Effect of Grid Support Functions and VRT/FRT Capability on Autonomous Anti-Islanding Schemes in Photovoltaic Converters

The high penetration of utility interconnected photovoltaic systems is is leading to a need for inverters to include grid support functions, to minimize the negative impact these variable distributed energy resources may have on system voltage and frequency. Unfortunately, grid support functions may interfere with island detection algorithms; specifically, it may be difficult for an island detection scheme to detect voltage and frequency deviations if that converter and other converters on the same bus actively modulate their real and reactive power outputs in response to voltage and frequency deviations while also tolerating greater deviation. This report provides analysis and simulation evidence to investigate the effect of advanced inverter functions on the performance of island detection schemes. A mitigation scheme is also presented and shown to be effective in simulation.