多断口真空开关开断过程模拟及最优开断策略研究

This project will research the microscopic physical process of the current interruption in multi-break vacuum circuit breakers (MVCB) by the numerical simulation and key experiments, and the optimal break strategy to realize the break voltage sharing will be obtained. Firstly, the arcing model of MVCB taking the inter-electrode plasma and anode as a whole will be established. The distribution of arc plasma parameters, anode surface temperature and status in each break, and the arc interaction between breaks will be simulated. Secondly, the post-arc dynamic dielectric recovery of MVCB will be built. The microscopic process of dynamic dielectric recovery and the macroscopic parameters, such as the post-arc current and the transient recovery voltage of each break will be calculated adopting the PIC-MCC method combining the SIMULINK module of MATLAB. Next, the optimal break model of MVCB will be found, taking the dynamic voltage sharing as the optimal object and the arcing conditions as the control parameters, the optimal break strategy of MVCB will be explored. Finally, the experimental system of MVCB will be set up. The arcing images of each break will be recorded and dealt with Digital image technology. The current and voltage of each break during arcing period and post-arc period will be measured. The numerical models will be verified by comparing the simulation and experiment results. The research findings will contribute to supply the theoretical support for the phasing switching operation of MVCB, improve it’s interruption performance and to promote the industrialized application of the MVCB in the super-voltage and high capacity field.

采用数值模拟结合关键实验，深入研究多断口真空开关开断电流燃烧和弧后介质恢复阶段的微观物理过程，提出断口动态均压的最优开断策略。课题首先建立极间等离子体流和阳极为有机整体的多断口真空开关电弧燃烧模型，模拟各断口电弧等离子体参数分布、阳极表面温度和状态及断口间电弧相互作用；然后建立多断口弧后动态介质恢复模型，采用PIC-MCC法结合MATLAB仿真平台，模拟各断口动态介质恢复微观过程和弧后电流、暂态恢复电压等宏观参数；其次建立多断口真空开关优化开断模型，以断口动态均压为优化目标，燃弧参数为控制参数，探索多断口真空开关的最优开断策略；最后搭建多断口真空电弧特性实验平台，拍摄各断口电弧图像并进行数字图像处理，采集燃弧期间和弧后各断口的电流和电压，与仿真结果对比，验证数值模型。研究成果将为多断口真空开关的相控开断提供理论依据，进一步提高其开断性能，加快推进在高压、大容量领域的工业化应用。

多断口真空开关是有望替代SF6断路器的新型高压、大容量和环保型开关发展方向，其开断机理，特别是电弧燃烧和动态介质恢复物理过程的深入研究是关键问题。课题首先建立多断口真空开关电磁场分析模型，计算不同空间结构布置下各断口磁场分布、等效电容和杂散电容等参数，分析断口电压不均匀性，探讨断口自均压可行性；然后建立真空电弧燃烧模型和阳极热物理模型，模拟分析真空电弧电磁特性和阳极热过程，还搭建了电弧图像处理平台，采用脉冲耦合神经网络结合电弧图像，定量和定性深入研究燃烧过程；最后建立真空电弧弧后动态介质恢复模型，搭建MATLAB仿真平台，模拟真空电弧全开断过程。研究成果将为多断口真空开关的相控开断提供理论依据，进一步提高其开断性能，加快推进在高压、大容量领域的工业化应用。