期刊文献+
共找到3,265篇文章
< 1 2 164 >
每页显示 20 50 100
Investigation on some key problems of large power AC-DC-AC converter
1
作者 LI Chongjian~(1)) and WANG Chengsheng~(2)) 1) Automation Research and Design Institute of Metallurgical Industry,Beijing 100071,China 2) Hybrid Process Industry Automation System and Equipment Technology State Key Lab,Beijing 100071,China 《Baosteel Technical Research》 CAS 2010年第S1期100-,共1页
China is an important country in iron and steel industry.Power electronics converters are widely used.For the cold rolling mills of high speed,AC-DC-AC converters should be used.In the paper,the design and the control... China is an important country in iron and steel industry.Power electronics converters are widely used.For the cold rolling mills of high speed,AC-DC-AC converters should be used.In the paper,the design and the control system of the large power three-level AC - DC - AC converter with IGCTs is investigated,and a back-to-back large power three-level AC - DC - AC converter with IGCTs has been got. With a series experiments,the performance of the converter is examined.The experiment result indicates the converter reaches the design requirement and it shows excellent performance.The converter system has been put into use safely.It is estimated that the AC - DC - AC converter system will be used in the drive systems for rolling mills in the near future. 展开更多
关键词 large power ac - DC - ac IGCT CONVERTER
下载PDF
Electrical characteristics of new three-phase traction power supply system for rail transit 被引量:1
2
作者 Xiaohong Huang Hanlin Wang +4 位作者 Qunzhan Li Naiqi Yang Tao Ren You Peng Haoyang Li 《Railway Engineering Science》 2023年第1期75-88,共14页
A novel three-phase traction power supply system is proposed to eliminate the adverse effects caused by electric phase separation in catenary and accomplish a unifying manner of traction power supply for rail transit.... A novel three-phase traction power supply system is proposed to eliminate the adverse effects caused by electric phase separation in catenary and accomplish a unifying manner of traction power supply for rail transit.With the application of two-stage three-phase continuous power supply structure,the electrical characteristics exhibit new features differing from the existing traction system.In this work,the principle for voltage levels determining two-stage network is dissected in accordance with the requirements of traction network and electric locomotive.The equivalent model of three-phase traction system is built for deducing the formula of current distribution and voltage losses.Based on the chain network model of the traction network,a simulation model is established to analyze the electrical characteristics such as traction current distribution,voltage losses,system equivalent impedance,voltage distribution,voltage unbalance and regenerative energy utilization.In a few words,quite a lot traction current of about 99%is undertaken by long-section cable network.The proportion of system voltage losses is small attributed to the two-stage three-phase power supply structure,and the voltage unbal-ance caused by impedance asymmetry of traction network is less than 1‰.In addition,the utilization rate of regenerative energy for locomotive achieves a significant promotion of over 97%. 展开更多
