Application and Performance of Electronic Exciters for Large A-C Generators

Power rectifiers have proved themselves as efficient and reliable converters of a-c to d-c power for many industrial applications. They also have been used to a limited extent as exciters for synchronous motors and condensers. This paper discusses the requirements of rectifiers when used to excite large a-c generators and presents the results of tests made to determine performance under various operating conditions. The results cover preliminary tests that were made on a laboratory model in addition to extensive and more complete tests on an electronic exciter now installed in the Springdale generating station of the West Penn Power Company. The electronic exciter was designed to serve eventually as the main exciter for an 81,250-kva 3,600-rpm turbine generator just installed, but it is now supplying excitation to a 47,100-kva 1,800-rpm turbine generator. Switching arrangements are provided for exciting either unit from the electronic exciter or from an existing motor-driven exciter.