【摘要】 充电机是电动汽车发展的基础设施,LLC变换器因其良好的效率特性在电动汽车充电机中有着广泛的应用,但LLC变换器对电压增益比较敏感,同时电动汽车动力电池组的电压在充电过程中,变化范围很宽,会导致等效充电效率低,充电能耗高。为了解决这个问题,论文基于锂电池的充电特性曲线,以整个充电过程消耗的能量为优化指标,提出了反映充满电池所需要的电量多少的充电机充电效率评估函数。针对宽的电压输出范围和LLC变换器转换效率对电压增益敏感的矛盾,提出了一种三段式混合控制方式,根据不同的输出电压和功率,LLC变换器工作于常规的调频模式、谐振工作模式和超谐振频率谐振模式,达到以最少的耗能充满电动汽车动力电池的效果。通过损耗计算对等效效率与分段参数之间的关系进行了比较分析,对三段式控制器进行了优化设计;最后搭建了10 kW LLC变换器实验样机进行了验证。更多还原

【Abstract】 LLC converter is now used in the electric vehicle charger for excellent efficiency characteristics.In the other hand its narrow voltage gain characteristics impede its being widely used.The loss of LLC converter are analyzed with different working condition in the paper.And then one hybrid controller is introduced which combine with the sub-resonant-frequency FM mode fixed switching frequency and super-resonant-frequency FM mode to get high efficiency in wide voltage range.The equivalent efficiency with different subsection parameters control strategies are compared by loss calculation.Finally three control strategy are applied in a 10 kW LLC converter prototypes to verify the design method.更多还原