Typical Defect Analysis And Improvement Method Of High Voltage Switchgear In Power Grid Maintenance

With the development of power systems,the system structure is becoming more and more complex,and the operation and maintenance cost of system equipment also keeps increasing.The operation and maintenance cost has become one of the most basic and major costs in the production of power enterprises.High-voltage switchgear is very important in the control and protection of power systems,and its reliability directly affects the safe and stable operation of the power system.At present,the operation characteristics of the equipment are mainly obtained through preventive tests.However,this acquisition method increases the maintenance cost of the equipment on the one hand,and on the other hand,frequent maintenance operations and excessive disassembly and repair will have a certain negative impact on the equipment and reduce the reliability of the equipment operation.Condition based maintenance has the advantages of real-time understanding the equipment operation,intelligent research and judgment of changing trend,avoiding equipment power failure test and saving maintenance cost,etc.It is one of the key technologies for power system equipment maintenance and is an inevitable trend of equipment maintenance development.Based on the diversity of charged detection methods,this paper studies the causes of partial discharge in high-voltage switchgear based on the large number of equipment application data of Jinan Power Supply Company,and then studies principle of various partial discharge detection by comparing the pattern recognition of typical partial discharge,to explore the feasibility and advantages of combining various partial discharge detection methods in the actual power grid.In this paper,the factors affecting abnormal discharge of switch cabinet are analyzed in detail,and the key factors affecting abnormal discharge of switch cabinet are identified.Effective measures for abnormally discharge elimination are established for each key influencing factor.The effectiveness of each measure is verified by experiments.Aiming at the defect of tulip contacts in the 10kV vacuum circuit breaker,an effective method to eliminate the spring defect is proposed and verified by experiments.At the same time,the BLK222 spring mechanism is taken as a typical example.The main reason for the aging of the spring mechanism is analyzed,and the improvement scheme of the spring mechanism is determined.A new type of HMB hydraulic spring mechanism vacuum oiling device was developed for the problem of hydraulic oil mixing with air bubbles.The actual operation results show that the device can reduce the maintenance cost and operating cost of the hydraulic mechanism and avoid the safety risks of operation and maintenance.Through a large number of theoretical research and engineering cases,this paper comprehensively analyzes the typical faults,detection methods and improvement measures of three types of high-voltage switchgear(switch cabinet,circuit breaker,GIS),which has both theoretical support significance and practical guidance for operation and maintenance of high-voltage switchgear.