In the power system, the arc extinguishing ability of primary and secondary deep fusion circuit breakers is one of the key factors to ensure the stable operation of the system. Its performance is directly related to the timeliness, safety and reliability of circuit fault handling as well as the reliability of the entire system. The strength of arc extinguishing ability not only affects the service life of the circuit breaker itself, but also has a profound impact on the stable operation of the power system through fault handling efficiency and control of system disturbances.
Primary deep fusion circuit breakers are mainly used for on-off control and fault protection of the main circuit. Their arc extinguishing ability directly determines whether the fault current can be quickly cut off and the continuous burning and spread of the arc can be suppressed when serious faults such as short circuit and overload occur in the main circuit. When a fault occurs in the main circuit, the strong fault current will generate a strong arc between the contacts of the circuit breaker. If the arc extinguishing ability is insufficient, the arc may not be extinguished in time, resulting in serious erosion of the contacts by the arc, and even causing serious accidents such as explosion and fire of the circuit breaker. This will not only cause damage to the circuit breaker itself, but also expand the scope of the fault, affecting the normal power supply of the entire power system, resulting in large-scale power outages, and causing huge losses to industrial production and residents' lives. The primary deep-fuse circuit breaker with efficient arc extinguishing ability can extinguish the arc in a very short time, quickly cut off the fault current, limit the duration of the fault, thereby reducing the damage to the main circuit equipment caused by the fault and maintaining the stable operation of the main circuit of the power system.
Secondary deep-fuse circuit breakers are usually used in secondary circuits such as control, protection, and measurement. Although their operating voltage and current are relatively lower than those of the primary circuit, their arc extinguishing ability is equally important. As the "nerve center" of the power system, the secondary circuit is responsible for important functions such as transmitting control signals, monitoring system status, and starting protection devices. When short circuits, poor contact, and other faults occur in the secondary circuit, if the arc generated between the contacts cannot be extinguished in time, it may cause distortion of the control signal, misoperation or refusal of the protection device, thereby affecting the normal operation of the primary equipment and even making the protection mechanism of the entire power system ineffective. For example, in the relay protection circuit, if the arc extinguishing ability of the secondary deep-fuse circuit breaker is insufficient, the continuous existence of the arc may cause the relay coil to burn out, making it impossible for the protection device to operate in time when the primary equipment fails, causing the scope of the fault to expand. Therefore, the reliable arc extinguishing ability of the secondary deep-fuse circuit breaker is the key to ensure accurate secondary circuit signal transmission and reliable operation of the protection device, and plays an indispensable role in maintaining the stability of the control and protection functions of the power system.
The impact of arc extinguishing ability on system stability is also reflected in the control of transient processes in the power system. When a power system fails, a complex electromagnetic transient process will occur, in which the burning and extinguishing process of the arc will directly affect the magnitude and duration of transient overvoltage and overcurrent. If the primary and secondary deep-fuse circuit breakers can extinguish the arc quickly, they can effectively suppress the increase of transient overvoltage and the fluctuation of transient current, reduce the impact on other electrical equipment in the system, and avoid problems such as system oscillation and equipment insulation damage caused by excessive transient processes. On the contrary, circuit breakers with weak arc extinguishing ability may cause the transient process to be prolonged, causing the system to be in an unstable state for a long time, increasing the risk of system instability. For example, in a high-voltage power system, the slow arc extinguishing of a primary deep-fuse circuit breaker may cause an operating overvoltage, endangering the insulation safety of equipment such as transformers and cables, and thus affecting the overall stability of the system.
The arc extinguishing ability of the circuit breaker is closely related to its own arc extinguishing structure and arc extinguishing medium. Common arc extinguishing structures include longitudinal blowing arc extinguishing, transverse blowing arc extinguishing, longitudinal and transverse blowing arc extinguishing, etc. Different structural designs will affect the movement path and cooling effect of the arc in the arc extinguishing chamber. Arc extinguishing media such as air, SF6 gas, vacuum, etc. have significant differences in insulation strength and arc extinguishing performance. The primary deep-fuse circuit breaker usually uses SF6 gas or vacuum with strong arc extinguishing performance as the arc extinguishing medium, combined with a complex arc extinguishing chamber structure to meet the arc extinguishing requirements in the high voltage and high current scenarios of the main circuit. Due to the low working voltage and current, the secondary deep-fuse circuit breaker mostly uses air arc extinguishing or simple arc extinguishing devices, but it is still necessary to ensure that the arc can be effectively extinguished when the secondary circuit fails. Reasonable arc extinguishing structure and high-quality arc extinguishing medium selection are the basis for improving the arc extinguishing ability of the circuit breaker and ensuring the stability of the system.
In addition, the stability of the arc extinguishing ability cannot be ignored. During the long-term operation of the power system, the circuit breaker may experience multiple opening and closing operations, the performance of the arc extinguishing medium may decline due to aging and decomposition, and the arc extinguishing structural components may also affect the arc extinguishing effect due to wear. If the arc extinguishing ability gradually weakens with the passage of time, the circuit breaker will not be able to reliably extinguish the arc in subsequent fault handling, increasing the safety hazards of system operation. Therefore, it is an important measure to maintain the stability of the power system to regularly detect and maintain the arc extinguishing ability of primary and secondary deep fusion circuit breakers to ensure that their arc extinguishing performance is always in good condition. For example, gas humidity detection and leakage monitoring of SF6 circuit breakers, vacuum degree testing of vacuum circuit breakers, timely detection and handling of the problem of arc extinguishing medium performance degradation can effectively prevent system failures caused by the decline of arc extinguishing ability.
From the perspective of overall system coordination, the arc extinguishing ability of primary and secondary deep fusion circuit breakers needs to match other protection devices and equipment in the power system. When a fault occurs, the arc extinguishing speed of the circuit breaker should be coordinated with the action time of the relay protection device to ensure that the circuit breaker can quickly extinguish the arc and cut off the fault current after the protection device issues a trip command. If the arc extinguishing capacity of the circuit breaker is insufficient, even if the relay protection device operates correctly, it may not be able to clear the fault in time, resulting in the protection device to operate beyond the level and expand the scope of power outage. At the same time, the arc extinguishing capacity of the circuit breaker should also be adapted to the short-circuit capacity of the power system. If the short-circuit capacity of the system increases and the arc extinguishing capacity of the circuit breaker is not improved accordingly, the fault current will not be effectively cut off, threatening the stability of the system. Therefore, in the planning, design and operation of the power system, it is necessary to comprehensively consider the matching of the arc extinguishing capacity of the circuit breaker with other elements to ensure that the entire system can coordinate actions in the event of a fault and quickly resume stable operation.
The arc extinguishing capacity of the primary and secondary deep fusion circuit breakers has an important impact on the stability of the power system by affecting the efficiency of fault handling, transient process control, equipment reliability, and system coordination. Both the primary deep fusion circuit breaker of the main circuit and the secondary deep fusion circuit breaker of the control protection circuit need to have reliable arc extinguishing capabilities and maintain their stable performance in long-term operation. By rationally selecting arc extinguishing structures and media, strengthening equipment maintenance and inspection, and ensuring coordination with other parts of the system, the arc extinguishing capability of the circuit breaker can be effectively improved, providing a solid guarantee for the safe and stable operation of the power system.
