Adaptive Mho relay for synchronous generator loss‐of‐excitation protection: a capability curve limit‐based approach

Abstract

Loss-of-excitation (LOE) relays work under pre-defined operating characteristics. If an abnormal condition should arise, such operating characteristics might not be suitable for current system conditions. In this study, an adaptive real-time data-based analytical methodology is proposed for improving LOE protection performance. The core idea is to generate in real time an adaptive operating characteristic for the Mho relay, based on the well know Berdy's method. The adaptive Mho operating characteristic is derived through the proposed methodology using the generator capability curve. Validation is obtained through comparative simulation test cases using DigSilent Power Factory® program. Test case results show that the proposed protection adaptive analytical methodology displays secure and effective high speed LOE detection, indicating potential for real-life applications.