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This article proposes an active balancer, which features bidirectional charge shuttling and adaptive equalization current control, to fast counterbalance the state of charge (SOC) of cells in a lithium-ion battery (LIB) string. The power circuit consists of certain bidirectional buck-boost converters to transfer energy among the different cells back and forth. Owing to the characterization of the open-circuit voltage (OCV) vs SOC in LIB being relatively smooth near the SOC middle range, the SOC-inspected balance strategy can achieve more precise and efficient equilibrium than the voltage-based control. Accordingly, a compensated OCV-based SOC estimation is put forward to take into account the discrepancy of SOC estimation. Besides, the varied-duty-cycle (VDC) and curve-fitting modulation (CFM) methods are devised herein to tackle the problems of slow equalization rate and low balance efficacy, which arise from the diminution in balancing current as the SOC difference between the cells decreases in the later duration of equalization especially. The proposed strategies have taken the battery nonlinear characteristic and circuit parameter nonideality into account and can adaptively modulate the duty cycle with the SOC difference to keep balancing current constant throughout the balancing cycle. Simulated and experimental results are given to demonstrate the feasibility and effectiveness of the same prototype constructed. Compared with the fixed duty cycle and the VDC methods, the proposed CFM has the best balancing efficiency of 81.4%, and the balance time is shortened by 27.1% and 18.6%, respectively. 相似文献
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以Linear公司的LT8705为控制核心,针对宽范围直流输入、稳压输出用电设备的供电要求,研制了一款高性能的同步整流buck-boost模块电源。该模块电源集成了DC-DC单元、驱动电路单元、电压及电流环路工作状态反馈单元、电流控制功能单元,同时,对电路中的关键电路参数进行了计算。实验结果表明,该模块电源实现了预期功能,满足应用要求。 相似文献
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基于超级电容储能的统一负荷质量调节器的研究 总被引:4,自引:3,他引:1
以电能质量问题责任分离为出发点,将电能质量划分为供电质量和负荷质量.针对解决负荷质量问题,提出了一种基于超级电容储能的统一负荷质量调节器.调节器以并联型APF拓扑为基础,在其直流母线上配置了新颖的由双管升降压斩波电路控制的超级电容储能系统,利用超级电容的储能,调节器能够实现快速补偿负荷的波动功率或突变功率,使系统侧只需向负荷提供单位功率因数、电流波形正弦、没有冲击的有功功率.仿真研究验证了统一负荷质量调节器拓扑及其控制策略的正确性和有效性,能够有效改善负荷品质,提高电能质量. 相似文献
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为提高无刷直流电动机的控制性能,减小电机换相区间转矩脉动,提出基于双向Buck-Boost供电的无刷直流电动机换相转矩脉动的抑制方法。分析了双向Buck-Boost控制模式和该电路的输出电压控制算法,仿真结果验证了电压控制算法及抑制电磁转矩脉冲的有效性。 相似文献
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针对现有"电力电子技术"教材中普遍存在的对Buck-Boost变换器的分析不完整等问题,本文基于伏秒平衡原理对Buck-Boost变换器进行了全面分析,推导出变换器全范围的输入输出电压关系,电流连续模式(CCM)和断续模式(DCM)的临界工作条件以及电路各参数对电流纹波和电压纹波的影响等。本文一方面有助于更全面深入地理解Buck-Boost变换器的工作原理及特性,另一方面有助于DC-DC变换器分析方法的统一,具有一定的教学指导意义。 相似文献
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摘要对目前矩阵变换器存在电压传输比低的缺陷进行了研究,提出了一种新型的杯为buck-boost矩阵变换器(BBMC)的电路拓扑结构。介绍了该拓扑结构的基本构成及其工作原理,分析推导了其电压传输比与占空比之间函数关系的解析表达式,阐述了离散滑模控制策略的基本设计方法,最后通过仿真对其有效性和可行性进行了验证。结果表明:该新型拓扑结构能实现输出电压和频率的任意调节,其电压传输比既可大于1,也司小于l,且直接输出高品质的正弦波而无需滤波环节,谐波含量小,从而有效解决了传统矩阵变换器申,压传输比低的难题,具有较好的应用价值。 相似文献
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In this paper, a new modified fuzzy Two-Level Control Scheme (TLCS) is proposed to control a non-inverting buck-boost converter. Each level of fuzzy TLCS consists of a tuned fuzzy PI controller. In addition, a Takagi–Sugeno–Kang (TSK) fuzzy switch proposed to transfer the fuzzy PI controllers to each other in the control system. The major difficulty in designing fuzzy TLCS which degrades its performance is emerging unwanted drastic oscillations in the converter output voltage during replacing the controllers. Thereby, the fuzzy PI controllers in each level of TLCS structure are modified to eliminate these oscillations and improve the system performance. Some simulations and digital signal processor based experiments are conducted on a non-inverting buck-boost converter to support the effectiveness of the proposed TLCS in controlling the converter output voltage. 相似文献
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文章提出了一种用电解电容和三相变换电路构成的双电层电容器仿真器模型,阐述和分析了该仿真器模型的工作原理,并在PSIM6.0环境下对仿真器模型进行了计算机仿真,仿真结果验证了所提出的仿真器模型的正确性,它能够用小容量的电解电容有效地模拟大容量的双电层电容器。 相似文献