Active Power Control of Voltage-Controlled Photovoltaic Inverter in Supporting Islanded Microgrid Without Other Energy Sources

The active power control of increasing renewable energy resources is a growing concern. For example, solar energy exploitation is highly dependent on the central controller and other resources. Previous research has introduced some solutions for this problem, but the performance is usually unsatisfactory in power allocation, communication dependence, mode switch, and algorithm complexity. This article proposes a straightforward but effective strategy for the two-stage photovoltaic (PV) inverter, which uses the voltage-control method to adjust the PV inverter's output power and match the load demand. Moreover, reference power tracking is used instead of traditional maximum power point tracking. The mode detection and switch strategies are proposed to solve the power shortage problem, making the PV inverter maintain the voltage-control method even in the power shortage state. Even without adequate support from other facilities, the proposed method can control the PV inverter to organize an islanded microgrid if PV arrays' maximum power is larger than the load demands. Therefore, solar energy can further participate in grid support and ensure that the microgrid is more stable, robust, and economical. Finally, the proposed methods are verified in simulation and experiment.