Mixed-Mode Effect on Motor Common Mode Current

摘要

This paper presents the mixed-mode effect on motorcommon mode current (CMC) in an adjustable speed drive(ASD). It is expected that the motor CMC is lower than inverteroutput CMC. However, the measurement result of the ASD showsthat the AC motor input CMC is higher than the inverter outputCMC in a frequency range. By using a mixed-mode (MM) 6-portnetworks, it is proven that the AC motor input CMC is higherdue to an MM CMC which is generated from differential modecurrent.