共查询到17条相似文献,搜索用时 109 毫秒
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本文提出了一种新型三相电压型整流器LCL滤波器的设计方法,该方法根据IEEE-519标准要求的电流谐波限制条件,将谐振频率fres,网侧电感Lg与变流器侧电感Lr的比例因子r作为已知量,利用SVPWM调制方式产生谐波电压幅值进行迭代运算来计算LCL滤波器参数。分析结果表明:LCL滤波器的谐振频率决定了其总电感量IT,网侧电感、变流器侧电感值可以根据r的取值灵活确定,系统功率因数要求限制了滤波电容值Cf的上限。文章详细闸述了LCL滤波器参数的取值原则与设计步骤,并给出了设计实例,仿真结果验证了所提设计方法的有效性。 相似文献
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LCL滤波器在并联型有源电力滤波器中的设计 总被引:1,自引:0,他引:1
在满足相同的高频滤波效果的情况下,LCL滤波器所需的总电感值比L滤波器小,因此更适于在大功率、开关频率较低的电流源控制型并网设备上应用。然而针对该类型滤波器的参数设计不仅关系到开关频率处纹波抑制效果,同时也会影响电流控制器的性能。随着高频谐波抑制效果明显的LCL滤波器在并联型有源滤波器中应用,基于谐波电流跟踪控制器的LCL参数设计需要进一步研究,因此文中基于并联型有源电力滤波器给出一套LCL滤波器设计方法,并通过仿真验证该LCL滤波器的有源电力滤波器的有效性。 相似文献
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提出了新型并网逆变器的高阶功率滤波器的拓扑电路,称为LLCL滤波器。采用新型LLCL型滤波器对单相光伏并网逆变器进行滤波,LLCL滤波器通过在传统LCL滤波器的电容支路中串联一个小的电感达到在开关频率处产生串联谐振,相比LCL型滤波器能够更大程度地对串联谐振频率处的电流谐波进行衰减,可以减少电感装置的体积和重量,减少动态响应时间。更重要的是,能够减少电网侧的电感值,这样可以提高特征谐振频率点,有利于并网逆变器的控制。对比分析了传统LCL滤波器和LLCL滤波器的性能,证实和评估LLCL滤波器的优越性。对LLCL滤波器进行了参数设计,使用Matlab仿真软件搭建模型,仿真结果表明系统具有较好的稳态性能,且抗干扰性能好。 相似文献
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针对SHEPWM调制方法应用于精密开关校验电源中出现的选定消去的谐波部分幅值略高,不能满足调节精度要求的问题,依据对原有的SHEPWM的理论分析,提出了一种优化的SHEPWM调制方法,建立了此种优化SHEP-WM的理论模型,并依据建立的数学模型对此种优化方法控制的单相两重化全桥逆变器进行了仿真。仿真结果表明这种优化的SHEPWM控制策略下的校验电源可以达到更高的调节精度,更优的消谐效果。 相似文献
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新能源并网逆变器入网电流通用控制 总被引:1,自引:0,他引:1
太阳能电池、风力发电,以及燃料电池等新能源发电中的并网逆变器技术的研究已经成为一个重要的研究方向。为了消除逆变器输出电流中的高次谐波,通常采用LCL滤波器对谐波进行处理。但是LCL滤波器是无阻尼三阶系统,使输出容易产生谐振,因此逆变器电流控制器的研究成为了研究的热点。本文就当今使用较为热门的电容电流内环、入网电流外环的双闭环控制策略进行分析,使用MATLAB/Simulink进行仿真,并在仿真中加入功率因数(PF)的验证。从仿真结果看出该方案可有效地避免入网电流谐振,入网电流能很好地跟踪并网电压,达到同频同相,功率因数约等于1,并且在FFT谐波分析中达到满意的效果。 相似文献
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LCL滤波器可以有效抑制高次谐波,然而LCL滤波器的使用增加了系统阶数,对系统控制策略提出了更高的要求。为此,采用一种基于极点配置的电流双环控制策略,以DSP作为主控制器,充分利用DSP控制器的CLA、高精度PWM和AD等模块,使其硬件电路大大简化。最后,通过极点配置的方法选定控制参数,整个系统操作简单、控制灵活、功能强大,实现了节能降耗和精密制动。 相似文献
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Model-based generation of low distortion currents in grid-coupled PWM-inverters using an LCL output filter 总被引:3,自引:0,他引:3
Bolsens B. De Brabandere K. Van den Keybus J. Driesen J. Belmans R. 《Power Electronics, IEEE Transactions on》2006,21(4):1032-1040
In this paper, a single phase inductance-capacitance-inductance (LCL) output stage for grid coupled inverters is designed and built. An accurate model and observer of the output filter and the distorted grid voltage are implemented. The paper deals with the construction of a 14-state model, and the feedback control loop to obtain adequate closed loop response. Simulations indicate a good performance of the controller, with a total harmonic current distortion (THD) below 1%. Experimental results confirm simulations, and illustrate the correct operation of the Kalman observer to estimate the distorted grid voltage (THD 3%). The observer only uses the inverter current measurement as input. The output filter effectively reduces the pulsewidth modulation harmonics in the grid current. 相似文献
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Grid current regulation of a three-phase voltage source inverter with an LCL input filter 总被引:16,自引:0,他引:16
