检索结果-内蒙古大学图书馆

An analog-digital merged neural circuit using pulse width modulation technique

ANALOG INTEGRATED CIRCUITS AND SIGNAL PROCESSING 2000年第3期25卷 319-328页

作者： Morie, T Funakoshi, J Nagata, M Iwata, A Hiroshima Univ Fac Engn Higashihiroshima 7398527 Japan Fujitsu Ltd Kawasaki Kanagawa 2118588 Japan

This paper presents a neural circuit using PWM technique based on an analog-digital merged circuit architecture. Some new PWM circuit techniques are proposed. A bipolar-weighted summation circuit is described which attains 8-bit precision in SPICE simulation at 5 V supply voltage by compensating parasitic capacitance effects. A high performance differential-type latch comparator which can discriminate 1 mV difference at 100 MHz in SPICE simulation is also described. Next, we present a prototype chip fabricated using a 0.6 mu m CMOS process. The measurement results demonstrate that the overall precision in the weighted summation and the sigmoidal transformation is 5 bits. A neural network has been constructed using the prototype chips, and the experimental results for realizing the XOR function have successfully verified the basic neural operation.

关键词： LSI implementation neural networks pulse-width modulation PWM

来源：评论

学校读者我要写书评

暂无评论

Full bridge ZCS PWM converter for high-voltage high-power applications

引用

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2002年第2期38卷 515-526页

作者： Iannello, C Luo, S Batarseh, I Univ Cent Florida Sch Elect Engn & Comp Sci Orlando FL 32816 USA

This paper presents a comprehensive study of a full bridge (FB) zero-current switched (ZCS) PWM converter which is suitable for high-voltage and high-power de application that achieves ZCS for all active switches, and zero-voltage-switched (ZVS) operation for all diodes on the high voltage side. The given converter utilizes component parasitic parameters, particularly for the high-voltage transformer, and employs fixed-frequency phase-shift control to implement soft-switching commutations. Detailed steady state analysis of the converter power stage is presented for the first time and the major features of the converter's power stage are discussed. Small-signal characteristics are also presented and accompanied by a discussion of the controller design and implementation. A design example is also presented based on the steady state analysis and is validated by simulation. Theoretical and simulated results are in good agreement.

关键词： pulse-width modulation HIGH voltages VOLTAGE-frequency converters

来源：评论

学校读者我要写书评

暂无评论

Development of a single-phase five-level PWM rectifier for integrated power quality compensation based on sliding mode control

引用

INTERNATIONAL JOURNAL OF ELECTRONICS 2002年第5期89卷 381-401页

作者： Lin, BR Chen, DJ Natl Yunlin Univ Sci & Technol Dept Elect Engn Power Elect Res Lab Touliu 640 Yunlin Taiwan

A single-phase five-level pulse-width modulation (PWM) rectifier with the function of power factor correction and current harmonics elimination is proposed to obtain a clean line current from an ac source. The adopted rectifier uses neutral point diode clamped topology to reduce the voltage stress of power devices. Line current tracking, dc link voltage regulation and neutral point voltage compensation are performed by the inner loop current controller, outer loop voltage controller and voltage balance compensator, respectively. A variable structure-based current controller is employed to achieve a sinusoidal mains current. The effectiveness of the proposed control scheme, with the function of power factor correction as well as current harmonics elimination, is confirmed by the experimental results.

关键词： HARMONICS (Electric waves) pulse-width modulation

来源：评论

学校读者我要写书评

暂无评论

A hysteresis current control for single-phase multilevel voltage source inverters: PLD implementation

引用

IEEE TRANSACTIONS ON POWER ELECTRONICS 2002年第5期17卷 731-738页

作者： Zare, F Ledwich, G Queensland Univ Technol Sch Elect Elect & Syst Engn Brisbane Qld 4001 Australia

In most high-performance applications of voltage source pulse-width modulation inverters, current control is an essential part of the overall control system. In this paper, a hysteresis current control technique for a single-phase five-level inverter with flying-capacitor topology is proposed. Logic controls and a programmable logic device are suitable for handling a large number of switches and implementation of state transitions. This method also considers how to improve unbalanced voltages of capacitors using voltage vectors in order to minimize switching losses. The simulation and experimental results describe and verify the current control technique for the inverter.

关键词： current control multilevel inverter PLD pulse-width modulation

来源：评论

学校读者我要写书评

暂无评论

Extension of operation of space vector PWM strategies with low switching frequencies using different overmodulation algorithms

引用

IEEE TRANSACTIONS ON POWER ELECTRONICS 2002年第5期17卷 788-798页

作者： Narayanan, G Ranganathan, VT Indian Inst Sci Dept Elect Engn Bangalore 560012 Karnataka India

This paper investigates the operation of four space vector-based synchronized pulse-width modulation (PWM) strategies in the overmodulation zone using three different overmodulation algorithms. It is shown that the symmetries in the PWM waveforms generated can be preserved in the overmodulation zone also. With any given overmodulation algorithm, the voltage control characteristics (i.e., fundamental voltage versus control variable) are found to vary with PWM strategy, pulse number and type of clamping. The inverse of the appropriate voltage control curve is used during premodulation to maintain the modulator gain constant. The differences in the nature of the voltage control characteristics with the different overmodulation algorithms are brought out. These characteristics are compared and contrasted against those at high switching frequencies. The harmonic distortion in the different cases is evaluated and compared. It is shown that the bus clamping strategies perform better than the conventional strategy with any given overmodulation algorithm employed. These strategies, which exploit the flexibilities in the space vector approach, are useful in high power drives on account of their superior waveform quality at low switching frequencies and high dc bus utilization.

