DC-Voltage Switch Fuse Integration for Compact HV Protection
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Solution Overview
Problem
High-voltage onboard electrical systems in motor vehicles face challenges with existing switching and protection devices due to high installation space requirements and inadequate triggering characteristics, particularly with high allowable overcurrents and manufacturing-related component tolerances leading to increased break times.
Innovation Solution
A compact switching and protection device integrating a DC-voltage switch with a fuse, where the fuse is either a wire or a series of conductor paths embedded within an electric insulator bridge, utilizing materials that outgas or conduct heat to extinguish arcs, and incorporating arc splitters or insulators to enhance arc extinguishment, reducing installation space and improving triggering accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hermetically sealed fuses with ceramic or plastic housings are used, then protection function is provided, but installation space requirement increases
Solution Approach 1:
The fuse is integrated into the housing of the DC-voltage switch, combining the protection function and switching function into a single compact unit. This eliminates the need for separate hermetically sealed fuse housings, thereby reducing installation space while maintaining protection functionality.
Solution Approach 2:
The housing serves multiple functions: it provides structural support for the DC-voltage switch, acts as a protective enclosure, and serves as the hermetically sealed housing for the fuse. This multi-functionality reduces the number of separate components and overall installation space.
2Reliability
If multiple fusible elements are connected in parallel, then protection capability is enhanced, but break time increases due to manufacturing tolerances
Solution Approach 1:
The patent changes the configuration from parallel connection to series connection of fusible elements. This parameter change in the electrical circuit topology eliminates the problem of manufacturing tolerances accumulating in parallel connections, thereby reducing break time while maintaining protection capability through the series fuse design.
3Adaptability or versatility
If high allowable overcurrents are permitted, then system flexibility is improved, but triggering characteristics become inadequate
Solution Approach 1:
The DC-voltage switch provides dynamic control capability, allowing the system to adaptively respond to different current conditions. The switch can be controlled to open or close based on system requirements, providing flexibility while the integrated fuse ensures reliable triggering characteristics through its precise melting characteristics.
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 solution achieves reduced installation space and faster, more reliable arc extinguishment, addressing the limitations of traditional hermetically sealed fuses by integrating the fuse within the switching device and employing materials that enhance arc extinguishment through pressure and thermal conductivity.
Implementation Method 1
If the wire is overloaded during a fault current flow, the wire vaporizes in an explosive manner.
Implementation Method 2
The pressure waves and changes in the conductivity of the wire or the resulting switching arc thus occurring due to the explosion process
Implementation Method 3
the bridge is made of a material which is strongly outgassing at the melting temperature of the fuse
Implementation Method 4
an insulator is arranged in such a way that it is moved between the contacts during the melting of the fuse, to interrupt the arc
Data Source
AI summary
A switching and protection device for high-voltage onboard electrical systems having a DC-voltage switch and a fuse, wherein the DC-voltage switch includes a housing, at least two fixed contacts, and a bridge designed to be movable with respect to the fixed contacts, wherein the bridge is formed from an electric insulator, wherein two contacts are arranged on the bridge such that, during a movement of the bridge in the direction of the fixed contacts, the two contacts make contact with the fixed contacts, wherein the two contacts arranged on the bridge are electrically connected to each other via the fuse.