A Multi-Functional Single-Stage Power Electronic Interface for Plug-In Electric Vehicles Application

This paper proposes a Zeta-derived non-isolated single-stage power electronic interface for on-board application of plug-in electric vehicles, which provides all modes (plug-in charging, propulsion, and regenerative braking) of vehicle operation. In addition, the proposed converter can charge the battery through universal input voltage range, i.e., 90–260 V due to buck/boost operations in plug-in charging mode. In propulsion and regenerative braking modes, the proposed converter operates as conventional boost and buck DC/DC converter, respectively. Compared to existing single-stage converters, the proposed converter has least components to those converters which have buck/boost operation in plug-in charging mode. A voltage/current stresses and loss analysis of the converter have been investigated for each mode of converter operation. Detailed simulation and experimental results are given to show the effectiveness of the proposed converter.     

Single-stage three-phase boost power factor correction circuit for AC–DC converter

This article presents a single-stage three-phase power factor correction (PFC) circuit for AC-to-DC converter using a single-switch boost regulator, leading to improve the input power factor (PF), reducing the input current harmonics and decreasing the number of required active switches. A novel PFC control strategy which is characterised as a simple and low-cost control circuit was adopted, for achieving a good dynamic performance, unity input PF, and minimising the harmonic contents of the input current, at which it can be applied to low/medium power converters. A detailed analytical, simulation and experimental studies were therefore conducted. The effectiveness of the proposed controller algorithm is validated by the simulation results, which were carried out using MATLAB/SIMULINK environment. The proposed system is built and tested in the laboratory using DSP-DS1104 digital control board for an inductive load. The results revealed that the total harmonic distortion in the supply current was very low. Finally, a good agreement between simulation and experimental results was achieved.     

一种新型原边反馈反激式数字控制LED驱动电源设计

设计了一种采用新型数字控制方法的原边反馈反激式LED恒流驱动电源。该电源电路运用拐点检测法测量副边电路放电时间,运用增量式PID算法调节恒流和功率因数,实现对电路的精确恒流控制和保持较高的功率因数。通过分析其控制原理,给出设计流程,最终基于FPGA实现控制,进行了样机设计和算法验证。实验结果表明所提出电路全工作范围内恒流精度达到6%,功率因数高于0.97,整机效率超过80%。本电路结构简单,控制精度高,具有较高的实用价值。     

推挽式单级电流源高频链逆变拓扑研究

提出了一种新型的适用于低压输入的实现隔离DC/AC变换的结构拓扑-- 推挽式单级推挽电流源高频链逆变电路拓扑,介绍了它的工作原理,给出了参数设计及器件选择准则.研制的48VDC输入220V/50Hz输出500VA的实验样机证明了该电路的可行性,并表明了该电路具有结构简洁、可靠性高、电气性能优及效率较高的特点,是低压输入逆变器的一种理想拓扑.     

858矿的爆破振动对相邻巷道的影响

为了避免858矿掘进爆破对相邻巷道的振动影响,对该矿巷道掘进爆破的地震波强度进行了监测。通过对监测数据进行萨道夫斯基公式回归,分析计算出适用于当地的K和a值;利用回归得到的萨道夫斯基公式进行计算,得到最大单段装药量与保护岩柱宽度的关系;根据858矿的安全生产设计要求,并考虑推进爆破对相邻巷道的影响,掘进爆破最大单段装药量为35.54kg。     

