Which configuration involves one or more buses added to a single bus substation?

The configuration that involves one or more buses added to a single bus substation is known as a Main Bus and Transfer Bus system. In this arrangement, the primary bus, or the "main bus," is responsible for carrying the bulk of the load, while the transfer bus serves as an auxiliary that provides support and flexibility. This configuration enhances reliability and allows for maintenance or upgrades to be performed on the main bus without disrupting the flow of electricity.

In contrast, a single bus system only consists of one bus, which limits redundancy and can create operational challenges during maintenance. A double bus system involves two buses that operate simultaneously and offer more reliability and flexibility than a single bus but does not involve the distinct roles of a main and transfer bus. Multiple bus configurations may consist of several buses arranged in various manners but are not specifically defined by the role of a main and an auxiliary bus as in the case of the Main Bus and Transfer Bus configuration.