共查询到19条相似文献,搜索用时 125 毫秒
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根据LLC的拓扑结构和工作原理,建立LLC全桥谐振变流器的数学模型。基于模型中谐振电感、谐振电容、变压器的励磁电感及输入电压等与输出电压的模型关系,对LLC变流器的系统增益特性与系统参数之间的关系进行分析,得到一种电流角的设计方法。基于变压器励磁电感的电流与谐振电感电流的比值,采用此方法设计了一台3.3 kW,额定谐振频率为100 kHz的全桥LLC谐振变流器。实验结果证实了此设计方法的可行性。 相似文献
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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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《现代电子技术》2019,(23):104-109
针对直驱永磁风力发电系统中发电效率低和变流器输出电流谐波大的问题,研究风力机和直驱永磁同步发电机(D-PMSG)的数学模型,提出一种双空间矢量脉宽调制(SVPWM)式机侧与网侧变流器并网控制策略。为了实现最大风能捕获,机侧变流器采用转速外环与具有前馈解耦的双电流内环闭环控制策略。为了保证直流电压恒定性与输出电流快速响应性,网侧变流器采用电压外环与具有前馈解耦的双电流内环闭环控制策略,实现功率解耦控制和单位功率因素控制。此外,为了减小变流器输出电流的谐波,机侧与网侧均采用SVPWM调制技术。最后,在Matlab/Simulink环境下进行系统并网控制仿真和电流谐波的快速傅里叶变换(FFT)分析。仿真结果表明,文中所提的控制策略满足风力发电系统的并网控制要求,且系统的动态响应好、电流谐波含量少。 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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目前,彩色电视摄象机中普遍采用了晶体管开关型行扫描电路,对其行扫描电流的非线性失真多数采用“饱和电感”及引入”预失真电流”等方法来校正.这些方法在某种程度上改善了线性,但效果尚不够理想.如引入预失真电流后,校正电流为抛物状,仅抵消指数型电流中二次谐波分量,信号中残存三次谐波等高次 相似文献
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介绍仅用一个主开关管及一个辅助开关提高设备的输入侧三相交流功率因数的零电流关断(ZCS)升压型变换器的基本电路,说明升压电感电流工作在不连续状态的必要性。采用三相整流电压的6次谐波前馈(注入),以减小三相电源的5次庇波电流。减小主开关管关断损耗采用了零电流关断电路。 相似文献
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In this article, the PWM inverter works as a controlled fundamental current source in the single phase series hybrid active power filter (APF) based on fundamental magnetic flux compensation (FMFC). The series transformer can exhibit the self-impedance of primary winding to harmonic current, which forces harmonic current to flow into passive power filter. With the influence of harmonic current, the voltage of primary winding of transformer is a harmonic voltage, which makes the inverter output currents have a certain harmonic component, and it degrades the filtering characteristics. On the basis of PWM inverter, the mathematical model of series hybrid APF is established, and the filtering characteristics of single phase APF are analysed in detail. Three methods are gained to improve filtering characteristics: reasonably designing the inverter output filter inductance, increasing series transformer ratio and adopting voltage feed-forward control. Experimental results show that the proposed APF has greater validity. 相似文献
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马国胜 《信息技术与信息化》2000,(3)
本文介绍了一种在直流电源中运用的带滤波电感的GQS滤波电路,此电路在传统滤波电路的基础上,加用滤波电感,可大大降低对电网的谐波污染,提高电源的功率因数。 相似文献
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文中提出了一种基于有源滤波与光伏发电的并网逆变器的控制方法,在并联型有源电力滤波器的基础上拓展了新能源发电功能,采用电压电流双环对并网逆变直流侧电压和系统电网输出有功电流进行控制。该并网逆变器既可以滤除负载的谐波和补偿负载的无功功率,也可以实现有功功率的有效传输,适于未来微电网中并网逆变器的应用研究。 相似文献
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基于Zeta变换器的单相功率因子校正电路 总被引:1,自引:0,他引:1
分析了基于Zeta变换器的功率因子校正(PFC)电路;研究了工作在不连续导电模式的Zeta变换器实现功率因子校正的机理;推导出了保证电路实现功率因子接近1的临界电感值。SPICE仿真和实验结果都证明了理论分析是正确的,为设计功率因子校正的Zeta变换器提供了理论依据。 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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Rectifier line current harmonics interfere with proper power system operation, reduce rectifier power factor, and limit the power available from a given service. The rectifier's output filter inductance determines the rectifier line current waveform, the line current harmonics, and the power factor. Classical rectifier analysis usually assumes a near-infinite output filter inductance, which introduces significant error in the estimation of line current harmonics and power factor. A quantitative analysis of single and three-phase rectifier line current harmonics and power factor as a function of the output filter inductance is presented. For the single phase rectifier, one value of finite output filter inductance produces maximum power factor and a different value of finite output filter inductance produces minimum line current harmonics. For the three phase rectifier, a near-infinite output filter inductance produces minimum line current harmonics and maximum power factor, and the smallest inductance that approximates a near-infinite inductance is determined 相似文献
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Detjen D. Jacobs J. De Doncker R.W. Mall H.-G. 《Power Electronics, IEEE Transactions on》2001,16(6):821-827
A new hybrid power filter is presented for three phase industrial power systems which include passive power factor correction equipment (PFC). The hybrid filter damps resonances occurring between line impedances and the PFC. In addition, the hybrid filter topology can be used to compensate harmonic currents. The capacitors of the PFC, which generally cause resonant problems in harmonic distorted networks, can be used for passive filtering by connecting a transformer with a low magnetizing inductance in series hence creating a single harmonic trap. The primary side of the transformer is connected to a low VA-rated three-phase current controlled inverter which builds the active part of the hybrid topology. Simulation results and experimental results are presented verifying the damping and harmonic compensation performance of the proposed topology 相似文献