Standby Power Supply for Telecommunications Equipment

With the power shortage and nonavailability of power at certain locations, the use of captive power is becoming more common. In fact, every industry has their own standby generating sets. Utilities like post and telegraphs, airports, etc. use engine-alternator sets as emergency power supplies. Due to the development of technology, varied types of new electrical equipments have come in use. With the advent of thyristors, drives, rectifiers and other control equipment using thyristors have become popular. The thyristor loads inject lot of harmonics in the supply lines. High current harmonics generated on the ac input to rectifiers sometimes lead to unsuccessful operation of thyristor converters, when supplied from standby generating sets. Problems can be solved in the following ways: - By reducing the harmonic content of the thyristor converters. - By designing suitable engine-alternators which can accept these harmonics and work successfully. This paper covers the work being carried out in designing such alternators which would provide reliable power supply to rectifier panels using thyristors, feeding the telecommunications equipment. The special problems of brushless alternators when supplying thyristor loads are also included.