Active Fuse Control Circuit for Sleep-Mode Short-Circuit Detection
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Solution Overview
Problem
Conventional active fuse control schemes in battery management systems (BMS) suffer from low control reliability due to the inability to detect short circuits in sleep mode and the long detection time required to break the fuse, which is typically limited to 10 ms.
Innovation Solution
A battery pack active fuse control apparatus with a short-circuit current detect circuit and process circuit that are constantly powered, allowing for current sampling and overcurrent detection without waking up the BMS, enabling the active fuse to break within 3 ms by adjusting resistor values to match different high-voltage battery systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional active fuse control scheme is used with current sensor sampling, then the BMS can detect overcurrent when awake, but the detection time exceeds 10 ms and short circuits cannot be detected in sleep mode
Solution Approach 1:
The patent segments the current detection function from the main BMS control unit by implementing a dedicated hardware detection circuit that operates independently in sleep mode. This segmentation allows the detection function to continue operating without requiring the entire BMS to wake up, thereby reducing detection time and improving reliability during low-power states.
Solution Approach 2:
The patent implements preliminary action by maintaining the detection circuit in a ready state during sleep mode, with pre-configured threshold comparison and immediate break control capability. This preliminary preparation ensures that when a short circuit occurs, the system can respond immediately without needing to wake up and initialize the full BMS, achieving detection within 10 ms.
2Reliability
If the BMS wakes up to detect short circuit, then detection can be performed, but the response time is too long to break the fuse within 10 ms
Solution Approach 1:
The patent replaces the software-based control mechanism with a hardware-based detection and control circuit. This substitution eliminates the need for software processing and wake-up sequences, enabling direct hardware-level detection and immediate fuse breaking response, thereby achieving the required 10 ms response speed.
Solution Approach 2:
The patent introduces a dedicated hardware detection circuit as an intermediary between the current sensor and the fuse control. This intermediary circuit continuously monitors current and can directly trigger the fuse break without requiring BMS wake-up, serving as a mediator that enables fast response while keeping the main BMS in sleep mode.
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 improves the reliability of active fuse control by enabling rapid detection and breaking of the fuse during sleep mode, reducing short-circuit duration and enhancing vehicle safety.
Implementation Method 1
a current sampling chip to sample current flowing through the shunt resistor
Data Source
AI summary
A battery pack active fuse control apparatus includes a battery management system and a shunt resistor, where the battery management system includes a short-circuit current detect circuit and a short-circuit current process circuit that are constantly powered. The shunt resistor and an active fuse are connected in series with a power supply loop of a battery pack. The short-circuit current detect circuit is connected to the shunt resistor and the short-circuit current process circuit. The short-circuit current process circuit is connected to the active fuse. The short-circuit current process circuit, upon receiving the short-circuit overcurrent signal, controls the active fuse to break.