Model Predictive Control and Grid Voltage Sliding Mode Observer for LVRT of Grid-Connected Inverters

This paper introduces a model predictive control (MPC) strategy for grid-connected inverters under low voltage ride-through (LVRT) conditions. The proposed MPC dynamically adjusts the inverter's reference current signal to optimize reactive power compensation using a minimum cost function. This ensures the selection of an optimal voltage vector for compensation. Traditional voltage feedback signals may be inaccurate due to grid frequency deviations during LVRT, affecting control performance. To tackle this issue, a sliding mode observer (SMO) is proposed to replace conventional voltage sensors. This reduces the reliance on hardware and enhances system robustness. The observer's design includes an enhanced filtering and compensation scheme to address inaccuracies in grid signal sampling during LVRT. The simulation results demonstrate that the proposed control method can achieve LVRT control of grid-connected inverters.