基于DSP的双极性双调制波高频链逆变器实现

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。     

全桥高频链逆变电源的混合控制策略研究

针对全桥高频链逆变器的控制,提出一种混合式正弦脉冲脉位调制控制策略,高频变压器传递SPWM波,通过对输出电压与电流进行过零比较与逻辑组合,得到周波变换器高频和低频混合驱动脉冲.介绍了全桥高频链逆变器的工作原理,并应用Matlab仿真软件对电路控制算法进行了仿真,同时制作了容量为200VA的实验样机.仿真和实验结果验证了所提控制方案的可行性与正确性.     

全桥电流源高频链逆变器

全桥电流源高频链逆变器基于Ｆｌｙｂａｃｋ变换器,由全桥高逆变器、高频变压器和调波变换器三部分组成。其高频变压器不仅能实现电了事离和电压增益的调整功能,而且还能存储能量。该逆变器解决了电压源高频链逆变器固有的电压过冲冲问题,降低了周波变换器的开关损耗,简化了高频变压器的结构,减低了逆变器的开关电压应力。本文介绍了其拓扑结构,工作原理、控制方案和简要的设计,仿真结果和机机的实验结果证明逆变器具有下述估     

串联谐振电流源高频链正弦波逆变器的工作原理和控制方法

提出一种新型的串联谐振电流源模式隔离的高频链正弦波逆变器拓扑结构,详细介绍了其工作原理。结合该逆变器的控制难点,采用适于该逆变器拓扑运行特色的控制策略及四象限逻辑组合方式,并给出了谐振槽的参数确定方法。在48V直流输入、220V/50Hz交流输出的1kW实验样机上进行实验,实验结果验证了该逆变器控制方案及实施方法的正确性。同时通过周波变换器结构的变形,构成了各具特色的拓扑簇。     

高频链中高频变压器的分析与设计

高频链逆变技术用高频变压器代替传统逆变器中笨重的工频变压器，大大减小了逆变器的体积和重量。在高频链的硬件电路设计中，高频变压器是重要的一环。叙述了高频变压器的设计过程。实验结果证明该设计满足要求。     

高频链技术的发展与应用

介绍了高频链技术在电压源型、电流源型和直流变换器型三种高频链逆变电源中的发展和应用，给出了各自的框图及电路拓扑结构。着重介绍了三相双向电压源型高频链逆变器的电路结构及其工作原理，同时还介绍了几种降低三相高频链逆变器电路功率损耗的方法。     

全桥电流源高频链逆变器

全桥电流源高频链逆变器基于Flyback变换器,由全桥高频逆变器、高频变压器和周波变换器三部分组成。其高频变压器不仅能实现电隔离和电压增益的调整功能,而且还能存储能量。该逆变器解决了电压源高频链逆变器固有的电压过冲问题,降低了周波变换器的开关损耗,简化了高频变压器的结构,减低了逆变器的开关电压应力。本文介绍了其拓扑结构、工作原理、控制方案和简要的设计。仿真结果和样机的实验结果证明该逆变器具有下述优点：紧凑的拓扑结构、简单的控制方案和高频变压器结构、良好的动态响应、带非线性负载能力和低开关电压应力。     

光伏并网逆变器控制系统的研究

介绍了一种SPWM光伏并网高频链逆变器的控制策略,利用UC3879的控制功能实现了单极性SPWM移相控制,将光伏电池电压逆变成标准的正弦单相220V/50Hz交流电压,并保证了输出电流与电网电压同频同相。装置简单,易于高频化,能实现无冲击并网。     

一种新型数字SPWPM逆变器

针对电压型高频链逆变器的控制,论述了一种新型数字正弦脉宽脉位调制(SPWPM)控制策略,分析了该控制策略的工作原理,并利用C8051单片机实现了该控制系统的算法.样机实验结果表明,采用该控制策略的逆变器克服了传统SPWM模式逆变器的缺点,既具有高频电气隔离功能,又有电路拓扑简洁等优点.实验结果也证实了该逆变器及其控制系统的可行性和有效性.     

