With the integrated online state monitoring system for HV disconnectors, the first-order vibration frequency of disconnectors can be obtained by using the maximum entropy spectrum estimation based on the vibration frequency of disconnectors collected, and the change of the vibration frequency is monitored to judge the incomplete on and off positions of disconnectors, loose contact and other faults. The temperature signals are collected to judge the contact overheating fault based on the absolute temperature and the temperature difference between the phases. The motor current signals are collected to judge the jamming of the transmission mechanism by comparing the motor current similarity. The angle of the spindle is collected as an auxiliary criterion for determining the on and off positions of disconnectors. Image signals are collected to determine the on and off positions of disconnectors based on mature image acquisition methods and algorithms for on and off position similarities.

         The ISD-500 integrated online state monitoring system for HV disconnectors developed by Unitech has been successfully put into operation in Jiangxi, Jilin, Sichuan, Xinjiang, Jiangsu, Ningxia and other regions. Equipped with high-precision vibration acceleration sensors, the system can realize online monitoring and fault early warning of disconnectors through vibration signal recording and analysis.