Views: 0 Author: Site Editor Publish Time: 2022-01-03 Origin: Site
Overhead line as an important part of distribution network, is the transmission conductor with insulator on the upright tower at the ground with power transmission to the transmission line, the erection and maintenance more convenient, cost is low, and the characteristics of the widely distributed, but there are lines easy ageing, vulnerable to the influence of weather and environment caused by the fault.
The insulation rate of power grid lines in urban areas and surrounding areas has reached more than 90%, but in the vast combination of urban and rural areas, towns and rural areas, the utilization rate of bare wires is still high, there are running situations across water, tall plants, very close to buildings and densely populated areas. In the rainy, windy and other bad weather, these areas are the major disaster areas of power distribution network trip and electric shock casualties, seriously affecting the personal safety of the people and the reliability of distribution network operation.
To address the above problems, The State Grid Corporation of China issued the Guidance on The Operation and Inspection of The Special Action of Pressure Drop in Electric Shock Cases in 2018, which clearly pointed out the investigation and treatment of potential electric shock hazards such as "three-cross" sections of power transmission and distribution lines, densely populated areas, exposed and broken lines in fishing places, and private connections of households under low voltage.
Insulation transformation of overhead bare wires in important sections can eliminate potential safety hazards, prevent personal shock injury and ensure power supply reliability of distribution network. At present, the insulation transformation of overhead line mainly includes the following four schemes :(1) replacing the insulated wire; (2) Install buckle insulation sleeve outside the bare wire; (3) Tape wrapping and other local insulation; (4) Robot insulation coating. Because of the robot automatic coating, using the robot will be self-curing insulating adhesive evenly coated to the overhead bare wire, convenient construction, uniform coating, coating does not affect the electrical performance of the wire, the overall effect is excellent.
Robot insulating coating can be realized under the condition of no power outage on overhead bare wires for fast, reliable, and the insulation of the in situ transformation, without wire replacement, shorten the construction period, reduce the comprehensive cost, greatly reduces the power failure the effects on the production, living, easy to implement, is currently the overhead line insulation reform one of the most safe and effective method.
For some special lines, only local insulation treatment (such as a few tens of meters or a certain distance needs to be insulated) can be done, then the on-site insulation coating scheme becomes the best solution of bare wire insulation scheme.