Implementation of automatic bus transfer scheme on multi-function microprocessor based relays

This paper presents the basic principle and a comparative analysis of the various automatic bus transfer schemes in practice and their applications in the industries and power plants. The prime objectives of this paper are as follows: the illustration of a flexible residual voltage automatic bus transfer scheme implementation using a multi-function microprocessor based relay, a study of its onsite-testing criteria, and finally the inferring of its common troubleshooting stages encountered in the real-world application. Use of the numerical IEDs are recommended for simplification of the automatic bus transfer system, component cost reduction and increased system reliability, and the availability of events for transfer analysis.