Positive Sequence Superimposed Based Islanding Detection Method Used in Distributed Generation

Abstract

This paper presents a passive method based localized islanding detection method for distributed generation (DG) connected to a main grid. The approach in this paper is based on the calculation of the magnitude of positive sequence based superimposed components of current and voltage, and the angle between them at the DG end. These three physical quantities altogether are used to identify the islanding. The prevailing active detection techniques introduce deliberately disturbances into the system which might lead to problems related to power quality, stability, and reliability of the power system. On the contrary, passive methods based islanding detection techniques has the issue of large non-detection zone (NDZ). The proposed technique overcomes the NDZ problem and does not introduce any disturbances. PSCAD/EMTDC is used to simulate the two systems. Various tests are carried out on these systems to access the execution of the proposed method and it was found that the suggested method has least NDZ and can detect the islanding within 10 ms well below the time required by a recloser which is 150 ms.