Views:179 Author:Site Editor Publish Time: 2020-10-06 Origin:Site
In the power system, the distribution lines have the characteristics of wide distribution, huge numbers, and complex operating environments. Real-time monitoring of the entire line cannot be carried out. Therefore, it is very susceptible to tripping due to external factors, which affect the normal life and production of residents. Next, we will analyze some of the phenomena of the power distribution line fault tripping and propose corresponding solutions.
1) When the accident alarm sounds, the circuit breaker first trips, then close, and finally trips. The corresponding ammeter, active power line fault indicator and reactive power meter will swing accordingly, and finally, all indicate zero. The red light of the short circuit fault indicator of the trip circuit breaker turns off and the green light flashes for a short time, and then returns to normal, then it immediately turns red light off and the the green light flashes
2) The signals of "re-closing action", "fault recorder action", "outlet trip", "protection action" or "transceiver action" are sent out.
1) Reset the sound, record the time of failure, check the optical signal, meter indication and circuit breaker tripping, check the protection action, record and reset the action signal, if there is a circuit breaker control switch on the control panel, reset the tripping circuit breaker switch handle. Preliminarily judge the nature and scope of the cable short circuit based on the above phenomenon, and report the name of the tripping circuit, time, re-closer and protection action, the information provided by the fault indicator and the protection device to the dispatcher.
2) On-site check, all three phases of the circuit breaker are in the open position.
3) Carry out a detailed inspection of the loops and electrical equipment related to the faulty circuit in the factory, such as circuit breakers, isolating switches, transformers, cable heads, coupling capacitors and wave traps, and check them for abnormalities and malfunctions. For example, check the tripping circuit breaker for mechanical damage, whether the fuel tank or gas storage tank is broken or displaced or deformed, whether the casing or insulator is broken, whether the wire is burned or deformed, whether the oil color of the oil circuit breaker and the oil level is normal, whether there is fuel injection, whether the various parts of the hydraulic operating mechanism and the pressure and other parameters are normal, whether the closing power insurance of the electromagnetic operating mechanism is intact, etc.
4) Combined with the inspection and analysis of the protection action, determine whether the circuit breaker has indeed undergone a re-closing process, rule out the re-closing action signal and the circuit breaker failed to close due to the operating mechanism and other reasons.
5) If the line protection is activated twice and the re-closing action is performed, it can generally be judged that a permanent power short circuit fault has occurred on the line and the re-closing is unsuccessful. In principle, the dead short circuit should be removed before powering. If there is no problem with the equipment, the relay protection is intact, the circuit breaker itself is intact, the operating mechanism is working normally, the air pressure or hydraulic pressure is at the rated value, and the number of circuit breaker tripping is within the allowable range, the dispatcher should be reported. According to the weather, protection action, etc., in strict accordance with the dispatching or on-site regulations, judge whether it can be sent once.
6) Report the inspection and analysis to the dispatch and relevant departments, cut off the ac short circuit line according to the dispatch order, and hang a ground wire or close the grounding switch on the line, take safety measures, and send power according to the dispatch order after the electrical short circuit is eliminated.
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