高压直流继电器磁吹系统的建模与设计

Modeling and Design of Magnetic Blowing System for High Voltage Direct Current Relay

高压直流(HVDC)继电器触头系统结构紧凑,难以利用栅片或产气材料来提高触头的开断性能。通过磁吹系统的外加磁场能够加快电弧的运动速度,提高灭弧能力。永磁体作为磁吹系统的关键部分,其外部磁感应强度分布不均匀,且尺寸对磁场的大小和分布影响较大,这对磁吹系统的设计造成了一定的困扰。针对此问题,该文建立磁吹系统三维有限元模型,重点分析永磁体尺寸对其外部磁场的影响,并建立相关数学模型;分析永磁体外部磁场分布的特点,得出外部磁场分布均匀度与永磁体尺寸的关系。最后,结合高压直流继电器的开断电弧特性,考虑电弧的受力情况及电弧的停滞时间,对永磁体的尺寸、充磁方向及安装位置进行设计,为提升高压直流继电器触头开断性能奠定了理论基础。

Due to the compact structure of the HVDC relay contact system,it is difficult to use grids or gas producing materials to improve the breaking performance of the contacts.The arc movement speed can be accelerated by the external magnetic field of the magnetic blowing system,which improves the arc extinguishing ability.As a key part of the magnetic blowing system,the permanent magnet has an uneven distribution of external magnetic induction,and its size has a great influence on the size and distribution of the magnetic field,which causes certain difficulties for the design of the magnetic blowing system.In response to this problem,this paper established a 3D finite element model of the magnetic blowing system,focusing on the analysis of the impact of the permanent magnet size on its external magnetic field,and established a relevant mathematical model.It also analyzed the characteristics of the external magnetic field distribution of the permanent magnet,and obtained the relationship between the uniformity of the external magnetic field distribution and the size of the permanent magnet.Finally,combined with the characteristics of the HVDC relay's breaking arc,this paper designed the size,magnetization direction and installation position of the permanent magnet in the magnetic blowing system by considering the force and stagnation time of the arc.It lays a theoretical foundation for improving the contact breaking performance of HVDC relays.