关键词 Three-phase ac power supply Two-stage power supply structure Electrical characteristics Current distribution Voltage losses Regenerative energy
下载PDF
基于ACE与YOLOv5的电力遥感图像检测算法
3
作者 张弢 蒋东东 +1 位作者 田喆文 王艺霖 《计算机仿真》 2024年第1期277-283,共7页
针对电力遥感图像采集时存在大量浓烟以及数据样本少等问题,提出一种基于对数变换的改进型自动色彩均衡与改进后YOLOv5s模型的遥感图像去雾检测算法,旨在通过提高数据集的图像质量进而提高检测网络的检测精度。构建的改进型自动色彩均... 针对电力遥感图像采集时存在大量浓烟以及数据样本少等问题,提出一种基于对数变换的改进型自动色彩均衡与改进后YOLOv5s模型的遥感图像去雾检测算法,旨在通过提高数据集的图像质量进而提高检测网络的检测精度。构建的改进型自动色彩均衡对电力遥感图像去雾增强,并通过图像质量和特征提取两方面进行了实验数据对比,实验结果表明改进的自动色彩均衡算法优于其它算法。其次,通过YOLOv5s检测算法对增强后的数据集进行训练,引入mosaic数据增强算法,并通过构建ghost卷积模块和NAM注意力模块降低了网络参数、提升了网络检测精度。 展开更多
关键词 电力遥感图像 自动色彩均衡算法 目标检测 多尺度金字塔
下载PDF
Systematic Evaluation of Deep Neural Network based Dynamic Modeling Method for AC Power Electronic System
4
作者 Yunlu Li Guiqing Ma +1 位作者 Junyou Yang Yan Xu 《CES Transactions on Electrical Machines and Systems》 CSCD 2023年第2期137-143,共7页
Since the high penetration of renewable energy complicates the dynamic characteristics of the AC power electronic system(ACPES),it is essential to establish an accurate dynamic model to obtain its dynamic behavior for... Since the high penetration of renewable energy complicates the dynamic characteristics of the AC power electronic system(ACPES),it is essential to establish an accurate dynamic model to obtain its dynamic behavior for ensure the safe and stable operation of the system.However,due to the no or limited internal control details,the state-space modeling method cannot be realized.It leads to the ACPES system becoming a black-box dynamic system.The dynamic modeling method based on deep neural network can simulate the dynamic behavior using port data without obtaining internal control details.However,deep neural network modeling methods are rarely systematically evaluated.In practice,the construction of neural network faces the selection of massive data and various network structure parameters.However,different sample distributions make the trained network performance quite different.Different network structure hyperparameters also mean different convergence time.Due to the lack of systematic evaluation and targeted suggestions,neural network modeling with high precision and high training speed cannot be realized quickly and conveniently in practical engineering applications.To fill this gap,this paper systematically evaluates the deep neural network from sample distribution and structural hyperparameter selection.The influence on modeling accuracy is analyzed in detail,then some modeling suggestions are presented.Simulation results under multiple operating points verify the effectiveness of the proposed method. 展开更多
