Enhancing Ancillary Grid Services with Integrated PV System under Unbalanced Load and Weak Grid Scenario

The paper introduces a grid-connected ancillary photovoltaic (PV) system that supplies power to the grid and a nonlinear load. It employs a Third Order Generalized Integrator Quadrature Signal Generator (TOGI-QSG) control for a D-STATCOM type Voltage Source Converter (VSC). In comparison with conventional control algorithms, it ensure symmetrically balanced grid currents, unity power factor correction, and harmonic mitigation, even under conditions such as unbalanced nonlinear loads, fluctuations in solar irradiation, and disturbances in grid voltage. The Maximum Power Point Tracking (MPPT) algorithm, based on Perturb and Observe (P&O), is utilized to maximize power extraction from the solar photovoltaic array. The real-time performance of the system is evaluated using the Opal-RT OP4510 simulator across diverse operational scenarios, including load imbalances, sudden changes in solar irradiance. The work adheres strictly to revised harmonic control standards such as IEEE std. 519 and IEC std. 62109.