Integrated Aircraft Contactor Protection for Irreversible Fault Isolation
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Solution Overview
Problem
Existing electrical installations for high power applications, such as those in aircraft, suffer from increased mass due to the inclusion of separate safety switches like pyrotechnic single-use safety switches, which are necessary for overcurrent protection but add bulk.
Innovation Solution
A contactor with integrated protection system that switches between open and closed states and irremediably maintains the open state upon detection of anomalies, eliminating the need for separate safety switches by incorporating a pyrotechnic or fuse-based protection system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate single-use safety switch is added in series with the contactor for overcurrent protection, then the protection capability is improved, but the mass of the electrical installation increases
Solution Approach 1:
The patent integrates the protection system directly into the contactor structure, merging two previously separate components (contactor and safety switch) into a single unified device. The protection system includes a fuse element and pyrotechnic charge that are incorporated within the contactor housing, eliminating the need for a separate series-connected safety switch while maintaining overcurrent protection capability.
Solution Approach 2:
The contactor is designed to perform multiple functions: it serves as both the switching device and the protection device. The integrated protection system enables the contactor to detect overcurrent conditions, activate pyrotechnic mechanisms, and irreversibly open the circuit, thereby combining the functions of a controllable switch and a protective safety device into one multi-functional component.
2Reliability
If a separate safety switch is used for protection, then the protection function is improved, but the device complexity increases
Solution Approach 1:
The protection system is merged with the contactor structure, integrating the fuse element, pyrotechnic charge, and switching mechanism into a single unified device. This reduces the total number of separate components in the electrical installation while maintaining comprehensive protection functionality.
Solution Approach 2:
The contactor is designed as a multi-functional device that combines switching control and overcurrent protection capabilities. The single device performs both the function of a controllable switch and a protective safety mechanism, thereby reducing device complexity by eliminating the need for separate protection components.
3Weight of stationary object
If the contactor is integrated with a protection system, then the mass is reduced, but the reliability must be maintained through irreversible opening upon anomaly detection
Solution Approach 1:
The protection system employs a single-use pyrotechnic mechanism with a fuse element that is designed to be consumed during protection activation. When an overcurrent anomaly is detected, the pyrotechnic charge detonates, melting the fuse element and creating an irreversible open circuit. This disposable protection mechanism ensures reliable fault isolation while maintaining a compact, integrated design.
Solution Approach 2:
The pyrotechnic explosion, which is a harmful event, is converted into a beneficial protective action. The controlled detonation of the pyrotechnic charge serves to rapidly melt the fuse element and open the circuit during fault conditions, transforming a potentially dangerous phenomenon into a reliable protection mechanism that irreversibly isolates the fault.
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
Reduces the overall mass of the electrical installation by integrating protection functions within the contactor, effectively limiting the impact of short circuits without additional components, and ensuring reliable operation by preventing the contactor from switching back to the closed state after an anomaly is detected.
Implementation Method 1
The protection system comprises a pyrotechnic system
Implementation Method 2
the protection system comprises a fuse element
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a contactor (38) configured to occupy open and closed states, comprising at least one actuator (44) configured to at least switch and/or maintain the contactor (38) in the closed state upon receipt of a closing signal, as well as a protection system (48) configured to occupy a first state in which the protection system (48) allows the contactor (38) to switch between the open and closed states, as well as a second state, upon receipt of a protection signal, in which the protection system (48) irremediably maintains the contactor (38) in the open state. Integrating the protection function into the contactor (38) tends to limit the mass of an electrical installation comprising at least one such contactor (38). The invention also relates to an electrical installation comprising such a contactor (38) and to an aircraft comprising such an electrical installation.