Modeling and Control of Multi-functional 3-ϕ Grid-Connected Photovoltaic Power System

For the last decade, significant growth in electricity generation from photovoltaic power systems has been recorded. Due to the high penetration of renewable energy sources (RESs) into the power grids, future power networks will be more volatile to power oscillations, generation-demand imbalance, voltage fluctuations, and frequency oscillations caused by the intermittence nature of these sources and lack of system inertia. This paper introduces a multifunctional two-stage grid-connected PV power system based on detailed mathematical modeling and innovative control techniques to provide efficient ancillary services to meet the grid code requirements and to overcome the issues of photovoltaic generation. The simulation results show that the designed multifunctional PV power system is capable of operating at MPPT or suboptimal operation to ensure the ancillary services of ramp-rate control, active and reactive power control, frequency regulation, harmonic filtering, and ac voltage regulation, under varying operating and atmospheric conditions.