关键词 ac power electronic system Dynamic behavior Neural network Systematic evaluation
下载PDF
AC/DC通信电源模块远场电磁辐射发射预测研究 被引量:1
5
作者 王伟新 舒俊华 +1 位作者 睢宁宁 和军平 《电源学报》 CSCD 北大核心 2024年第5期44-51,共8页
AC/DC通信电源产生的电磁辐射易超过限值,对其电磁辐射机理和预测方法开展研究有助于改善电磁兼容性设计。首先,在分析AC/DC通信电源模块共模电磁噪声的形成源头和传播路径后,提出其远场电磁辐射可分解为由“输入端口”、“输出端口”... AC/DC通信电源产生的电磁辐射易超过限值,对其电磁辐射机理和预测方法开展研究有助于改善电磁兼容性设计。首先,在分析AC/DC通信电源模块共模电磁噪声的形成源头和传播路径后,提出其远场电磁辐射可分解为由“输入端口”、“输出端口”共模电压驱动的2类辐射。然后,提出将共模电压驱动源与寄生辐射体的辐射传递函数相结合,进行远场电磁辐射预测的新方法;设计频谱分析仪+电阻衰减器,实现各共模电压驱动源的频谱测量;采用FEKO电磁仿真软件,通过数值计算得到各寄生辐射体的辐射传递函数。最后,实现了4 kW AC/DC通信电源模块辐射预测,并实测验证了其有效性。 展开更多
关键词 ac/DC通信电源 远场辐射发射 电磁预测 电磁仿真 寄生辐射体
下载PDF
隔离型双向AC-DC矩阵变换器闭环控制方法研究
6
作者 李志轩 刘桂英 明旺 《电工材料》 CAS 2024年第2期33-37,43,共6页
根据隔离型双向AC-DC矩阵变换器(Isolated AC-DC Matrix Converter,IAMC)没有中间电容缓冲环节,输入和输出变换器控制之间存在耦合,研究提出了IAMC两级功率变换器的控制方法。通过对全桥变换器进行闭环控制进而实现对直流侧输出电流和... 根据隔离型双向AC-DC矩阵变换器(Isolated AC-DC Matrix Converter,IAMC)没有中间电容缓冲环节,输入和输出变换器控制之间存在耦合,研究提出了IAMC两级功率变换器的控制方法。通过对全桥变换器进行闭环控制进而实现对直流侧输出电流和功率的直接控制;三相-单相矩阵变换器实现对有功和无功功率的独立控制,以满足网侧功率因数的高精度控制。所提控制策略有效降低了两级变换器的耦合强度,保证了系统的良好性能。在MATLAB中进行仿真,结果表明,所提出的控制方法在使系统电能质量得到提高的同时,可以实现单位功率因数可调,验证了所提控制策略的正确性和有效性。 展开更多
关键词 双向隔离型ac-DC矩阵变换器 功率传输 功率因素 闭环控制
下载PDF
高效单片AC/DC电源管理集成电路设计
7
作者 苑维旺 《中国科技纵横》 2024年第16期84-86,共3页
随着科技快速发展,电子产品的复杂程度不断升级,日益向小型化、智能化、高效能方向迈进。电源管理系统作为电子产品中的重要系统之一,其重要作用逐渐凸显。本研究设计了一种单片AC/DC开关电源集成电路,该电路具有效率高、体积小、可靠... 随着科技快速发展,电子产品的复杂程度不断升级,日益向小型化、智能化、高效能方向迈进。电源管理系统作为电子产品中的重要系统之一,其重要作用逐渐凸显。本研究设计了一种单片AC/DC开关电源集成电路,该电路具有效率高、体积小、可靠性高等优点。因此,本文基于高效的单片AC/DC电源管理集成电路构成,对其进行了优化设计,希望能够为我国电源管理系统设计行业的相关工作提供参考和借鉴。 展开更多
关键词 单片ac/DC 电源管理 集成电路设计
下载PDF
基于单片机的AC-DC变换电路设计
8
作者 韩瑶辉 张璐 陆安山 《现代电子技术》 北大核心 2024年第22期25-29,共5页
传统的AC-DC变换电路由于要通过高频变压器来实现电压变换,存在效率较低、电源的波纹很难降低等问题。因此,设计一种以单片机为核心控制器件的新型单相AC-DC变换电路。单相AC-DC变换电路设计结合BOOST开关器、输入负反馈和脉冲宽度调制... 传统的AC-DC变换电路由于要通过高频变压器来实现电压变换,存在效率较低、电源的波纹很难降低等问题。因此,设计一种以单片机为核心控制器件的新型单相AC-DC变换电路。单相AC-DC变换电路设计结合BOOST开关器、输入负反馈和脉冲宽度调制,采用单片机辅助控制相结合的方式实现闭环控制,保证输出的稳定和高效。该电路包括全波桥式整流电路、BOOST开关器、电压反馈电路、电流采样电路和功率因数测量电路,通过负反馈控制UC3845芯片来改变PWM控制信号,从而调整BOOST开关器开关的通断,使输出电压稳定在36 V。单相AC-DC变换电路具有PFC功能,可通过LCD将实时的PF值进行检测,显示输出电流、输出电压、功率因数等数据。另外,在输出端设计了过流保护报警功能,该设计选取STC51单片机系列中的89C52RC芯片作为控制核心,结合电流电压检测共同来实现。实验结果表明,实测负载调整率为0.28%,电压调整率为0.28%,功率因数为0.91,说明所设计电路优于传统的AC-DC变换电路,具有转换率高的特点。 展开更多
关键词 单片机 ac-DC变换 BOOST开关器 功率因数 过流保护 脉冲宽度调制 负反馈
下载PDF
Industrial frequency single-phase AC traction power supply system for urban rail transit and its key technologies 被引量:1
9
作者 Qunzhan Li 《Journal of Modern Transportation》 2016年第2期103-113,共11页
