真空直流开断固有介质恢复强度研究

发布时间：2018-11-10 18:08

【摘要】：为研究直流开断过程中触头开距、燃弧时间及电流过零时的di/dt对真空开关开断能力的影响,对真空开关分断之后的固有介质恢复强度进行了测量,即不加恢复电压下触头间隙介质的自由恢复过程。文中设计了永磁斥力混合式快速机构,并采用转移强迫过零开断的方法,在合成回路实验系统中进行了真空小电流直流开断。搭建了用于测量弧后固有介质恢复强度的高压脉冲产生电路,在电流过零之后采用单电源高压脉冲放电法测量了不同触头开距、不同燃弧时间及不同di/dt下的触头间隙的固有介质恢复强度。研究结果表明:该文实验条件下的直流开断过程中存在一个临界开距,在此开距范围内,选择较快的分断速度和较短的燃弧时间,能够提高电流过零后电极间隙的固有介质恢复强度。同等开距同样的燃弧时间下,选择较低的反向电流过零频率能够提高电流过零后的固有介质恢复强度。
[Abstract]:In order to study the influence of contact opening distance, arc burning time and current over 00:00 on the opening capacity of vacuum switch during DC breaking, the recovery strength of natural medium after breaking vacuum switch was measured. That is, the free recovery process of contact gap medium without restoring voltage. In this paper, a hybrid fast mechanism with permanent magnetic repulsion force is designed, and the vacuum low current DC break is carried out in the synthetic circuit experiment system by using the method of transferring forced zero crossing. A high voltage pulse generation circuit used to measure the recovery strength of the natural medium behind the arc is built. After the zero current is crossed, the different contact opening distance is measured by the single source high voltage pulse discharge method. The intrinsic medium recovery strength of contact gap under different arc burning time and different di/dt. The results show that there is a critical opening distance in the process of DC breaking under the experimental conditions. In the range of the opening distance, a faster breaking speed and a shorter arc burning time are selected. It can improve the intrinsic dielectric recovery strength of electrode gap after current crossing zero. With the same open distance and the same arc time, the recovery strength of the natural medium after zero crossing can be improved by choosing a lower zero crossing frequency of reverse current.
【作者单位】：大连理工大学电气工程学院;
【基金】：国家自然科学基金项目(51277019,51337001)~~
【分类号】：TM564

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