How Photovoltaic Inverter Firmware Could Affect PQ

Abstract

This paper describes the impact of photovoltaic power plant inverter firmware on voltage quality parameters in low voltage distribution grids. The DSO identified the photovoltaic power plant with the power of 60kW as a source of high flicker level in distribution network. Then authors of this paper were involved in general analysis of all factors, which led to high flicker level. Very unusual behaviour of inverters was identified by using tailored power quality analyzer. The measurement result was used to claim incorrect inverter functionality to the manufacturer. The flicker level decreased significantly after the firmware replacement.