Adaptive distance protection against transition resistance for distribution networks containing distributed generation

Abstract With the introduction of a large number of inverter interfaced distributed generators (IIDG), the measured impedance under a non-metallic short-circuit fault will not correctly reflect the distance from the protection installation to the fault point. Aiming at this problem, this paper analyzes the composite sequence diagrams under different types of faults in distribution networks containing IIDGs, uses the power-side fault components to find the additional impedance angle, and calculates the corresponding short-circuit impedance by combining with the impedance complex-plane relationship. To propose an adaptive distance protection scheme for distribution networks containing IIDG. The solution process utilizes single-ended electrical quantities on the power supply side to solve the problem that distance protection is affected by the controlled characteristics of IIDG fault output and transition resistance, and finally the protection scheme is verified by PSCAD/EMTDC, and the results show that it has good reliability under different types of faults.