Power Hardware-in-the-Loop Testing of Residential PV Inverters in the Conditions of Weak Network

The paper presents the results of the power hardware-in-the-loop study of four commercially available residential solar inverters. This study was performed for Hydro-Québec TransÉnergie as part of a mandate to characterize the behavior of PV inverters and assess their impact on the transmission system. The particular focus of the paper is the behavior of the inverters in the conditions of weak network or high penetration level. Firstly, an analysis using a simple network model is done, and the resonance conditions are determined via linear analysis and subsequent experimental tests. Furthermore, a realistic model of an actual rural distribution feeder in Québec is used to validate the findings. The results demonstrate that the undesirable effects of the resonance are common among various commercial products and can potentially disrupt normal operation of the power grid.