General criteria for the 21st century substation design:
For the substation development to reach its technical and economical potentials, the focus has moved now to studying how substations may enable more intelligence in the network, which is labeled the “smart grid” development. It has been concluded that the 21st century substation design should meet the following improved criteria: reliability, security, interoperability, re-configurability, controllability, maintainability, flexibility, reduced cost and environmental impact. An estimate of the importance of the different criteria is shown in Fig. 1. The four major criteria commonly emphasized by substation designers are reliability, cost, operational flexibility and environment impact.
Figure 1. Different criteria for the 21st century substation design
