Battery Impedance Monitoring for Secondary Battery Fault Detection
Solution Overview
Problem
Existing battery management systems face challenges in accurately detecting abnormalities in secondary batteries, particularly during rest periods and constant current operation sections, leading to reduced efficiency in abnormality detection.
Innovation Solution
A battery management system that includes an electrochemical impedance spectroscopy (EIS) measurement module, a processor to calculate real intercepts of impedance values, and an alarm module to notify abnormalities, enabling accurate detection of secondary battery abnormalities across all operation sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an equivalent circuit model (ECM) is used to estimate impedance, then the method is simple to implement, but the measurement precision deteriorates in rest period and constant current operation section
Solution Approach 1:
The patent changes the measurement parameters by applying AC signals at different frequencies to the battery terminals. By measuring impedance across multiple frequency points rather than using a single-frequency or model-based approach, the system achieves accurate impedance estimation in all operation sections including rest period and constant current operation, without relying on ECM simplifications.
2Measurement precision
If electrochemical impedance spectroscopy (EIS) measurement is performed, then the measurement precision of impedance is improved, but the device complexity increases
Solution Approach 1:
The battery management system integrates EIS measurement functionality into existing battery monitoring infrastructure. The same processor and basic measurement circuits used for voltage and current monitoring are extended to perform multi-frequency AC signal generation and impedance calculation, allowing one system to serve multiple functions without proportionally increasing complexity.
Solution Approach 2:
The system uses the battery's own operational characteristics and existing sensor data (voltage, current, temperature) to support EIS measurements. The processor leverages available measurement circuits and computational resources already present in modern BMS, eliminating the need for entirely separate dedicated EIS measurement hardware.
3Reliability
If continuous monitoring is performed across all operation sections, then the reliability of abnormality detection is improved, but the loss of time and energy increases
Solution Approach 1:
The system performs EIS measurements periodically at selected frequency points rather than continuously across all frequencies. By strategically choosing measurement intervals and frequency points based on battery operation state, the system maintains reliable abnormality detection while minimizing the time and computational resources required for measurements.
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 system improves the accuracy and efficiency of abnormality detection in secondary batteries, complementing vulnerabilities in existing methods based on equivalent circuit models, and enabling effective monitoring in various battery operations.
Implementation Method 1
an electrochemical impedance spectroscopy (EIS) measurement module that measures an EIS of a secondary battery
Data Source
AI summary
The present disclosure relates to a battery management system and a method for controlling the same. The battery management system according to an embodiment of the present disclosure may include an alarm module configured to provide an alarm in a designated manner; an electrochemical impedance spectroscopy (EIS) measurement module configured to measure an EIS of a secondary battery; and a processor configured to receive an EIS measurement result from the EIS measurement module, calculate real intercepts of impedance values for the secondary battery based on the received EIS measurement result, determine whether the secondary battery is abnormal based on the calculated real intercepts, and control the alarm module to provide an alarm notifying that the secondary battery is abnormal if there is an abnormality in the secondary battery as a result of the determination. The present disclosure may improve the accuracy and/or efficiency in abnormality detection of the secondary battery.