Abstract
In the sensorless dc brushless motor driver, it is composed ofa three-phase driver circuit, a commutation detector circuit andan auxiliary power circuit. The sensorless motor driving methodcan reduce cost and increase its reliability. A motor/generatorbi-directional power converter is adopted to reduce the cost, andthe engine and motor combination is used to simplify the originalcharging circuit. Thus, the system can be operated into twomodes, of which one is motor driver mode (motor mode) and theother is generator charger mode (generator mode).