Impact Of Grid Connected Inverter Filters On Network Impedance And Harmonics

Filters in photovoltaic inverters play a vital role of attenuating high frequency harmonics and improving the quality of the power transferred from the photovoltaic (PV) panels to the grid. Inverter filters form part of the inverter output impedance and can be connected to the grid even if the inverter does not produce any active power. This paper focuses on the impact of inverter filters on the low voltage (LV) network impedance and assess the change in existing harmonic current and voltages. The impact of inverter filters on the network series and parallel resonance impedance assuming high proliferation of PV energy is assessed, including the resulting change in flow of harmonic current and voltage distortions.