Abstract
In recent years, distortion of power source voltage waveform has become noticeable, as electrical appliances with rectifier circuits have been widely used. Connecting capacitor induction motor (CRM) to such distorted supply, or controlling CRM by simple controller with switching device such as triacs, harmonic voltage is supplied to CRM. In that case, CRM produces electromagnetic vibrations caused by not only the fundamental voltage but also time-harmonic voltages in the distorted voltage. In addition, CRM produces electromagnetic vibration due to backward magnetic field. Thus, it is difficult to clarify the relationship between electromagnetic vibration of CRM and harmonic voltages.
In this paper, the causes of the electromagnetic vibration of CRM operating under distorted wave supply voltage are discussed. First, a general equation of dominant electromagnetic force waves is shown considering not only forward magnetic fields but also backward magnetic fields. Using the general equation, causes of dominant electromagnetic vibration are clarified. Next, by means of discussing in details of some examples of the dominant vibration, the relationship between the vibration and harmonic voltages becomes evident. Furthermore, the relationship between the vibration and backward magnetic field is clarified.
