A PLL-Less Scheme for Single-Phase Grid Interfaced Load Compensating Solar PV Generation System

This paper proposes a single-phase double-stage scheme for grid interfaced load compensating solar photovoltaic (PV) generating system. The scheme serves twofold objectives of alleviating power quality issues such as power factor correction and harmonics mitigation, while simultaneously extracting the maximum power generated by the PV unit. A simple notch-filtering control algorithm is designed to facilitate extraction of the real component of load current, exempting the services of a phase locked loop (PLL). The absence of a PLL reduces the system dependence on the proportional-integral (PI) controller tuning, which in turn improves the dynamic response and makes the system quite robust. The proposed solar PV generation system retains its ability of mitigating harmonics on cloudy days and also provides opportunity for night time utilization of available resources. The system has been analyzed under both linear and nonlinear varying loads using and an experimental verification of the results is carried out on a developed prototype of the system.