Research On Single-phase Grounding Fault Location Based On Main And Distribution Network Integration

With the rapid development of the national economy and the continuous improvement of people’s living standards,the public’s demand for a better life has become increasingly urgent.Electricity,as the basic energy source for industrial production and residential activities,the high quality and reliable operation of it is particularly important.The 20 th National Congress of the Communist Party of China confirmed the significant role of energy security in the national security system and the modernization of capabilities,which put forward higher requirements for power supply.The stable operation of distribution network has a direct impact on the reliability of power supply and user satisfaction,as it is the bridge connecting power production and electricity users.China’s distribution network is mainly small-current grounding system,with single-phase grounding is one of the common faults.Although the grounding fault current is small when a single-phase grounding fault occurs in small-current grounding system,it still brings threat to the safety and reliability of the entire system.The traditional manual grounding search mainly relies on the dispatchers’ own experience,which is not only inefficient and time-consuming but also likely to cause multiple power outages to users.This doesn’t meet the requirements of the new development situation.There is an urgent need for new methods that can quickly,accurately,and with less manual intervention,carry out fault location,isolation,and power restoration after a single-phase grounding fault occurs in small-current grounding system.With the construction of distribution automation,a large number of distribution network devices have achieves remote monitoring.Dispatchers can monitor equipment online in real-time and also have direct remote control capabilities.Based on extensive domestic and foreign literature research,this paper analyzes the phenomenon and hazards of single-phase grounding in small-current grounding system,studies the main network grounding control technology,the operating principle of distribution network feeder automation and the load transfer strategy.This paper conducts an analysis of the current situation and problems of the distribution network in the Changzhou area,and in view of the good coverage rate of distribution automation in the region,research on locating single-phase grounding in small-current system is carried out.This research compares and analyzes the manual method of finding grounding fault and carries out research on single-phase grounding fault location based on the three main functions of signal acquisition,strategy analysis,and control execution.Combined with a large number of line test results,the functional design scheme is completed.The master station injection method is used for testing to confirm the correctness of the design scheme.Actual cases are tracked and analyzed after the design scheme is implemented to confirm the results and optimize the scheme.This research breaks through the barrier of five-level dispatching by innovatively integrating and collaborating the information of the main and distribution networks.The system autonomously generates a pulling table with independent strategy and controls pulling in sequence,which not only realizes the automatic line selection of the main network,but also realizes automatic positioning and automatic power restoration in the distribution network.With the implementation of the research,the processing time is shortened and the processing efficiency is improved after a single-phase grounding fault occurs in small-current grounding system.This research reduces the time for handling a single-phase grounding fault,which takes more than 2 hours when using traditional manual methods,to the minute level,and demonstrating excellence in improving power supply reliability,enhancing quality service level,and leaning the management level of the distribution network.The study is developed based on the distribution network dispatching control system,no additional hardware investment is required.It can effectively solve the problem of finding and locating single-phase grounding faults in the small-current grounding system with low R&D and transformation costs.It has universality and good promotion potential,providing ideas for the same type of distribution network to find single-phase grounding faults.