252kV真空灭弧室纵磁触头磁场分析及优化

Analysis and Optimization of Axial Magnetic Field Characteristics of 252 kV Vacuum Interrupter Contacts

真空灭弧室的触头对真空断路器短路电流开断能力和额定电流导通能力有重要的影响。该文采用三维有限元方法对用于252kV真空灭弧室的单匝线圈纵磁触头的磁场特性进行了单因素分析和正交回归分析,包括电流峰值时纵向磁感应强度、电流过零时纵向磁感应强度和导体电阻值,得到了磁场特性和触头设计参数之间的回归方程,并且找出了影响磁场特性的显著因素。理想的纵向磁场特性应当是电流峰值时纵向磁感应强度强,电流过零时纵向磁感应强度弱,以及导体电阻值小。将基于实验设计的优化、有限元分析和统计分析结合在一起,可以达到这种理想的纵向磁场特性。采用这种方法,得到了一种252kV纵向磁场触头的优化设计参数。

Contacts of vacuum interrupters have important influence on nominal current carrying capability and short circuit current interrupting capacity of vacuum circuit breakers. By using 3D finite element method, axial magnetic field （AMF） characteristics of single coil contacts used in 252 kV vacuum interrupters were analyzed with single factor analysis and orthogonal regression analysis. The analyzed AMF characteristics include axial magnetic flux density at current peak, axial magnetic flux density at current zero, and conductor resistance. Regression equations that link AMF characteristics and contact parameters were given. Contact parameters that have significant influence on AMF characteristics were shown. Ideal AMF characteristics should be as follows： strong axial magnetic flux density at current peak, weak axial magnetic flux density at current zero and low conductor resistance. It is shown that the ideal AMF characteristics can be achieved by combination of optimization based on design of experiment, finite element method, and statistical analysis. By this way optimal contact parameters are found for a 252 kV AMF contact.