Factors affecting arc extinction on a Petersen-coil system

THE effectiveness of the Petersen coil in extinguishing line-to-ground arcs on a transmission system is ordinarily attributed to the fact that the current in the arc is kept at a low value. Another factor of perhaps greater importance is that characteristic of the Petersen-coil system which results in a very low rate of rise of recovery voltage across the arc terminals. Although this characteristic has long been recognized,^1,2 the engineering literature would seem to indicate that its importance has not been thoroughly considered. This paper calls attention to the importance of the rate of rise of recovery voltage, presents the circuit theory pertaining to the voltage recovery rate, points out some practical aspects of the Petersen-coil system design, and compares the theory with published records of operation. It is hoped that this analysis will lead to a better understanding of Petersen-coil systems which will permit their more effective use. With continued study of system operating records, it may become possible to predict the effectiveness of a system even before it is built.