论文总字数：19837字

摘 要

近年来随着大量新能源发电机组并网运行，大大增加了电网的复杂性。同时，电网中存在的大量非线性的设备使电网中产生大量的谐波，为了解决这一问题，可以通过在电网中增加滤波器来提高电网电能质量。目前滤波器主要分为L型和LCL型滤波器，而随着电能质量要求不断提高，L型已经逐渐被淘汰，而LCL型APF在高频段存在的谐振问题严重威胁着电网的安全运行。因此，本文对基于LCL两电平有源滤波器展开研究，比较不同的控制策略对于谐波以及谐振问题的效果，设计了LCL系统的参数并选择了电流电压双闭环的控制策略对滤波器进行控制。

本文首先介绍了有源滤波器的连接类型与分类，分别论述了并联型有源滤波器和两电平有源滤波器的系统组成和拓扑结构，分析了它们的工作特点。同时还介绍了基于瞬时无功理论的谐波检测方法作为本次仿真实验的理论基础。然后为了解决LCL滤波器的谐振问题，本文通过在电容支路串联阻尼电阻的方法增加系统阻尼，经过设计计算选择了合适的系统阻尼，有效地抑制了谐振现象。同时，阅读相关文献，本文选择了双闭环控制策略，并分别对电流和电压两个闭环系统的设计。以上便完成了LCL两电平APF的基本设计。最后，根据对比选择，在Simulink模块中对本文提出了基于LCL两电平并联型APF的模型进行仿真，仿真结果表明，经过该两电平滤波器模型滤波后，电网的总谐波失真THD，HRI3和HRI5都明显降低，达到了电网对电能质量的要求，因此该模型能有有效抑制电网中的谐波。

关键词：两电平有源滤波器；LCL谐振；双闭环控制策略

Simulation study on APF

of two-level active power filter based on LCL

Abstract

In recent years, as a large number of new energy generating units are connected to the grid, the complexity of the power grid has been greatly increased. At the same time, a large number of non-linear devices in the power grid cause a large number of harmonics in the power grid, which seriously deteriorates the power quality. In order to solve this problem, the power quality of the power grid can be improved by adding filters in the power grid. At present, filters are mainly divided into L-type and LCL-type filters. With the continuous improvement of power quality requirements, L-type filters have been gradually eliminated, and the resonance problems of LCL-type APF in high frequency bands seriously threaten the safe operation of the power grid. Therefore, this paper studies the LCL two-level active filter, compares the effects of different control strategies on harmonics and resonance problems, designs the parameters of the LCL system and selects the current and voltage double closed-loop control strategy for the filter. control.

This paper first introduces the connection type and classification of active filters, separately discusses the system composition and topology of parallel active filters and two-level active filters, and analyzes their working characteristics. At the same time, the ip-iq harmonic detection method based on instantaneous reactive power theory is introduced as the theoretical basis of this simulation experiment. Then in order to solve the resonance problem of the LCL filter, this paper increases the system damping by connecting a damping resistor in series with the capacitor branch. Through design calculation, the appropriate system damping is selected to effectively suppress the harmonic phenomenon. At the same time, reading the relevant literature, this paper selects the current and voltage double closed-loop control strategy as the control strategy of the filter in this paper, and separately designs the two closed-loop systems of current and voltage. This completes the basic design of the LCL two-level APF. Finally, according to the comparison and selection, a model based on LCL two-level parallel APF is proposed in this paper. The control strategy part adopts the voltage and current double closed-loop control strategy. Then use Simulink module to build a simulation model. The simulation results show that after the two-level filter model is filtered, the total harmonic distortion THD and odd harmonic ratio HRI3 and HRI5 of the power grid are significantly reduced, which reaches the power quality of the power grid. Requirements, so this model can effectively suppress harmonics in the power grid.

Key Words：Two-level active power filter ; LCL resonance ; Double closed-loop control strategy; Simulink simulation

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1 研究的背景和意义 1

1.2 有源滤波器概述 1

1.3 本课题研究的内容 3

第二章 基于LCL的两电平APF原理 5

2.1 并联型有源滤波器系统 5

2.2 两电平APF 5

2.3 谐波检测算法 7

2.4 本章小结 8

第三章 滤波器的设计 9

3.1 LCL谐振问题 9

3.1.1 增加系统阻尼的方法 9

3.1.2 LCL滤波器的参数设计 10

3.2 电流电压双闭环控制策略 11

3.2.1 电流内环控制器 11

3.2.2 电压外环控制器 12

3.3 本章小结 13

第四章 基于LCL两电的APF仿真 14

4.1 仿真参数的设置 14

4.2 仿真模型搭建 14

4.3 Simulink仿真结果 16

4.4 本章小结 17

第五章 结束语 19

致 谢 20

参考文献 21

绪论

1.1 研究的背景和意义

十九世纪中叶，发电机、内燃机以及一系列电器的发明，电力能源作为一种清洁能源，逐渐被应用到工业生产中去，同时也走进了千家万户，从此人类社会进入了电气化时代。后来到了上个世纪七十年代第三次工业革命爆发，电子计算机技术得到了快速发展，人类社会逐渐进入了信息化社会。而社会信息化的强大支持就是大量电子设备的应用，这进一步刺激了电力能源地消费。进入21世纪以后，中国经济搭上了发展的快车，大量的工厂如雨后春笋一般发展壮大，电力能源消费也居于世界前列。

但是近年来经济发展带来环境问题不断出现，环保问题逐渐被提到了舆论地风口浪尖。在国家地扶持下，风能、水能、太阳能等清洁能源得到了快速发展，大量的风能发电机组、光伏阵列以及其他的分散式新能源发电机组实现了并网发电。这些新能源机组在提高发电量的同时，也给电网的运行带来了新的挑战“电力污染”。所谓的污染就是由于大量电力设备以及非线性负载的接入，电网中出现了大量滤波。这些谐波严重影响了电能的质量和电网地安全运行。随着工业制造精度地不断提高，大量精密设备被应用到生产中去，而这些设备对电能质量的要求也不断提高，因此几年来大量学者开始研究电网滤波这一课题。

剩余内容已隐藏，请支付后下载全文，论文总字数：19837字