Electrical equipment maintenance

Electrical equipment maintenance refers to the process of dealing with various abnormal or faulty electrical equipment in a hydroelectric power plant and returning it to normal. The whole process is mainly to deal with defects, and the electrical equipment is also selectively disassembled and disassembled. And assembly, adjustment and testing, and trial operation.

(1) Purpose of electrical equipment maintenance
Electrical equipment maintenance is an important measure to ensure the safe and economic operation of equipment, improve equipment reliability, and give full play to the potential of the equipment. The maintenance process includes: preparation, disassembly, cleaning, inspection, repair or replacement, assembly, adjustment and testing before maintenance. And trial operation, etc. By overhauling the equipment, the following objectives should be achieved: ①eliminate equipment defects, eliminate hidden dangers, and enable the equipment to operate safely; ②maintain the technical indicators of the equipment, and extend the service life of the equipment; ③improve the utilization and efficiency of the equipment to ensure that The equipment can operate economically.

For the maintenance of electrical equipment, the policy of “prevention first, planned maintenance” should be implemented. Hydropower stations should prepare an annual maintenance plan and a three-year rolling plan once a year according to the requirements of the competent authority and combined with the situation of the unit, and submit it to the competent authority for approval. implement.

The overhaul of electrical equipment is mainly planned overhaul, in addition to accident overhaul and temporary overhaul. There are two main types of planned overhaul: overhaul and minor repair. Among them, overhaul is to conduct a more comprehensive inspection, cleaning and repair of equipment; minor repair is to eliminate defects found in the operation of equipment, and focus on inspection of easily wearable parts and perform necessary treatments. , Cleaning and testing; accident maintenance refers to the forced inspection, repair or replacement of the damaged parts of the electrical equipment after the failure of the electrical equipment. Temporary maintenance refers to the temporary partial inspection, repair or replacement of electrical equipment that is found to endanger safety defects or abnormalities during operation.

After the electrical equipment has been overhauled, it should be adjusted and tested. Adjustment refers to the adjustment process of electrical equipment after installation or assembly in order to make the equipment reach technical indicators or certain specifications. The test refers to the equipment performance testing carried out in accordance with the items and periods specified in the regulations. It mainly includes handover tests and preventive tests (sometimes tests are required before equipment maintenance to detect the health and damage degree of the equipment). The handover tests are performed on the equipment The test performed after installation or overhaul is used to detect the quality of the installation or overhaul and determine whether the equipment can be put into operation; preventive test refers to the test that must be carried out on electrical equipment that has passed a certain operating time regardless of the operating conditions Discover hidden defects and their severity in time to facilitate timely maintenance and repair, and prevent problems before they happen.

(2) Period and items of electrical equipment maintenance
The overhaul period of electrical equipment refers to the time between two overhauls of the same type, and its length depends on the technical condition of the equipment. The overhaul items refer to the various contents that need to be carried out in the overhaul. The overhaul projects of the electrical equipment of Wangyao Hydropower Station can be divided into two types: standard projects and special projects.

Standard items are items that must be carried out for each major repair. The main contents include: ①Comprehensive inspection, cleaning, measurement and repair of equipment. Old equipment that has mastered the law can be carried out with emphasis; ②Eliminate defects in equipment and systems; ③ Carry out monitoring, testing and appraisal, and replace parts regularly.

Special projects are projects that are carried out selectively according to the specific status of the equipment. Special projects include technological transformation projects that have significant changes to the structure of the system equipment (called major special projects).
The minor repairs of main electrical equipment can also be divided into two types: standard items and special items. The content of the standard items includes: eliminating defects in operation; focusing on cleaning, inspecting and handling vulnerable and wearable parts, and carrying out actual measurements and tests when necessary. . The minor repair before the overhaul should be carefully inspected and recorded, and certain overhaul items should be determined accordingly. Special items should be decided according to actual conditions.

In the electric power regulations, the major equipment overhaul and minor repair cycles, standard items, special items, and the number of days to be out of service are specified. Implementation rules should be formulated in accordance with regulations, regular inspections and repairs, and personnel should be put in on time, so as not to affect the stable operation of the entire power system.