The advantages of series capacitor compensated lines in long distance transmission are well known. There are, however, problems encountered in the protection of such lines and these basically arise because, under faulted conditions, the primary system parameters are often subjected to rapid changes due largely to capacitor protective gap operation. The successful longer term development of new transmission line protection techniques is heavily dependent upon a detailed knowledge of the behaviour of practical compensated e.h.v. feeder configurations. In this thesis methods have been developed for accurately simulating the responses of series compensated system using digital simulation techniques based on frequency domain methods. The digital simulation of practical series compensated systems with shunt reactors has hitherto presented a particularly difficult problem. This thesis highlights these problems and outlines the basis of the techniques which have been developed to overcome them. In particular, the basis of some of the novel techniques developed for simulating the essentially random nature of series capacitor spark gap operation together with the non-linearities associated with single pole autoreclosure techniques has been explained. Interesting results relating to the responses of a practical 500 kV long distance transmission interconnection and its effect on the performance of modern distance protection has been presented. By examining the performance of the present day distance protection as applied to series compensated lines with spark gap operations, this work has contributed to the solution of a major problem associated with such lines.
|Date of Award||1981|