Battery Pack State Analysis via Voltage Standard Score Scatter Plot
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Solution Overview
Problem
Current methods lack an effective way to visually assess the status of each battery pack in a cluster, as they are connected in series, making it difficult to identify and replace the worst-performing cells, which affects the safety and efficiency of energy storage power stations and new energy vehicles.
Innovation Solution
A method and system that acquire cell voltages, perform data cleaning, calculate voltage standard scores, plot scatter points based on mean and standard deviation, and perform closed curve fitting to analyze the state of each battery pack, allowing for timely identification of abnormal packs and issuing warnings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If battery packs are connected in series for charging and discharging, then the overall performance is determined by the worst-performing cell, but it becomes difficult to visually identify and assess the status of each individual battery pack
Solution Approach 1:
The patent transforms the one-dimensional voltage data into a two-dimensional visualization space by plotting voltage standard scores against their standard deviations. This dimensional transformation enables visual assessment of battery pack status while maintaining the series connection architecture for reliable energy storage operation.
Solution Approach 2:
The patent introduces voltage standard scores as an intermediary metric that mediates between raw voltage measurements and battery pack status assessment. This intermediary transformation allows indirect visualization of battery pack health without changing the series connection structure, resolving the contradiction between reliability and detectability.
2Productivity
If the worst-performing single cells are replaced, then the capacity of the entire battery pack can be increased, but the smallest unit that can be directly replaced is the battery pack
Solution Approach 1:
The patent segments the battery cluster into individually assessable units by calculating and visualizing performance metrics for each battery pack. This segmentation enables identification of specific underperforming packs that should be replaced, moving from blanket replacement of entire packs to targeted replacement of only the worst-performing units, thereby improving productivity while reducing complexity.
Solution Approach 2:
The patent changes the assessment parameter from raw voltage to voltage standard scores, which normalize performance across different battery packs. This parameter transformation enables direct comparison and identification of underperforming packs, allowing for capacity optimization through selective replacement based on quantified performance thresholds.
3Measurement precision
If data cleaning is performed on cell voltages, then the accuracy of voltage standard score calculation is improved, but the processing time and computational complexity increase
Solution Approach 1:
The patent applies partial data cleaning by focusing only on essential preprocessing steps needed for voltage standard score calculation, rather than comprehensive data cleaning. This selective approach maintains measurement precision while minimizing processing time, as the visualization method is robust to minor data variations and doesn't require exhaustive cleaning of all potential data issues.
Data Source
AI summary
The invention provides a method, a system and a terminal device for analyzing states of battery packs in a battery cluster. The method includes acquiring cell voltages of each battery pack in the battery cluster within a preset time; performing data cleaning on the acquired cell voltages; calculating a voltage standard score of each cell based on the cell voltages after data cleaning; calculating a mean value and a standard deviation of said voltage standard score; for each battery pack, plotting scattered points based on the mean value and the standard deviation, and performing closed curve fitting to the scattered points to obtain a closed curve; and analyzing the state of the battery pack based on the closed curve.