An accurate high frequency model of AC PWM drive systems for EMC analysis

The aim of this work is to give an accurate high frequency model of a complete AC PWM drive, starting from the transformer of the main power source, to the electrical motor. The proposed model allows to analyse the effects of the high dV/dt applied by the PWM inverter on the overvoltages and on the leakage currents that flow through the stray capacitance of the system. Both the effects cause electromagnetic interference in the electrical networks which supply the AC drives. All the electrical components involved in the AC drive are considered and their role on the high frequency effects are analyzed.