关键词： harmonic distortion induction motor drives inverters overmodulation pulse-width modulation space vector vectors voltage control

来源：评论

学校读者我要写书评

暂无评论

Performance, design and control of a series-parallel (CL²-type) resonant DC/DC converter

引用

IEE PROCEEDINGS-ELECTRIC POWER APPLICATIONS 2002年第5期149卷 360-368页

作者： Chakraborty, C Ishida, M Univ Tokyo Dept Elect Engn Tokyo 1138656 Japan Mie Univ Dept Elect & Elect Engn Tsu Mie 5148507 Japan

The three-element resonant network has various topological alternatives, one of which, a prospective compound topology, is investigated in detail. The converter uses one capacitor (C) and two inductors (L-2), to form a compound type CL2 network. Various advantages and limitations of the converter are detailed, and a new design procedure for such converters is also introduced. The converter may be controlled by varying the switching frequency or by pulse-width modulation. An experimental prototype has been produced and an excellent performance in the lagging power-factor mode has been confirmed.

关键词： bridge circuits Power convertors and power supplies to apparatus switching circuits electric current control lagging power factor mode series-parallel resonant DC/DC power converter PWM power convertors capacitor resonant power convertors switching frequency three-element resonant network inductors pulse-width modulation performance DC-DC power convertors Control of electric power systems Current control Voltage control voltage control design procedure

来源：评论

学校读者我要写书评

暂无评论

Novel single-phase AC/DC converter with two PWM control schemes

引用

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2002年第3期38卷 1000-1010页

作者： Lin, BR Hung, TL Natl Yunlin Univ Sci & Technol Dept Elect Engn Touliu 640 Yunlin Taiwan

A novel single-phase ac/dc converter with two pulsewidth modulation (PWM) schemes is proposed to draw a sinusoidal line current with nearly unity power factor, achieve balanced neutral point voltage and regulate the de bus voltage. With the aid of neutral point clamped scheme, a three-level voltage pattern is generated on the ac side of the proposed rectifier. To track the line current command derived from a voltage controller and a phase-locked loop circuit, a hysteresis current control scheme is used in the inner loop control. A capacitor voltage compensator is employed to achieve the balanced neutral point voltage. To investigate the effectiveness of the proposed control scheme, the simulation and experimental results based on a laboratory prototype circuit are performed.

关键词： ELECTRIC current converters pulse-width modulation

来源：评论

学校读者我要写书评

暂无评论

FOC and DTC: Two viable schemes for induction motors torque control

引用

IEEE TRANSACTIONS ON POWER ELECTRONICS 2002年第5期17卷 779-787页

作者： Casadei, D Profumo, F Serra, G Tani, A Univ Bologna Dipartimento Ingn Elettr I-40136 Bologna Italy Politecn Torino Dip Ingn Elettr Ind I-10129 Turin Italy

Field-oriented control and direct torque control are becoming the industrial standards for induction motors torque control. This paper is aimed to give a contribution for a detailed comparison between the two control techniques, emphasizing advantages and disadvantages. The performance of the two control schemes is evaluated in terms of torque and current ripple, and transient response to step variations of the torque command. The analysis has been carried out on the basis of the results obtained by numerical simulations, where secondary effects introduced by hardware implementation are not present.

关键词： digital signal processor direct field oriented control direct signal processor direct torque control discrete space vector modulation field oriented control pulse-width modulation

来源：评论

学校读者我要写书评

暂无评论

Full binary combination schema for floating voltage source multilevel inverters

引用

IEEE TRANSACTIONS ON POWER ELECTRONICS 2002年第6期17卷 891-897页

作者： Kou, XM Corzine, KA Familiant, YL Univ Wisconsin Dept Elect Engn Milwaukee WI 53201 USA

This paper presents schema of operation for floating voltage source multilevel inverters. The primary advantage of the proposed schema is that the number of voltage levels (and thus power quality) can be increased for a given number of semiconductor devices when compared-to the conventional "flying capacitor" topology. However, the new schema requires fixed floating sources instead of capacitors and therefore is more suitable for battery power applications such as electric vehicles, flexible ac transmission systems and submarine propulsion. Alternatively transformer/rectifier circuits may be used to supply the floating sources in a similar way to cascaded H-bridge inverters. Computer simulation results are presented for 4-level, 8-level, and 16-level inverter topologies. A 4-level laboratory test verifies the proposed method.

关键词： flying capacitor multilevel inverters pulse-width modulation voltage-source

来源：评论

学校读者我要写书评

暂无评论

Theoretical and experimental investigation of a pulse-width modulated digital hydraulic position control system

引用

CONTROL ENGINEERING PRACTICE 2002年第6期10卷 645-654页

作者： Keles, O Ercan, Y Gazi Univ Fac Engn & Architecture Dept Engn Mech Muhendislik Mimarlik Fak TR-06570 Ankara Turkey

In this study, the open loop and closed loop behaviours of a pulse-width modulated hydraulic system are investigated both theoretically and experimentally. First a mathematical model is formulated for the system and methods for obtaining system responses to pulse-width modulated inputs are developed. Using these methods, the responses of the servo valve, the open loop as well as closed loop hydraulic systems are calculated for pulse-width modulated step and sinusoidal inputs. Effect of pulse frequency on the sinusoidal response is investigated. An experimental set-up, which consists of a PC as the controller, a pulse-width modulator, a servo valve driven hydraulic system and feedback elements, was constructed. Experiments show that precise position control can be achieved by using pulse-width modulated inputs in electro-hydraulic control systems. The results obtained for sinusoidal reference inputs show that the pulse frequency should be more than 50 times the reference input frequency for a satisfactory performance of the tested system, if the reference frequency is less than 10 Hz. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： pulse-width modulation electro-hydraulic system electro-hydraulic servo valves hydraulic position control

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：