The development of a neural network-based multi-function protection relay

The protection of DC traction circuits from fault conditions is a difficult task. The paper describes the development of a neural network to be used in a multifunction protection relay. The neural network developed can discriminate between normal train operation and short-circuit conditions on the DC traction supply. The neural network provides fault protection and location. The neural network was trained and tested using both simulated and actual data. The paper presents results showing that the neural network can discriminate between faults on a DC traction system and the normal operation of both camshaft and chopper controlled rolling stock. Conclusions are given on the advantages and disadvantages of using neural networks, along with their possible use in also locating a fault.