VAr support from solar PV inverters

This paper provides an overview of the need and applications for solar photovoltaic (PV) inverters with Volt/VAr feature to provide grid support during steady state and/or system events. This paper will also provide test results from residential and commercial PV inverters designed to operate according to German standards, which now allows voltage support. The residential inverters output voltage was 230 volts line-to-ground and the commercial was 400 volts line-line, reflecting the typical German residential and commercial voltage configurations respectively. The inverters frequency was adjusted to 60 Hz in order to reflect American standard practices. The testing was performed in Southern California Edison´s (SCE) Distributed Energy Resources (DER) Laboratory in Westminster, California. The primary reason for the testing is to explore features not presently required by U.S. standards. The results detailed here provide information that can be used to develop national standards for voltage regulation features on PV inverters.