To avoid stray current and maintain the benefit of no phase-split in the DC traction power supply system, an AC traction power supply system was proposed for the urban public transport such as metro and light rail tra... To avoid stray current and maintain the benefit of no phase-split in the DC traction power supply system, an AC traction power supply system was proposed for the urban public transport such as metro and light rail transit. The proposed system consists of a main substation (MSS) and cable traction network (CTN). The MSS includes a single-phase main traction transformer and a negative-se- quence compensation device, while the CTN includes double-core cables, traction transformers, overhead catenary system, rails, etc. Several key techniques for the proposed system were put forward and discussed, which can be summarized as (1) the power supply principle, equivalent circuit and transmission ability of the CTN, the cable-catenary matching technique, and the selection of catenary voltage level; (2) the segmentation technology and status identification method for traction power supply network, distributed and centralized protection schemes, etc.; (3) a power supply scheme for single-line MSS and a power supply scheme of MSS shared by two or more lines. The proposed industrial frequency single-phase AC traction power supply system shows an excellent technical performance, good economy, and high reliability, hence provides a new alternative for metro and urban rail transit power supply systems. 展开更多
关键词 Urban rail transit 50 Hz industrial frequency single-phase ac traction power supply Cable traction
下载PDF
一种高效率半桥LLC型的AC/DC变换器设计
10
作者 田斌 孙泉辉 《电气传动》 2023年第11期25-30,共6页
AC/DC开关电源是电力系统的主要动力来源,其发展趋势是:容量大、功率密度大、效率高、功率因数低、谐波含量低。但现有的数字电源仍存在着一些普遍问题:抗干扰能力差、结构功能简单、无法满足电厂和变电站等相关场所使用需求。设计了一... AC/DC开关电源是电力系统的主要动力来源,其发展趋势是:容量大、功率密度大、效率高、功率因数低、谐波含量低。但现有的数字电源仍存在着一些普遍问题:抗干扰能力差、结构功能简单、无法满足电厂和变电站等相关场所使用需求。设计了一种基于芯片控制的半桥开关电源,对其主电路进行了理论分析,并对EMI整流滤波电路、PFC功率因数校正电路、LLC半桥电路等电路进行了详细的设计。实验测试结果表明,该设计合理,具有大容量、高效率、高功率因数、低纹波等特点,能够充分满足目前的市场需求。 展开更多
关键词 高效率 功率因数校正 半桥LLC ac/DC变换器 低纹波
下载PDF
Study on Transformer Magnetic Biasing Control Method for AC Power Supplies 被引量:5
11
作者 卢家林 孙晋 苏彦民 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2001年第4期17-22,共6页
This paper presents a novel transformer magnetic biasing control method for high-power high-performance AC power supplies. Serious consequences due to magnetic biasing and several methods to overcome magnetic biasing ... This paper presents a novel transformer magnetic biasing control method for high-power high-performance AC power supplies. Serious consequences due to magnetic biasing and several methods to overcome magnetic biasing are first discussed. The causes of the transformer magnetic biasing are then analyzed in detail. The proposed method is based on a high-pass filter inserted in the forward path and the feedforward control. Without testing magnetic biasing of transformer, this method can eliminate magnetic biasing of transformer completely in real-time waveform feedback control systems though the zero error of the Hall effect sensors varies with time and temperature. The method has already been employed in a 90KVA AC power supply. It is shown that it offers improved performance over existing ones. In this method, no sensors are used such that the zero error of the Hall effect sensors has not any influence on the system. It is simple to design and implement. Furthermore, the method is suitable for various power applications. 展开更多
