Applications and construction of transformer on-load tap-changing gear

The paper deals briefly with the development of tap-changing gear and indicates some of the fields of application of tap-changing gear in power supply systems. The various circuit diagrams in common use, and the types of tap-changing equipment, are classified, and brief descriptions are given of a number of typical equipments. The fundamental principles of methods of remote electrical and automatic control are indicated, and the effect of impulse voltages on the design of tap-changing gear is referred to. The paper concludes with a brief section on economical types of voltage regulators for rural lines, and a section giving a statement of operating experience gained over a number of years, with some notes on earlier troubles and their remedies. It is not within the scope of the paper to make comparisons between regulation by tap-changers and by other forms of regulator, as the paper is restricted to transformer tapchanging gear and its applications.