At 3:16:40 on September 17th, the Foshan Power Supply Bureau of Guangdong Power Grid Corporation connected to the 110kV Taiping Station self-healing 110kV Taiping Station 731 Nencha Line-Trunk 42 Tower 42T1 switch overcurrent protection action tripped, 3 At time 19 minutes 41 seconds, the master station succeeded in self-healing. The self-healing mode of this line is fully automatic self-healing. It takes 3 minutes and 01 seconds from the occurrence of the fault to the fault isolation and restoration of the non-faulty area. The restoration of 9 distribution variables and 363 medium and low voltage users saves about 0.5 MW of load and reduces About 726 households were out of power, which greatly shortened the scope and time of failure.
It is reported that this is the first fully automatic closed-loop self-healing in the entire network since Guangdong Power Grid launched the self-healing construction of the distribution network master station, marking that the distribution network automation is moving in a more advanced direction.
Strong hardware seizes the “bull nose” of the distribution network upgrade
Statistics show that in recent years, more than 95% of user power outages are caused by the distribution system, and half of the power grid losses occur in the distribution network. With the rapid development of social economy, residents and enterprises have higher and higher requirements for power supply, and the traditional distribution network operation and maintenance model is becoming more and more unable to meet the needs, and the research of distribution network self-healing technology is put on the agenda.
“We first applied for a science and technology project at the end of 2017. In the middle of last year, Guangdong Power Grid Corporation put forward a request for self-healing technology research in the distribution network, which accelerated our research and development process.” Guangdong Power Grid Corporation, a first-level skilled expert, Foshan Power Supply Bureau, distribution network owner Ouyang Weinian, a backbone researcher of self-healing technology at the station, introduced, “To carry out self-healing technology research and development, the hardware is inseparable from the transformation of distribution network automation, and the software needs to build a corresponding platform to solidify the dispatcher’s power grid scheduling experience The programming language realizes the intelligent operation and maintenance of the distribution network.”
In view of this, in addition to the self-healing transformation of the existing distribution network in the qualified areas, the Foshan Power Supply Bureau also pays attention to checking whether the new distribution network meets the basic conditions for self-healing. As of the end of August, the bureau has put 205 feeder groups into closed-loop operation, covering 451 feeders, and the overall self-healing coverage rate is 11.02%.
In addition, the Foshan Bureau is also advancing the construction of a “high-reliability distribution network” pilot project in Gaoming district, creating a “three remote + self-healing” smart grid. As of the end of August, the coverage rate of automatic switchgear in the entire district has reached 98%. The number of households is 0.018 hours, and the pilot construction work is proceeding in an orderly manner.
Grasp the software to improve the basic data quality of the distribution network
“We carry out research on the self-healing of the main station of the distribution network, not only to make the distribution network’conscious’, but also to have the’hands-on ability’.” Ouyang Weinian told the author, “The self-healing technology of the main station is when the distribution network fails. , It can autonomously locate and isolate faults quickly, and restore power to non-faulty areas, realizing the time for non-faulty areas to be restored from manual power to program automatic power recovery.”
After more than a year of research and development, the bureau has made breakthroughs in the self-healing of the main station. On September 17, it completed the first fully automatic closed-loop self-healing without manual intervention on the entire network.
“In the process of carrying out research on the self-healing technology of the distribution network master station, we found that the effect of improving the data quality of the distribution network terminal is also very obvious.” Ouyang Weinian introduced, “The distribution network has a complex structure and huge basic data. Data quality is directly related The level of self-healing technology, in other words, is directly related to the efficiency of quick power recovery. In the past two years, we have continuously discovered problems through the’general physical examination’ of the distribution network and formed a rectification list. The rectification rate of the distribution network terminal data has reached 80 %.”
In terms of improving the scientificity and operability of the system, the bureau resolves issues such as the scientific rationality of self-healing action logic through global multi-professional linkage methods such as automation, scheduling, livelihoods, and relay protection, and through weekly and monthly reporting mechanisms.
It is understood that the Foshan Power Supply Bureau started early in the field of self-healing of the main station of the distribution network. In addition to seeking breakthroughs in the technical field, it also actively compiled guidelines for the self-healing of the main station, including the management requirements for the maintenance of fixed value, the quality management requirements for terminal equipment operation, and the new network access Equipment automation management specifications, etc., to solve the inconsistency in the self-healing management of the distribution network, and to provide a reference for the promotion and application of the main station self-healing technology in the province.