Chapter 5 - UHVAC Substation and Main Electrical Equipment

Abstract

The main electrical connection of a substation, generally known as the primary connection of the substation, serves to indicate the connection mode of such electrical equipment as transformers, circuit breakers, disconnectors, instrument transformers, busbars, and surge arresters, as well as the electrical connection between the substation and the power system. The selection of the main electrical connection scheme has a direct impact on the sizing and arrangement of electrical equipment of the substation, relay protection and control mode, operation reliability, flexibility, and economy, as well as the safety of repair, operation, and maintenance. Generally, the selected connection mode of a substation can only be determined after several expansions from the initial connection to the final connection. The design of the transitional connection is also an important part of the design of the main electrical connection at every construction stage of the substation, and directly affects the safety, flexibility, and economy of the substation in the early construction stage or in various expansion stages. The main electrical connection scheme can only be determined by taking into account such factors as the reliability, economy, flexibility, land occupation, and likelihood of expansion of the substation.