汽轮机复水泵国产化改型

乙烯装置裂解气压缩机组是乙烯行业最核心的设备,其汽轮机复水器凝渡泵对抗汽蚀能力要求很高。目前乙烯行业基本采用热井泵,由于结构缺陷和工艺波动的影响,故障偏多.中原乙烯装置裂解气压缩机组GB／T201凝液泵为热井泵,该设备的不稳定性长期困扰生产。经过充分技术分析与论证,从经济性和稳定性出发,将超汽蚀叶形的诱导轮技术应用于单级离心泵,进行设备改型.经与北京巡航高科技有限公司合作,按照满足GB3215—82和API两个标准的要求,对设备结构、材料、密封等进行设计、制造,确定了工艺性能,并对现场工艺流程进行了重新布局。该泵于2003年12月单机试运完毕后成为备用泵,至今已间断运行四个阶段,累计165天。从运行统计数据分析,此泵的机械状态和工艺性能良好,完全能够满足生产需要。对比两种型式复水泵的运行情况,可以得出结论：新增卧式复水泵的稳定性要远好于热井泵因此,此次复水泵国产化改型是成功的,消除了生产隐患,为装置长周期运行打下了良好的基础,同时也为今后新建乙烯裂解装置复水泵的选型提供了新路.     

Observation of Lithium Isotope Effect Accompanying Electrochemical Insertion of Lithium into Tin

Electrolysis of an organic electrolyte solution containing lithium ions was conducted to observe lithium isotope fractionation accompanying electrochemical insertion of lithium from the electrolyte to tin metal. The experimental setup consisted of a three-electrode electrolysis cell with a tin wire as cathode, lithium foils as anode and reference electrode and 1 M LiPF₆ dissolved in 1:2 volume ratio of ethylene carbonate and methylethyl carbonate as electrolyte and a power supply. The supplied electric energy was mostly consumed for the lithium insertion from the electrolyte to the tin cathode within the range of the cathode potential, relative to the reference electrode potential, from 0.05 V to 0.30 V. The single-stage separation factor increased with increasing cathode potential and seemed to asymptotically approach to the limiting value of 1.015 at 25®C, with ⁶Li being preferentially fractionated into tin metal.     

两种矩阵变换器的调制策略比较仿真研究

矩阵变换器是实现"绿色"电源变频器最具发展前景的技术方案,研究与开发矩阵变换器具有重要的意义。矩阵变换器可分为常规的单级和双级两种拓扑结构,文章通过仿真来综合比较这两种矩阵变换器的调制策略,即将单级矩阵变换器的开关函数调制策略、SVPWM调制策略与双级矩阵变换器的SVPWM的调制策略进行比较研究,并在双级矩阵变换器的逆变级采用了合理插入零矢量的调制方式。通过Matlab/Simulink仿真软件验证它们的调制策略的可行性,并进行综合比较与分析,证明了双级矩阵变换器具有更好的性能,对矩阵变换器及其调制策略的选取具体一定的参考价值。     

带有源缓冲的单级单相电流型逆变器

为了实现单级升压逆变,提出了一种带有源缓冲的单级单相电流型PWM逆变器,及其状态量限定下的输出电压反馈复合单周期控制策略,并对构成这种逆变器的电路拓扑、控制策略、关键电路参数设计、系统建模和仿真等进行了深入分析和研究,获得了重要结论。该逆变器电路拓扑主要由储能电感、有源缓冲电路、电流型单相逆变桥构成,存在三种工作模式和四种电路模态,通过三种工作模式的灵活切换达到限定储能电感电流和缓冲电容电压等状态量的目的,通过前馈储能电感电流和反馈输出电压的复合单周期控制实现输出正弦电压的稳定。1 kVA 100 V DC/220 V 50 Hz AC逆变器的原理实验结果表明,所提出逆变器能实现单级升压逆变,具有输出电压波形质量高、负载适应能力强和动态性能好的优点。     

组合式三相单级PFC变换器研究

提出了一种组合式三相AC/DC单级功率因数校正(PFC)变换器,该变换器能同时实现PFC,输入输出侧电气隔离和输出电压的调节。介绍了变换器的基本结构,提出了一种正弦波调制的策略,使得输入电流具有很好的正弦度并与输入电压之间无相位差,实现PFC的功能。在此基础上,结合传统的输出电压电流双闭环控制,达到稳定输出电压的效果。实验证明了理论分析的正确性。