Company Name: Henan Xinchaoda Cable Co., Ltd.
Contact: Manager Guo
Address: Xibaishui Village, Xitao Town, Wuzhi County
Marketing Center: 1812, Building B, Building 3, Shenglong Plaza, Zhengdong New District, Zhengzhou
1.1 Lightning Strike
There are many types of lightning 10kV overhead line accidents, including insulator breakdown or burst, wire breakage, and distribution transformer burnout. Lightning strike accidents, of course, have a greater relationship with the objective cause of the lightning strike line, but also have a greater relationship with the defect of the equipment. Analyzing the reasons for the equipment is mainly due to the following reasons.
(1) Defective insulator quality. At present, the P-15 and P-20 pin insulators commonly used in distribution networks have outstanding quality defects, and insulation breakdown occurs during operation, thereby causing line grounding or short-circuits between phases. (2) The lack of lightning protection measures for 10kV lines. Beginning at the end of 1998, zinc oxide surge arresters were replaced in distribution transformers in many regions, but lightning protection measures were still lacking in overhead lines. (3) The contact of the wire connector is bad. Many regions used to use parallel groove clamps as adapters for 10kV lines. Even the parallel groove clamps do not have to be wound indirectly. The connection of the groove clamps or the winding wiring is not an excellent connection of the wires. The connection of the wires is poor. Can not withstand the impact of large load current or weak lightning current. (4) The grounding installation of the arrester is unqualified. Unqualified grounding installation, the grounding resistance is greater than 10Ω, the leakage can be poor, and the lightning current cannot flow into the ground quickly.
1.2 The breeze blows down the tower accident
A pole tower designed at a very large design wind speed of 25m / s can blow a breeze below level 10. The pole tower has no results. The reason for the wind to blow down the pole tower is secondary to the following reasons.
(1) 10kV lines and towers were not constructed according to the design requirements, and the bases of the towers were not strong or buried deep enough. (2) Breeze wind speed exceeds the maximum design wind speed. The speed of typhoon 10 is 25m / s, the speed of typhoon 11 is 30m / s, and the speed of typhoon 12 is 33m / s.
1.3 External force destruction accident
External force destruction is also one of the frequent accidents of 10kV overhead lines. According to the destruction methods, these types of accidents can be divided into the following categories: 10kV overhead lines (columns) caused by vehicle collisions; 10kV overhead line trips caused by kite collisions The theft of metal fittings caused the pole tower to tilt or fall down; the base of the pole tower or the root of the cable was hollowed out and destroyed, causing the down pole; the tools or materials built in violation of the rules touched the wires and caused short-circuit trips.
2 Anti-accident measures
2.1 Anti-lightning and anti-accident measures
(1) Replacement, installation of pillar insulators or porcelain crossarms. Lightning strikes on 10kV overhead line pin insulators are extremely common equipment accidents. The reason for this type of accident is that in addition to the increasing number of thunderstorms in the local area, the quality of pin insulators is not a secondary reason. You can change this type of insulator to Pillar insulators or porcelain crossarms. (2) Install a zinc oxide lightning arrester. In empty areas, because there are no small buildings to cause lightning, direct lightning strikes are common. Therefore, it is advisable to install line-type zinc oxide lightning arresters on empty 10kV overhead lines. The distribution network equipment of new devices such as distribution transformers, On-column switches and cable numbers must also be equipped with zinc oxide lightning arresters to enhance lightning protection and maintenance of 10kV lines and equipment. (3) Use Amp clamp. In the future reconstruction and maintenance of 10kV lines, ditch clamps are gradually eliminated as wire connectors, and it is strictly forbidden to wind wires without clamps, and Amp clamps with better connection functions should be selected. (4) Introspection, rectification and grounding installation. Reflectively measure the grounding resistance of the grounding installation on the 10kV line, and rectify it if it fails to ensure that the grounding resistance value meets the requirements of the regulations.
2.2 Measures to Avoid Typhoon Accidents
(1) The 10kV line towers should stop introspection during the period of time, and develop a comprehensive introspection system. For the towers that are not strong enough to reinforce the foundation or add cables in time, the new towers should be constructed strictly according to the design requirements. (2) Appropriate progress and great design wind speed, South China can be designed at 30m / s breeze speed.
2.3 Anti-destructive measures
According to the types and causes of the 10kV line external force destruction accident mentioned below, the following measures are adopted.
(1) In order to eradicate or increase vehicle collision with pole tower accidents, the pole towers on the side of the road can be painted with reflective paint so as to arouse the attention of vehicle drivers. (2) Strengthen the publicity and education of Mr. Zhong Xiao, set up a noticeable warning sign beside the 10kV line, and stop flying kites within 300m on both sides of the 10kV line. (3) Strengthen the crackdown on the theft and destruction of 10kV transmission line materials and fittings, try to lose the cooperation of public security and security departments outside the country, formulate invalid measures and detailed prevention plans, and set up special departments to implement the measures for the destruction and theft of 10kV electrical equipment. Destroyers stop the severe blow. (4) The operation department inspects the bases of the towers, cables, and illegal structures of the 10kV line on a regular basis, stops the maintenance of the hollowed towers, cables, and foundations in a timely manner, promptly disposes and repairs the defective equipment, and stops the liquidation of illegal structures. sort out.
2.4 Enhanced operation detection
(1) The technical operation department should pay close attention to the load status of each 10kV feeder, adjust the load of each feeder in time, and strictly prohibit line overload operation. (2) In the peak load period, use an infrared thermometer to measure the temperature of the wire connector. Once the temperature is abnormal, stop handling immediately to prevent the wire from being blown at low temperatures. (3) A short-circuit fault indicator is installed on the 10kV line. Even if a short-circuit fault occurs on the 10kV line, the fault point can be quickly detected and removed in time to reduce the loss of the accident. (4) Remove the rust and oil from the pole barge interface, iron tower, and distribution transformer bench during the periodic stop, enhance the protection of the tower and the hardware, increase the corrosion of the hardware, and adhere to the strength of the tower.