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Role&Basic Requirements Of Isolation Switch In Power Systems

Jun 05, 2018

1. The role of isolation switch in power systems

In the application of the power switch system of large and medium-sized power plants, the main function of the isolation switch is to isolate the power supply, operate the switch, and pull and combine circuits with no current or small current, which has a major impact. In the maintenance and daily maintenance of large-scale electrical equipment in the power system of the power plant, the isolated power supply function of the isolation switch must be used to separate the electrical equipment that needs to be repaired from the live grid power supply, forming a visible disconnection for the technicians. The starting point is to ensure the personal safety of workers during the periodical overhaul and daily maintenance of technicians, reduce the damage to the machinery and equipment caused by flashover and other situations, and isolate the power supply in emergencies to reduce the loss. In the electrical main wiring in the form of double busbar connections in the power system, the advantages of the disconnector are fully utilized, and the busbars are connected to switch the electrical equipment from one set to another, reducing the difficulty and work of the power work. the amount. For example, if the pull and combine capacitor current does not exceed 5A no-load line, pull and combine the current is less than 2A no-load transformers and other functions.

2. Basic requirements of isolation switch in power systems

The isolating switch used in power equipment should have obvious visible power disconnect point after separating the power equipment, which can clearly identify whether the power of large-scale power equipment is isolated from the power grid and can truly ensure the safety of the equipment. It should be noted that there should be a safe insulation distance between the power supply and the disconnected point of the power grid to ensure that the device will not cause unexpected accidents that threaten the personal safety of the workers in case of over-current and current flashover. The equipment will not be damaged by the instantaneous flashover, which will affect the normal operation of the power system. When used in large-scale power facilities, it should have strong thermal and dynamic stability, sufficient insulation strength, and sensitive operating performance. Knife gates can be divided and processed efficiently and can perform accurate operations in the shortest time. For the isolating switch with grounding switch in the power system, it must be equipped with corresponding interlocking equipment, which can operate correctly in manual and emergency situations. For example, in the event of a power failure, the disconnector should be disconnected first and then manually or automatically closed grounded. The process of knife gates is carried out to ensure effective protection in the event of an accident. During the operation of the high-voltage disconnecting switch, strict attention shall be paid to the good contact between each circuit's connection point and gate, regular inspection and maintenance, to ensure that the surface of the gate will not be overheated and the phenomenon of surface corrosion will occur, and the temperature of the wax will be monitored for serious melting. The appearance of the situation, but also pay attention to the equipment used in the equipment porcelain, porcelain casing and other equipment to check whether the surface of the porcelain cracks, broken condition, timely replacement; monitoring the occurrence of flashover discharge traces, and Timely resolution. At the same time, we must regularly clean the dust and dirt on the isolation switch. We can use appropriate amounts of lubricant to lubricate the rotating parts, apply Vaseline to the gates, and other measures to ensure better cooperation among various components.