A comparative study of dynamic state estimation approaches for detecting loss of excitation failures

Abstract

Loss of excitation (LOE) is a characteristic failure of synchronous generators. In this article, we present a comparative study between different dynamic state estimation approaches to efficiently detect LOE. In this context, multiple modes of operation of the system are modeled in order to implement a faulty mode detection and diagnosis algorithm. This algorithm is continually monitoring the state variables of the generator to decide, in real-time, the most probable mode of operation. The main goal is to enhance the estimator robustness against mismatches between the model used and the real excitation system. To achieve this goal, we made a comparison between considering the field voltage as an unknown input and treating it as a constant with a high component of noise. Simulations using a two-area power system have shown that LOE detection times are not significantly degraded even if the the excitation system incorporates non-modeled effects.