A fault-tolerant voltage measurement method for series connected battery packs

•Developed a fault-tolerant voltage measurement method for series battery packs.•Developed matrix interpretation to demonstrate the viability of the method.•Developed methods to determine and isolate sensor or cell faults by location.•Validated the condition for valid sensor topology with proof.•Modeled and analyzed diagnostic confidence, cost and measurement accuracy.

This paper proposes a fault-tolerant voltage measurement method for battery management systems. Instead of measuring the voltage of individual cells, the proposed method measures the voltage sum of multiple battery cells without additional voltage sensors. A matrix interpretation is developed to demonstrate the viability of the proposed sensor topology to distinguish between sensor faults and cell faults. A methodology is introduced to isolate sensor and cell faults by locating abnormal signals. A measurement electronic circuit is proposed to implement the design concept. Simulation and experiment results support the mathematical analysis and validate the feasibility and robustness of the proposed method. In addition, the measurement problem is generalized and the condition for valid sensor topology is discovered. The tuning of design parameters are analyzed based on fault detection reliability and noise levels.