改进混合型限流断路器限流特性及换流电弧能量分析

Analysis of Current Limiting Characteristics and Commutation Arc Energy of Improved Hybrid Current Limiting Circuit Breaker

混合型限流断路器兼备了机械开关良好的静态特性和固态开关无弧快速分断的动态特性,是国际上断路器研究的新方向。为了对高di/dt电流下混合型限流断路器的换流电弧能量进行分析,在已研制出的两种混合型限流断路器样机基础上,开展了相同实验线路参数和设定动作值条件下的两种限流断路器方案的对比实验。改进方案可将电流上升率di/dt为18A/μs的短路电流限制到7.5kA,分断动作时间1ms,相比于初始方案,改进方案分断速度更快,限流能力更强。进而计算了2种方案在不同短路电流上升率下的换流电弧能量,并分析了电弧能量对触头烧蚀特性的影响。改进方案能够有效地降低换流电弧能量,减小电弧对触头的烧蚀,提高触头寿命。研究表明改进方案更适合需要多次分断高di/dt短路电流的应用场合。

It is a new way to research circuit breaker by developing the hybrid current limiting circuit breaker （HCLCB） with both the static characteristics of a mechanical switch and dynamic characteristics of solid-state switch. To analyze the commutation arc energies of two kinds of HCLCB with high di/dt short-circuit current, we comparatively researched two kinds of HCLCB prototypes under the same line parameters and setting responding value. The improved HCLCB could limit the short-circuit current to 7. 5 kA in less than 1 ms, and had faster operating speed and more effective capability of limiting short-circuit than the initial HCLCB. Moreover, we calculated the commutation arc energies with different short-circuit current rising rates, and analyzed the influence of the arc energy on the contacts burning characteristic. The calculated results show that the improved HCLCB can reduce the arc energy and relieve the contact erosion to increase the contacts life. Therefore, the improved HCLCB is more suitable for interrupting high di/dt short circuit current repeatedly applications.