基于有效值谐波检测新方法的大容量APF研究

发布时间：2019-05-19 12:57

【摘要】：有源电力滤波器(Active Power Filter,APF)被公认为是一种动态抑制谐波、动态补偿无功功率的新型电力电子装置。谐波指令电流的检测、补偿电流的产生和跟踪控制以及APF容量的提高是限制其广泛应用的三大关键技术，本文将对这三个关键技术进行研究。快速准确的谐波检测是实现补偿的先决条件。基于瞬时无功理论的ip-iq法虽然广泛应用，但是其复杂的坐标变换和低通滤波器的设计影响了检测的实时性。本文提出一种通过近似构造基波电流来提取谐波电流的方法，即利用负载电流有效值等效替代其基波有效值，利用锁相环获取负载电流基波相位或电网电压相位构造基波电流。另外，，研究了其直流侧电压控制策略，进一步分析了该算法的误差补偿和理论延时。最后，仿真和实验验证了该检测算法和控制策略的可行性。与此同时，补偿电流是否有效的跟踪控制，直接决定APF补偿效果。传统的滞环电流控制原理简单，动态响应快，可靠性高，鲁棒性强，但是开关频率不稳定。本文采用一种基于空间矢量的滞环电流控制新方法，既保留了传统滞环控制的优点，又在一定程度上稳定了开关频率。通过与传统滞环控制策略的仿真对比，证明了该方法的优越性。容量不足是限制APF运用到大容量场合的关键因素之一，本文在综合分析传统两电平和多电平APF的优缺点的基础上，采用两电平多模块APF并联的方法，通过均流，不仅提升了总容量和单个APF的利用率，还有利于输入电感的选型。另外，对模块间是否存在环流进行了理论分析。在理论分析基础上建立了MATLAB仿真模型，结果验证了所述方法的有效性和分析的正确性。最后，基于3模块并联的APF实验平台，进行了本文所提出的算法的验证，结果验证了所提算法的可行性和正确性。
[Abstract]:Active Power filter (Active Power Filter,APF) is recognized as a new type of power electronic device which can dynamically suppress harmonics and dynamically compensate reactive power. The detection of harmonic instruction current, the generation and tracking control of compensation current and the improvement of APF capacity are the three key technologies that limit its wide application. In this paper, these three key technologies will be studied. Fast and accurate harmonic detection is a prerequisite for compensation. Although the ip-iq method based on instantaneous reactive power theory is widely used, its complex coordinate transformation and the design of low-pass filter affect the real-time performance of detection. In this paper, a method of extracting harmonic current by approximate construction of fundamental current is proposed, that is, the effective value of load current is used to replace the effective value of fundamental wave, and the phase-locked loop is used to obtain the fundamental phase of load current or the voltage phase of power grid to construct the fundamental current. In addition, the DC side voltage control strategy is studied, and the error compensation and theoretical delay of the algorithm are further analyzed. Finally, the feasibility of the detection algorithm and control strategy is verified by simulation and experiment. At the same time, whether the compensation current is effective tracking control directly determines the compensation effect of APF. The traditional hysteretic current control principle is simple, the dynamic response is fast, the reliability is high, the robustness is strong, but the switching frequency is unstable. In this paper, a new method of hysteretic current control based on space vector is adopted, which not only preserves the advantages of traditional hysteretic control, but also stabilizes the switching frequency to a certain extent. Compared with the traditional hysteretic control strategy, the superiority of this method is proved. Insufficient capacity is one of the key factors that limit the application of APF to large capacity occasions. Based on the comprehensive analysis of the advantages and disadvantages of traditional two-level and multi-level APF, this paper adopts the method of two-level and multi-module APF in parallel, through current sharing. It not only improves the total capacity and the utilization rate of a single APF, but also facilitates the selection of input inductor. In addition, the existence of circulation between modules is analyzed theoretically. Based on the theoretical analysis, the MATLAB simulation model is established, and the results verify the effectiveness of the method and the correctness of the analysis. Finally, based on the three-module parallel APF experimental platform, the algorithm proposed in this paper is verified, and the results verify the feasibility and correctness of the proposed algorithm.
【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】：TN713.8;TM761

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