Testing Evidence and Analysis of Rooftop PV Inverters Response to Grid Disturbances

With ever-increasing rooftop photovoltaic (PV) penetrations in the bulk power system, comes the growing interest in understanding the behavior of PV inverters during grid disturbances. Providing a wealth of experimental evidence, this article presents results from testing 25 off-the-shelf residential PV inverters subjected to voltage and frequency perturbations. Notwithstanding compliance with Australian standards, test results demonstrate that the inverter operation can be jeopardized by grid disturbances such as frequency variations, rapid voltage sags, and phase-angle jumps. It is shown that inverters may abruptly disconnect or undesirably curtail their output power, potentially disrupting the security of systems with high power contribution from rooftop PV. The findings of this work ultimately contribute to explain aggregate behavior of rooftop PV during grid events recently experienced in Australia, and compel key points to consider in the development of future standards, forming a worthwhile case study for any region of the world with high PV penetration.