High Voltage SF6 Circuit Breaker Selection for a Substation

Modernizing high voltage substations by selecting proper gas circuit breakers is essential to meet the higher demands, new loads, and different load types. It ensures that the electricity supply is reliable and affordable to industrial and commercial customers. The critical issues are the asymmetric fault components on the high voltage side due to different dynamic loading scenarios among the customers. The gas circuit breaker selection must consider all the worst scenarios. This paper investigates a substation of 13SkV transmission and 13.2 kV distribution circuits. A procedure is proposed based on the steps required to plan and design a substation. Iteration was performed in different dynamic loading scenarios. The critical parameters like the maximum fault current, dc component, and peak asymmetrical fault current were found to select project-specific gas circuit breakers to ensure reliable and optimal power flow through the substation.