Interleaved boost converter with zero diode reverse-recovery loss

A three-phase interleaved continuous-inductor-current-mode (CICM) boost converter with zero diode reverse-recovery loss is proposed. In the converter, the di/dt of the output rectifiers is controlled by an integrated magnetic component. All the output rectifiers can be turned off softly and a very high efficiency is obtained. The equivalent-circuit model of the integrated inductors, the operation principle of the converter, and the design issues are discussed. Simulation and experimental results are presented.     

Power tracking for nonlinear PV sources with coupled inductor SEPIC converter

The photovoltaic (PV) generator exhibits a nonlinear i-v characteristic and its maximum power (MP) point varies with solar insolation. In this paper, a V2-based MP point tracking (MPPT) scheme is developed using a buck-boost transformation topology. Although several buck-boost transformation topologies are available we have considered here a coupled inductor SEPIC converter for experimentation. To achieve almost ripple-free array current we have used ripple steering phenomena with the help of integrated inductor. This integrated inductor not only reduces the magnetic core requirements but also improves converter performance. Mathematical models are formulated and tracking algorithm is evolved. A combined PV system simulation model is developed in the SIMULINK. For a given solar insolation, the tracking algorithm changes the duty ratio of the converter such that the solar cell array (SCA) voltage equals the voltage corresponding to the MP point. This is done by the tracking algorithm, which mainly computes the power proportional to square of terminal voltage and changes the duty ratio of the converter so that this power is maximum. The proposed algorithm is implemented in real-time with the help of Analog Device ADMC-401 DSP evaluation module. The tracking program is developed to perform experimental investigations using analog-to-digital converter (ADC) interrupt. Using this processor we are able to track the MP within 200 ms. The proposed peak power tracking effectiveness is demonstrated through simulation and experimental results.     

Synthesis and analysis of inductor-isolated switched-mode converter

A procedure is developed for the synthesis and analysis of complete classes of inductor-isolated PWM (pulse width-modulated) converters. The procedure is useful in the identification of converters in which the isolation inductors can be integrated with the rest of the inductors on the same magnetic structures. The information obtained from the procedure is useful in the selection of the converter most suitable for a given application and in the design of this converter with minimum component stresses, high power density, and low cost     

Fault-tolerance wide voltage conversion gain DC/DC converter for more electric aircraft

In this paper, a fault-tolerance wide voltage conversion gain DC/DC converter for More Electric Aircraft (MEA) is proposed. The proposed converter consists of a basic Cuk converter module and n expandable units. By adjusting the operation state of the expandable units, the voltage conversion gain of the proposed converter could be regulated, which makes it available for wide voltage conversion applications. Especially, since mutual redundancy can be realized between the basic Cuk converter module and the expandable units, the converter can continuously work when an unpredictable fault occurs to the fault-tolerant parts of the proposed converter, which reflects the fault tolerance of the converter and significantly improves the reliability of the system. Moreover, the advantages of small input current ripple, automatic current sharing and low voltage stress are also integrated in this converter. The working principle and features of the proposed converter are mainly introduced, and an experimental prototype with 800 W output power has been manufactured to verify the practicability and availability of the proposed converter.     

Analysis and design of a three-phase LCC-type resonant converter

A three-phase dc-to-dc LCC-type resonant converter with high-frequency transformer isolation is proposed. The operation and a simple analysis of the converter are presented. Design curves are obtained and a design example is given. SPICE simulation and experimental results are presented to verify the performance of the proposed converter for varying load conditions. The converter proposed has several advantages, e.g., operation in lagging PF mode for the entire load range, requires a narrow variation required in switching frequency, reduced component size and stresses, etc     

A fixed frequency LCL-Type series resonant converter

A fixed frequency LCL-type series resonant converter (SRC) which uses an inductive output filter is proposed. Steady-state analysis of the converter is presented using complex ac circuit analysis. Based on the analysis, a simple design procedure is given. Detailed space integrated control experiment (SPICE) simulation results are presented to evaluate the performance of the designed converter under varying load and supply voltage conditions. Also, detailed experimental results obtained from a metal-oxide-semiconductor field-effect transistor (MOSFET) based 500 W converter are presented to verify the analysis and SPICE simulation results. The results obtained from the analysis, SPICE simulation and the experimental converter are compared. The proposed converter requires a narrow variation in pulsewidth while maintaining lagging power factor mode of operation for a very wide variation in the load as well as supply voltage     

A Pulsewidth-Modulated Dc-to-Dc Converter That Utilizes a Small Number of Components

In general, circuit reliability can be enhanced by either incorporating redundancy or by minimizing a circuits component count. Conventional nonregulating converters generally require two active devices, whereas in regulating converters or switching regulators as many as 10 transistors, either integrated or discrete, is not uncommon. A regulating dc-to-dc converter which provides useful regulation and which can be constructed with either two or three transistors is described.     

