SSI based control for single-stage single-phase PV-grid tied system with self-adjusting capability to voltage fluctuations

In this paper, a SSI (Sinusoidal Signal Integrator) based control technique is proposed for a single-stage single-phase solar photovoltaic (PV) grid tied with self-adjusting capability to voltage fluctuations. This system configures a solar PV array supplying the active power to single-phase grid and connected linear/nonlinear loads. The system aims at improving power quality, eliminating grid current distortions like harmonics, notches, bias etc., providing reactive power compensation while working under UPF (Unity Power Factor) mode. The proposed control technique for the system also provides capability for stable continuous operation during voltage disturbances in a grid such as voltage fluctuations (sag and swell). The control algorithm consists of MPPT (Maximum Power Point Tracking) technique and SSI based control for extraction of the fundamental component of load current. Simulation is done using MATLAB software and behaviour of the system is verified under varying loading and environmental conditions.