Rectangular Thomson Coil Drive for High Voltage Switches
Solution Overview
Problem
Existing high and medium voltage switches face challenges in achieving faster switching speeds and compact designs due to the limitations of traditional circular Thomson coil drives, which restrict the optimization of plunger dimensions and lead to higher inertia and larger sizes.
Innovation Solution
The use of a non-circular, substantially rectangular drive coil design that adapts to the shape of the plunger, allowing for smaller, lighter plungers and a more compact drive, which is mechanically connected to a switching assembly and housed in a fluid-tight enclosure with insulating fluid, eliminating the need for mechanical bushings and enabling faster switching speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a circular Thomson coil is used, then the drive structure is simple and easy to manufacture, but the plunger dimensions cannot be optimized leading to higher inertia and slower switching speed
Solution Approach 1:
The patent applies asymmetry by changing the coil geometry from a traditional circular shape to a rectangular shape. This asymmetric design allows the plunger to have an optimized rectangular cross-section that matches the coil geometry, enabling better dimensional optimization and reduced inertia for faster switching speed while accepting increased manufacturing complexity.
2Volume of moving object
If a circular Thomson coil is used, then the manufacturing process is straightforward, but the drive size is larger and less compact
Solution Approach 1:
The rectangular coil geometry replaces the circular design, creating a more compact drive volume. The asymmetric rectangular shape allows for tighter integration with the switching assembly and reduces the overall footprint of the drive mechanism, though it increases manufacturing complexity compared to traditional circular coils.
3Speed
If the plunger weight is reduced for faster switching, then switching speed improves, but the plunger requires stronger support structures increasing overall device complexity
Solution Approach 1:
The rectangular plunger design with optimized dimensions matches the rectangular coil geometry. This asymmetric design allows for weight reduction while maintaining structural integrity through the optimized rectangular cross-section, reducing the need for additional support structures and minimizing the increase in device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design reduces the weight and inertia of the plunger, enabling faster switching speeds and a more compact switch suitable for high and medium voltage applications, while maintaining high dielectric withstand levels and reducing the need for mechanical bushings.
Implementation Method 1
The current pulse in the coil generates a varying magnetic flux, which in turn generates a current with opposite direction in the plunger
Implementation Method 2
This generates a repulsive force between the coil and the plunger for driving the plunger away from the coil
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
A medium or high voltage switch has a switching assembly (12) actuated by two drives (18, 19). Each drive comprises a plunger (27) arranged between two Thomson coils (37, 38). The coils (37, 38) as well as the plunger (27) are rectangular for reducing the weight and therefore inertia of the drive and thus to increase drive speed.