SF_6断路器开断特性的数值仿真方法

笔者在LTE和LCE假设的条件下,以质量、动量和能量3个守恒方程以及电流连续方程为基础构建了SF6断路器开断过程中大电流燃弧阶段的电弧数学模型。电弧的欧姆热效应在电流场计算的基础上,通过在能量方程中加入源项来反映。文中对辐射模型以及湍流模型进行了讨论。喷口烧蚀效应通过增加独立的PTFE蒸汽质量守恒方程来考虑,从而构成了考虑喷口烧蚀效应的完备的控制方程组。这一控制方程组构成了SF6断路器开断过程大电流阶段的计算机仿真的基本数学模型,从而为"气体断路器数字化设计方法及仿真平台"的建立打下了基础。

Numerical Simulation Method for the Interrupting Characteristic of SF6 Circuit Breakers

With the assumptions of LTE and LCE,an arc mathematical model for high current arcing stage in interrupting process of SF6 circuit breakers is set up on the basis of the conservation equations of mass,momentum and energy as well as the continuum equation of the arc current.The intense ohmic heating of the arc is considered by adding a source term in the energy equation.Radiation model and turbulent model are described.A unique mass conservation for the ablated PTFE is added into the overall conservation equations to take account of the nozzle ablation.A complete set of the governing equations is therefore constructed for the computer simulation of SF6 gas circuit breakers,especially for the large current phase,which forms the fundamental work for the establishment of the computer simulation tools for gas circuit breakers.