Robust control of a forward-converter active battery cell balancing

Control of balancing current is important for the safety of battery cells and active cell balancing (ACB) power electronics. This paper presents a method, based on quantitative feedback theory (QFT), for robust control of balancing current despite uncertainties, which exist in the battery cells' and power electronics' dynamical models. A remarkable feature of QFT is its interactive graphical design environment, which gives useful insights for the selection of desired robust stability and performance specifications, controller structure, and parameters tuning. Without loss of generality, this paper describes the QFT-based balancing current robust control system design for a forward-converter-based ACB. This paper also presents an average model of the forward-converter-based ACB circuit, operating in more than two modes; a case that has not been addressed in literatures. The effectiveness of the proposed QFT-based balancing current robust control system is evaluated experimentally.