A Novel Internal Short Circuit Fault Diagnosis Method for Lithium-ion Batteries Based on Battery Equalization Information

Thermal runaway caused by internal short circuit (ISC) faults is the main safety issue of lithium-ion batteries. Although ISC fault diagnosis is crucial for reducing this risk, existing diagnostic methods are plagued by problems such as excessive computational complexity, inaccurate results, and even complete failure under battery balance conditions. To address these challenges, an ISC fault diagnosis method based on active battery balancing has been proposed, which only utilizes the balanced energy information. This method can perform ISC fault detection and quantification with extremely low computational complexity. Specifically, a fault diagnosis method for ISC with integrated driving and charging modes was developed by using a balanced topology based on flyback converters, achieving quantitative analysis of ISC resistance. The effectiveness of this method was verified through a series of experiments. The experimental results show that the ISC fault diagnosis can be completed in the shortest time of 4801 seconds, and the ISC resistance estimation error is mainly within 2%. It is worth noting that this method effectively overcomes the inherent limitations of traditional ISC diagnostic methods in battery balancing scenarios, thereby providing a reliable technical solution for ISC fault detection in battery management systems.