Verification of state-of-function algorithms for functional safety of lead batteries
Research Scientist, RWTH Aachen University
With increasing automated functions in todays and future vehicles, the functional safety of the low-voltage power supply including the lead battery as the main energy storage is getting increased attention. Advanced driver assistance systems, for example, rely on a secured availability of power for a certain period of time as the driver needs a certain lead-time to take over full control. Therefore, the safe determination of the state-of-function of the lead battery and the early detection of an impending failure are crucial. This presentation will discuss the need for a short-term diagnosis for the state-of-function with restricted use of historical data to prove its reliability. Instead, it should rely on stimuli for tracking of the battery state. These stimuli include frequent AC small-signal current ripples and occasional discharges for parameter determination. Based on this concept, a verification approach will be presented using laboratory measurements on a large selection of battery types and state-of-health conditions. The methodology and measurements are agreed and organised by a working group supported by the Consortium for Battery Innovation and includes a database for the measured data to which the members are contributing. The presentation will conclude with first results of the measurements and the verification process to support the suitability of the approach.
Jonathan Wirth has been working on lead‒acid batteries since 2013. At present, he is a research scientist at the Chair for Electrochemical Energy Conversion and Storage Systems (ESS) at the Institute for Power Electronics and Electrical Drives (ISEA), RWTH Aachen University. Jonathan’s main research topics include the dynamic charge-acceptance and water loss of automotive lead‒acid batteries under real-world conditions.