Existing operation box are usually large in size, has complicated circuits and many redundant circuits. This paper introduced the improvement of operation circuits and miniaturization and localization of operation box. Backconnecting type structure was replaced by layered type. Electrical modules, such as motherboard and indicator, were removed. The size was remarkably reduced while related standards were satisfied. After miniaturizing design, operation box could be install in primary breaker terminal box, intelligent control cabinet or other place. Installation size was reduced to 1/4 to 1/2. Quantity of terminals was reduced to 1/2.

intelligent substation, operation box, miniaturization, local installation, improvement design