The maintenance of power lines is a preventive maintenance work based on maintenance and measurement results.
In order to eliminate various defects found in line inspection and patrol inspection, prevent accidents and ensure safe and reliable power supply.
In order to maintain the safe operation of transmission and distribution line equipment and the necessary power supply reliability, the working group is called maintenance.
In order to improve the health level of equipment and restore the electrical and mechanical properties of transmission and distribution lines and their ancillary equipment to the original design, the overhaul is called overhaul.
In order to improve the power supply capacity of transmission and distribution lines and improve the system wiring, the work of replacing, adding or deleting some line segments is called transformation.
Power failure accidents such as pole falling, disconnection and hardware damage caused by earthquake, hail, rainstorm, flood and external force damage are called emergency repair.
2, power line maintenance cycle
The overhaul and maintenance items of power lines should be determined according to the equipment status and inspection and test results. Insulator cleaning, tower bolt inspection and fastening, tower grounding resistance test and other maintenance standard items. There is a fixed period.
1, all levels of power system networks must meet the requirements of allowable voltage deviation.
2, the reactive power supply and reactive load of power system, at peak or trough, should adopt the principle of basic balance between sub (voltage) layer and sub (electricity) area for configuration and operation, and should have flexible reactive power adjustment ability and maintenance and standby.
3. The planning and design of power system must include the planning of reactive power supply and reactive power compensation facilities.
In the design of power plants and substations, reactive power supply and reactive power compensation facilities should be designed according to the requirements of power system planning and design.
4. The power system should have emergency reactive power reserve, so as to ensure that the voltage is stable, the power supply is normal and voltage collapse does not occur in the areas where the load is concentrated under the following operation modes.
1) Under normal operation mode, a certain loop, or a maximum capacity reactive power compensation device, or a maximum capacity generator is suddenly lost in this area (including generator loss of excitation).
2) In the normal maintenance mode, when the accident mentioned in 1) occurs, it is allowed to take necessary measures, such as load cutting and shunt reactor cutting.
5, reactive power compensation equipment configuration and equipment selection, should be technical and economic comparison. For 220kV and above power grids, the role of improving power system stability should be considered.
6. It is of great significance to strengthen the connection and voltage support of the highest level voltage network of the receiving system and create conditions to improve the short-circuit ability of the system at this level as much as possible, so as to maintain the normal voltage level and prevent voltage instability. The distribution network should adopt a reasonable power supply radius.
7. According to the power grid structure and load nature, reasonably select the voltage regulating range and mode of tap-changer of step-up and step-down transformers in voltage networks at all levels.