高压直流真空开断中电磁热力多场强紧耦合精细仿真及应用

Fine research on the tight coupling of Electro-magnetic-thermal-stress multi field in high voltage direct current (HV DC) vacuum switch is a basic and key scientific topic for the power transmission and transformation equipment. It is difficult to describe the complex dynamics phenomenon of nonlinear dissipative system electromagnetic thermal properties and electrode materials physical parameters space-time variation for narrow-band, medium-band and wide-region discharge of the HV DC switches when the structure parameters and network change of net within net with conventional coupling model and forward numerical analysis. In this project, the whole system of multi-scale time-space and full arc dynamic physical-mathematical model is proposed to establish the full system condition model of multi-objective, multi-scale time-space, multi-dielectric media, multi-parameters (4M) for large current HV DC vacuum switch. The coordinated regulation of multi field is achieved through the fine simulation research of multiple field tight coupling approach. The multi-scale time-space correlation, single-objective, multi-objective and fine simulation analysis approach are obtained by the technology route of modelling, multi field fine simulation analysis and the prototype experiment. And the mechanism of full arc for medium frequency vacuum breaking during current zero is researched to determine the full view of DC arc switches unknown region. The method of fine analysis of electromechanical thermodynamic materials with 4M system is proposed to solve the contradiction between convergence speed and fine analytical precision. And the theoretical significance is to create a novel approach of the research on DC switching arc. As for the application of the research, it can realize the multi field fine control and guide the design of HV switch with higher technic parameters.

高压直流真空开关电磁热力多物理场强紧耦合精细研究是输变电装备领域的基础与关键科学问题。常规耦合模型与正演研究难以描述网中网系统结构参数与网路变化时高压直流开关窄隙、中频带、宽频段放电非线性耗散系统电磁热及电极材料物性参数时空变性的复杂动力学现象。提出全运行工况下全系统时空多尺度全电弧动态物理数学模型，构建大电流高压真空直流断路器多目标、时空多尺度、多介质、多参数(4M)全工况全系统模型与多场强紧耦合精细仿真研究，实现多场协同调控。由建模、多场精细分析到样机实验的技术路线，找到时空多尺度关联度分析方法、单目标与多目标分析方法与精细仿真方法，研究中频真空电弧零区全电弧开断机理，确定不为认知的直流真空开关电弧全貌；提出4M系统机电磁热力材料流固联合精细分析方法，解决收敛速度与精细分析精度矛盾。创建基于电磁热力多场强紧耦合精细仿真的高压开关电弧研究新路径，实现直流电弧调控，指导高参数高压开关设计。

伴随新能源系统快速发展，高技术参数直流断路器作为新型电力系统控制与保护的安全卫士，其自主设计与研发所涉及的关键科学问题与核心技术研究具有理论与工程实际意义。本项目以典型技术参数、换流拓扑结构方案下直流真空断路器为研究对象，从电磁热力多物理场强紧耦合精细模拟分析出发，研究常规耦合模型与正演研究难以找到网中网系统参数变化时直流真空开关换流参数群组、灭弧室结构以及快速机构联动可靠配合方案的难题。开展了真空直流断路器多目标、多尺度、多参数、多场强紧耦合精细仿真研究。采用多物理场建模、精细分析到样机实验的技术路线，研究了中频真空电弧零区开断机理，实现了换流回路优化拓扑与直流真空主开关耦合下的电弧调控。建立了直流真空电弧物理数学模型、换流回路模型及场路耦合模型、中频真空电弧鞘层发展模型、快速机构与灭弧系统联动的直流开断模型，找到了直流短路开断的换流回路拓扑与多参数群组配合方案，研究了机构运动特性与电弧调控的配合机理，以及换流过程小间隙中频真空电弧零区动力学行为演化规律，给出了零区电弧输运特性定量表征。结合实际工况条件，提出了包括快速机构设计、触头结构设计与换流拓扑优化的直流真空断路器开断极限域设计方案，自主设计完成了直流开断精细化数值仿真与样机实验。采用理论分析与样机实验相结合的数字孪生模型迭代优化技术路线，验证了模型与设计方案的可行性与有效性，并可指导不同技术参数直流真空开关的自主化设计。