6 - Operation and maintenance

Abstract

This chapter discusses the operation and maintenance of transformers. The first section describes the design and layout of the transformer installations. The second section outlines the subject of neutral earthing. The chapter briefly looks at the principal aspects in so far as they affect transformer design and operation. The third section is about the transformer noise. Noise emission by transformers in operation is inevitable. In approaching the noise problem it is therefore essential to consider not only the engineering aspects, but also to remember that noise is a subjective phenomenon involving the vagaries of human nature. Next, the chapter explains the parallel operation of transformers, which is affected when both the HV and LV windings of two (or more) transformers are connected to the same set of HV and LV busbars, respectively. A short description of the transient phenomena occurring in transformers is also included here. While using transformers, it is important to learn the methods for its protection, which are incorporated in this chapter. The last section is devoted to the description of the influence of transformer connections upon the third-harmonic voltages and currents. The purpose of this section is to state the fundamental principles of third-harmonic voltages and currents in symmetrical three-phase systems; to indicate their origin in respect of transformers; and to marshal the facts; and finally, to indicate their undesirable features.