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三相四线制并联型有源电力滤波器的研究

Research on Shunt Active Power Filter in Three-phase Four-wire System

【作者】 夏雨

【导师】 黄洪全;

【作者基本信息】 广西大学 , 控制理论与控制工程, 2017, 硕士

【摘要】 目前,各种电力电子装置被应用到生产和生活当中,提高了生产效率并且改善了人们的生活,但这些非线性负载也产生出大量的谐波,恶化了用电环境。有源电力滤波器(Active Power Filter,APF)动态响应速度快、补偿性能受电网阻抗影响小,不仅可以抑制谐波,而且对无功功率和不平衡电流都具有良好的补偿效果,因此受到广泛关注。本文以应用在三相四线制系统中的四桥臂有源电力滤波器为研究对象,重点研究其谐波电流检测算法及控制策略,最后进行仿真和实验。影响有源电力滤波器补偿效果的因素有很多,其中谐波电流检测算法的检测速度和精确度是很重要的一个方面。本文详细地说明和分析了常用的pq检测算法和ip-iq检测算法的原理,还对在三相四线制系统中就是否要分离零序电流分量的问题进行了公式推导和分析。控制策略是有源电力滤波器的核心内容,包括电流环的控制策略和电压环的控制策略两部分。电流环通过一定的控制方法和调制方法产生PWM波去驱动开关元件的开通和关断,使得补偿电流动态跟踪指令电流变化。本文把PI控制器和重复控制器并联起来作为电流环的控制器,以保证系统具有良好的动态响应速度和跟踪性能。电压环是利用一定的控制方法把直流侧电压维持在一个合适的值,其控制方法通常使用的是PI控制,但是PI控制鲁棒性较差,面对复杂多变的负载,其往往达不到理想的控制效果。针对PI控制的不足,本文将模糊控制和PI控制相结合,得到参数模糊自整定PI控制方法,该方法可以根据控制对象的状况实时修正参数,提高控制效果。根据理论分析和设计,本文利用MATLAB软件搭建仿真模型,针对非线性负载进行仿真,对比补偿前后电流变化,验证理论的正确性。最后搭建实验平台,在非线性负载下进行实验,实验结果表明该装置具有良好的抑制谐波和补偿不平衡电流的能力。

【Abstract】 At present,a variety of power electronic devices have been applied to production and life,improving production efficiency and people’s lives.But these non-linear load also produce a lot of harmonics,worsening the electricity surroundings.Active power filter has fast dynamic response speed and the grid impedance has little influence on the compensation performance.It not only can suppress the harmonics,but also has a good compensation effect on reactive power and unbalanced current,so it has attracted widespread attention.In this paper,the four-leg active power filter that is used in the three-phase four-wire system is the research object,and its harmonic current detection algorithm and control strategy are focused on emphatically.Finally,the simulation and experiment are carried out.There are many factors that can affect the compensation effect of active power filter,the detection speed and precision of harmonic current detection algorithm is one of the important aspects.In this paper,the principle of the commonly used pq detection algor:ithm and ip-ip detection algorithm are described and analyzed in detail.The problem whether to separate the zero sequence current component in the three-phase four-wire system was carried out by formula derivation and analysis.The control strategy is the core of the active power filter,which includes two parts:the control strategy of current loop and the control strategy of voltage loop.The current loop generates the PWM wave to drive the switching element to turn on and off by a certain control method and modulation method,make compensation current dynamic track the change of instruction current.In this paper,the PI controller and the repetitive controller are connected in parallel as the controller of the current loop,so as to ensure the system has good dynamic response speed and tracking performance.The voltage loop uses a certain control method to maintain the DC side voltage at a suitable value.The control method usually uses the PI control,but the PI control is less robust,and in the face of complex and variable loads,it is often short of the ideal control effect.In this paper,the fuzzy control and PI control are combined to get the parameters of the fuzzy self-tuning PI control method,the method can modify the parameters in real time according to the condition of the control object,and improve the control effect.In this paper,according to the theoretical analysis and design,MATLAB is used to build the simulation model and simulate in nonlinear load,the current changes before and after the compensation are compared,and the correctness of the theory is verified.Finally,the experimental platform is built.The experiment is carried out under the nonlinear load,and the experiment results show that the device has good ability of restraining harmonics and compensating unbalanced current.

  • 【网络出版投稿人】 广西大学
  • 【网络出版年期】2018年 01期
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