一种低压燃料电池用逆变器的设计

研制了一种适用于低电压大电流输入的具有高频链燃料电池逆变器,详细介绍了这种逆变器的电路拓扑结构、控制策略和实现方法。该逆变器由前级Boost型推挽变换器和后级DC/AC逆变桥构成,为有效地提高逆变器的效率,在实际中采取了多种措施。研制了一台12V/50Hz/1kW的样机,通过工业现场中实际运行,表明该逆变器电气性能优良,为该逆变器在低压大电流工况下的应用提供了一种理想解决方案。     

Users' Needs Lighting, Start-Up Power, Transportation, Mechanical Utilities, Heating, Refrigeration, and Production

The needs for emergency and standby power to enhance industrial and commercial power systems are frequently left wanting due to ignorance of the needs or of the systems available to satisfy the needs. This paper discusses various situations which require or desire emergency or standby power and mentions suitable systems for each application. The areas discussed include lighting, start-up power, transportation, mechanical utilities, heating, refrigeration, and production.     

光、城市、生活、未来……——世博轴及地下综合体工程艺术灯光景观

工程介绍 世博轴及地下综合体工程（简称世博轴）位于浦东世博园核心区。南起耀华路,跨雪野路、南环路、北环路、及浦明路,到滨江世博公园。     

Grades, Quizzes, Motivation, and Computers

The following paper describes the use of a simple FORTRAN computer program that may be used to determine course grades. The program is based on processing a set of IBM punched data cards. Each card contains the name of a student and all of his grades, including the final examination grade. The program may also be used to predict the final examination grade, based on previous quiz grades, and then, in turn, to predict the final course grade. It is thus possible to use this program periodically throughout the entire semester in order to provide the student, as well as the instructor, with a measure of his progress.     

Dual-rotor, radial-flux, toroidally wound, permanent-magnet machines

A novel machine family-dual-rotor, radial-flux, toroidally wound, permanent-magnet (RFTPM) machines-is proposed in order to substantially improve machine torque density and efficiency. After the principles of operation, configurations, and features are discussed, the machine design and optimization guidelines are given. A prototype has been designed, built, and tested. The measured torque density of the prototype, which well matches the design value, is almost three times of that of the induction machine with the same power of 3 hp and speed. Meanwhile the efficiency is still kept high and the material cost is kept low by using ferrite magnets. Three novel approaches are proposed to reduce the cogging torque in the RFTPM machines, whose validity is verified by finite-element analysis results and experimental measurements.     

A new soft-switched, thyristor-based, regenerative, quasi-resonant,current regulated inverter

A variety of soft-switching techniques have been proposed to reduce the switching losses and EMI problems that occur with higher switching frequencies in hard-switched converters. In this paper, a new, quasi-resonant, soft-switched, three-phase inverter is presented which uses 12 thyristors as the power electronic switches, and hence has potential for use in high-power applications. The converter is fully current-regulated, suitable for high-performance motor drive applications, and is capable of 4-quadrant operation to allow regeneration back into the DC supply. The operation and the control of the inverter are described in detail and simulation and experimental results are presented     

Industrial system grounding for power, static, lightning, andinstrumentation, practical applications

Practically every structural steel building erected for industrial use incorporates reinforcing steel bars installed in the concrete footings. This, without any additional effort, constitutes a grounding electrode. The quantity of electrodes is directly related to the building area. When the structural steel framework is erected and interconnected, these electrodes are also interconnected in a parallel arrangement. Similarly, high-voltage metal transmission towers are installed using a metal footing base embedded in a concrete filled hole. The four tower legs are effectively in parallel and offer an adequate low ground resistance such that additional electrodes are generally not required. This brings us to the main point: the reinforced concrete footings, reinforced concrete grade beams, and other reinforced concrete structures provide, with a little work, an effective, reliable, and cost attractive system grounding vehicle