A Composite Method for Islanding Detection Based on Vector Shift and Frequency Variation

Abstract

Islanding detection is an important issue for distributed generation operating with main network. To solve the problem of reliability and sensitivity of conventional vector shift method, this paper presents a composite islanding detection method utilizing both angle change and frequency variation derived from distributed generator terminal voltage. The method consists of main criterion and auxiliary criterion, each one having its own setting and calculating algorithm. The establishment and working principle of the proposed method are described in detail. PSCAD/EMTDC based simulations on a test system are conducted and analyzed. Simulation results show that the composite method is sensitive and reliable.