Measurement of switching transients in 115 kV substation

Bus current transients, electric and magnetic field transients, and current transients coupled onto control and CT cables produced by switching operations in a 115 kV ring bus have been measured and characterized. The similarities and differences among transients observed when energizing and deenergizing relatively short sections of bus during disconnect switch and circuit breaker opening and closing operations are summarized and discussed. The results are used to further the understanding of switching transient characteristics and to validate a model that predicts the detailed nature of the transients reported, for use in ongoing investigations to assure continued satisfactory performance in substation protection equipment