Transductor-assisted tap changing on a 50 c/s locomotive with semiconductor rectifier

The principles and advantages of transductor-assisted tap changing are described and the design of a particular a.c. locomotive incorporating this feature is explained. The particular type of transductor circuit employed is examined in detail, together with the reasons for its selection, its method of operation and its performance in practice. The advantages to locomotive performance of controlling the tap changer so as to automatically regulate the traction current are discussed and the performance of a prototype system is described.