Autonomous control integrating fast voltage regulation and islanding detection for high penetration PV application

Distributed renewable energy generation offers unique advantages compared with large fossil-fuel power plants. These advantages include higher efficiency, increased reliability and less pollution. However, renewable generation will cause adverse impact on the distribution system because of the stochastic generation feature. System voltage problem and unintentional islanding are two impediments to further increase the penetration level of renewable resources. An autonomous controller, with both fast voltage regulation and islanding detection facilitation functions, is proposed in this paper to address these two issues. By developing adaptive voltage reference generation mechanism, the distributed generators (DG) at different locations can be actively involved in the system voltage regulation. If the grid is lost, the islanding detection function will be seamlessly triggered without influencing the system power quality. A multiple-PV system is built in RTDS to test the controller coordination capability. The controller is also implemented in a PV inverter prototype. Simulation and experimental results are provided to verify the effectiveness of the proposed controller.