Abstract
Renewable energy resources are integrated into microgrid through power converters. During abnormal situations like PV intermittency and load variations, the controller plays the most key role. In this paper, a combined control method is proposed and it consists of model predictive control (MPC) and sliding mode control (SMC) for power converters. The voltage source inverter (VSI) is controlled by using MPC, while the DC-DC boost converter is controlled by using SMC. Discrete state space model of interlinking inverter, LC-filter and load is used to predict the future trend of load voltage for each of the eight switching states. On the other hand, the detailed SMC model for boost converter is analyzed for fast convergence rate with finite-time convergence and chattering free signals. A comparison between the proposed control method and the control method based on PID is presented to illustrate the superiority of the proposed method. The performance of the proposed control strategy is verified by the simulation results. The controller performance is analyzed under different scenarios including fluctuating generation and variable loads. Unlike conventional PID controllers, the proposed strategy is simple and robust with a fast-dynamic response.