Many grid connected power electronic systems, such as STATCOMs, UPFCs, and distributed generation system interfaces, use a voltage source inverter (VSI) connected to the supply network through a filter. This filter, typically a series inductance, acts to reduce the switching harmonics entering the distribution network. An alternative filter is a LCL network, which can achieve reduced levels of harmonic distortion at lower switching frequencies and with less inductance, and therefore has potential benefits for higher power applications. However, systems incorporating LCL filters require more complex control strategies and are not commonly presented in literature. This paper proposes a robust strategy for regulating the grid current entering a distribution network from a three-phase VSI system connected via a LCL filter. The strategy integrates an outer loop grid current regulator with inner capacitor current regulation to stabilize the system. A synchronous frame PI current regulation strategy is used for the outer grid current control loop. Linear analysis, simulation, and experimental results are used to verify the stability of the control algorithm across a range of operating conditions. Finally, expressions for ""harmonic impedance" of the system are derived to study the effects of supply voltage distortion on the harmonic performance of the system. 相似文献
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提出了一种新型微带发夹型滤波器,通过在传统发夹滤波器结构之后采用短路短截线与高次谐波四分之一波长开路短截线并联谐振的方法,可在不影响中频信号的前提下,对高次谐波进行有效抑制.同时在开短路支节之间串联一段微带径向短截线,能实现对谐波的宽带抑制.仿真结果表明此滤波器结构紧凑,具有良好的级联特性,在结构和性能上具有较大优势,适用于多种微波通信系统. 相似文献
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An injection method for an active filter which eliminates the harmonics present in AC lines by injecting PWM harmonic compensating current is proposed. In the proposed method, the active filter produces a pulsewidth modulation (PWM) current that cancels the existing harmonics up to any order completely. To generate such PWM current, both inverter and DC current source is needed. The current source can be replaced by a large inductor without any external power source. This can be achieved by providing the inverter with rectifying capability because the inverter has the same circuit structure as the rectifier. Therefore, the proposed model of PWM injection current includes not only the harmonic components to suppress the existing harmonics up to any order, but also the fundamental one, to raise the inductor current to any desired value. The characteristics of the injection method are investigated through a digital computer simulation. Feasibility is proved by the experimental results 相似文献
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Huynh Tue 《Communications, IEEE Transactions on》1976,24(12):1317-1321
By factorizing a finite sum of harmonics, an expression is obtained for an FM demodulator output when the modulating signal is a simple sinusoid and the RF filter is an ideal bandpass filter. Using this result, harmonic distortions and the signal-to-distortion ratio are defined and computed; several curves are drawn to show the variation of these quantities in terms of the modulation index and the normalized bandwidth. 相似文献
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Jun Tian Qiaofu Chen Lu Cheng Changzheng Zhang 《International Journal of Electronics》2013,100(10):1071-1084
In this article, the principle of a novel shunt hybrid active power filter (APF) based on magnetic flux compensation is proposed. The parallel transformer can exhibit nearly zero impedance to harmonic current whereas the zero magnetic flux condition is satisfied for harmonics, which leads harmonic current to flow into the transformer branch. Meanwhile, the transformer can exhibit continuously adjustable impedance to the fundamental current based on fundamental magnetic flux compensation, which works together with the passive power filter to compensate for reactive power. A mathematical model is established for system stability analysis and steady state estimation. The experimental results verify that the performance of the proposed APF is satisfactory in harmonic suppression as well as reactive power compensation. 相似文献