Battery management system with testing protocols for kW-class vanadium redox flow batteries

A Battery Management System (BMS) for a kW-class vanadium redox flow battery (VRFB) was developed and is reported in this paper. This kind of BMSs is intrinsically different from those of solid-state batteries, due to the very different battery operating principle. Such BMS was built entirely in-house around a desktop computer provided with LabVIEW software which results in an expandable and flexible system capable of providing the battery with SCADA functions. It acquires and processes all data generated by the thermo-fluid and electric sensors, which are necessary to carry out the subsequent analyses. Moreover, this BMS also creates the feedback signals for controlling every operation, including experiments such as polarization curves plotting and efficiency computation. As regards polarization curves, this algorithm implements an experimental protocol that allows to obtain such performance in reproducible conditions and possibly comparable with those of similar stacks. The efficiency computation algorithm computes the energy absorbed (or delivered) by the battery while acquiring and controlling all signals so as to ensure safe conditions. The management of signal between stack and BMS includes the galvanic insulation of cell and stack voltages, consisting of multiple opto-isolators and a DC/DC transformer.