Evaluation of Multi-Inverter Anti-Islanding With Grid Support and Ride-Through and Investigation of Island Detection Alternatives

The report, Evaluation of Multi-Inverter Anti-Islanding With Grid Support and Ride-Through and Investigation of Island Detection Alternatives, documents results from a set of laboratory simulations and experiments. This report documents results from a set of laboratory simulations and experiments to determine the impact of photovoltaic (PV) inverter grid support functions on various anti-islanding detection methods. The project team included Sandia National Laboratories and Northern Plains Power Technologies. Topics covered include: (1) Testbed setup for conducting the laboratory experiments (inverters tested were single-phase 3 kilowatt, and three-phase 50 kilowatt). (2) The grid support functions studied were volt-var (with watt priority), frequency-watt, and ride-through. (3). The anti-islanding methods studied were non-continuous positive feedback on frequency error with and without increasing magnitude (two of the most commonly-used methods in modern inverters) and impedance-detection methods (methods that manipulate the negative sequence current). (4) Observations of run-on-time and non-detection zone were made at various active and reactive power conditions, at various irradiance levels, and with various grid support functions. (5). The use of collaborative controls as a mitigation measure was explored in simulations.