Current Interharmonic Prediction Control Based on MPC and Lyapunov for Grid-Connected PV System

In this paper, we propose a model predictive control (MPC) and Lyapunov stability theory-based PV grid-connected inter-current harmonic prediction control approach. To begin, an interharmonic current amplitude calculation method based on the delta function orthogonality theorem is developed in order to achieve real-time sampling and computation of interharmonic current amplitude in grid-connected PV systems. Second, an interharmonic current prediction model is established by combining the proposed interharmonic current amplitude calculation method with a two-step prediction model of the grid-connected PV system's output current. Next, the interharmonic cost function is constructed, and a model prediction control method with an interharmonic suppression function is proposed to realize the prediction control of the grid-connected PV system's interharmonic current. The system's stability was then ensured by establishing stability constraints based on Lyapunov stability theory for the selection of alternate switching states. Finally, the effectiveness of the proposed strategy is verified by simulation and experiment.