Passive anti-islanding scheme based on reactive power in the smart grids

Identification of intentional and unintentional islanding situation of the dispersed generators is one of the important protection concerns in both traditional and smart grids. Regarding the safety and reliability problems of the distribution networks an exact diagnosis index is required to discriminate loss of main network from existing occurrences of parallel operation. Hence, this paper presents a new passive-based islanding detection method, according to change in ∂V_DG/∂Q_load index. The proposed methodology can be used in both traditional and smart grids. This technique has been applied for a sample network to evaluate the performance of the proposed method with different scenarios, including the islanding and non-islanding occurrences. At the end, the proposed method has been compared with the ROCOV relays. Simulation results show that the proposed method has smaller NDZ than the ROCOV relays and can be used as an effective alternative instead of the ROCOV relays.