Model Predictive Control for Three-phase Grid-Connected Inverters

Abstract

Demands of renewable energy are increasing due to its effectiveness and sustainability. However, this energy source depends much on the weather and is unstable. Therefore, it needs to be connected to the power network via grid-connected inverters using power electronics devices. The power quality of inverter outputs depends much on the control strategy and modulation. The conventional control methods such as the proportional-integral (PI) and proportional resonance (PR) use the control loops and depend on the controller coefficients. The hysteresis current control method offers the best dynamic response. However, its switching frequency is very difficult to control. This paper presents a method basing on the model predictive control. In the proposed method, the inverter switching states are optimally chosen to minimize the cost function. This helps inverters reduce the switching counts while ensuring the low output harmonics. Thus, this can help inverters decrease the switching loss. The simulation results on Matlab/Simulink have validated the effectiveness of the proposed control method compared with that of the hysteresis current one.