A Novel Grid-Forming Control Strategy for Two-Stage PV Systems with Improved Power Output Capability

With the enormous integration of renewable energy into the power system, more distributed generations (DGs) based on renewable energy sources (RESs) are expected to participate in voltage regulation for system support and disturbance rejection. Therefore, multiple grid-forming (GFM) control techniques have been developed. However, power output capability is equally crucial for RESs, as they must accurately and promptly regulate output power to fulfill the upper-level demand or track the maximum power point (MPP), particularly in environments that change regularly. Unfortunately, there hasn't been much relevant study done on it so far. By reshaping the power synchronization loop, this paper proposes a novel holistic two-stage GFM-PV control strategy which can contributed to the flexible and robust operation of the power system dominated by RESs even under limited energy storage devices. The effectiveness of the proposed control strategy is verified by experimental results.