Fault Analysis And Treatment Of Central Switchgear In Rizhao Power Grid

There are 46 high-risk and important customers in Rizhao power grid above 10KV, the number of customer substations which operating mid-set switch cubicle (enclosed with armored metal) is 152, accounting for 98.06% of the total. Mid-set switch cubicle as the main operating equipment for customers'power transformation, many power failure incidents occur,which are caused byrefusal-operation, short-circuit and insulation problfailure of the switch cubicle each year. The power failure incidents bring great economic loss to the power customers, and cause a serious threat to the safe operation of power grid and equipment. If effective measures are not taken to prevent the potential security risks of production activities, accidents threatening power grid and equipment will happen, which may bring negative impact to the enterprise operating and safety and sustainable development.This article analyzes the operation situation of Rizhao grid cabinet, the fault occurrence time, type and location of system statistics and the anatomy of fault equipment. The investigation to the fault site is carried on, and the fault of cabinet electricity is analysed. Active exploration in safety equipment manufacture, installation and operation is carried on. Under the condition of market economy, the customer electricity safety should be strengthened, and new methods to safeguard the cabinet design improvement and daily operation should be employed. Such methods helps improve the operation reliability of cabinet, reduce the number of failures, ensure the electrical equipment safe operation and promote the customers to improve electrical safety level.Firstly, by analyzingrunning condition of mid-set switch cubicle in Rizhao, counting times, types and sites of the faults, analyzing the failure equipments and the failures, surveying the failure site, the auther drew a conclusion that the main fault parts are mechanical devices and insulation equipments. Secondly, the causes for mechanical faults of switch cubicles were analyzed by the way of site testing and equipment data measuring. The conclusion that the short route between the moving contact and the fixed contact and lacking test of mechanical transmission structure were the main impact factors of mechanical faults was reached.The method of increasing the length of the fixed contact, adjusting the reconstruction methods of mechanical transmission mechanism should be adopted to promote the effect. Thirdly,Insulated parts of the switchgear were analyzed statistically, and the insulation damaged parts were measured. It was found that the heat dissipation in the switchgear was not smooth and the temperature was high. The high-pressure chamber and the switchgear were not well sealed, leading to the deterioration of the insulation parts. Cabinet of the cooling device to reduce the busbar, knife contact resistance, switch cabinet dust, moisture treatment and other transformation programs, the number of equipment insulation failure decreased significantly.According to the research results, the auther redacted the "Rizhao power supply company business expansion project design standards", "Rizhao power supply company customer equipment management regulations", "Rizhao power supply company switch cabinet construction standards" and other equipment management's work relevant documents and work regulations. Moreover, the auther promoted the equipment standards and construction requirements, the technology was generalized for all the switch cabinets in Rizhao power grid, which lead to reduced failure rate of mid-set switch cubicles in Rizhao, promoting the reliability of equipment operation, the level of the power grid safety, economic benefit and social benefit.