ZCS-PWM boost rectifier with high power factor and low conduction losses

A new single-phase high power factor rectifier is proposed, which features regulation by conventional pulsewidth modulation (PWM), soft commutation, and instantaneous average line current control. A new zero-current-switching PWM (ZCS-PWM) auxiliary circuit is configured in the presented ZCS-PWM rectifier to perform ZCS in the switches and zero-voltage-switching (ZVS) in the diodes. Furthermore, soft commutation of the main switch is achieved without additional current stress by the presented ZCS-PWM auxiliary circuit. A significant reduction in the conduction losses is achieved, since the circulating current for the soft switching flows only through the auxiliary circuit and a minimum number of switching devices are involved in the circulating current path and the proposed rectifier uses a single converter instead of the conventional configuration composed of a four-diode front-end rectifier followed by a boost converter. Seven transition states for describing the behavior of the ZCS-PWM rectifier in one switching period are described. The PWM switch model is used to predict the system performance. A prototype rated at 1 kW, operating 60 kHz, with an input ac voltage of 220 V/sub rms/ and an output voltage 400 V/sub dc/ has been implemented in laboratory. An efficiency of 97.2% and power factor near 0.99 has been measured. The analysis and design of the control circuitry are also presented.     

直流28V2A固态功率控制器的初步设计

固态功率控制器是利用功率型固体器件的导通与截止来控制功率电路的通断。本文提出了额定断开电压为直流28V,额定导通电流为2A 安的固态功率控制器的一种具体电路的设计。对电路的原理及元件选择作了说明和分析,采用消颤抖电路可消除由于机械开关触头的颤抖而引起的误动作,提高电路的可靠性。     

Impact Potential of New Power Electronic Technologies

New technological advances in the area of power electronics are having an increasing impact on the design of aerospace control systems. These next generation power components promise improved system performance through increased electronic efficiencies. Applying state-of-the-art packaging concepts as an integral part of the system design will allow these devices to be utilized in a space efficient and reliable manner. The first portion of this paper looks at two such next generation components. The first is a High Voltage Integrated Circuit (HVIC) that provides a bridge between the low voltage controller logic and the high voltage motor winding invertor. This device achieves size reduction and an increase in reliability through integration of low and high voltage logic networks on a single integrated circuit. The second is the Insulated Gate Transistor (IGT). This device provides a high voltage switch with MOS-like drive characteristics. The present and future expectations of these power devices are discussed. This paper then looks at new packaging techniques for power devices. The impact of parasitic circuit effects have significant impact on power circuit performance. Finally, this paper looks at an example control application. The design is that of a permanent magnet motor driven actuator. The drive motor uses 270 vdc for supply voltage. Within the intelligent system controller, is the capability to control the current demands of the motor. The new power electronics devices are making the design feasible in both thermal and volume efficiency. This topic includes projected controller sizing into the 1990s.     

压气机静子叶片转角主备控制器转换装置改进

为了确保某型航空发动机高压压气机可调静子叶片转角控制系统主备控制器转换的可靠性,对系统原有的控制器转换装置进行了改进,加入了新的转换机构.仿真计算结果表明,若数字电子控制器故障后,未按照预定要求输出0脉冲占空比,而输出了固定的非0脉冲占空比信号或随机的不可预测的脉冲占空比信号,原系统的正常工作将受到较严重的影响;而采用...     

MULTI-CONTROLLER STRUCTURE OF SUPERMANEUVERABLE AIRCRAFT

Supermaneuver flight is often operated withhigh angle- of- attack and high angular rates.Su-per- maneuver flight cannot be controlled by aconventional gain- scheduled controller but canbe controlled by using a nonlinear dynamic- in-version controller[1～ 3] .　　 This paper presents a method to use twokinds of controllers,nonlinear dynamic- inver-sion and conventional gain- scheduled con-trollers,in a flight control system.The nonlin-ear dynamic- inversion controller is used to con-trol superm…     

Improved ZCS-PWM commutation cell for IGBTs application

An improved zero-current-switching pulsewidth-modulated (ZCS-PWM) commutation cell is presented, which is suitable for high-power applications using insulated gate bipolar transistors (IGBTs) as the power switches. It provides ZCS operation for active switches and zero-voltage-switching (ZVS) operation for passive switches. Besides operating at constant frequency and reducing commutation losses, the proposed ZCS-PWM switch cell has no additional current stress and conduction loss in the main switch. To demonstrate the feasibility of the proposed ZCS-PWM commutation cell, it was applied to a boost converter. Operating principle, theoretical analysis, design guidelines, and a design example are described and verified by experiment results obtained from a prototype rated 1 kW and operating at 40 kHz. The PWM switch model and state-space averaging approach is also used to estimate and examine the steady-state and dynamic character of ZCS-PWM boost converter system. Finally, the application of the proposed soft-switching technique in the dc-dc nonisolated converters is presented.     

