Multi-fault online detection method for series-connected battery packs

The safety problem is an important factor restricting the development of electric vehicles which caused by many kinds of faults in the power battery pack. How to diagnose the multiple faults in the battery pack becomes the focus and difficulty. This paper proposes a multi-fault detection method for battery management systems. Instead of measuring the voltage of individual cells, an interleaved connected voltage measurement method is presented which considers the effects of the contact resistance and reliability of voltage sensors. A matrix interpretation is developed to demonstrate the viability of the proposed sensing topology. A methodology is introduced to isolate fault type among sensor fault, connection fault and cell abuse fault, and then determine where the failure occurs. Measurement noise and battery inconsistency have been considered in MATLAB & Simulink simulation model. Simulation results shows the mathematical analysis of distinguishing three type faults is correct. The feasibility of proposed method is validated.