Integrated Pyrotechnic Contactor for Fast Current Interruption
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Solution Overview
Problem
Existing contactors struggle to quickly and reliably open in extreme overcurrent conditions, such as in automobile accidents, and may not prevent re-closure, posing risks of fire or explosion.
Innovation Solution
A contactor with an integrated pyrotechnic interrupter that includes a pyrotechnic ignitor to rapidly open the contacts by actuating a plunger to drive the conductive bridge away from the stationary contacts, using a pyrotechnic force to ensure secure separation and prevent re-closure, complemented by a contactor controller to manage current levels and trigger the pyrotechnic interrupter when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a conventional electromagnet coil is used to open the contactor, then the contactor can be opened under normal conditions, but it cannot open quickly enough in extreme overcurrent conditions
Solution Approach 1:
The patent combines a conventional electromagnet coil with a pyrotechnic ignitor system into a single contactor assembly. The electromagnet handles normal opening operations, while the pyrotechnic ignitor provides rapid forced opening capability for extreme overcurrent conditions, merging two different actuation mechanisms into one integrated system.
Solution Approach 2:
The patent changes the operational parameters by introducing a pyrotechnic ignitor that generates extreme thermal and mechanical energy momentarily. This allows the system to transition from electromagnetic actuation (normal conditions) to pyrotechnic actuation (extreme conditions), fundamentally changing the energy parameter to achieve ultra-rapid opening.
2Loss of time
If the contactor is opened quickly using a pyrotechnic ignitor, then the contactor can arrest current in less than 2ms, but the device complexity increases
Solution Approach 1:
The pyrotechnic ignitor serves multiple functions: it acts as a rapid actuator for forced opening, provides a mechanical barrier through the plunger to prevent re-closure, and creates a visible indication of activation. This multi-functionality reduces the need for separate components and justifies the added complexity by delivering multiple benefits from a single integrated system.
Solution Approach 2:
The contactor is designed with the pyrotechnic ignitor and plunger mechanism pre-positioned and ready for immediate activation. The system prepares the forced opening mechanism in advance, so when extreme overcurrent conditions are detected, the rapid opening can occur in less than 2ms without delay for mechanical assembly or positioning.
3Reliability
If the electromagnet coil is deenergized to open the contactor, then the electrical pathway is broken, but the contactor may reclose under certain conditions
Solution Approach 1:
The pyrotechnic plunger acts as a mechanical intermediary between the pyrotechnic ignitor and the contact bridge. When activated, the plunger physically pushes the contact bridge away from the stationary contacts and can be designed to engage with a locking mechanism, providing a mechanical barrier that prevents re-closure even if the electromagnet were to re-energize.
Solution Approach 2:
The opening mechanism is segmented into two independent systems: the electromagnet coil for normal operation and the pyrotechnic ignitor with plunger for forced opening and prevention of re-closure. This segmentation allows each subsystem to perform its specific function optimally without interfering with the other, ensuring reliable prevention of re-closure when the pyrotechnic system is activated.
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 contactor effectively arrests current in less than 2ms, providing rapid and secure separation of contacts to protect electrical components from high current, and prevents re-closure, enhancing safety in extreme conditions.
Implementation Method 1
a pyrotechnic interrupter including a pyrotechnic ignitor and a movable plunger positioned in the trench
Implementation Method 2
actuating the pyrotechnic ignitor to rapidly open the contacts by actuating a plunger to drive the conductive bridge away from the stationary contacts
Implementation Method 3
a contactor includes an electromagnet coil and a movable, 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
Data Source
Figure 1
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AI summary
An electrical contactor 10 including a contactor assembly 12 including a housing 20, an electromagnet coil 16 and an electrically conductive core 18 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 22 connected to a lower end of the core 18 and movable with the core, an interrupter assembly 14 including a base 50 located below the bridge 22 and having a trench 52 formed in a top surface thereof, an input bus bar 28 and an output bus bar 30 disposed on the base on opposing sides of the trench, and a pyrotechnic interrupter 54 disposed within the trench. The pyrotechnic interrupter 54 includes a plunger 56 and pyrotechnic ignitor 58 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.