基于LCL滤波器的有源电力滤波器控制方法研究

发布时间：2019-03-29 17:07

【摘要】：近年来随着经济的飞速发展,越来越多的电力电子装置和非线性负载被广泛应用到各个领域,对公用电网的电能质量造成了严重影响。另一方面,对电能质量比较敏感的设备对电能质量的要求越来越高。有源电力滤波器(Active Power Filter,APF)作为一种抑制谐波污染提高电能质量的重要设备,在低压配电网中被广泛应用。APF工作时开关器件的通断会产生开关纹波电流。开关纹波电流会加大电网中其他负荷的损耗,降低它们的使用寿命。与L滤波器相比,LCL滤波器具有更高的高频阻抗,可以更好的滤除开关纹波电流,逐渐被应用到各种电力电子装置中。LCL滤波器是一个三阶系统,参数设计复杂。在应用到APF中时,不仅要考虑LCL滤波器的开关纹波电流抑制能力和谐振问题,还要考虑LCL滤波器对APF补偿性能的影响。本文通过简化LCL滤波器的数学模型,得出一种简单的LCL滤波器设计方法。针对LCL滤波器的谐振问题,研究了无源阻尼方法和有源阻尼方法对谐振进行抑制,以及离散系统无阻尼情况下的稳定性分析。将谐波分次检测结合前馈补偿控制方法应用到基于LCL滤波的APF系统中。研究了该方法基本原理、优点以及实现方法。在MATLAB/Simulink中搭建仿真模型,对LCL滤波器设计和APF的控制方法的正确性和有效性进行仿真验证。在现有的硬件平台基础上对软硬件系统进行改进和优化,使APF实验装置实现了所设计的功能。系统稳定运行,补偿结果也达到了预期的效果。
[Abstract]:In recent years, with the rapid development of economy, more and more power electronic devices and nonlinear loads have been widely used in various fields, which has a serious impact on the power quality of the public power grid. On the other hand, devices sensitive to power quality have higher and higher requirements for power quality. Active power filter (Active Power Filter,APF), as an important device to restrain harmonic pollution and improve power quality, is widely used in low-voltage distribution network. Switching ripple current will increase the loss of other loads in the grid and reduce their service life. Compared with L-filter, LCL filter has higher high-frequency impedance and can filter off switching ripple current. LCL filter is a third-order system and its parameter design is complex. When applied to APF, not only the switching ripple current suppression ability and resonance of LCL filter should be considered, but also the effect of LCL filter on the performance of APF compensation should be considered. In this paper, by simplifying the mathematical model of LCL filter, a simple design method of LCL filter is obtained. Aiming at the resonance problem of LCL filter, the passive damping method and active damping method are studied to suppress the resonance, and the stability analysis of discrete system without damping is studied. Harmonic detection combined with feedforward compensation control method is applied to APF system based on LCL filter. The basic principle, advantages and implementation of the method are studied. The simulation model is built in MATLAB/Simulink to verify the correctness and validity of the design of LCL filter and the control method of APF. On the basis of the existing hardware platform, the hardware and software system is improved and optimized, so that the designed function of the APF experimental device is realized. The system runs stably and the compensation results also reach the expected effect.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM761

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