State Grid Changji Power Supply Company: First Domestic Application of Temporary Voltage Drop Management Device Deployed in Changji

CHANGJI,China,Nov. 20,2024 -- On November 18,the State GridChangji Power Supply Company successfully deployed an innovative project,"Research on Key Technologies for Managing Temporary Voltage Drops in Distribution Networks and Development of Supporting Equipment," at the 220 kV Changji substation. This deployment marks the first domestic application of such equipment,independently developed by the company.

In recent years,with the expansion of the power grid infrastructure and adjustments in the operational modes of primary and secondary distribution networks,instances of instantaneous voltage fluctuations and inter-phase short circuits have become frequent. Temporary voltage drops often last from 10 milliseconds to one minute. Prolonged voltage drops can lead to abnormal equipment shutdowns,and the issue of voltage drops in the main network can progressively impact the user side. This often results in the activation of low-voltage side circuit breakers on operational lines,interrupting circuits and affecting the continuous electricity supply to consumers.

To address these challenges,the company established a technology innovation team to tackle the problem of temporary voltage drops in the grid. They proposed a technology based on eddy-current self-driving for open-type voltage drop management and conducted practical research on the operation of rapid switch-type bus voltage maintenance devices. After nine months of development,they produced an eddy-current self-driving device for managing voltage drops in distribution networks. This device is capable of rapid fault current detection and isolation,achieving self-recovery within 20 milliseconds of a voltage drop.

It is reported that voltage drops in distribution networks can lead to unstable electricity usage,affecting the consumer experience. The successful application of this device in the substation has validated the effectiveness and feasibility of this management technique and equipment. It will further stabilize the supply voltage through technical means,enhancing the level of quality service.