アウターロータ型ブラシレスDCモータの駆動方式による特性比較

抄録

An outer rotor type motor can have higher torque than an inner rotor type; a brush-less DC motor has no mechanical friction loss and is maintenance-free. Therefore, an outer rotor type brushless DC motor has been used in business machines and electric vehicles using a square wave driving system. Such motors are difficult, however, to rotate at low speeds because of its detent torque and torque ripple induced by a square wave driving system. We propose a sine wave driving system. If magnetic flux distribution of the motor is sine wave distribution, this system has less torque ripple than a square wave driving system. We compare characteristics of a sine wave driving system with those of the conventional square wave method.