A simplified reactive power control for single-phase grid-tied photovoltaic inverters

The objective of this paper is to propose a simplified reactive power control (SRPC) strategy for the single-phase grid-tie photovoltaic (PV) inverter. The proposed SRPC method is to sense the inverter´s output current, where a simplified power calculation is integrated into the SRPC, to easily calculate the actual reactive output power. Then, the power error between the reference value and the measured one can be eliminated by using a proper compensator to improve the controlled accuracy. Besides, the proposed SRPC can reduce the computational burden, significantly, so a low-cost micro controller unit can be adopted instead of using the high-level digital signal processor. In this paper, the operational principle and mathematical derivation of the proposed SRPC strategy will be introduced. Finally, a 1 kVA prototype PV inverter with the SRPC strategy was built to verify the performance of the proposed reactive power control strategy.