共查询到20条相似文献,搜索用时 171 毫秒
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构成高频开关电源产品的电子元器件有三大类:一是高频变压器和电感器组件使用的各种功率铁氧体磁性材料、金属铁粉芯磁环等;二是工作在开关脉冲状态的高频、高压大电流MOSFET和IGBT,以及低频大功率电网输入整流器等电力电子器件;三是控制系统选用的各类专用集成电路芯片,如PWM、光电耦合器、驱动IC、运算放大和电压比较IC、精密基准IC等。 相似文献
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研究了电压型高频链逆变器的拓扑及控制方式。选用了全桥全波式高频链逆变器作为主电路,采用双极性双调制波控制方案解决双向电压型高频链逆变器的固有电压过冲问题。理论分析了电路拓扑和控制策略的合理性和变换器开关器件实现软开关的可行性。设计了基于双极性双调制波控制的软件程序及数字PI控制器算法的TMS320F2812的闭环控制系统。实验结果表明,高频逆变桥开关管实现了ZVS开通,周波变换器开关管实现了ZCS关断,高频链逆变器输出高质量的正弦波电压,证明了基于DSP控制的双极性双调制波控制模式的高频链逆变器可行性。 相似文献
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针对直流微网DC/DC变换器的软开关实现机理进行了探讨。首先介绍了微网的应用背景,阐述了直流微网相对于传统交流微网的优势及变换器高频化的意义,然后对直流微网系统的基本结构进行了简要概述,并分析了成功实现软开关的几个基本条件。结果表明软开关技术对于微网变换器的高频化有着重要意义,合理选择死区时间是软开关成功的关键。 相似文献
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高频电源模块的噪声主要来自功率变换和输出整流滤波电路。ZVZCSPWM全桥变换器实现了开关管的软开关,但其输出整流二极管不是工作在软开关状态,输出整流二极管在换流时,变换器的副边存在寄生振荡。本文讨论其产生原因及抑制办法。 相似文献
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Kazuhiro Umetani Fujiyuki Iwamoto Keisuke Yagyu 《IEEJ Transactions on Electrical and Electronic Engineering》2014,9(3):315-323
This paper proposes a novel soft‐switching boost chopper with a lossless LC snubber, suitable for improving the efficiency of the electric propulsion system of vehicles. The snubber circuit is beneficial owing to the following features: zero‐current switching turn‐on and zero‐voltage switching turn‐off are achieved regardless of the operating conditions; it requires only one additional switch with smaller current rating compared to the main switch; the additional switch can be controlled by basic arithmetic; and the main switch is free from additional voltage or current stress caused by the soft‐switching operation. Along with theoretical discussions, experimental results are also presented on the circuit behavior and the resulting improvement of the energy conversion efficiency. These results show the usefulness of the chopper for improving the efficiency of electric vehicles. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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电动汽车永磁同步电机驱动系统的研究 总被引:9,自引:1,他引:9
根据电动汽车的性能要求,从永磁同步电机的模型出发,分析了不同磁密分布和电流波形下的电机感应电势和转扭,以及不同控制方式对系统性能的影响,并论述了系统控制的基本原理和系统低速回馈制动的方法,最后给出了计算机仿真和试验结果。 相似文献
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In this paper, a soft switching DC–DC converter is presented for a hybrid energy storage system (HESS) in an electric vehicle (EV), using fixed boundary layer sliding mode control (FBLSMC) and variable switching frequency modulation. This strategy is aimed at improvement of the transient performance, energy transfer efficiency and system robustness for the HESS which is composed of a battery, an ultracapacitor (UC) and a bidirectional DC–DC converter. The state-space model of such DC–DC converter is firstly established involving all operating modes and system uncertainties. The FBLSMC scheme is proposed for the satisfactory voltage/current tracking despite system uncertainties. It can guarantee the system robustness and avoid the chattering existing in conventional sliding mode control (CSMC). In order to ensure the soft switching under transient load variations, a variable switching frequency modulation method is introduced into the controller. Finally, experimental results confirm that (1) within the full-load range the efficiency of the DC–DC converter with variable switching frequency is ~96% in contrast to 90% efficiency at hard switching, and (2) the energy delivered by the UC follows the reference closely for EVs. 相似文献
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大规模的电动汽车充电负荷具有大功率、波动性和不确定性的特点,将给电网带来峰值增高、电压波动等不利影响。为了降低电动汽车充电负荷对电网的不利影响,建立了电动汽车充换电站换电池的充电优化模型。通过对换电池在充电过程中充电时间、充电功率和电池电量的实测数据进行拟合,得到了电动汽车换电池的充电特性。以此为基础,建立了电动汽车充换电站的换电池有序充电模型,该模型在满足充电机数量、电动汽车对换电池的需求、充换电站容量和变电站容量约束的前提下,最小化所属变电站负荷曲线的离差平方和,并应用遗传算法实现了有序充电模型的快速求解。以山东省某电动汽车充换电站为算例,证明了该模型的快速性、正确性和有效性。 相似文献
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This paper proposes a methodology to determine separately the peak and continuous power ratings of a switched reluctance motor (SRM) for electric propulsion of an electric vehicle (EV). The input data consist of the EV main specifications (e.g., rated and maximum velocities, vehicle mass, driving schedules). Estimation of the variations of the copper and core losses with vehicle speed and motor output power is necessary to calculate the continuous power rating. The loss variations are estimated by considering the SRM operation principles and assuming (if not known) loss values at only one operating point. Using the obtained expressions, the SRM efficiency contours can be then estimated before designing and building the SRM. The SRM thermal duty can be reduced by appropriate choice of the individual loss components in the design process 相似文献