DC-DC Converter Boost Mode for High Voltage Cable Disconnection Detection
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Solution Overview
Problem
Existing systems fail to detect disconnected high voltage cables in electric and hybrid electric vehicles, leading to potential safety hazards and performance issues, as they only measure voltage at the main ESS contactors and not between contactors and other vehicle components.
Innovation Solution
A system that uses a DC-DC converter in boost mode to apply a safe test voltage along high voltage cables, allowing for accurate measurement of cable connections before the main ESS contactors are closed, ensuring all cables are properly connected before power is applied.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage is measured only at the main ESS contactors, then the measurement system is simple, but disconnected cables between contactors and vehicle components cannot be detected
Solution Approach 1:
The voltage measurement system is segmented into multiple measurement points: one at the main ESS contactor and additional points at each vehicle component (inverter, motor generator, power converter, etc.). This segmentation allows detection of cable disconnections in any segment of the high voltage system while maintaining a modular measurement architecture that balances detection precision with system complexity.
2Reliability
If a test voltage is applied before closing main ESS contactors, then cable connections can be verified, but the system requires additional control steps
Solution Approach 1:
A test voltage is applied to the high voltage cables through the DC-DC converter before the main ESS contactors are closed. This preliminary action verifies cable integrity and connection status in advance, preventing unsafe operation. The controller coordinates this test sequence automatically, integrating the additional verification step into the existing startup protocol without requiring separate manual procedures.
Solution Approach 2:
The DC-DC converter serves as an intermediary device that applies a controlled test voltage to the high voltage cable system before main power connection. This intermediary approach allows safe verification of cable integrity using a lower, controlled voltage source rather than directly applying full ESS voltage, thereby enhancing safety while maintaining systematic control.
3Productivity
If high voltage cables are not verified before operation, then the system starts quickly, but safety hazards such as fires or shocks may occur
Solution Approach 1:
Cable connection verification is performed as a preliminary action during the vehicle startup sequence, before the main ESS contactors are closed and full power is applied. The controller automatically executes the test voltage application and measurement protocol, ensuring cable integrity is confirmed before operation begins. This integration minimizes the impact on startup time while eliminating safety hazards from undetected disconnections.
4Measurement precision
If multiple voltage measurement points are implemented, then cable disconnections can be detected, but the measurement system becomes more complex
Solution Approach 1:
The existing DC-DC converter and controller are utilized to perform multiple functions: normal voltage regulation, test voltage application, and cable connection verification. By making these existing components multi-functional, the system achieves precise cable connection detection at multiple points without adding dedicated measurement hardware, thereby maintaining measurement precision while limiting the increase in system complexity.
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 method effectively detects disconnected cables, preventing potential fires or shocks by ensuring all high voltage cables are connected before power is supplied, thereby enhancing safety and vehicle performance.
Implementation Method 1
uses a DC-DC converter in boost mode to apply a safe test voltage along high voltage cables, allowing for accurate measurement of cable connections
Data Source
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AI summary
A system and method described herein detects the presence of an unconnected condition in high voltage component cables in an electric or hybrid-electric vehicle having a high voltage battery or energy storage system. The system includes a DC-DC converter which is capable of operating in either a step-down mode (e.g., as a buck converter) or a boost mode. The system uses the DC-DC converter operating in boost mode to create a sufficient, yet safe, measuring voltage on the main high voltage cabling of the vehicle before allowing the energy storage system to begin supplying high voltage power to the system components. The measurements are taken at various points near the individual components to determine if the cable has become disconnected.