With the rapid development of China's power grids, short-circuit current problems have gradually become a prominent factor restricting the growth of grid load and grid development. The power system has an urgent demand for high-voltage and large-capacity switchgear.
Relying on the science and technology project of the State Grid Corporation of China, GJDW Power Material Technology Corporation has successfully developed high-performance graphene-modified high-voltage circuit breaker electrical contact products after 5 years of joint research and development.
In recent years, the maximum short-circuit current of some 252 kV (kV) and above substations in the East China Power Grid and South China Power Grid has reached or exceeded 63 kA (kA), which has brought severe challenges to the safe operation and capacity expansion of large power grids. . The realization of the upgrade of the electrical contact material of the high-voltage circuit breaker interrupter can directly realize the expansion, avoiding the huge cost of expanding the substation, and is an effective means to solve this problem.
"The breaking times of high-voltage and large-capacity circuit breakers are mainly restricted by the life of the electrical contacts in the circuit breaker. The electrical contact materials for high-voltage circuit breakers currently used mainly adopt copper-tungsten alloy technology routes.
The current copper-tungsten alloy electrical contact products have low flexibility and elongation, and are prone to fracture during the action; the material has insufficient ablation resistance, and arc ablation can easily cause electrical contacts to crack and fail. Therefore, effectively improving key performance indicators such as wear resistance, conductivity, and arc ablation resistance of electrical contact materials is of great significance to reducing the failure rate of circuit breakers and maintaining the safe and stable operation of the power grid.
The synergistic improvement of the arc ablation resistance and friction and wear resistance of electrical contacts is the key to improving the short-circuit resistance of high-voltage circuit breakers.
The project team broke through the key technology of the directional composition design of the graphene electrical contact material and the integrated molding of activation sintering dissolution and infiltration, and realized the industrial-grade preparation of multiple types of graphene modified electrical contacts, with key performance indicators such as electrical conductivity and bending strength. It is fully superior to domestic and foreign active products, greatly improves the electrical life of active high-voltage circuit breakers, and fills the technical gap in the field of China's graphene-modified high-voltage switch electrical contact materials.