Abstract: At present, there are numbers of substandard secondary intelligent devices operating in the smart substation, which are potentially risky. It is necessary to replace, rectify and debug such substandard devices. In order to prevent the security risks that may occur in the process of renovation. A study is made on the secondary device renovation scheme with incomplete shutoff of 220 kV smart substations. The proposed scheme includes rotatory power shutoff of different bays for merging unit renovation, debugging methods for such secondary smart devices as intelligent terminals, and the secondary security measures. The scheme formulates one-on-one dual security measures according to the security risks in the process of renovating different intervals. The scheme is characterized with high security and strong operability, and has been successfully implemented in the intelligent equipment renovation of Lu Ping substation.

Key words: smart substation, secondary safety measures, merging unit rectification, intelligent terminal rectification