A Centralized Substation Protection Scheme that detects hidden failures

摘要

One of the top reliability concerns in power systems classified by NERC is hidden failures in protection schemes. Such failures are defects that go undetected under normal operating conditions but manifest themselves during faults or transients, which may lead to the false operation of relaying schemes. Specifically, hidden failures typically lead to incorrect input to relays and adversely affect protection logic, often with catastrophic results. This paper introduces a centralized protection scheme that detects hidden failures in real time under normal or abnormal operating conditions and eliminates their consequences. The approach entails acquiring all data collected by the relays, meters, and fault recorders in a substation to a central computing device. The proposed centralized protection scheme uses a dynamic state estimation method to detect hidden failures. The method requires accurate physically-based models of the entire substation. In the case of detection, the proposed scheme identifies the type of hidden failure. The paper describes the system conceptually and sheds light on its infrastructure.