Automatic Reconnection From Intentional Islanding Based on Remote Sensing of Voltage and Frequency Signals

This paper presents a control strategy for automatic reconnection of a microgrid after an intentional islanding. Remote signals of voltage and frequency at both sides of the coupling circuit breaker are communicated to the generating site, and used as additional signals to the voltage and speed control loops, respectively. The proposed automation strategy is simulated on a real MW-scale microgrid located at a rural area in Rio de Janeiro, Brazil, and supplied by two small hydro synchronous generators. The results show that a smooth reconnection of the microgrid to the utility grid can be achieved when the proposed automation is utilized.