A Hybrid Control Technique for Harmonic Elimination, Power Factor Correction, and Night Operation of a Grid-Connected PV Inverter

This article investigates a hybrid control scheme to grant multiple functions to a grid-connected PV inverter. This strategy guarantees constant energy supply independently of the intermittent nature of solar energy. Further, it contributes to the mitigation of power-quality issues such as harmonic cancellation and power-factor correction. The control scheme comprises a current control loop based on passivity theory, which improves the inverter power quality, while the operation under null or intermittent generation conditions is ensured by the proportional-integral-based voltage control loop. Therefore, the proposed strategy extends the inverter operation in conditions in which there is no power generation. These additional functions decrease the total harmonic distortion and improve the power factor of the active power demanded from and supplied to the grid. Simulation tests and experimental results are presented to verify the suggested control approach and validate the operation and effectiveness of the system with the control scheme.