Study On126KV Vacuum Circuit Breaker On Fiber-controlled Vacuum Interrupter Modules

The line fault current becomes larger with the great increasing capacity of transmission lines, which propose more strict requirements to the equipment performance. SF6gas is widely applied arc-quenching medium in high voltage lines. But the use of SF6gas is limited due to the environmental demands. So the research of its replacement is extremely urgent. Vacuum medium has excellent arc-quenching capacity, however, the saturation effects between gap length and breakdown voltage limit vacuum circuit breaker’s development at higher voltage level. Series-parallel of vacuum interrupters can make it develop in the direction of high voltage and large current, this paper introduces a model of126kV VCB with three40.5kV vacuum circuit breakers in series.Synchronization technology is a new technology in smart grid. Its objective is to inhibit transient process generated during the switching operation by controlling the circuit breaker operated in the optimum phase of the voltage or current. When opening, it can improve the breaking capacity of the circuit breaker by controlling its arc extinguishing in optimal arcing interval. This article describes the characteristics and practical significance of synchronization technology, the basic principle of the synchronization technology and its operation process. Theoretical basis for synchronization technology of vacuum circuit breaker is provided.The action synchronism of three fractures will directly cause different medium recovery characteristic of each fracture, causing arc-quenching ability’s distinction of different fractures. This paper analyzes the action synchronism of multi-fractures impact on breaking capacity, and proposes a suitable solution.This paper has tested the capacity of126kV VCB and fiber-controlled module, using circuit breaker standard test program and synthesis loop circuit. The feasibility of developing multi-fractures vacuum breaker to the high-voltage field is fully demonstrated, and valid data provided a good reference value for future research.