A new model predictive current controller with common mode voltage alleviation in three-phase inverters

Pulse width modulation controlled inverters produce Common-Mode Voltage (CMV), which is the main culprit of many system drawbacks ranging from Electromagnetic Interference (EMI) issues to bearing damage and insulation aging. Former methods for common-mode voltage reduction based on voltage control cause a great deal of extra harmonic distortion in output currents. In this paper, a method named as Near State based Model Predictive Control (NS-MPC) is proposed which by using Model Predictive Control (MPC) algorithm operating in a low sampling frequency and applying the real non-zero state vectors of the converter used together with new virtual state vectors produced by Near State PWM (NSPWM) generates the switching pattern in each sampling cycle. Theory and simulations show that this proposed method exhibits superior common mode voltage reduction along with a generally satisfactory performance.