级联H桥有源滤波器研究

发布时间：2018-06-01 16:07

本文选题：有源滤波器 + 单重H桥　；参考：《中国矿业大学》2014年硕士论文

【摘要】：有源电力滤波器(APF)是一种能够动态抑制谐波和补偿无功的电力电子装置。普通的两电平拓扑结构，因电压等级低，，容量低而在某些场合下的应用被限制。而级联型拓扑能够直接输出高压，输出相同电平下所需器件数目最少，而将APF的应用范围拓宽到大功率场合。本文以单重H桥级联型有源滤波器为研究对象，对其中若干关键技术进行了深入研究。谐波电流的检测是有源电力滤波器的关键技术之一，检测的快速性与准确性直接影响到整个系统的补偿性能。本文采用一种改进的滑窗迭代DFT谐波电流检测方法，利用离散傅立叶原理及滑窗迭代方法，通过引入固定的迭代因子，以及重建迭代方程组环节，从而省去了电压锁相环节及旋转因子重构环节。减小了系统的计算量，而且便于数字化实现。传统的空间矢量不能直接使用于单重级联H桥拓扑结构。本文采用错时空间矢量的调制方法，首先介绍了单重级联H桥拓扑与组合变流器的等价关系，随后分析了该调制方法的原理及实现方法，其综合了载波移相等效开关频率高以及空间矢量SVPWM直流侧电压利用率高的优点。本文采用LCL滤波器代替传统单电感滤波器，作为有源滤波器的输出滤波器与电网相连，并采用无源阻尼的方法对三阶LCL系统实现谐振抑制。它兼顾了低频段增益和高频段衰减。分析了LCL滤波器各元件的制约关系，并利用实例设计，验证了适用于单重H桥有源滤波器的各参数具体的选择方法。最后通过MATLAB仿真平台对所设计的滑窗迭代DFT谐波检测方法，适用于单重H桥拓扑结构的错时空间矢量调制方法，以及无源LCL参数选取方法进行了仿真验证，并通过实验平台对部分理论进行了实验验证。
[Abstract]:Active Power filter (APF) is a kind of power electronic device which can dynamically suppress harmonics and compensate reactive power. General two-level topology whose applications in some cases are limited due to low voltage levels and low capacity. The cascade topology can output high voltage directly and the number of devices required at the same output level is the least. The application of APF can be extended to high power applications. In this paper, some key technologies of single H bridge cascaded active filter are studied. Harmonic current detection is one of the key technologies of active power filter (APF). The speed and accuracy of detection directly affect the compensation performance of the whole system. In this paper, an improved sliding window iterative DFT harmonic current detection method is adopted. The discrete Fourier principle and sliding window iterative method are used to reconstruct the iterative equations by introducing a fixed iteration factor. Thus, voltage phase locked loop and rotation factor reconstruction are eliminated. The calculation of the system is reduced, and it is easy to realize digitally. The traditional space vector can not be directly used in single cascade H bridge topology. In this paper, the equivalent relation between single cascade H bridge topology and combined converter is introduced by using staggered space vector modulation method. Then, the principle and implementation of this modulation method are analyzed. It combines the advantages of high carrier phase shift equivalent switching frequency and high utilization of DC side voltage of space vector SVPWM. In this paper, LCL filter is used to replace the traditional single inductor filter, which is used as the output filter of the active filter to connect to the power grid, and the passive damping method is used to suppress the resonance of the third-order LCL system. It takes into account the gain of low frequency band and the attenuation of high frequency band. The constraint relation of each component of LCL filter is analyzed, and the method of selecting parameters suitable for single H-bridge active filter is verified by an example design. Finally, the iterative DFT harmonic detection method with sliding window is simulated on the MATLAB simulation platform, which is suitable for the staggered space vector modulation method of single H bridge topology and the passive LCL parameter selection method. Some of the theories are verified by experiment platform.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM761;TN713.8

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