Pouch Cell Insulation Evaluation Using AC Impedance Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for evaluating the insulation of secondary battery pouch-type cells are limited in measurement reliability, often requiring separate apparatuses for insulation voltage and resistance tests, and struggle to detect infinitesimal damages to the packing material.
Innovation Solution
An apparatus and method that apply AC voltage to a secondary battery cell, using impedance analysis to determine insulation status, integrating voltage and resistance test functions into a single unit for improved measurement reliability and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate apparatuses are used for insulation voltage and resistance tests, then measurement coverage is comprehensive, but device complexity and cost increase
Solution Approach 1:
The patent combines insulation voltage test and insulation resistance test functions into a single integrated apparatus. The measurement module includes a signal generator that can output both DC voltage (for insulation voltage test) and AC voltage (for insulation resistance test), eliminating the need for separate test equipment and reducing overall system complexity.
Solution Approach 2:
The measurement module is designed with multi-functionality to perform both insulation voltage testing and insulation resistance testing using a single apparatus. The signal generator can switch between DC and AC output modes, and the analysis unit can process both types of test results, making the apparatus universally applicable for different insulation evaluation needs.
2Measurement precision
If traditional insulation testing methods are used, then equipment requirements are simple, but measurement precision for infinitesimal damages is insufficient
Solution Approach 1:
The patent employs AC voltage instead of traditional DC voltage for insulation resistance testing. This parameter change allows the measurement to detect infinitesimal damages more effectively because AC signals can penetrate and reveal subtle insulation breakdowns that DC measurements might miss, significantly improving measurement precision for detecting minor damages.
Solution Approach 2:
The patent replaces traditional mechanical insulation testing methods with electrical impedance analysis. By measuring the impedance characteristics of the battery cell under AC voltage, the system can detect insulation issues without physical contact or mechanical stress, improving both precision and non-invasiveness of the measurement.
3Reliability
If AC voltage impedance analysis is used, then measurement reliability is improved, but energy consumption increases
Solution Approach 1:
The patent applies AC voltage at controlled amplitude and duration sufficient to obtain reliable impedance measurements for insulation evaluation. The testing uses partial action (brief measurement periods) rather than continuous energy application, achieving adequate measurement reliability while minimizing unnecessary energy consumption beyond what is required for accurate detection.
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 proposed solution enhances measurement reliability by accurately detecting insulation breakdowns and damage levels in secondary battery cells using AC voltage impedance analysis, while also simplifying inspection processes and reducing costs.
Implementation Method 1
applying, by the measurement module, AC voltage to the cell, analyzing, by a controller, output signals in response to the applied AC voltage, calculating impedance based on the analyzed output signals
Data Source
AI summary
An apparatus for evaluating insulation of the secondary battery is configured to apply alternating current (AC) voltage to a cell of the secondary battery and to determine whether the corresponding cell is insulated through impedance acquired based on output signals in response to the applied AC voltage.