Battery Protection Circuit for Micro Short Detection
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Solution Overview
Problem
Existing power storage devices fail to detect micro short circuits in secondary batteries, leading to potential safety hazards such as abnormal heat generation and accidents, as conventional protection circuits do not monitor voltage and current within the recommended range, allowing instantaneous large currents due to micro short circuits.
Innovation Solution
A novel battery control circuit and protection circuit that includes a first circuit portion for controlling charging, a second circuit portion for generating voltage and current, and a third circuit portion with a comparator to detect micro short circuits by comparing voltages, utilizing transistors with specific channel formation regions and capacitors to retain signals and calculate potential differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional protection circuits are used to limit charging and discharging, then basic battery protection is achieved, but micro short circuits cannot be detected leading to safety hazards
Solution Approach 1:
The patent replaces conventional voltage threshold comparison with a time-constant-based detection system. By measuring the charging time required to reach a specific voltage threshold and comparing it against a reference time constant, the system can detect micro short circuits that conventional circuits miss. This substitution of detection methodology enables reliable micro short circuit detection while maintaining basic protection functions.
Solution Approach 2:
The patent introduces a capacitor as an intermediary element in the charging circuit. The capacitor's charging time constant serves as a mediator between the power source and battery, allowing the system to indirectly detect micro short circuits through timing measurements. This intermediary approach enables detection without requiring direct measurement of tiny leakage currents.
2Volume of moving object
If thinner separators are used to reduce battery size, then battery dimensions are reduced, but micro short circuits occur more easily
Solution Approach 1:
The patent implements preliminary detection of micro short circuits before they can cause harmful effects. By continuously monitoring charging time constants and detecting anomalies early in the charging process, the system can identify potential micro short circuits in thin-separator batteries before they lead to thermal runaway or other safety incidents. This preliminary action compensates for the increased risk inherent in thinner separator design.
3Productivity
If high-speed power feeding at high voltage is implemented, then charging speed is improved, but micro short circuits occur more easily
Solution Approach 1:
The patent implements a feedback mechanism that continuously monitors the charging time constant and adjusts charging parameters accordingly. During high-speed charging, the system measures the time required to charge the capacitor to the threshold voltage and compares it against expected values. If deviations indicate a micro short circuit, the system can reduce charging current or terminate charging, thus enabling high-speed charging while mitigating the increased risk of micro short circuits.
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 enables early detection of micro short circuits, improving safety by preventing abnormal heat generation and reducing power consumption, while also allowing for evaluation of State of Health (SOH) of secondary batteries.
Implementation Method 1
a third circuit portion with a capacitor, and a comparator. The comparator has a function of comparing the first voltage and the second voltage
Implementation Method 2
utilizing transistors with specific channel formation regions and capacitors to retain signals
Implementation Method 3
a third circuit portion with a capacitor, and a comparator. The comparator has a function of comparing the first voltage and the second voltage
Data Source
AI summary
A battery control circuit with a novel structure, a battery protection circuit with a novel structure, and a power storage device including either of the battery circuits are provided. The power storage device includes a first circuit portion, a second circuit portion, a third circuit portion, and a secondary battery; the first circuit portion has a function of controlling charging of the secondary battery; the first circuit portion has a function of supplying the start time and the end time of the charging of the secondary battery to the third circuit portion; the second circuit portion has functions of generating a first voltage and a first current and supplying them to the third circuit portion; the third circuit portion has a function of generating a second voltage by charging the first current in a capacitor; and the third circuit portion has a function of comparing the first voltage and the second voltage.