High voltage electrical equipment for common faults and processing

by:Mings     2020-05-23
Common faults in the operation of high voltage electrical equipment and processing methods, focus on 10 kv circuit breaker ( Vacuum, sulfur hexafluoride) , isolating switch, bus, transformers, transformer, cable and lightning arrester failure and treatment method, engineering and technical personnel may refer to this article, according to the actual circumstances of the high voltage electrical equipment accidents, analysis processing, in order to ensure safe operation of electrical equipment, reduce the influence caused by accident, as far as possible to prevent, eliminate the accidents in the bud. Voltage above 250 v as stipulated in the regulations is called high pressure, here we talk about 10 kv complete sets of equipment, mainly is the switchgear, metering tank, capacitor cabinets, etc. , of course also include into line, transformer, etc. Transformer 1. Voltage transformer fault phenomenon: the running voltage transformer primary side blown fuse. ( 1) Due to the voltage sensor of turn-to-turn happens inside, layer or interphase short circuit and a phase ground fault, is likely to be blown fuse. ( 2) Secondary loop failure, a failure in the transformer secondary side secondary side fuse selection is too large and cause a side fuse fusing. ( 3) 10 kv to unity. One to 10 kv system, the other two phase of voltage rise of square root of three times, for voltage transformer Y0 / Y0 wiring, will become the two relatively normal voltage line voltage, caused by the voltage current is added, may fuse fuse. ( 4) Power system, ferroresonance. In recent years due to the large increase in power distribution lines, cable and user, make the 10 kv power distribution system of electric parameters changed a lot, gradually formed the resonance condition, together with some excitation characteristic of voltage transformer is not good, therefore, ferroresonance overvoltage often occur, when the power system harmonic eddy currents on voltage transformer, besides causing a side fuse break, also often lead to voltage transformer fire accident. Analysis: when a voltage transformer primary side blown fuse, should pull open isolating switch voltage transformer, and take the second insurance, check whether the fuse, the exclusion of voltage transformer fault or secondary fault itself, to replace the fuse will be qualified voltage transformer in operation. 2. Current transformer fault phenomenon: in the operation of the current transformer appear because the iron core is overheating. Analysis: running inductance transformer overload, secondary open circuit, and insulation damage cases, such as discharge can cause abnormal voice, caused by semiconductor paint besmear brushs uneven local corona, as well as the core for clamping screw loose, can also cause larger noise. Current transformer core overheating may be caused long-term overload or secondary loop open iron core magnetic saturation. If discover the abnormal phenomenon, first of all, should be carefully observed and through the instrument and so on to determine the cause of abnormal sound or core overheating, if it is should be taken to reduce the load caused by overload, below rating and observe its operation. If it is caused by the secondary loop, should immediately stop running ( Or will reduce load to * * * * * * limit) , during the processing of the necessary safety measures to prevent electric shock. If because of its insulation damage caused by discharge, it should be replaced. Lightning arrester ( 1) Fault phenomenon: magnetic insulation damage. Analysis: should analyze the failure reasons of running arrester magnetic insulation, and replacement. ( 2) Fault phenomenon: in the operation of the explosion. Analysis: general due to the bad sealing arrester be affected with damp be affected with damp and changed features. Because of the zinc oxide lightning arrester has good volt-ampere characteristic, is widely used, the relative fault is lower, should strengthen the yearly check, pilot test, etc. Cable fault phenomenon: single-phase grounding short circuit, two phase and phase grounding short circuit. Analysis: due to the power cable is belong to another professional, and the fault is interphase short circuit of power cable, even single phase short circuit but due to reasons such as discharge time is long, will soon develop into more than two phase short circuit. So should check the cable line in the cause of tripping and processed after sending, otherwise may cause more accidents. Processing method is to check point of failure, and then processing, processing after the experiment, qualified rear can either.
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