大容量多电平APF控制策略研究

发布时间：2019-05-25 01:10

【摘要】：伴随着电力电子设备的大范围应用,非线性负载给电力系统带入大量的谐波。因此对谐波的治理得到了人们广泛的关注。有源电力滤波器(APF)因其可以实时、动态地补偿谐波和无功的优点而受到了人们高度的重视。目前,有源电力滤波器在低压配电系统领域已经得到了很好的应用,但是在高压、大容量场合的应用却仍然不成熟。制约其应用的主要因素是功率器件的开关频率和工作电压之间的矛盾。而本文介绍的载波移相调制技术(CPS-SPWM)和H桥级联拓扑结构解决了以上问题。本文首先对大容量、多电平技术的发展及拓扑结构做了系统介绍。然后重点对级联H桥拓扑结构在APF中的应用进行研究。详细分析了级联H桥的调制技术CPS-SPWM和级联H桥电路的工作模式。对于APF的谐波检测环节,简单介绍了瞬时无功功率理论及其在谐波检测技术中的应用。电流跟踪控制方面,重点分析了PI+重复控制的复合控制技术,给出了控制参数的选择方法。同时对于级联H桥APF主电路参数的选择也做了较为详细的介绍。最后着重分析和介绍了级联H桥APF的关键技术——直流侧电压的平衡。首先从直流侧和电网之间的能量流动关系入手,分析了电压不平衡对系统造成的影响。接着利用数学公式推导出造成级联H桥各直流侧电压不均衡的机理。最后通过分层的电压控制实现了各模块、各相之间电压的平衡。
[Abstract]:With the wide application of power electronic equipment, nonlinear load brings a large number of harmonics to the power system. Therefore, the control of harmonics has been widely concerned. Active power filter (APF) has attracted great attention because of its advantages of real-time and dynamic compensation for harmonics and reactive power. At present, active power filter (APF) has been well applied in the field of low voltage distribution system, but it is still immature in high voltage and large capacity situations. The main factor restricting its application is the contradiction between the switching frequency and the working voltage of the power device. The carrier phase shift modulation (CPS-SPWM) and H bridge concatenated topology introduced in this paper solve the above problems. In this paper, the development and topology of large capacity and multi-level technology are introduced systematically. Then the application of cascade H-bridge topology in APF is studied. The modulation technology CPS-SPWM of cascade H bridge and the working mode of cascade H bridge circuit are analyzed in detail. For the harmonic detection of APF, the instantaneous reactive power theory and its application in harmonic detection technology are briefly introduced. In the aspect of current tracking control, the compound control technology of PI repetitive control is analyzed, and the selection method of control parameters is given. At the same time, the selection of main circuit parameters of cascade H-bridge APF is also introduced in detail. Finally, the voltage balance on DC side, which is the key technology of cascade H-bridge APF, is analyzed and introduced. Starting with the energy flow relationship between DC side and power grid, the influence of voltage imbalance on the system is analyzed. Then the mechanism of voltage imbalance on the DC side of the cascade H bridge is derived by using the mathematical formula. Finally, the voltage balance between each module and phase is realized by hierarchical voltage control.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM761;TN713.8

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