Automatic Inspection and Diagnostic System for Army Tactical Vehicles

A tactical system designed to inspect and diagnose malfunctions in all army tactical vehicles including jeeps, trucks, and tanks is known as Ready Multipurpose Automatic Inspection and Diagnostic System (READYMAIDS). The laboratory model developed to prove the feasibility of design is discussed together with design problems such as instrumenting a vehicle without modifications. The system uses a small digital computer in addition to switching, measurement, and loading devices. These devices are integrated into a small transportable unit. Results to date, problem areas, and possible solutions are described.     

Novel single-stage half-bridge series-resonant buck-boost inverter

A novel single-stage half-bridge series-resonant buck-boost inverter (HB-SRBBI) is proposed. The main attribute of the novel inverter topology is the fact that it generates an ac output voltage larger or lower than the dc input one, depending on the instantaneous duty cycle. This property is not found in the classical voltage source inverter (VST), which produces an ac output instantaneous voltage always lower than the dc input voltage. The proposed inverter circuit topology provides the main switch for turn-on at zero-current-switching (ZCS) by an auxiliary resonant cell built before the output choke. A state-space averaging approach is employed to analyze the system. A design example of 500 W ac/dc inverter is examined to assess the inverter performance and it provides high power efficiency above 90.7% under the rated power.     

Reverse-Bias Second Breakdown of High-Power Darlington Transistors

The reverse-bias second breakdown (RBSB) characteristics of high power Darlington transistors are discussed. The Darlingtons investigated are rated at 400 V maximum voltage and 100 A maximum current. Devices with and without speed-up diodes (connected between the bases of the input and output transistors) were studied. A nondestructive system for characterizing the RBSB behavior of these devices is described. The RBSB behavior was found to vary unpredictably with varying reverse base current magnitude. It was also found that the RBSB behavior of the Darlingtons was a function of the forward base current magnitude. This is in marked contrast to what has been found for discrete devices. The presence of a speed-up diode also influenced the RBSB behavior of these devices.     

Modelling and design of wing tip devices at various flight conditions using a databased aerodynamic prediction tool

A design study of wing tip devices at high and low speeds is described. The basis of the design study is an equivalent drag approach containing both aerodynamic drag gain and structural weight penalty. A comprehensive parameter study is carried out using a rapid aerodynamic prediction tool named Lift and Drag Component Analysis (LIDCA). Adding to an available lifting-line method a databased module for airfoil data is employed that uses results of two-dimensional flow simulations by multidimensional interpolation. Detailed validation studies of the method at high lift and high speed have demonstrated good accuracy. RANS computations of the selected wing tip designs confirm the predicted benefits at cruise condition. The results of the most effective wing tip designs are analysed at both flight conditions. Finally, options for improving the performance at take-off are suggested.     

大型客机后缘铰链襟翼气动机构一体化设计研究

我国正在开展大型客机的研制工作,增升装置设计是其中的关键技术之一。借鉴A350和波音787的后缘增升装置及其机构特点,研究了后缘铰链襟翼气动和机构一体化的设计。后缘铰链襟翼,是利用简单铰链机构驱动的后缘单缝襟翼增升装置,该机构由于构造简单、维护方便、制造成本低等优点备受青睐。详细介绍了基于CATIA二次开发创建的后缘铰链襟翼气动机构一体化设计模块,并嵌入到原大型飞机增升装置气动机构一体化设计平台上,获得较好的效果,为我国未来大型客机增升装置设计奠定了技术储备。     

Economical Design of Wind Generating Plants

A definitive analysis technique is proposed for designing wind generating plants to produce electrical energy at minimum cost. The method employs variation in essential design parameters: rated power level, rated wind velocity, design wind velocity, and number of generator poles. These parameters in turn define wind turbine radius, turbine speed, rated torque at step-up gear input, and step-up gear ratio. When these are combined with site (or region) specific wind statistics, appropriate wind plant cost functions, and criteria by which to compute annual cost of ownership, the result yields the cost of produced energy for the several design variations. The selected design is that one for which the cost of produced energy is minimum.     

