A novel islanding detection based on adaptive active current disturbance

This paper presents an active islanding detection method based on injecting adaptive active current disturbance according to the amplitude of the voltage at the point of common coupling (PCC) detected after islanding occurred to reduce the disturbance on the inverter´s output current. According to the amplitude of the voltage of PCC detected after islanding, the resistance value of the load can be obtained. Then the relationship between the minimum active disturbance current which can trigger islanding protection and the amplitude of PCC voltage is deduced. The required active disturbance current can be adaptively added to the inverter according to the amplitude of PCC voltage. As a result, the islanding can be detected after power failure without non-detection zone (NDZ). According to IEEE Std.1547.1 and IEEE Std.929-2000, the simulation results show that the proposed algorithm is correct and effective. The experiment results also show that compared to the constant and periodic disturbance methods, the disturbance on the inverter´s output current is significantly reduced by using the proposed adaptive active current disturbance algorithm.