Battery Cell Voltage Sensing with Switched Current Isolation
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Solution Overview
Problem
Existing battery management systems face inaccuracies and reliability issues in measuring battery cell voltages due to shared sensing and driving current lines, which cause voltage errors due to internal resistors in the battery module.
Innovation Solution
A battery management apparatus and system that temporally separates the sensing line and driving current line by using a switching unit to control electrical connections and a controller to manage the on/off state of the switching unit during voltage measurement, utilizing an internal resistor and a power supply unit with capacitors to maintain accurate voltage measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If battery modules are connected in parallel to increase current output, then the current output capability is improved, but the internal resistance increases and power loss increases
Solution Approach 1:
The battery system is divided into multiple battery packs, each containing series-connected battery modules. This segmentation allows the system to achieve high current output through parallel connection of packs while maintaining low internal resistance within each pack through optimized series configuration, thereby reducing overall power loss.
Solution Approach 2:
The patent transitions from a single-dimensional parallel connection approach to a multi-dimensional configuration where battery packs are arranged in both series and parallel combinations. This dimensional change enables simultaneous optimization of voltage, current, and internal resistance characteristics to minimize power loss while maximizing power output.
2Quantity of substance
If multiple battery packs are connected in parallel, then the system capacity is improved, but the management complexity increases
Solution Approach 1:
Multiple battery packs are merged into a unified management system with a central controller that coordinates all packs. This combining approach increases system capacity while managing complexity through centralized control, where the single controller handles monitoring, balancing, and protection for all parallel-connected packs, avoiding the need for separate management systems for each pack.
Solution Approach 2:
The battery management system is designed with multi-functional capabilities that can handle various tasks across multiple packs through a single controller. This universal design reduces management complexity by consolidating functions such as state monitoring, charge balancing, and safety protection into one integrated system that scales with the number of packs.
3Quantity of substance
If inconsistent battery modules are connected in parallel, then the available battery capacity is limited by the weakest module, but using only consistent modules reduces system utilization
Solution Approach 1:
The battery system is segmented into modular packs that can be independently configured and managed. This segmentation allows inconsistent modules to be distributed across different packs rather than forcing all modules into a single parallel configuration, enabling the system to utilize the total capacity of all modules while maintaining balanced performance through pack-level management.
Solution Approach 2:
The battery management system implements dynamic monitoring and control that adjusts operating parameters based on the state of individual modules and packs. This dynamic approach allows the system to optimize performance by actively managing inconsistent modules, redistributing loads, and adjusting charge/discharge rates to maximize overall system utilization rather than being limited by the weakest module.
Data Source
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AI summary
A battery management apparatus according to an embodiment disclosed herein includes a switching unit configured to control electrical connection with a battery module and a controller configured to measure a voltage of a battery cell included in the battery module and to control a driving current transferred from the battery module by controlling on/off of the switching unit when the voltage of the battery cell is measured.