关键词 ac machinery Electric power supplies to apparatus Feedback control Hall effect High pass filters Real time systems SENSORS
下载PDF
Analysis and Design Aspects of a Series Power Semiconductor Array with Digital Waveform Control Capability for Single Phase AC Voltage Regulators and Other Applications
12
作者 Nihal Kularatna Chandani Jindasa 《Circuits and Systems》 2011年第3期249-259,共11页
A series connected power semiconductor array, with digital control capability could be used for developing single phase AC regulators or other applications such as AC electronic loads. This technique together with an ... A series connected power semiconductor array, with digital control capability could be used for developing single phase AC regulators or other applications such as AC electronic loads. This technique together with an ordinary gapless transformer could be used to develop a low cost AC voltage regulator (AVR) to provide better or comparable specifications with bulky ferro-resonant AVR types. One primary advantage of the technique is that digital control can be used to minimize harmonics. Commencing with a review of AC voltage regulator techniques for single phase power conditioning systems, an analysis and design aspects of this technique is presented with experimental results for AVRs. Guidelines on how to utilize the technique in a generalized basis is also summarized together with a summary of a technique for achieving harmonic control. 展开更多
关键词 power Conditioners ac Voltage REGULATORS (AVR) power SEMICONDUCTORS Digital Control Electronic ac Loads
下载PDF
基于移相和调频的单级双向AC-DC变换器临界电流调制策略 被引量:1
13
作者 王章毅 陆道荣 +2 位作者 李想 郎天辰 胡海兵 《电工技术学报》 EI CSCD 北大核心 2023年第14期3888-3897,共10页
传统双有源桥单级AC-DC变换器的移相调制难以实现全范围软开关,开关管损耗大,效率难以进一步提高。针对此问题,该文提出一种基于临界电流模式(BCM)的调制策略,将移相和调频相结合,实现所有开关管的零电压开通,从而有效地降低了开通损耗... 传统双有源桥单级AC-DC变换器的移相调制难以实现全范围软开关,开关管损耗大,效率难以进一步提高。针对此问题,该文提出一种基于临界电流模式(BCM)的调制策略,将移相和调频相结合,实现所有开关管的零电压开通,从而有效地降低了开通损耗。该文分析单级式双向AC-DC变换器的临界电流调制基本原理和软开关实现条件,并推导出软开关条件下的移相和频率数学表达式。搭建DC 48 V、AC 220 V、500 W实验样机,最高效率达到94%,通过实验验证该调制策略的有效性和正确性。 展开更多
关键词 移相控制 变频运行 ac-DC变换器 功率因数校正 零电压软开关
下载PDF
基于单级AC/DC脉冲激励源的电容式无线输电系统
14
作者 李克喆 肖文勋 《自动化与仪表》 2023年第9期6-10,15,共6页
电容式无线输电(CPT)系统的原边激励源通常是由工频整流器和高频逆变器组成的级联变换器,使用的半导体和无源元件数量较多,导通损耗也较高。该文提出了一种新型的单级AC/DC变换器,与传统的变换器相比,该变换器只使用2个开关管和2个二极... 电容式无线输电(CPT)系统的原边激励源通常是由工频整流器和高频逆变器组成的级联变换器,使用的半导体和无源元件数量较多,导通损耗也较高。该文提出了一种新型的单级AC/DC变换器,与传统的变换器相比,该变换器只使用2个开关管和2个二极管,可以将工频交流电变换成CPT系统所需的直流脉冲激励源。该文介绍了该变换器的工作原理,提出了实现高功率因数、软开关的设计方法。最后,通过硬件实验证明了该变换器在电容式无线输电系统中的可行性,实现了开关管的零电压导通,具有高输入功率因数。 展开更多
关键词 电容式无线输电(CPT) ac/DC脉冲激励源 功率因数校正 软开关
下载PDF
Performance of PSS to Damp Power Oscillations Caused by an HVDC Link in AC-DC Power System
15
作者 Mokhtar Benasla Tayeb Allaoui Mostefa Brahami 《Energy and Power Engineering》 2014年第1期1-9,共9页
