Parameter design of permanent magnet holding mechanism in fast vacuum switch based on finite element analysis

To reduce the cost of the permanent magnet holding mechanism and enhance the reliability of structural parameter design, this paper develops a static magnetic field model using finite element simulation. It establishes the relationship curves between the maximum holding force and both the radius of the moving core and the thickness of the permanent magnet. The findings indicate that the maximum holding force initially increases and then decreases with an increase in the radius of the moving core. In contrast, it consistently increases with the heights and thickness of the permanent magnet, with the rate of increase being rapid at first and then gradually slowing. Based on these results, the optimal structural parameters for the low-voltage fast vacuum switch permanent magnet holding mechanism are determined: a moving core height of 5 mm, a permanent magnet height of 15 mm, and a magnet thickness of 7 mm.