基于LCL滤波器的三相三线并联型APF研究

发布时间：2018-04-15 18:28

本文选题：有源电力滤波器 + LCL滤波器　；参考：《西南交通大学》2017年硕士论文

【摘要】：以电力电子装置为代表的非线性负载已成为人们生产、生活中必不可少的部分,其大量应用使得电网谐波污染日趋严重。有源电力滤波器(Active Power Filter,APF)具有补偿精度高、响应快、功能灵活、不易受电网影响等优点,在电能质量标准的要求和市场需求的推动下,采用有源电力滤波器治理谐波必将成为电能质量治理的重要发展方向之一。论文以基于LCL滤波器的三相三线并联型APF为研究对象,对其主电路参数和控制策略从以下方面进行了研究:首先,研究了 LCL滤波器谐振原理,指出在LCL滤波器传递函数中引入阻尼项是一种理想的谐振阻尼方法。从传递函数的角度研究了滤波电容串联电阻和并联电阻的无源阻尼法,揭示了其阻尼本质是引入了阻尼项,而并联电阻的方式由于只引入了阻尼项,是一种理想的阻尼形式。从配置阻尼项的角度研究了四种状态变量反馈的有源阻尼法的可行性,指出了滤波电容电流比例反馈是最佳的方法。其次,建立了APF在三相静止abc坐标系、两相静止αβ坐标系和两相旋转dq坐标系下的数学模型。分析了 APF稳态工作时的能量交换形式和功率流动关系,给出了基于能量波动的直流母线电容参数设计方法。研究了APF补偿目标和LCL滤波器频率特性,提出了一种适用于APF的LCL滤波器参数设计方法。然后,从工程应用角度对基于时域的i_p-i_q法和基于频域的滑窗迭代DFT法这两种最常用的谐波检测方法进行了原理阐述和对比分析,指出滑窗迭代DFT法实用性更强。设计了直流母线电压控制器和软启动策略。基于三相静止坐标系推导了并网电流外环、滤波电容电流内环的电流双环数学模型,设计了电流控制器、电容电流反馈参数及电网电压前馈策略。最后,搭建了基于Matlab的仿真模型和基于TMS320F28335DSP的实验平台,对论文设计的主电路参数和控制策略进行仿真和实验,仿真与实验结果一致,验证了主电路参数和控制策略设计的有效性,同时也验证了 LCL滤波器在APF应用中的可行性以及相对L滤波器的优越性。
[Abstract]:The nonlinear load represented by power electronic devices has become an indispensable part of people's production and life. A large number of applications make the harmonic pollution of power grid become more and more serious.Active Power filter (APF) has the advantages of high compensation accuracy, fast response, flexible function and not easily affected by power network.Active power filter (APF) will become one of the important development directions of power quality control.The main circuit parameters and control strategies of three-phase three-wire parallel APF based on LCL filter are studied in the following aspects: firstly, the resonant principle of LCL filter is studied.It is pointed out that the introduction of damping term into the transfer function of LCL filter is an ideal resonant damping method.The passive damping method of filter capacitor series resistance and parallel resistance is studied from the point of view of transfer function. It is revealed that the damping is essentially a damping term, but the parallel resistance is an ideal damping form because only the damping term is introduced.The feasibility of active damping method with four state variables feedback is studied from the point of view of collocation of damping term. It is pointed out that filtering capacitive current proportional feedback is the best method.Secondly, the mathematical models of APF in three-phase stationary abc coordinate system, two-phase stationary 伪尾 coordinate system and two-phase rotating DQ coordinate system are established.This paper analyzes the energy exchange form and power flow relationship of APF in steady state operation, and gives a design method of DC bus capacitance parameters based on energy fluctuation.The APF compensation target and the frequency characteristics of LCL filter are studied, and a design method of LCL filter parameters suitable for APF is proposed.Then, from the point of view of engineering application, the principle of i_p-i_q method based on time domain and sliding window iterative DFT method based on frequency domain are expounded and compared. It is pointed out that the sliding window iterative DFT method is more practical.DC bus voltage controller and soft start strategy are designed.Based on the three-phase static coordinate system, the mathematical model of current double loop of grid-connected outer loop and filtered capacitor current inner loop is derived, and the current controller, capacitive current feedback parameters and voltage feedforward strategy are designed.Finally, the simulation model based on Matlab and the experimental platform based on TMS320F28335DSP are built. The main circuit parameters and control strategy designed in this paper are simulated and experimented. The simulation results are consistent with the experimental results.The effectiveness of the design of the main circuit parameters and the control strategy is verified, and the feasibility of the LCL filter in the application of APF and its superiority over the L filter are also verified.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM761

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