城市轨道交通大容量直流快速断路器的研发

Research and Development of High-power and High-speed DC Circuit Breaker for Urban Rail Transit

为实现城市轨道交通直流快速断路器的国产化,研制了1 800 V/80 k A大容量直流快速断路器。重点介绍了直流大容量短路开断相关系统的设计,通过电磁场和动力学耦合仿真,获得了直接过流脱扣器的动态特性,通过建立空气直流电弧的磁流体动力学（MHD）模型,分析了电弧在开断过程中的运动以及弧根转移过程。基于仿真结果研制的样机按照IEC标准顺利通过了全部型式试验。仿真和试验结果表明：脱扣时间和电弧转移过程对开断性能具有重要的影响,该断路器开断短路电流时电弧转移迅速,电弧电压上升较快且不存在停滞现象,脱扣时间小于5 ms,燃弧时间在12 ms以内,具有开断100 k A短路电流的能力,从而验证了仿真对实际产品设计的指导意义。

In order to realize the domestic manufacture of high-speed direct current（DC） circuit breaker for urban rail transit, we developed a 1 800 V/80 k A high-power and high-speed DC circuit breaker, and described the design of high-power DC short-current breaking system in detail. By electro-magnetic field and dynamic coupling simulation, the dynamic characteristic of the direct over-current release is obtained. Through establishing the magneto-hydrodynamic（MHD） model of air DC arc, the arc root movement and transfer process during breaking is analyzed. The prototype, which is manufactured based on the simulation, has passed all type tests according to the IEC standards. The simulation and test results show that the release time and the arc transferring progress have a significant impact on the breaking capacity. During fault current breaking progress of this circuit breaker, the arc transfers rapidly, and the arc voltage increases fast without stagnation. The release time is less than 5 ms, the arcing time is less than 12 ms, and the circuit breaker can break the fault current of 100 k A. The guidance significance of simulation on product design is verified.