Low Complexity Model Predictive Control of PUC5 based Dynamic Voltage Restorer

Abstract

This paper proposes the mitigation of grid voltage disturbances using a 5-level Packed U Cells (PUC5) based dynamic voltage restorer (DVR) solution. The proposed DVR is controlled by using a lower complexity multi-objective model predictive control (MPC) approach, which regulates the injection of the compensation voltage in series and synchronism with the grid during the voltage disturbance events, the auxiliary capacitor voltage, while controlling the PUC5 output current. For a similar problem (PUC7), the capacitor voltage constraint should be heavily considered in order to ensure proper and stable operation of the inverter. For the selected PUC5 structure, the existing redundant switching states offer more flexibility in synthetizing the output voltage levels leading to an optimized output performance. This lowers the complexity of the proposed MPC through extremely decreasing the priority of the capacitor voltage control. Theoretical analysis and simulation results are given to show the high performance of the proposed solution.