Pyrotechnic Contactor Interrupter for Fast Overcurrent Isolation
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Solution Overview
Problem
Conventional contactors struggle to quickly and reliably open in extreme overcurrent conditions, such as those encountered in vehicle accidents, and may not prevent re-closure, which can lead to further damage or safety hazards.
Innovation Solution
The integration of a pyrotechnic interrupter within the contactor, which includes a plunger and pyrotechnic ignitor, allows for rapid opening of the contactor by forcibly driving the electrically conductive bridge away from the stationary contacts when high and rapidly rising currents are detected, using a contactor controller to determine the appropriate action based on current levels and rates of rise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional deenergizing methods are used to open the contactor, then the device structure remains simple, but the opening speed is insufficient for extreme overcurrent conditions
Solution Approach 1:
The patent merges the pyrotechnic interrupter mechanism with the conventional contactor structure, integrating a pyrotechnic charge, plunger, and bridge assembly into the existing contactor housing. This combination enables both conventional electromagnetic operation and rapid pyrotechnic interruption within a single device, resolving the contradiction between simple structure and fast opening speed.
Solution Approach 2:
The patent introduces a pyrotechnic charge as an intermediary mechanism that converts chemical energy into mechanical force through controlled combustion. This intermediary enables rapid bridge movement and contact separation that cannot be achieved through electromagnetic deenergizing alone, achieving ultra-fast opening while maintaining the original electromagnetic control structure.
2Reliability
If the contactor is opened rapidly using pyrotechnic means, then current flow is arrested quickly, but the risk of re-closure increases without additional safety mechanisms
Solution Approach 1:
The patent implements preliminary action by positioning the plunger to physically block the bridge's return path before the pyrotechnic charge is activated. This pre-positioned mechanical barrier ensures that even if the pyrotechnic mechanism fails or is partially activated, the bridge cannot re-close, providing inherent fail-safe protection without requiring complex additional safety systems.
Solution Approach 2:
The patent converts the potentially harmful uncontrolled movement of the bridge during pyrotechnic activation into a beneficial safety feature. The forceful ejection of the bridge and its subsequent trapping by the plunger transforms the violent energy release into a reliable locking mechanism that prevents re-closure, turning a possible hazard into a safety advantage.
3Speed
If the pyrotechnic interrupter is activated during operation, then the bridge is forcibly driven to open the contactor, but mechanical stress on components increases
Solution Approach 1:
The patent extracts the bridge from its normal constrained path and redirects it through a dedicated ejection channel formed by the plunger and housing. This extraction allows the bridge to move freely under pyrotechnic force without encountering obstructions or creating excessive side loads on mounting components, reducing mechanical stress while maintaining high movement speed.
Solution Approach 2:
The patent changes the dimension of bridge movement from the normal horizontal contact separation path to a vertical ejection path through the plunger. This dimensional change allows the bridge to be accelerated more efficiently by the pyrotechnic charge and redirected into a safe trapped position, reducing mechanical stress on original contact components while achieving rapid opening.
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
The pyrotechnic interrupter effectively arrests current flow in less than 2 milliseconds, significantly faster than conventional methods, and ensures the contactor remains open, protecting electrical components from dangerous currents and preventing re-closure, thus enhancing safety and preventing potential fires or explosions.
Implementation Method 1
an electromagnet coil and an electrically conductive core disposed within or adjacent the coil. The core is attached to an electrically conductive bridge. When the coil is energized, it produces an electromagnetic field that shifts the core such that the bridge is moved into engagement with a pair of stationary contacts
Implementation Method 2
a pyrotechnic interrupter disposed within the trench. The pyrotechnic interrupter may include a plunger and pyrotechnic ignitor disposed below the plunger, wherein, when the pyrotechnic ignitor is actuated, the plunger forcibly drives the electrically conductive bridge from the first position toward the second position
Data Source
AI summary
An electrical contactor including a contactor assembly including a housing, an electromagnet coil and an electrically conductive core disposed within the housing, the core being movable relative to the coil under influence of an electromagnetic force produced by the coil, and an electrically conductive bridge connected to a lower end of the core and movable with the core, an interrupter assembly including a base located below the bridge and having a trench formed in a top surface thereof, an input bus bar and an output bus bar disposed on the base on opposing sides of the trench, and a pyrotechnic interrupter disposed within the trench. The pyrotechnic interrupter may include a plunger and pyrotechnic ignitor disposed below the plunger, wherein, when the pyrotechnic ignitor is actuated, the plunger forcibly drives the bridge away from the input bus bar and an output bus bar to break an electrical connection therebetween.