Power Battery Residual Energy Estimation for Mixed Cell Types
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Solution Overview
Problem
Existing methods cannot accurately estimate the residual energy of power batteries with multiple types of cells due to cell imbalance, limiting effective energy monitoring in electric vehicles and equipment.
Innovation Solution
A method to acquire residual energy by determining the available capacity and energy of each cell type, considering temperature and cell quantity, and summing these values to accurately calculate the battery's residual energy, while accounting for cell imbalance and energy state changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If energy estimation is made for a power battery pack with multiple types of cells using the same method as single-type cells, then the estimation process is simple, but the residual energy cannot be accurately estimated due to cell imbalance
Solution Approach 1:
The patent divides the power battery pack into multiple cell groups based on cell types (e.g., first cell group with first-type cells, second cell group with second-type cells). Each cell group is estimated separately using type-specific parameters and algorithms, then the results are combined. This segmentation allows accurate handling of cell imbalance while maintaining systematic efficiency.
2Measurement precision
If the available capacity of the power battery is determined by the minimum available capacity of all cells, then the cell imbalance effect is avoided, but the calculation complexity increases for multiple cell types
Solution Approach 1:
Instead of calculating the minimum across all individual cells (which would be complex for multiple types), the patent segments cells into type-based groups and determines the available capacity for each group separately using representative parameters. This reduces calculation complexity while maintaining accuracy by accounting for cell imbalance at the group level.
Solution Approach 2:
The patent uses copying by determining the available capacity of each cell group based on representative cells or averaged parameters of that type, then applying this copied value to calculate the total available capacity. This avoids complex individual cell analysis while preserving the essential imbalance characteristics.
Data Source
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AI summary
The embodiment of the present application provides an acquiring method and device of residual energy of a power battery. The acquiring method includes: acquiring an available capacity of a first type of cells and an available capacity of a second type of cells; determining a minimum available capacity of the available capacity of the first type of cells and the available capacity of the second type of cells as an available capacity of the power battery; determining available energy of the first type of cells in accordance with the available capacity of the power battery, a current temperature, and a quantity of cells of the first type of cells; determining available energy of the second type of cells in accordance with the available capacity of the power battery, a current temperature, and a quantity of cells of the second type of cells; and determining the sum of the available energy of the first type of cells and the available energy of the second type of cells as a quantity of residual energy of the power battery. The acquiring method is used for effectively and accurately acquiring the residual energy of a power battery with multiple types of cells.