Implementation of an active RLC load for unintentional islanding test

Inverters connected to electrical grids are required to properly detect islanding conditions, namely, the condition of operating isolated from the main grid. To verify the effectiveness of grid-tied converters in dealing with unintentional islanding conditions, test procedures based on resonant parallel RLC loads are recommended by standards. In this paper, we show the feasibility of using power electronic converters to implement active loads used to perform unintentional islanding tests. With this aim, the paper reports the implementation of an active RLC load by using a dc/ac converter. The equivalence of the emulated RLC load with respect to the desired one is shown by means of simulation and experimental results. An inverter having anti-islanding capabilities is considered in order to evaluate the suitability of the active load for unintentional islanding tests.