Computationally Efficient Model Predictive Control of a Four-Leg Inverter for Common Mode Voltage Elimination

This paper presents a computationally efficient modified model predictive control (MMPC) method with reduced computations applied to a four-leg voltage source inverter, with common-mode-voltage (CMV) elimination. The proposed MMPC method is based on reference voltage determination, which is then compared with the available finite-control-set (FCS) of the corresponding tetrahedron to evaluate the cost functions. The proposed MMPC significantly reduces the computational burden, compared to the standard, load current prediction based, cost function calculation for all states. Three main objectives are addressed by the proposed method: (a) to reduce the calculation time, (b) to eliminate the CMV from the system, and (c) to handle the unbalanced loading conditions. The proposed MMPC method is validated by extensive simulations in the Matlab-Simulink© software. Simulation results confirm the effectiveness of the proposed method.