永磁驱动重构型车载充电机三相DC/DC变流器的研究

提出了一种新型永磁驱动重构型车载充电机三相DC/DC变流器集成系统。该集成系统将永磁驱动的电机绕组和DC/AC逆变器重构成车载充电机实现电动汽车驱动-充电的集成,具有空间利用率高、充电快速和可靠性高等特点。分析了集成系统的结构和工作原理,推导了充电系统的三相DC/DC变换器数学模型。在此基础上,利用MATLAB/Simulink仿真软件搭建了驱动-充电集成系统仿真模型,对同步脉宽调制(PWM)控制和交错PWM控制策略进行仿真研究,分析对比了交流侧电压电流、直流侧电机绕组电感电流和直流侧电压波形。仿真结果表明,与交错PWM控制策略相比,同步PWM控制策略下该新型结构充电系统具有更好的运行性能。     

Suitability of pulse train control technique for BIFRED converter

Pulse Train/spl trade/ control scheme is presented and applied to a boost integrated flyback rectifier/energy storage dc-dc (BIFRED) converter operating in discontinuous conduction mode (DCM), which avoids the light-load high-voltage stress problem. In contrast to the conventional control techniques, the principal idea of Pulse Train technique is to regulate the output voltage using a series of high and low energy pulses generated by the current of the inductor. The applicability of the proposed technique to both the input and magnetizing inductances of BIFRED converter is investigated. Analysis of BIFRED converter operating in DCM as well as the output voltage ripple estimation is given. Experimental results on a prototype converter are also presented.     

Steady-state analysis of the constant-frequency clamped seriesresonant converter

A constant-frequency diode-clamped series resonant converter (CFCSRC) is proposed as a solution to problems associated with frequency-controlled resonant converters. This converter has two resonant frequencies, and control is achieved by varying the relative time spent at each switching frequency. Two zero-current-switching (ZCS) modes are examined and plotted in the output plane. An equation is given for the boundary between the two ZCS modes, as well as an expression for the boundary between ZCS and non-ZCS operation; both are plotted in the output plane. The output equation for the main mode is shown to be hyperbolic. Converter peak voltages limited to the input voltages, and peak currents are less than those of the frequency-controlled clamped series resonant converter over a large operating range. Data from a prototype converter are compared with theoretical data and are shown to be in good agreement with the theoretical model     

Design optimization for asymmetrical ZVS-PWM zeta converter

In this paper, a new soft-switching Zeta converter with an asymmetrical pulsewidth modulation (PWM) control is proposed. The proposed Zeta converter has the features of constant frequency operation, zero voltage switching (ZVS), and low voltage stress on the active switches. Moreover, it can achieve high power density, high efficiency, low switching loss, and low component count, which make converter operation at low to medium power level feasible. Operational principle of the Zeta converter is presented in detail, and a specific example is designed and implemented to verify its feasibility.     

Modeling of a new ZVS bi-directional dc-dc converter

A dual half-bridge (DHB) bidirectional dc-dc converter is a new proposed topology that has the advantages of decreased number of devices, soft-switching implementation, low cost, and high efficiency. Typical applications of this converter are the auxiliary power supply in fuel cell vehicles and battery charging and discharging systems where the power density, cost, weight, and reliability are critical factors. A switching-frequency-dependent state-space averaged model of the converter is developed here for either direction of power flow. This averaged model can be used to derive the steady-state characteristics and small signal dynamics of the proposed topology. It also provides a fast simulation tool to investigate the transient response of the converter. The simulated waveforms of the mathematical model are compared with the detailed circuit simulation to verify the accuracy of the modeling.     

Single-Stage Single-Switch Switched-Capacitor Buck/Buck-Boost-Type Converter

A new dc-dc converter featuring a steep step-down of the input voltage is presented. It answers a typical need for on-board aeronautics modern power architectures: power supplies with a large conversion ratio able to deliver an output voltage of 1–1.2 V. The proposed structure is derived from a switched-capacitor circuit integrated with a buck converter; they share the same active switch. The proposed solution removes the electromagnetic interference (EMI) emission due to the large di/dt in the input current of the switched-capacitor power supplies. Compared with a quadratic buck converter, it presents a similar complexity, a smaller reduction in the line voltage at full load (but less conduction losses due to smaller input inductor current and capacitor voltage), lower voltage stresses on the transistor and diodes, lower current stresses in the diodes, and smaller size inductors. A similar structure using a buck-boost converter as the second stage is also presented. The experimental results confirm the theoretical developments.     

装备采购中基于集成供应链的精益生产模式的研究

以航空装备采购者的视角,介绍了国外精益生产模式指导下集成供应链的精益生产模式和体系构成。认为精益生产是生产中不断探索追求的理想生产模式;集成供应链的精益生产是产品设计、制造和装配直至产品交付的整个过程巾,协调、处理和相应供应链上各方各环节间问题的有效途径。提出了我军工企业应该借鉴国外精益生产中特别是在平衡生产线、标准工作程序的建立和推行,工区可视控的推广,以及馈送生产线、脉冲生产线、移动生产线的建立等,努力提高经济效益,装备委托方应努力创新业务过程,改进工作,提高装备采购效益。     

