中文摘要：

断路器的弧后电流是断路器开断性能的重要参量,为了获取高精度、低干扰的弧后电流,本文提出了一种基于真空开关、转移电阻、保护间隙和高精度电流传感器构成的弧后电流测量方法,其中真空开关负责导通大电流,在电流过零前电流转移到转移电阻上,然后利用高精度电流传感器间接测量弧后电流。建立了弧后电流装置的电流转移过程模型,分析了电流转移完成时刻和转移电流峰值受转移电阻、电流大小和真空开关刚分时刻的影响。基于仿真得到弧后电流测量装置的参数,设计了弧后电流测量装置样机,对转移电阻进行了特殊无感设计并与保护间隙实现配合保护。最后进行了10 k V真空断路器在合成回路试验中的弧后电流测量,在开断5 k A电流时,弧后电流峰值为500 m A左右,脉宽5μs,弧后测量干扰小,波形平滑。对比试验结果和前人研究成果,验证了基于电流转移原理的弧后电流测量装置的可行性和准确性。

英文摘要：

The post-arc current of circuit breakers is one of key parameters of breaking performance. In order to gain the high-precision and low-interference post-arc current, we proposed a novel method for measuring post-arc current with a device composed of vacuum switch, transfer resistance, protective gap and high-precision current sensor. The main cur- rent I mostly flows through the vacuum switch while the main current completely transfers to transfer resistance just before the current approaches zero and the post-arc current is measured by the high-precision current sensor. The cur- rent-transfer model of the post-arc current measurement is established to gain the characteristic of the finish time and the peak value of current transfer influenced by the transfer resistance, current of main circuit and the contacts breakaway time.Based on the simulation parameters, the prototype of post-arc current measuring device is set up. The transfer resis- tance is specially designed to make it noninductive and the coordination of protection is gained with the protective gap. The expereimental results of post-arc current is got by the prototype in synthetic short-circuit test. The measuring result of post-arc current is accurate and hardly interfered. The peak value and pulse width are 500 mA and 5 Its, respectively, when the breaking current and voltage are 5 kA and 10 kV, respectively. The experimental results and previous research can verify the feasibility and accuracy of the novel post-arc current measuring device.