Vehicle Electrical Line Sizing With Temperature-Based Load Isolation
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Solution Overview
Problem
Existing vehicle electrical systems are oversized to prevent thermal damage, leading to increased costs and weight due to the need to accommodate maximum expected thermal loads, which are influenced by ambient temperature variations.
Innovation Solution
An electrical system with a control unit that prevents the electrical load from switching on outside its defined operating range, using switching elements to isolate the load from the voltage source when external conditions, such as temperature, exceed a predetermined limit, allowing for smaller conductor cross-sections and material savings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical conductors are oversized to prevent thermal damage, then reliability is improved, but weight and cost increase
Solution Approach 1:
The patent applies dynamics by making the switching element controllable based on ambient temperature conditions. The system dynamically adjusts its operation: when temperature is within the operating range, the load operates normally; when temperature exceeds the range, the switching element isolates the load. This dynamic control allows conductors to be sized for the narrower effective operating range rather than the absolute maximum temperature, reducing weight while maintaining reliability.
Solution Approach 2:
The patent changes the operational parameters of the electrical system by defining a specific operating range with upper and lower temperature limits. By establishing these parameter boundaries and using a switching element to enforce them, the system operates only within safe temperature conditions. This parameter-based control enables conductor sizing based on the effective operating range rather than worst-case scenarios, resolving the contradiction between reliability and weight.
2Reliability
If electrical conductors are oversized to prevent thermal damage, then reliability is improved, but cost increases
Solution Approach 1:
The controllable switching element enables dynamic operation of the electrical system based on temperature conditions. By dynamically isolating the load when ambient temperature is outside the operating range, the conductors only need to handle thermal loads within the defined operating range. This reduces the required conductor cross-section, lowering material costs while maintaining reliability through active temperature management.
Solution Approach 2:
By defining and enforcing temperature parameter boundaries through the switching element, the system changes its operational characteristics. The conductors are designed for the effective operating range rather than absolute maximum conditions, reducing material requirements and manufacturing cost while preserving reliability through parameter-based control.
3Adaptability or versatility
If the load operates in extended temperature ranges, then adaptability is improved, but thermal damage risk increases
Solution Approach 1:
The switching element provides preliminary anti-action by preventing the load from operating when ambient temperature is outside the safe operating range. Before thermal damage can occur, the system proactively isolates the load based on temperature conditions. This preventive approach allows the system to be adaptable to various temperature environments while protecting against thermal stress by stopping operation before harmful conditions arise.
Solution Approach 2:
The system uses parameter changes by establishing defined operating temperature ranges and using the switching element to enforce these boundaries. When ambient temperature exceeds the upper limit or goes below the lower limit, the switching element isolates the load, preventing operation under harmful thermal conditions. This parameter-based control enables adaptability to different environments while maintaining safety.
Data Source
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AI summary
A vehicle electrical system (4) for a vehicle (2) is described, comprising a voltage source (6) and an electrical load (8), the requirement for which depends on an external condition. Furthermore, the vehicle electrical system (4) includes a load path (10) with an electrical conductor (12) connecting the voltage source (6) to the electrical load (8), and a first switching element (14) located in the load path (10) for disconnecting the electrical load (8) from the voltage source (6). An operating range (AB) of the external condition is defined within which the function of the electrical load (8) is meaningful. A control unit (16) is arranged such that switching on the electrical load (8) is prevented when the external condition lies outside the operating range (AB). Finally, a method for designing an electrical conductor (12) of such a vehicle electrical system (4) is described.