基于重复控制的三相四开关并联型有源电力滤波器的研究

发布时间：2018-08-27 07:37

【摘要】：有源电力滤波器(active power filter, APF)在治理谐波、无功补偿和改善电网电能质量方面取得了明显的成效。本文的研究对象为三相三线制电网电流,详细分析传统的APF电路拓扑结构,在此基础上提出适用于低压中小容量谐波治理和无功补偿需求的三相四开关并联型有源电力滤波器(three Phase four switch shunt active power filter, TFSSAPF),主要围绕其谐波电流检测方法、空间矢量脉宽调伟(Space Vector Pulse Width Modulation, SVPWM)算法、指令电流控制策略以及直流侧串联双电容稳压控制等方面展开分析,将传统重复控制器进行改进,运用于TFSSAPF系统。本文首先介绍传统并联型有源电力滤波器谐波电流检测算法,在理论研究和仿真实现上分析ip-iq(?)波电流检测算法。本文在自适应滤波原理的基础上,提出将变步长最小均方(Least mean square, LMS)谐波检测算法应用于TFSSAPF系统的谐波电流检测中。通过仿真实验,验证了变步长LMS谐波检测算法具有更好的准确性与快速性,有效地解决稳态误差与收敛速度之间的矛盾。其次,本文发现传统的SVPWM算法不适用于TFSSAPF系统,提出一种适用于TFSSAPF系统的七段式SVPWM算法,实现了TFSSAPF系统三相补偿电流的输出。然后本文研究重复控制器的工作原理,将其进行改进,最后将其与传统的比例积分控制器并联结合组成指令电流控制系统,有效地抑制周期性扰动,实现补偿电流能够无静差地跟踪控制指令电流。再者本文详细分析直流侧电压波动的原因和传统的直流侧电压稳定方法。在传统的稳压方法基础上,提出一种适用于TFSSAPF系统的直流侧串联双电容稳压控制策略,将其与变步长LMS谐波电流检测环节相结合,有效地稳定直流侧串联双电容的电压,保证TFSSAPF系统稳定运行。最后,本文利用MATLAB7.0/simulink对TFSSAPF系统进行仿真建模,通过比较分析TFSSAPF系统的仿真结果,验证TFSSAPF系统达到抑制谐波和无功补偿的目的,将负载电流的畸变率从最初28.87%降低至3.13%,说明本文提出的谐波检测算法、七段式SVPWM算法和指令电流控制系统在谐波电流抑制方面取得显著的效果,仿真结果说明此方法具有一定工程实现价值。
[Abstract]:Active power filter (active power filter, APF) has achieved remarkable results in harmonic control, reactive power compensation and power quality improvement. The research object of this paper is three-phase three-wire network current. The traditional APF circuit topology is analyzed in detail. On this basis, a three-phase four-switch shunt active power filter (three Phase four switch shunt active power filter, TFSSAPF),) is proposed, which is suitable for low voltage, medium and small capacity harmonic treatment and reactive power compensation, and mainly revolves around its harmonic current detection method. The space vector pulse width modulation (Space Vector Pulse Width Modulation, SVPWM) algorithm, the command current control strategy and the DC side series double capacitor voltage stabilizing control are analyzed. The traditional repetitive controller is improved and applied to the TFSSAPF system. In this paper, the harmonic current detection algorithm of the traditional shunt active power filter is introduced, and the ip-iq (?) is analyzed on the basis of theoretical research and simulation. Wave current detection algorithm. Based on the principle of adaptive filtering, a variable step minimum mean square (Least mean square, LMS) harmonic detection algorithm is proposed for harmonic current detection in TFSSAPF systems. The simulation results show that the variable step size LMS harmonic detection algorithm has better accuracy and rapidity, and effectively solves the contradiction between steady state error and convergence speed. Secondly, this paper finds that the traditional SVPWM algorithm is not suitable for TFSSAPF system, and proposes a seven-segment SVPWM algorithm suitable for TFSSAPF system, which realizes the output of three-phase compensation current in TFSSAPF system. Then this paper studies the principle of repetitive controller and improves it. Finally, it is combined with the traditional proportional integral controller in parallel to form an instruction current control system, which can effectively suppress periodic disturbances. The compensation current can track the control command current without static error. Furthermore, the reason of DC side voltage fluctuation and the traditional DC side voltage stabilization method are analyzed in detail. Based on the traditional voltage stabilization method, a DC side series double capacitor voltage control strategy for TFSSAPF system is proposed. It is combined with the variable step size LMS harmonic current detection link to effectively stabilize the DC side series double capacitance voltage. Ensure stable operation of TFSSAPF system. Finally, MATLAB7.0/simulink is used to simulate and model the TFSSAPF system. By comparing and analyzing the simulation results of the TFSSAPF system, it is verified that the TFSSAPF system achieves the purpose of harmonic suppression and reactive power compensation. The distortion rate of the load current is reduced from 28.87% to 3.13%, which shows that the harmonic detection algorithm, the seven-segment SVPWM algorithm and the instruction current control system have achieved remarkable results in harmonic current suppression. The simulation results show that this method has certain engineering value.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN713.8;TM761

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