Multi-loop switched-capacitor equalizer based on LC resonant unit
The traditional series-parallel switched-capacitor equalizer produces impulse current during its operation,which will affect the reliability of the circuit.In order to improve the effect of this problem that acts on the circuit performance,as well as to increase the equalization speed of the circuit,a multi-loop switched-capacitor equalizer based on LC resonant unit was proposed.The LC resonant unit of this circuit is composed of equalizing capacitor in series with inductor,all the switches can operate in zero-current-switching mode.In this way,the switching losses will be effectively reduced,the impulse current can be effectively suppressed as well,so that the lifetime of switches can be prolonged,as well as the reliability of the equalizer is improved.In the proposed equalizer,two LC resonant units were used as the equaliza-tion branches between two energy storage groups,and as a result it can realize the equalization both be-tween battery cells and battery groups,which contributes to the equalization speed effectively with high e-qualization accuracy.The characteristics and working principle of the proposed equalizer were analyzed in detail,by means of building a simulation platform,the proposed equalizer was compared with the existing equalization circuits with similar type,and the advantage of the proposed equalizer on the improvement of equalization speed was verified.An experimental platform was set up to equalize five series-connected su-percapacitors.The experimental results verify that the proposed circuit can increase the equalization speed by 55.85%and has a significant inhibition effect on impulse current.
energy storage stackswitched-capacitorLC resonant unitgrouped equalizationzero-cur-rent-switchinginrush current
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维普
