Dual-layer active equalization control for series-connected batteries based on hybrid Cuk-flyback topology

Abstract

The inevitability of energy inconsistency among batteries within a battery pack poses operational challenges and potential safety hazards. It is imperative to swiftly harmonize the state of charge across all batteries to mitigate these issues. Addressing this concern, a dual-layer hybrid equalization topology is introduced, leveraging the Cuk circuit and flyback transformer. The battery pack is segmented into modules, with the Cuk circuit employed for intra-module equalization. Subsequently, the flyback transformer facilitates inter-module equalization. A multimodal equalization control strategy is devised, considering the status of individual modules to minimize repeated energy transfers between batteries. Simulation and experimental findings affirm that the proposed dual-layer active equalization control markedly mitigates the inconsistency among series-connected batteries, demonstrating rapid equalization and heightened efficiency.