Hybrid anti-islanding algorithm for utility interconnection of distributed generation

In this paper hybrid anti-islanding algorithm for utility interconnection of distributed generation is proposed. This algorithm is based on two detection schemes; namely active and passive. Active detection algorithm generates disturbances at the output by positive feedback and continuous feedback signal injection which is based on DQ implementation. On the other hand passive detection algorithm detects islanding by measuring voltage, frequency, active and reactive power. Using total harmonic distortion (THD) as an additional parameter is proposed in this paper. Passive detection algorithm uses several types of loads such as resistive, capacitive and inductive connected in parallel and compares the performance of the algorithm in each case.