共查询到17条相似文献,搜索用时 156 毫秒
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模块化多电平换流器(MMC)具有级联型多电平换流器"模块化"的优点,输出电压中的谐波含量少,在高压直流输电中具有巨大的应用潜力。介绍MMC的数学模型和工作原理,分析传统载波移相调制策略,针对其存在的缺点提出一种改进型载波移相PS-SPWM调制算法,即载波三角波移相-开关频率优化PWM法(PS-SFO-PWM),并与载波移相SPWM调制算法进行比较;针对MMC中特有的三相之间的环流问题,通过对其进行PI调节,使环流抑制在一定的范围内,利于功率的有效传输。最后,在Matlab/Simulink7.0环境下搭建了基于载波三角波移相-开关频率优化PWM法的5电平逆变器的仿真模型,仿真结果验证了所提方法具有直流电压利用率高、开关频率小等优点。 相似文献
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级联多电平变频调速技术是高压大功率场合广泛应用的一种技术;为了实现调速系统的高性能控制,提出矢量控制和三角载波移相PWM方法相结合的控制策略;阐述了级联多电平矢量控制系统的系统构成、基本原理、级联五电平主电路拓扑结构及其载波移相PWM控制技术;基于MATLAB/Simulink Blocks 工具箱的系统仿真结果表明级联多电平逆变器可以成倍提高等效载波频率,降低输出谐波含量,还验证了所提方案的可行性,系统能够获得良好的调速性能. 相似文献
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介绍了一种新颖的基于级联型多电平拓扑结构的开关式的功率放大器,采用多电平技术来改善D类功率放大器输出品质,采用先进的现场可编程门阵列来实现相移PWM技术,其开关频率是单个单元开关频率的2N倍,该触发信号发生器通过数据采集单元接收A/D转换的调制波信号,通过多路载波移相控制单元产生多路相移的三角载波及其反向信号,经比较控制单元产生PWM触发信号波形,并通过死区控制单元进行死区保护控制处理.通过闭环控制保证输出信号的跟随品质,着重研究了闭环控制的控制策略,试验结果表明,采用该控制策略实现的D类功率放大器,系统带宽较宽,具有较好的瞬时响应和输出品质. 相似文献
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严伟 《电子制作.电脑维护与应用》2013,(10):45
很多变频器生产企业都笼统地认为π/N和2π/N两种移相角度效果是一样的,本文对载波移相技术进行了数学分析,从理论上分析得出了两种移相角度之间的差异,并通过MATLAB仿真行了验证。 相似文献
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级联式多电平逆变器三角载波移相控制的研究 总被引:1,自引:0,他引:1
级联式多电平逆变器因其具有众多的优点,在高压变频调速领域中得到广泛应用.三角载波移相控制是级联式多电平逆变器常用的控制算法,在介绍级联式多电平逆变器的基础上,详细分析了三角载波移相控制方法的原理,在Matlab/Simulink仿真环境下对级联式多电平逆变器进行了仿真,并给出了TMS320C2812 DSP实现逆变系统的数字化控制方案,利用FPGA与DSP结合的方式实现多路SPWM脉冲对功率单元级联式逆变器进行控制.仿真和实验结果论证了FPGA与主控制器结合实时产生多路脉冲的可行性,验证了基于_二角载波水平移相级联式多电平逆变器具有优良的输出特性. 相似文献
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本文分析了逆变单元多电平串联结构逆变单元的工作模式,介绍了几种常用的PWM控制方法,以六单元串联多电平逆变器为例对其中三种多电平PWM方法进行了比较研究,从中得出多电平载波PWM控制方法输出电压波形dv/dt较小.总谐波含量也较低,最适合用于单元串联多电平逆变器的PWM控制。 相似文献
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This paper proposes a novel dual bridge asymmetric cascaded multilevel inverter to produce 21 level output which requires twelve switches and three sources only when compared with the conventional topologies such as multilevel DC link (MLDCL) and dual H-bridge (DHB). The successful working of the projected topology is validated by carrying out the simulation in MATLAB/Simulink. Modified GWO based PI controller with PWM technique (MGWO-PI-PWM) is applied for controlling the switches, which results in reduced Total Harmonic Distortion (THD).A detailed analysis and comparison study of the number of switches and DC sources required to produce the twenty one level output for the proposed topology is performed and compared with the conventional MLI topologies. A prototype of the inverter is developed and its spectral quality is analyzed. The simulation results are verified experimentally. 相似文献
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This research work focuses to put forward a novel inverter topology of multilevel voltage output. The presented topology is devised by means of switched-capacitor technique (SCT) and switched-capacitor cells count is decided by output levels quantity. In the technique introduced, SCT inverter is in a flexible configuration and has the capability to self-balance the capacitor's voltage with no use of auxiliary circuits what so ever. The topologies presented decrease power switches quantity, isolated dc power supplies, diodes, size and scheme budget when contrasted to similar traditional topologies. For instance, by the involvement of introduced SCMLI structure only 18 power switches were required for 33 levels of output voltage, power switch of 18 Body Diodes and voltage source of 1 dc. This inverter's working principle and anticipated modulation policies are offered, and investigation of power lose is also done. Lastly, the introduced multilevel inverter is assessed for its performance along with the experimental outcomes of the thirty three-level inverter. For permanent magnet synchronous motor (PMSM), multilevel drive is presented in this paper using FPGA (Field Programmable Gate Array) having SiC inverter. For power semiconductor devices, suitable alternate of Silicon (Si) is SiC MOSFET because of its superior material characteristics. So, in order to have accurate operation and achieve high frequency, presented a inverter using SiC MOSFET. 相似文献
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传统控制级联多电平逆变器的频率偏差较大,性能不稳定。为此,设计一种级联多电平逆变器母线电容波动均衡控制系统。在调频盲卷积开发平台的基础上,协调母线电容大数据采集器及均衡控制器的连接方式,完成新型系统的硬件运行环境搭建。利用线性聚类控制程序中的目标节点,移植调频盲卷积的协议栈及规划大数据的循环路径,完成新型系统的软件运行环境搭建,实现基于循环路径的级联多电平逆变器母线电容波动均衡控制系统的搭建。对比试验结果表明,与传统系统相比,应用均衡控制系统后,时域、频域调频波仿真波形的控制有效性均能达到65%以上。 相似文献