Finite Control Sets Model Predictive Control Of Clean Energy Power Grid-connected Inverter

With problems of environmental pollution and energy shortage increasingly prominent, much more attention has been paid to clean energy, such as solar energy, wind energy and so on. Control of grid-connected inverters for PV systems is the key of renewable energy power generation, which affects power quality directly. As a new control strategy, model predictive control(MPC) has good adaptability and robustness, which does not need inner current loop control or PWM modulation. In recent years, MPC receives increasing attention.Firstly, the status of the inverter control strategy is introduced. The mathematical models of three-phase inverter are established in static three phase coordinates and in rotary two-phase coordinates respectively, Three-phase grid-connected inverter power prediction model is established. According to the traditional control strategy–feedforward decoupling control, focuses on the model predictive control. Feedforward decoupling control is one of the widely used control strategy for inverter, the steady state performance is good, but the dynamic response speed is slow, and the control signal needs SVPWM modulation, so the control scheme is complex. In the dq rotation coordinate system, the model predictive direct power control strategy is proposed, The simulation and experimental results show that the control strategy can track power change fast, which realizes decoupling control of the output power and has good performance.According to model predictive direct power control research, the model predictive multiobjective coordinated control(MPMOCC) strategy is designed. A two-step power prediction is used to compensate time delay. In order to realize grid-connected inverter multi-objective coordinated control, an optimized cost function is designed by analyzing the influence mechanism of the cost function on the control quality and adding target additions. The MPMOCC strategy can decrease power ripple and reduce switching frequency.Finally, a 5kw three-phase grid experiment platform based on PE-PRO is built, Through comparison and analysis of experimental results, the effectiveness of the proposed scheme is verified.