【作者】 王连鹏；

【导师】 王尔智；

【作者基本信息】 沈阳工业大学 ， 电机与电器， 2008， 博士

【摘要】 SF₆高压断路器作为最重要的一类电器设备,它既承担着开断和关合输电线路的正常电流,也承担着在规定时间内开断输电线路中故障电流的任务。因此,开断特性是衡量SF₆高压断路器产品性能的最基本和最重要的技术指标。而SF₆高压断路器在开断过程中的介质恢复特性又是衡量其开断特性的重要依据之一,因而成为对SF₆高压断路器产品考核及现代化产品设计的重要组成部分。SF₆高压断路器开断过程中的介质恢复特性取决于液压操动机构的输出特性、灭弧室内电场、气流场的分布以及电弧等离子体能量的输运过程。传统的方法对介质恢复特性的数值模拟是将决定介质恢复强度的上述几部分分别计算,然后求出介质强度的恢复特性。本论文将机构动力学、电场、磁场及气流场的数学模型通过介质恢复特性联系起来,开展了介质恢复特性耦合数值模拟及其相关问题的研究。在操动机构与灭弧室更加理想配合的仿真研究方面:分析了储压筒、缓冲机构及液压缸的动力输出特性,研究了分闸速度与触头不同分断行程的关系。以分闸速度特性为目标函数,将操动机构输出特性与灭弧室触头运动位置联系起来,对液压操动机构的分闸速度特性进行了优化仿真,实现了液压操动机构与灭弧室之间更为合理的配合。在空载开断介质恢复特性的数值模拟方面:根据确立的机构动力学、电场以及气流场的耦合关系,建立了以介质恢复强度为联系纽带的数学模型;研究了电场和气流场剖分网格的耦合方法,使在介质恢复强度的数值模拟中,电场和流场的数值计算能够采用同一套剖分网格,在输入已知数据后,可实现介质恢复特性的全自动数值模拟;为了提高计算效率,开展了介质恢复特性数值模拟的并行计算及可视化研究。考虑到灭弧室内喷口对吹弧气体的控制作用,研究了喷口型面、结构对介质恢复特性的影响;根据激波形成理论,研究了利用激波提高介质强度恢复速度的喷口型面结构。在短路开断介质恢复特性的数值模拟方面:建立了短路开断下的机构动力学、电场及磁流体动力学的数学模型,确立了对短路开断介质恢复特性进行数值模拟的耦合关系。在输入已知数据后,可实现短路开断介质恢复特性全自动耦合数值模拟;分析和比较了Lorentz力对电弧形态及介质恢复特性的影响。更多还原

【Abstract】 As a kind of the most important electrical apparatus, high voltage circuit breaker is indispensable in power system. It not only takes switched normal current but also takes breaking fault current of power system in the appointed time. Its interrupting characteristics are the most important and essential technical performance to high voltage SF₆ circuit breaker. The Dielectric Recovery Property of high voltage SF₆ circuit breaker during the course of interrupting is one of very important criterion for measuring its interrupting characteristics. So it is an important content for modern product design of high voltage SF₆ circuit breaker.The numerical simulation of the dielectric recovery property for SF₆ high voltage circuit breaker depends on the output dynamic characteristics of hydraulic actuator, the distribution of flow field, electric field and the transportation of magneto hydrodynamics （MHD） in the arc quenching chamber. The conventional way for numerical simulation of dielectric recovery property is to calculate those three parts separately, then using numerical results to calculate dielectric recovery property. In this dissertation, the output dynamic characteristics of hydraulic actuator, the distribution of the electric field, magnetic field and flow field in the arc quenching chamber are linked through calculating the dielectric recovery strength, the investigations of coupled numerical simulation for dielectric recovery property and correlated problems have been done.In the aspect of investigation for the best match between actuator and arc quenching chamber:The output chatacteristics of pressure reservoir, buffer gear and hydraulic cylinder have been analyzed, the relation between breaking velocity and movable contact position has been researched. The objective function for velocity performance of hydraulic actuator has been established, the output characteristics of hydraulic actuator and the movable contact position have been related, and optimization design for the breaking velocity of SF₆ circuit breaker has been carried out in the dissertation. The more reasonable match between hydraulic actuator and arc quenching chamber has been achived.In the aspect of numerical simulation of no load dielectric recovery property:The mathematics model of mechanical kinetic, electric field and flow field related by the dielectric recovery property was established according to their coupled relations; the coupled method of subdivision grid for electric field and flow field had been investigated, and the same grid for the simulation of electric field and flow field was used during the course of computation dielectric recovery strength. The figure of numerical simulation for dielectric recovery strength was auto displayed after the given data were inputted to the program. The parallel method and the visualized technology have been researched in order to accelerate compute efficiency.Considering the controlling effect of arc nozzle on gas flow property during the breaking process, the influences to dielectric strength recovery properties by contour and dimension of arc nozzle were researched. According to the theory of shock wave, the contour of arc nozzle was also researched by using the shock wave to improve the recovered speed of dielectric strength.In the aspect of numerical simulation of short circuit dielectric recovery property:The arc mathematics model between the interacting electric field and flow field has been put forward, and the mathematics model of mechanism kinetic, electric field and MHD has been set up, then the coupled relation was ascertained. The figure of short circuit numerical simulation for dielectric recover strength was auto displayed after the given data inputted to the program. The influence of arc shape and dielectric recovery property by Lorentz force was analyzed.更多还原