Observability Degree Criteria Evaluation For Temperature Observability In A Battery String Towards Optimal Thermal Sensors Placement

Temperature measurement in battery strings is most critical not just for safety reasons but also to restrain operating conditions that would reduce the battery lifetime. However, placing a thermal sensor in each individual battery cell within a battery string implies cost and space. In this paper, the optimal number and location of thermal sensors in a forced-cooled battery string is discussed. Different observability Gramian-based observability criteria are used to evaluate and compare observability degree of placement of different number and different combinations of sensors locations in the battery string. The observability degree is further verified by evaluating the observer performance for the different sensor locations. The most suitable observability criteria to ascertain the optimal location of such thermal sensors are recommended.