Variability Mitigation for Grid Stabilizing of PV Systems with Power Limit Control

This paper proposes a power limiting control (PLC) method for photovoltaic (PV) systems that can produce the desired power while mitigating the variability against the environmental change. The maximum power point tracking (MPPT) control, which only aims to extract the maximum power from the sun, causes power variations as the environment changes. The existing PLC methods also show severe variability because those methods adjust the power generated from the PV array instead of the power injected to the grid. In the proposed PLC method, the power injected to the grid is directly adjusted instead of PV array power by using output power control. Therefore, the highly reliable operation of grid-connected PV systems can be achieved. The fundamental concept of proposed PLC method is explained, and its performance is verified with an existing PLC method by simulation test.