Battery SOH Estimation Using SOC-Aware Voltage Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for calculating the state of balance (SOB) by voltage in battery packs do not accurately reflect the state of charge (SOC) information, leading to distorted and SOC-dependent calculations of SOB, which affects the accurate estimation of a battery's state of health (SOH).
Innovation Solution
An apparatus and method that calculate the state of balance by voltage by reflecting SOC information, using a processor to set allowable limits, calculate voltage drop rates, and derive quantile orders to accurately estimate the SOH of a battery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If state of balance (SOB) by voltage is calculated based on voltage distribution of cells, then voltage balance can be assessed, but SOC information is not reflected causing distorted and SOC-dependent calculations
Solution Approach 1:
The patent transforms the SOB calculation from using only voltage parameters to using both voltage and SOC parameters. By introducing SOC as an additional parameter and establishing a correspondence relationship between voltage and SOC, the calculation becomes more comprehensive and less distorted by SOC variations.
Solution Approach 2:
The patent introduces a voltage-SOC correspondence relationship as an intermediary element that connects voltage measurements with SOC information. This intermediary allows the SOB calculation to indirectly incorporate SOC information without requiring direct SOC measurements, thus resolving the information loss problem.
2Reliability
If voltage deviation increases in battery packs, then cell imbalance occurs leading to overcharging or overdischarging, but safety risks and capacity limitations increase
Solution Approach 1:
The patent performs preliminary assessment of cell voltage balance using the improved SOB calculation method before dangerous conditions develop. By continuously monitoring and identifying imbalance trends early, the system can take preventive actions such as adjusting charging currents or activating balancing circuits before overcharging or overdischarging occurs.
Solution Approach 2:
The patent establishes a feedback mechanism where SOB calculations based on both voltage and SOC information continuously inform the battery management system. This feedback loop enables real-time detection of imbalance conditions and triggers appropriate control actions to maintain safety and prevent harmful events.
Data Source
AI summary
The present invention relates to an apparatus and method capable of estimating a battery state of health, and more particularly, provides an apparatus and method for more accurately calculating the state of balance by voltage of a battery to reflect SOC information as well as the voltage distribution of the battery, and measuring the state of health of the battery on the basis of the state of balance by voltage.