基于USB总线的ARINC429总线测试仪设计

利用USB总线通用和即插即用的特点,研制了基于USB总线接口的AR INC429总线测试仪,该总线测试仪利用USB总线来收发AR INC429总线数据,测试计算机通过USB总线便可与各种AR INC429总线的设备进行数据通信,使AR INC429总线测试更加方便快捷。文中详细介绍了总线测试仪的系统结构,给出了硬件系统设计思想,并详细讨论了测试仪软件系统结构、数据结构以及应用程序接口调用流程。     

An Ultrahigh Speed CAMAC Interface for a Large Flight Simulator System

The real-time simulation subsystem (RTSS) at the NASA Langley Research Center in Hampton, VA, consists of several CDC CYBER computers and over 20 flight simulation sites. This simulation network is used by the Langley Center to advance the state of aeronautics and to improve air safety. The current simulator interface system at NASA-Langley was installed in 1968 and uses centrally located analog and discrete conversion equipment. Of the alternatives studied by NASA for a replacement RTSS, only the network and input/output (I/O) system conforming to the international computer automated measurement and control (CAMAC) standards meets their requirements. The CAMAC serial highway provides a distributed I/O system with an extremely high data throughput approaching 24 000 000 information bits/per second. Fiber-optic links transmit the data over paths to 1 km. For multisite simulations, a computer-controlled electronic switch configures site highways in any combination. The CAMAC system uses analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and synchro converters with 16 bits of resolution to give the needed system performance. The time to acquire data from 80 16-bit ADCs and 960 discrete inputs and transfer them to the CYBER central memory is less than 320 ?s. Similarly, the time from CYBER central memory to the setting of 256 16-bit DACs and 960 discrete outputs is less than 650 ?s.     

以PC机作为测控核心系统的导弹舵机CAT软件包

 本文介绍采用IBM-PC/XT型计算机测控核心系统的导弹舵机计算机辅助试验（CAT）系统软件包。有开关没置、零点校验、传感器标定、静态测试、动态测试和数据处理等六个程序文件,采用FORTRAN 77和宏汇编（MASM）语言混合编制。采用批处理方式联接程序文件,而各程序文件间的数据传递则利用数据文件实现,因此程序编写、调试和扩展比较方便。系统具有计算机自动给出测试信号,自动没置测试系统开关的功能。软件广泛采用汉字菜单和汉字人机对话的方式,并具有简单判断故障能力,故不但提高了测试自动化程度,而且使用方便,符合我国国情。软件包经过多次联试证明是可行的。     

双总线通信架构的航电系统双机备份技术研究

针对采用两种通信总线作为主要通信的复杂航电系统,通过研究其体系结构,利用故障树对系统可能故障进行分析,优化了单总线通信系统中主备机表决算法,设计了一种双总线通信系统中主备机的同步和双机切换机制,提升了双机切换的性能,实现了系统故障时的平滑切换运行,提高了双机切换的实时性和双机备份系统的可靠性。     

Modeling the protection system components of the space stationelectric power system

To facilitate protection system studies on the space station electric power system, there is a need to develop a model that can accurately and conveniently simulate both the power system and the protection system. Models for two major protective devices, the remote bus isolator and the remote power controller, are described. These models have been installed in a power system model resembling one channel of the space station power system. The usefulness of these models in protection system studies Is demonstrated     

20T气垫车气控系统设计

对某20T气垫车气控系统进行了设计,对主要元器件进行了计算及选型。该气控系统成功实现了气垫车整车满负载全向运动,满足了用户的使用要求,并为气垫车气控系统的设计及实践积累了经验。     

The Feasibility of Packaging High-Frequency Microcircuits Inside the Magnetic Core

A design goal for miniaturization has long been the elimination of the magnetic circuit. In practice, the size/weight penalties are decreased by operation at higher frequency where core size can be effectively reduced. When microcircuitry is considered, the magnetic circuit is designed out. Either RC or active networks replace inductance, or it is externally added to the microcircuit. This paper will demonstrate that the microcircuit elements can be readily interconnected inside of ferrite pot cores. Linear circuits using the magnetic circuit to advantage can be packaged in the same volume as the transformer, inductance, or filter alone. The natural RFI and radiation shielding, as well as heat transfer capabilities, are inherent with this form of packaging. For illustration, a 2-kV, 20-?A power supply featuring a 60-kHz, class C oscillator; a 10-volt, 100-mA converter featuring a 300-kHz square-wave oscillator; and a 9.5-volt, 100-mA switching regulator are packaged inside ferrite pot cores. With this technique only functional input-output connections are necessary, since the microcircuitry interconnections are inside the pot core.     

ZVT boost converter using a ZCS auxiliary circuit

A soft switching boost converter with zero-voltage transition (ZVT) main switch using zero-current switching (ZCS) auxiliary switch is proposed. Operating intervals of the converter are presented and analyzed. Design considerations are discussed. A design example with experimental results obtained from a 600 W, 100 kHz, 380 V output, power factor corrected, ac-to-dc, boost converter using insulated gate bipolar transistors (IGBTs) is presented, Results show that the main switch maintains ZVT while the auxiliary switch retains ZCS for the complete specified line and load conditions