基于H桥级联的多电平并联型有源滤波器研究

发布时间：2018-07-24 10:15

【摘要】：随着近年来国民经济的飞速发展和生活水平的不断提高,以电力电子技术为基础的中大功率装置以及非线性负载在工业和民用系统中得到大量应用,这对电网的稳定性和电能质量造成严重影响。有源电力滤波器(Active Power Filter, APF)作为一种新颖的电力电子技术领域装置,因其优越的谐波抑制和无功补偿性能,正受到越来越多的关注并得到应用。但是,受电力电子开关器件耐压和开关频率的限制,APF并不能完全适应高压大功率的工作环境。本文结合实际应用,研究了基于H桥级联多电平技术的并联型有源滤波器,通过模块化的级联以提高APF的耐压和增加输出电平数,在高压大功率谐波补偿场合有很好的应用前景。同时讨论了H桥级联多电平技术的拓展应用,对该拓扑进行电力电容器组柔性投切的可能性做出设想并进行实验验证。首先,对基于瞬时无功功率理论的d_q检测法进行分析,并作为本文所研究的并联型有源滤波器检测方法。针对电流跟踪控制方法,介绍了直接电流控制方法中的三角载波比较控制法,并就该方法分析了PI控制器和重复控制器的原理并进行控制器的设计,再将两者结合,研究基于这两种控制法的复合控制策略,该复合控制策略既保证了跟踪误差的尽可能小,又兼顾了变流器的响应速度。就所研究的并联型有源滤波器模型中开关器件IGBT的型号、H桥功率模块中直流侧电容数值以及交流侧单电感滤波器的选型进行了分析计算。其次,讨论了该H桥级联有源滤波器的单极倍频载波移相调制方法,就单极倍频控制方法,具体分析了单极倍频CPS-SPWM方法中输出波形基波分量和谐波分量的组成。由于每个H桥功率单元直流稳压电容互相独立,且模块间损耗存在差异,运行时直流侧电压会产生波动,因此讨论了两层结构的直流侧电压均压稳压控制方法,即上层进行相间直流电压总压的稳压,下层进行每个H桥功率单元直流侧的均压,并分别就控制器设计和充放电情况进行分析。然后,以PSIM仿真软件为实验仿真平台,搭建了三相星形连接H桥三级联拓扑的APF仿真模型。设计并组装了H桥级联APF的硬件实验平台,并对主电路、控制系统和结构设计进行阐述,就软启动、直流侧稳压、定量发无功和谐波补偿等功能分别进行实验和记录,验证了本文所述的理论和各种控制策略的可行性和正确性。最后,在分析H桥级联多电平技术的相关控制方法,并实验研究基于该拓扑结构的APF的基础上,为进一步讨论H桥级联多电平技术的优越性和应用领域拓展,同时基于江苏省电力公司经济技术研究院的项目依托,探讨了将H桥级联多电平技术运用到电力电容器组的柔性投切技术当中。在原先H桥级联APF硬件实验平台的基础上,改造了一套柔性投切试验平台,介绍了主电路连接方式及其控制方法,对电容器组进行柔性投切,并对补偿容量进行动态控制,分析该方法对电能质量指标的改善。
[Abstract]:With the rapid development of the national economy and the continuous improvement of the living standard in recent years, the power and electronic technology based medium and large power devices and nonlinear loads have been widely used in industrial and civil systems, which have a serious impact on the stability and power quality of the power grid. Active power filter (Active Power Filter, APF) Because of its superior harmonic suppression and reactive power compensation performance, the device of a novel power electronic technology field is being paid more and more attention and has been applied. However, APF can not fully adapt to the working environment of high voltage and large work rate due to the pressure and switching frequency of power electronic switching devices. The parallel active filter based on H bridge cascaded multilevel technology can improve the voltage and output level of APF by modularization cascade. It has a good application prospect in the high-voltage and high-power harmonic compensation situation. At the same time, the extended application of cascaded multilevel technology of H bridge is discussed, and the flexible switching of the power capacitor bank is carried out in this topology. First, the d_q detection method based on the instantaneous reactive power theory is analyzed, and as the parallel active filter detection method studied in this paper, the three angle carrier comparison control method in the direct current control method is introduced, and the PI method is introduced, and the method is analyzed in this method. The principle of the controller and the repetitive controller is designed and the controller is designed. Then the combination of the two is combined to study the compound control strategy based on these two control methods. The compound control strategy not only ensures the minimum tracking error as small as possible, but also takes into account the response speed of the converter. In the study of the shunt active filter model, the switch device IGBT The model, the DC side capacitance value of the H bridge power module and the selection of the AC side single inductor filter are analyzed and calculated. Secondly, the monopole frequency shift modulation method of the H bridge cascaded active filter is discussed, and the single pole frequency doubling control method is used to analyze the output waveform base wave component of the single pole frequency doubling CPS-SPWM method. The composition of harmonic components. Because the DC voltage stable capacitor of each H bridge power unit is independent of each other, and the loss among modules is different, the DC side voltage will fluctuate during operation. Therefore, the DC side voltage and voltage steady voltage control method of the two layer structure is discussed, that is, the upper layer carries out the voltage steady voltage of the phase direct current voltage, and the lower layer carries out each H bridge power. The controller design and charge discharge situation are analyzed respectively. Then, using PSIM simulation software as the experimental simulation platform, the APF simulation model of the three-phase star connected H bridge three cascade topology is built. The hardware experiment platform of the H bridge cascade APF is designed and assembled, and the main circuit, the control system and the structure design are carried out. In this paper, the functions of soft start, DC side voltage stabilizing and quantitative reactive power and harmonic compensation are tested and recorded respectively. The feasibility and correctness of the theory and various control strategies described in this paper are verified. Finally, the related control methods of the H bridge cascade multilevel technology are analyzed, and the APF based on the topology is studied experimentally. In order to further discuss the advantages and application fields of H bridge cascaded multilevel technology, based on the support of Jiangsu electric power company's economic and Technical Research Institute, the application of cascaded multilevel technology of H bridge to the flexible switching technology of power capacitor banks is discussed. On the basis of the original H bridge cascade APF hardware experimental platform, the transformation is made. A set of flexible cutting and cutting test platform is introduced. The connection mode and control method of the main circuit are introduced, the capacitor bank is flexibly cast, and the compensation capacity is dynamically controlled, and the improvement of the power quality index is analyzed.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM761

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