one of the main concerns for the development of the associated pulsewidth modulation (PWM) technique. This paper presents a novel PWM technique for BLDCM drives fed by MOSFET inverters, which significantly reduces the conduction losses, and thereby dramatically reduces the heat dissipation. Comparative results with conventional PWM technique will be fully explored to highlight the advantages of the presented novel technique. Experimental results derived from spindle drive will be presented to confirm the theoretical analysis.