HVDC (High Voltage Direct Current) systems are increasingly being applied to improve power system operation and controllability. However, inappropriate setting of HVDC controller may have a detriment effect on the sys... HVDC (High Voltage Direct Current) systems are increasingly being applied to improve power system operation and controllability. However, inappropriate setting of HVDC controller may have a detriment effect on the system performance. Generally, PSS (Power System Stabilizer) is known as a simple concept, easy to perform, and computationally effective to enhance damping of power system oscillations through excitation control of synchronous generator. This paper examines the effectiveness of the PSS to enhance the dynamic performance of AC-DC power systems and to compensate the negative damping of HVDC system. The dynamic performance is evaluated by examining the system response to various disturbances. In order to ensure the reliability of the simulation test results as well as the performance of the PSS, detailed HVDC modeling is adopted using SimPowerSystems toolbox in the MATLAB, and some important conclusions are drawn. 展开更多
关键词 HVDC PSS ac-DC power Systems power System Stability
下载PDF
一种新型单级隔离型AC-DC变换器研究 被引量:1
16
作者 刘猛 孙孝峰 +2 位作者 王洪龙 赵巍 张韶磊 《中国电机工程学报》 EI CSCD 北大核心 2023年第7期2802-2814,共13页
文中提出一种新型单级式隔离AC-DC变换器及控制方案。所提结构在不改变图腾柱无桥功率因数校正(totem pole bridge-free power factor correction,TP-PFC)和双向全桥(dual active bridge,DAB)两级式AC-DC变换器特性的前提下,将TP-PFC高... 文中提出一种新型单级式隔离AC-DC变换器及控制方案。所提结构在不改变图腾柱无桥功率因数校正(totem pole bridge-free power factor correction,TP-PFC)和双向全桥(dual active bridge,DAB)两级式AC-DC变换器特性的前提下,将TP-PFC高频桥臂和DAB原边侧第一个桥臂进行开关复用,减小了开关器件数目。同时,相较于TP-PFC和DAB两级式AC-DC变换器,取消了直流母线电解电容并且抑制了交流电感电流尖峰。利用其拓扑特点及所提出的控制方案,实现了拓扑开关器件的全范围软开关。首先详细分析所提拓扑结构的工作特性,包括工作模态、拓扑优点、功率特性及软开关特性;其次基于对拓扑的分析,提出控制简单的控制策略;最后,对所提拓扑结构及控制方案进行实验验证。 展开更多
关键词 ac-DC变换器 移相控制 功率因数校正 零电压开关
下载PDF
Practice and Prospect of AC/DC Hybrid Power Grid in Southern China
17
作者 By Wang Jiuling China Southern Power Grid Co., Ltd. 《Electricity》 2005年第A04期37-42,共6页
China Southern Power Grid is a unique EHV AC/DC hybrid transmission network that operates in China. In its service area, the distribution of energy resources and the development of economy are extremely unbalanced, so... China Southern Power Grid is a unique EHV AC/DC hybrid transmission network that operates in China. In its service area, the distribution of energy resources and the development of economy are extremely unbalanced, so long-distance and bulk power transmission are needed; besides, the geography and climate conditions are serious, rains, fogs, lightning and typhoon as well as high temperature are common all the year round. Facing these challenges, the power grid enhanced stability control, improved the equipment and strengthen the network structure. In the future, the power grid plans to optimize the disposition of power sources and build digitalized power system. 展开更多
关键词 ac/DC HYBRID power GRID stability control
