Reactive power compensation using derated power generation mode of modified P&O algorithm in grid-interfaced PV system.

A local load connected with the grid-interfaced photovoltaic (GIPV) system demands reactive power compensation at the distribution level. The compensation either fulfilled by the PV inverter or grid side arrangements such as capacitor bank, static VAR compensator or tap-changing transformers. Amongst both, the inverter has merit to compensate reactive power without using an additional compensator or oversizing the inverter rating. However, it always depends upon the availability of irradiance and especially when the inverter transfers power with full capacity has no margin to generate the reactive power. Therefore, to make the system flexible according to the demand of the local loads and to create a margin to generate the reactive power at any time instant, a GIPV system with modified perturb & observe (MP&O) maximum power point tracking (MPPT) technique has been proposed. This proposed technique with an intermediate boost converter extracts maximum power more efficiently as compared to the traditional MPPT technique. On the other hand, it curtails the generated active power and provides margin for the PV inverter to generate the reactive power. Further, the PV inverter generates active and reactive power to the local loads as well as transfer power to the grid using inverter control. The inverter control comprises of decoupled instantaneous active and reactive power control. In this control scheme, it maintains the DC-link voltage and power flow between the GIPV system and the grid under all available irradiance conditions. In this respect, a 30 kW GIPV system is simulated and performance of the system is validated using real-time OP4510 hardware-in-loop (HIL) setup. • Modified P&O MPPT technique is proposed to extract the PV power. • Derated mode of Modified P&O MPPT technique is implemented to curtail the active power. • Smart utilization of PV inverter's capability for the reactive power compensation. • Simulation results are validated using Opal-RT OP4510. [ABSTRACT FROM AUTHOR]