The ＂capillaries＂ of the power grid can be ＂self-healing＂ in

Within 1 minute, the power grid actively completes the detection and positioning of power supply faults, blocks the fault area, and recovers the power supply to the non fault area. Recently, the reporter learned from State Grid Shandong Qingdao power supply company that by the end of this year, all 10kV lines in Qingdao, Shandong Province will have the ability of “self-healing” for this kind of power supply fault. This means that Qingdao’s power distribution network fault “self-healing” can fully sink to the “capillary” level, leading the country in terms of coverage scale and use depth.

 

Fault “self-healing” is a fundamental ability for the city’s distribution network to move towards intellectualization. The purpose is to complete uninterrupted power supply, and then improve the power supply reliability of the whole city. In recent years, many Qingdao citizens, especially those in the urban area, have a significant feeling about the change of electricity consumption: the sudden blackout rarely occurs, and the significant power supply instability is just a second like the flashing light. To a large extent, these problems are related to the “self-healing” ability of Qingdao distribution network. In the past, when a power failure occurred in the distribution network, the staff of the power supply company searched for the fault by means of manual line patrol, then blocked the fault area and recovered the non fault area for power supply. This process takes a long time, tens of minutes less and hours more. Not only the users in the fault area are unable to use electricity, but also the users in the non fault area will suffer a long-term “affected power outage”. The fault “self-healing” is through the active transformation of the distribution network, which shortens the process to within one minute, which means that users in the non fault area of a line will only feel the extremely short flash of power consumption at any time, and will not be “cut off”.

 

If the urban distribution network is compared to the human blood supply system, the 10kV line is equivalent to the “capillary” in the system, which connects the upper level substation and residential area. The meaning of fault “self-healing” of all 10kV lines in Qingdao is that only the fault active positioning and blocking of power grid and the rehabilitation power supply of non fault areas can be accurate to the smaller scale of the community, further reduce the impact of power outage, and then reduce the time of power outage of every household in Qingdao, so as to improve the reliability of power supply in Qingdao. It is estimated that the failure outage rate of all 10kV lines and their radiated distribution areas in the city will be reduced by more than 20%.

 

According to the staff of operation and inspection department of State Grid Qingdao power supply company, the power distribution network has achieved the ability of “self-healing”, involving both hardware and software transformation. In terms of hardware, according to the construction plan of Qingdao’s international first-class urban distribution network, the city’s 10kV lines should be transformed from radial to ring network “handle”, and the core area of the city should be transformed from simple ring network structure to double ring network, with real-time monitoring and control equipment such as fault indicator and active control terminal installed; in terms of software, data aggregation, analysis, research and judgment, and initiative should be built. The active power distribution system for control function, all 10kV line control and monitoring equipment are connected to the system. When the fault occurs, the distribution active system will actively locate the fault area according to the fault information, determine the fault and load transfer strategy, and remote control the corresponding switch to restore the power supply to the non fault area, so as to reduce the impact of power outage.

 

Next year, Qingdao will further upgrade the “self-healing” ability of the distribution network, promote the construction of the Internet of things for distribution equipment, and further extend the “self-healing” ability to the “last kilometer” of power supply – each unit building in each residential area. At that time, when the power supply is abnormal, each family will be able to obtain the relevant information in real time.

 

In addition, it is reported that State Grid Qingdao power supply company is also constantly enriching the operation state detection means of distribution network equipment. Using the world-class live detection skills such as partial discharge, infrared imaging, cable intelligent guard, etc., while ensuring the normal use of electricity by residents, the real-time control of the operation status of the equipment, and the danger of finding fault is repaired or replaced by live working methods in advance, so as to ensure the further decline of residents’ perception of power failure.