Common Mode and Differential Mode Prediction in a Drive System with Transmission-Line Theory

In drive systems, high-frequency leakage currents with frequencies up to several 10 MHz are likely to occur due to the switching operation of power electronic systems. Those leakage currents can unintentionally affect other components such as circuit breaker or residual current breaker and are hard to predict in most applications. A new model for the evaluation of the leakage current associated with each component in a three-phase system is proposed. The simulation model is easily adjustable according to the associated frequency range and it can evaluate both common mode and differential mode current. The proposed model result demonstrates a good agreement with the measurements up to 10 MHz.