Performance Evaluation of Some Industrial Loss of Field Protection Schemes Using a Realistic Model in The RTDS

Loss of field (LOF) relay, with ANSI code 40, is one of the most important protection functions for synchronous generators in power plants. Although many LOF protection schemes have been presented in the literature during the last decades, a few numbers of them such as impedance and admittance based schemes are accepted by the industry. This paper explores and compares the performances of some industrial LOF protection schemes through simulation studies and from speed, reliability and security viewpoints. The simulation studies are carried out in the real-time-digital-simulator, where a realistic power generation unit is developed by employing the phase domain model of synchronous generator. Using such a realistic system, various types of LOF events can be simulated in accordance with IEEE Standard C37.102-2006, so that the performance of any method can be evaluated through careful LOF studies.