下载PDF
Research on power electronic transformer applied in AC/DC hybrid distribution networks 被引量:15
18
作者 Yiqun Miao Jieying Song +6 位作者 Haijun Liu Zhengang Lu Shufan Chen Chun Ding Tianzhi Cao Linhai Cai Yuzhong Gong 《Global Energy Interconnection》 2018年第3期396-403,共8页
The AC/DC hybrid distribution network is one of the trends in distribution network development, which poses great challenges to the traditional distribution transformer. In this paper, a new topology suitable for AC/D... The AC/DC hybrid distribution network is one of the trends in distribution network development, which poses great challenges to the traditional distribution transformer. In this paper, a new topology suitable for AC/DC hybrid distribution network is put forward according to the demands of power grid, with advantages of accepting DG and DC loads, while clearing DC fault by blocking the clamping double sub-module(CDSM) of input stage. Then, this paper shows the typical structure of AC/DC distribution network that is hand in hand. Based on the new topology, this paper designs the control and modulation strategies of each stage, where the outer loop controller of input stage is emphasized for its twocontrol mode. At last, the rationality of new topology and the validity of control strategies are verified by the steady and dynamic state simulation. At the same time, the simulation results highlight the role of PET in energy regulation. 展开更多
关键词 ac/DC hybrid distribution network power electronic transformer(PET) Clamping double sub-module(CDSM) Energy router
下载PDF
地铁车站低压配电系统电动机设备采用AC 660V配电的研究 被引量:3
19
作者 张振宇 张文明 +2 位作者 刘晓波 吕馨 刘世钊 《建筑电气》 2023年第4期43-48,共6页
通过分析电动机定子绕组接线形式,输入电压与电磁功率、转矩关系,以及电动机负荷配电系统元件、电缆,从而得出地铁电动机设备均可采用AC 660V供电的结论。通过对比分析说明地铁电动机设备采用AC 660V供电时,具有大幅节约有色金属,降低... 通过分析电动机定子绕组接线形式,输入电压与电磁功率、转矩关系,以及电动机负荷配电系统元件、电缆,从而得出地铁电动机设备均可采用AC 660V供电的结论。通过对比分析说明地铁电动机设备采用AC 660V供电时,具有大幅节约有色金属,降低初期投资及减小线缆损耗的优势。 展开更多
关键词 地铁车站 ac 660V配电 三绕组变压器 电压损失 投资 线路损耗 电动机设备 配电电缆
下载PDF
OFDM系统中基于最优阈值ACE的PAPR抑制 被引量:1
20
作者 吴群 周晓 王成优 《工程科学学报》 EI CSCD 北大核心 2023年第1期150-157,共8页
动态星座图扩展(Active constellation extension, ACE)是一种能够有效降低正交频分复用(Orthogonal frequency division multiplexing, OFDM)系统峰均功率比(Peak-to-average power ratio, PAPR)的方法,为解决现有ACE算法因选择固定限... 动态星座图扩展(Active constellation extension, ACE)是一种能够有效降低正交频分复用(Orthogonal frequency division multiplexing, OFDM)系统峰均功率比(Peak-to-average power ratio, PAPR)的方法,为解决现有ACE算法因选择固定限幅阈值而限制降低PAPR效果的问题,提出一种最优阈值ACE(Optimal threshold ACE, OTACE)算法,该算法能在每次迭代时根据信号功率求得最合适的限幅阈值,从而增强抑制PAPR的效果.通过数据拟合得到合适的迭代次数,在此基础上对OTACE算法抑制PAPR的效果进行了仿真分析,仿真结果表明,与凸集映射(Projection onto convex sets, POCS)和智能梯度投影(Smart gradient projection, SGP)算法相比,OTACE分别能提高5 dB和3 dB左右的PAPR增益.在广电1、广电6和巴西A三种信道下,分别在多普勒频移为20 Hz和60 Hz时测试OTACE算法对系统误码率(Bit error rate, BER)的影响.实验结果显示,采用OTACE可提高系统的BER性能,并且与POCS相比,OTACE可提高1 dB左右的信噪比(Signal-to-noise ratio,SNR)增益;与SGP相比,OTACE在高SNR时有明显的优势. 展开更多
关键词 正交频分复用 峰均功率比 动态星座图扩展 迭代 阈值
下载PDF
上一页 1 2 164 下一页 到第
使用帮助 返回顶部