Dual Signal Path for Reliable High-Voltage Disconnection
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Solution Overview
Problem
Existing motor vehicles with electric motors face challenges in reliably and quickly disconnecting high-voltage energy stores from the electrical system during emergency situations, such as accidents, due to potential malfunctions in signal transmission.
Innovation Solution
A motor vehicle design featuring a low-voltage electrical system with a dual signal path, utilizing semiconductor switches and a logic evaluation unit to ensure reliable signal transmission, allowing for safe disconnection of the high-voltage energy store by changing signal levels on two signal lines, and incorporating a pyrotechnic element for irreversible disconnection in emergency modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single signal path is used to disconnect the high-voltage energy store, then the device complexity is reduced, but the reliability of disconnection is compromised due to potential signal transmission malfunctions
Solution Approach 1:
The signal path is divided into two separate signal lines (first signal line and second signal line) that both connect the low-voltage vehicle electrical system to the high-voltage vehicle electrical system. This segmentation ensures that if one signal line fails, the other can still reliably transmit the emergency signal to disconnect the high-voltage energy store, thereby improving reliability while maintaining manageable complexity through modular design.
2Reliability
If a dual signal path is implemented to ensure reliable signal transmission, then the reliability of disconnection is improved, but the device complexity increases
Solution Approach 1:
Both the first signal line and the second signal line are merged into a common evaluation logic unit that processes signals from both lines. This merging approach allows the system to evaluate multiple signal paths through a single logic unit, improving reliability through redundancy while avoiding the complexity of completely separate evaluation systems for each signal line.
3Reliability
If pyrotechnic elements are used for irreversible disconnection, then the reliability of emergency disconnection is improved, but the ease of repair worsens due to component replacement requirements
Solution Approach 1:
The system performs preliminary diagnostic testing of the signal lines and evaluation logic unit before an emergency occurs. This preliminary action ensures that the pyrotechnic elements and associated disconnection mechanisms are properly configured and functional, maximizing their reliability when needed while enabling proactive identification and replacement of components that may require future maintenance, thereby improving ease of repair through planned maintenance cycles.
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
This solution provides a reliable and fast shutdown of the high-voltage electrical system with minimal delay, preventing accidental disconnections and ensuring safety during emergencies, while allowing for diagnostic testing of signal lines to maintain system integrity.
Implementation Method 1
a separator is installed in the power source, which causes the disconnection of the short-circuit conductor by means of the heat of the short-circuit current in the short-circuit conductor
Data Source
AI summary
A motor vehicle with an electric motor, in particular a hybrid or electric vehicle, has a high-voltage vehicle electrical system with a high-voltage stored energy source which supplies electrical energy to the electric motor for driving the motor vehicle, and a low-voltage vehicle electrical system for supplying electricity to a number of consumers in the motor vehicle. An electrical signal path is provided between the low-voltage vehicle electrical system and the high-voltage vehicle electrical system and powered by the voltage from the low-voltage vehicle electrical system. A controller in the motor vehicle is configured to cause a predetermined change of the signal on the signal path from a first signal state to a second signal state, wherein the first signal state indicates normal operation of the motor vehicle and the second signal state indicates an emergency state of operation of the motor vehicle which deviates from normal operation. The high-voltage vehicle electrical system is designed to separate the high-voltage stored energy source from the high-voltage vehicle electrical system in response to the predetermined signal change. The signal path includes a first and a second signal line, wherein the predetermined change of the signal on the signal path includes a change of the signal level on each of the first and second signal lines.