Indoor handcart type high-voltage vacuum circuit breaker due to the impact of some component assembly, debugging process, operation and maintenance is not in place and other factors, handcart type circuit breaker in the operation sometimes has refusal to point, refusal, control circuit disconnection, can not enter and exit the car and other issues, these problems inspection and handling is not good, will threaten the safe production and operation of power. Through the analysis of common fault cases of indoor handcart high-voltage vacuum circuit breakers, the author discusses how to strengthen the maintenance of handcart high-voltage circuit breakers and improve the reliable and safe operation of circuit breakers.
In the operation and maintenance of power equipment, the circuit breaker is the most important control and protection equipment in the power system, and is one of the equipment with more faults in the power system, especially the 6-10kV circuit breaker, frequent operation, relatively many failures, its failure may cause significant losses and social impact to the power system and users, once the failure occurs, unreliable action, not only will burn the coil, but also is likely to burn other equipment, so that the accident expands, causing huge economic losses and social impact.
Through the maintenance and test in recent years, this paper introduces the possible faults, causes and treatment countermeasures of the handcart vacuum circuit breaker and the test items and data after the maintenance for reference.
Common fault phenomena, causes and countermeasures
1. The handcart cannot be promoted or pushed out, which is mainly manifested as difficulty in entering the car, which will cause equipment damage when it is serious, and pose a threat to production. The causes and countermeasures are shown in Table 1.
Table 1 Possible causes and countermeasures
2. The circuit breaker cannot be closed, which is manifested as the closing iron core action, and the circuit breaker is not successfully closed; the closing iron core does not move, which is manifested as the circuit breaker control circuit is not passable or the mechanism does not store energy. The causes and countermeasures are shown in Table 2.
Table 2 Possible causes and countermeasures
3, the circuit breaker does not divide the gate, the electromagnet core deformation, stuck, the gusset plate and the semi-shaft of the gate are fastened too much; the core of the gate, due to the transmission system is stuck, resulting in the circuit breaker gate is not in place and other phenomena. The causes and countermeasures are shown in Table 3.
Table 3 Possible causes and countermeasures
4. The motor does not store energy or the motor rotates non-stop, which is mainly manifested as the motor circuit micro switch is not switched, the energy storage circuit rectifier bridge breakdown or motor failure. The causes and countermeasures are shown in Table 4.
Table 4 Possible causes and countermeasures
5. The contact closing bounce time is large, the contact stroke is large, and the three phases are inconsistent, resulting in excessive contact pressure, and its reaction force will be correspondingly large, causing the contact to bounce. The causes and countermeasures are shown in Table 5.
Table 5 Possible causes and countermeasures
6. The time of the split and closing is seriously exceeded, and the time of the sub-closing is related to the amount of semi-shaft buckle and the flexibility of the mechanism and the body transmission system. The causes and countermeasures are shown in Table 6.
Table 6 Possible causes and countermeasures
Precautions
1. Take advantage of the power outage maintenance opportunity to lubricate the mechanical friction parts of the vehicle-type circuit breaker and the operating mechanism to reduce frictional resistance.
2. The main technical data of the test switch after maintenance meets the requirements of technical standards, and the test items are complete and qualified.
Conclusion
At present, the 10kV vacuum circuit breaker in the substation of the power supply enterprise has gradually replaced the less oil circuit breaker, and has played an active role in the process of oil-free transformation. Compared with the less oil circuit breaker, the vacuum circuit breaker has the advantages of being suitable for frequent operation, small maintenance and maintenance, flameproof, explosion-proof, and high operational reliability, but the maintenance management should be strengthened in the process of installation and commissioning, and the inspection of the mechanical parts of the spring mechanism, lubrication, especially the mechanical characteristics of the parameter test work, improve the reliable operation of the handcart circuit breaker, and eliminate the fault and abnormality in the bud.
This article is compiled from "Electrical Technology", the title of the paper is "Indoor Handcart Type High Voltage Vacuum Circuit Breaker Common Fault Analysis and Countermeasures", the authors are Ren Dongming and Gai Hanzhang.