Hybrid Natural and Forced Active Balancing Control of Battery Packs State of Charge Based on Partnership for a New Generation of Vehicles

Abstract

Battery packs are widely used in electric vehicles, and their state-of-charge is one of the essential issues that affect the performances, whilst the balance between parallel and series cell of the battery pack always has an obvious effect. To enhance the working performance of the lithium-based power battery pack, a hybrid natural and forced active balancing control (HNFABC) strategy is proposed and adopted to the balancing circuit that is proposed in this work. These converters, which are advantageous in natural balancing and forced equalization, accelerate the balance speed of natural equilibrium in the final stage and protect the battery from being repeatedly charged and discharged. Simulation and experimental results show that HNFABC is not only simpler than other traditional balance control strategies but also faster in the equalization process. The idea of combining natural equilibrium and forced equilibrium can be inspired to be used in some related industries.

The control and evaluation method of the cascaded buck–boost converter for equalization on battery strings

“…7 Further development in the control of the topology is implemented to simplify the process and reduce the power loss on the switches. [8][9][10] Besides, a systemic evaluation method is presented in Shan et al, 11 in which various topologies could be evaluated by their average efficiency under the same situation. Another practical balancing strategy is proposed to mitigate the problem of the inconsistent battery capacity of lithium batteries in new energy vehicles in reference.…”

“…To handle this issue, a novel interleaved converter in which each module could work synchronously with a constant duty rate 7 . Further development in the control of the topology is implemented to simplify the process and reduce the power loss on the switches 8‐10 . Besides, a systemic evaluation method is presented in Shan et al, 11 in which various topologies could be evaluated by their average efficiency under the same situation.…”

Design and Implement of Staggered Parallel Lithium Battery Equalization Converter With Jumper Switches

“…The current of natural active balancing is low leading to a little time-consuming at the end of equalization. Yewen Wei et al proposed a hybrid forced and natural method in reference (Wei et al, 2018) that could relatively reduce the time of the equalization process. Then, the matrix solution of the working time of the equalizer switch array can directly obtain the switch control scheme in the independent equalizer, avoiding the energy circulation caused by the repeated conduction of the same group of switches in the independent converter (Wei et al, 2019b).…”