Abstract
This paper presents a plain method to calculate the voltage waveform at the motor input terminals from the inverter output terminal voltage and also a method to reduce the voltage. The voltage waveform at the motor input terminals is obtained by the frequency domain calculation using the transfer function of the cable and the frequency characteristics of the voltage waveform at the inverter output terminals. The analysis using this method clarifies the mechanism of the rise of the maximum voltage at the motor input terminals, that is, the ringing at the motor input terminals, which occurs at specific frequencies at which transfer gain increases, causes the rise of the maximum voltage. Therefore, to decrease the maximum voltage at the motor input terminals, it is effective to shorten the cable length or cancel the ringing voltage by pre-switching.
