ABSTRACT
This chapter deals with some of the specific items that need to be considered in the configuration and location of both indoor, cabin-type metal-enclosed switchgear and outdoor air-insulated substations, and argues that some air-insulated open switchgear is also located inside buildings, with the appropriate screening and access protection. One of the important factors in the design of a substation is its location. System phasing and transformer vector group choice is an important part of substation design, as it defines the angle difference between systems of different voltages. Transformers that interconnect the high- and extra-high-voltage networks often use Wye-Auto or Wye/Delta/Wye connections, which keep the vectors of these higher-voltage networks in phase. Surge arrestors are used to protect equipment against high-voltage surges entering the station or produced by switching equipment operations. The Delta-Wye connection is used to provide a low-voltage-side ground source without the need for a grounding transformer, although grounding resistors are often used to limit network ground-fault levels.
