Simplified Reactive Power Control for Single-Phase Grid-Connected Photovoltaic Inverters

The objective of this paper is to propose a simplified reactive power control (SRPC) strategy for single-phase grid-tied photovoltaic (PV) inverters. With the proposed SRPC strategy, a cost-effective microcontroller can be adopted to achieve an effectively reactive power control. Moreover, the current-mode asynchronous sigma-delta modulation (CASDM) is adopted to enhance the current control´s dynamic response and reduce both the current harmonic distortion and electromagnetic interference. In this paper, the operational principle of the proposed SRPC is introduced. Then, the small signal analysis for the PV inverter with the CASDM is presented. Finally, a 1-kVA single-phase PV inverter was built to verify the performance of the proposed control strategy.