Research on DC Microgrid Protection Based on Improved Dual-Slope Current Differential Protection

Abstract

This paper presents a fault detection method based on an improved dual-slope current differential protection. Traditional current differential protection needs to consider both the action sensitivity in the case of internal faults and the protection reliability in case of external faults. The braking coefficient cannot be set too low, so the sensitivity to internal high-impedance faults is low. For this reason, this paper improves the traditional current differential protection. On the basis of the dual-slope current differential protection method, it adds a judgment delay time with inverse time characteristics. Without changing the original performance of the differential protection, it increases its sensitivity to internal high-impedance faults improves the power supply capacity of the system.