Power analysis of effects of MOSFET intrinsic characteristics on motor drive application

Inhalt:
The significant advantages of brushless DC (BLDC) motor in terms of safety, reliability, power efficiency, and control precision render BLDC motor one of the most promising candidates to replace conventional brushed motors in battery powered applications including medical equipment, home appliances, cordless power tools and industrial automation. The rapid advancement in the motor performances has simultaneously stimulated interests in developing efficient motor drive controllers with optimized power MOSFET devices. On the power MOSFET devices for motor drives applications, every new silicon technology development is based on the application requirements, in which the MOSFET characteristics might be changed, or improved, to provide significant added value to the customer. A great challenge in this process is to fit the important component parameters onto a smaller silicon area and thus reduce the manufacturing costs. Achieving the best solution means knowing how to choose the most appropriate MOSFETs. A common practice for designers evaluating the power stage is to measure the temperature and correlate the power losses with the temperature measurement, but this only provides the overall power losses. The lack of detailed analysis on power losses makes a good design very difficult. This paper presents the influences of MOSFETs with different intrinsic properties on brushless DC (BLDC) motor drive inverter with block-commutation control. A detail analysis on efficiency, power losses and distribution on the effects of MOSFET intrinsic characteristics will be revealed in this paper.