Abstract
The excitation force of the capacitor motor is composed of many peak frequency components. The highest peak level of the force occurs at 100 Hz. This frequency is two times the power supply frequency. Therefore, we call this frequency component the "2f component", and discuss the force of this 2f component. When the motor operates, the torque of the motor fluctuates at two times the power supply frequency. This vibration torque is the cause of the excitation force of 2f component. Based on the mechanism of the generation of excitation force, we propose the calculation methods for obtaining the excitation force of 2f component. In this method, the excitation force of 2f component was estimated from both the calculate value of the vibration torque and F-E model of the motor. To obtain the vibration torque of the motor, we employed the two-phase equivalent cirquit of the capacitor motor. And then we calculated the vibration torque acted on the motor housing, throughout this calculation process, the excitation force of 2f component is finally obtaind. It was eventually demonstrated that calculation results approximately fit in measured one.
