Leakage Current Mitigation Technique in Solar PV Array System Using Passive Filter

The parasitic capacitances in the transformerless solar photovoltaic (PV) array system develop the closed-loop path and generate the leakage current. As a result, it hampers the system performance with the presence of the leakage current such as electromagnetic interference, lessened the lifespan of PV panel, etc. To solve these issues, the passive filter is designed herein for the solar PV array system to suppress the leakage current. The frequency-domain analysis of the system is performed herein to carry out the optimum filter parameters. In this design approach, there is not any need for additional semiconductor switches, unlike the state-of-art systems. The adaptive controller is adopted herein to extract the fundamental component of the load current in order to provide effective harmonic compensation. Simulation results demonstrate that the presented passive filter effectively suppresses the leakage current within limits based on the DIN and NB/T grid codes. Additionally, several comparative analyses are performed to validate the practical feasibility and effectiveness of the presented system. The real-time hardware-in-loop (HIL) performance is analyzed for manifold operating cases. The total harmonic distortions (THDs) of the grid currents are accomplished within 5% as per the revised IEEE standard 519 and IEC standard 61727.