基于辅助进气门的进气道/发动机一体化稳定性控制研究

为了实现发动机在大机动飞行时高品质稳定运行,提出了一种基于辅助进气门调节的进气道/发动机一体化稳定性控制方法。基于进气道CFD模型,通过飞行条件和辅助进气门开度计算出口性能参数,考虑总压畸变对风扇特性的影响,建立了进气道实时模型和总压畸变模型,并将其与发动机部件级模型匹配,建立进/发一体化模型。为了直接控制发动机安全裕度,选取发动机部分可测参数作为输入,通过非线性拟合方法建立风扇喘振裕度实时估计模型,相比于直接压比控制可以充分发挥发动机的潜能。进/发一体化控制是通过调节辅助进气门开度,控制进气道出口总压恢复系数,以满足发动机进口截面需求,并基于H∞鲁棒控制实现对发动机的转速和安全裕度的控制。仿真结果表明,所提出的方法可以实现发动机在大机动飞行过程中安全稳定工作,推力损失不超过2%。     

Modelling of the electromagnetic field in the interplanetary space and in the Earth's magnetosphere

A magnetohydrodynamic model of the solar wind flow is constructed using a kinematic approach. It is shown that a phenomenological conductivity of the solar wind plasma plays a key role in the forming of the interplanetary magnetic field (IMF) component normal to the ecliptic plane. This component is mostly important for the magnetospheric dynamics which is controlled by the solar wind electric field. A simple analytical solution for the problem of the solar wind flow past the magnetosphere is presented. In this approach the magnetopause and the Earth's bow shock are approximated by the paraboloids of revolution. Superposition of the effects of the bulk solar wind plasma motion and the magnetic field diffusion results in an incomplete screening of the IMF by the magnetopause. It is shown that the normal to the magnetopause component of the solar wind magnetic field and the tangential component of the electric field penetrated into the magnetosphere are determined by the quarter square of the magnetic Reynolds number. In final, a dynamic model of the magnetospheric magnetic field is constructed. This model can describe the magnetosphere in the course of the severe magnetic storm. The conditions under which the magnetospheric magnetic flux structure is unstable and can drive the magnetospheric substorm are discussed. The model calculations are compared with the observational data for September 24–26, 1998 magnetic storm (Dst _min=−205 nT) and substorm occurred at 02:30 UT on January 10, 1997. This revised version was published online in August 2006 with corrections to the Cover Date.     

Table-Aided Design of the Energy-Storage Reactor in DC-to-DC Converters

A new procedure for the selection of magnetic cores for use in energy-storage dc-to-dc power converters that eliminates the need for an automated computer search algorithm and stored data file is presented. The converter configurations included in the procedure are the three commonly encountered single-winding converters for voltage stepup, for current stepup and voltage stepup/current stepup, and for the two-winding converter for voltage stepup/current stepup. For each converter configuration, three types of controllers are considered: constant-frequency, constant on-time, and constant off-time. Using concepts developed from analyses of these converters by considering the transfer of energy by means of an energystorage inductor or transformer, a special table of parameters calculated from magnetic core data is constructed, which leads to a considerably simplified design procedure.     

BIT综合表示模型研究

 在分析机内测试(BIT)主要设计要素组成的基础上,提出了BIT综合表示模型。建立了BIT综合表示模型的数学定义,包括BIT单元模型、BIT层次关系集合、BIT数据传送方式集合、BIT执行次序集合和BIT综合表示模型。在数学定义的基础上,进一步建立了BIT综合表示的框图模型和表格模型,这两种模型可以直接用于工程分析。最后,以某辅助导航系统为案例,进行了BIT综合表示模型的应用,给出了框图模型结果和表格模型结果,验证了该模型的可用性和有效性。     

Algorithms for Power Converter Design Optimization

A practical optimization approach for power converters is established which allows conception of a design to meet all powercircuit performance requirements and concurrently to optimize a defined quantity such as weight or losses. In addition to facilitating a cost effective design, the computer-aided approach provides a means to readily assess a) the weight-efficiency tradeoff, b) impacts of converter requirements and component characteristics on a given design, and c) optimum power-system configurations. The following two popular algorithms for nonlinearly constrained optimization are utilized to design the power converter: 1) the sequential unconstrained minimization technique, SUMT Version 4; 2) the ALAG penalty function technique, ALAG5. These algorithms are compared, and suggestions are made for improving the efficiency of the optimization algorithms for power converter design.     

简谐力激励下多组件结构系统的整体优化设计

多组件结构系统整体优化设计通过协同优化支撑结构拓扑构型和组件布局来使结构系统的位移响应最小。本文提出通过模态加速度法（MAM）求解多组件结构系统的位移响应,并以位移响应值最小作为优化目标;引入多点约束（MPC）方法模拟组件与设计域间的铆钉或螺栓连接形式;采用有限包络圆法（FCM）来避免组件之间及组件与设计域边界产生干涉。建立了多组件结构系统整体优化问题的数学模型,并对动响应目标函数关于设计变量的灵敏度进行了推导。最后,通过几个算例验证了整体优化方法在简谐力激励下求解问题的可行性及其在实际问题中的有效性。