直流多触点换流式气体电弧均压分断调控机理研究

随着航空航天及中低压工业领域的快速发展，直流供电系统容量和电压不断提高，目前直流开关难以满足耐环境、轻重量的要求，小体积大容量直流分断技术研究成为前沿课题。本项目提出一种大功率直流多触点换流式分断原理，以增大额定电流和提高分断电压；研究不同触头参数下通流支路接触电阻动态变化规律和电流转移特性，获得触头间电流无弧转移条件；搭建大功率直流实验平台与电弧形态高速采集系统，理论分析与实验研究氢气氮气等气氛环境和外置磁场驱动下的电弧等离子体特性，建立直流电弧动态数学模型，获得灭弧支路分断机理；考虑多触点串联灭弧支路电感和电容寄生参数，采用差异磁场和触头结构调控方法研究熄弧过程中动态均压及绝缘效应，掌握多触点串联协同灭弧机理;提出换流式大容量直流接触器设计原理和方法，为研制适用于航空航天和工业领域2.5kV/3kA直流接触器提供理论依据，本项目研究对突破大容量直流分断技术瓶颈具有重要的理论和实际意义。

With the rapid development of aerospace and LV/MV industries, the capacity and voltage of DC power supply system are constantly improving. Small-volume and large capacity DC breaking technology has become a frontier topic as DC switches are difficult to meet the requirements of environment resistance and light weight. This project proposes a high-power DC multi-contact commutation breaking principle to increase the rated current and breaking voltage. By studying the dynamic change and current transfer characteristics of the contact resistance of the through-flow branch under different contact parameters, the arcless transition condition between the contacts is obtained. A high-power DC experimental platform and a high-speed arc morphology acquisition system are built. The arc plasma characteristics in hydrogen and nitrogen atmosphere and driven by external magnetic field are studied theoretically and experimentally. The dynamic mathematical model of DC arc is established and the breaking mechanism of arc extinguishing branch is obtained. The influence of parasitic parameters of inductance and capacitance of multi-contact series arc extinguishing branch is analyzed. The dynamic voltage sharing and insulation effect in the process of arc extinguishing are studied by using differential magnetic fields and contact structure control method, and the mechanism of multi-contact series coordinated arc extinguishing is mastered. The design principle and method of commutated high-capacity DC contactor are presented, which provides theoretical basis for the development of 2.5kV/3kA DC contactor suitable for aerospace and industrial fields. This project has important theoretical and practical significance for breaking through the bottleneck of large capacity DC breaking technology.