Prediction of common mode conducted EMI in PWM inverter-fed machine system

In ships, more and more power electronics converters are used in the same power mains. Such power supply system can be called an isolated power system. System-level EMI prediction is necessary. All interference sources in the system should be considered. But numerical simulation is time consuming and need special software. EMC engineers need fast prediction method rather than a very precise model. Based on simple frequency domain calculation, a quickly prediction method is proposed in this paper. Adopting this method, the common mode interference in an inverter-fed machine system is calculated. Prediction and experimental results about verify this method.