三相四线制并联有源电力滤波器研究

发布时间：2018-03-25 12:13

本文选题：三相四线制　切入点：有源电力滤波器　出处：《合肥工业大学》2015年硕士论文

【摘要】：随着现代工业的发展,非线性负载开始广泛使用,谐波及无功电流对电网的污染已不容忽视,有源电力滤波器(active power filter, APF)的诞生为此提供了有效的解决方案。目前三相三线制APF应用已较为成熟,而对于我国大多采用三相四线制线路的市政电网,三相四线制并联APF由于能够补偿网侧三相和中线上谐波及无功电流,开始逐步受到关注。论文针对有源电力滤波器的发展历史、研究现状、基本原理进行介绍,着重对三相四线制主电路拓扑、谐波检测理论、控制理论可行性进行各种对比分析。考虑到三相四线制系统的不对称性,其存在零序电流,故而传统的谐波检测算法可能并不适用,论文采用了一种适合于三相四线制不对称负载的谐波检测新方法,并可使得逆变器仅需补偿无功及谐波电流而降低了直流侧电容的设计。在控制算法上进行各种控制方式的比较,最终将比例调节与重复控制理论相结合,设计了电流双环重复控制系统,提高了电流环跟踪的快速性与稳态精度。在MATLAB/Simulink里,搭建电容中点型三相四线有源电力滤波器拓扑模型,通过前面分析得出的谐波检测理论及控制策略计算参数,修改仿真参数,验证谐波检测方法与控制策略的理论可行性。在仿真验证所选取主电路拓扑可行的基础上,搭建TI公司TMS320F2812的DSP芯片作为其硬件电路的主控芯片,负责数据采样、谐波检测、电流跟踪控制、PWM占空比计算发波、系统保护等。通过长期实验和优化,三相网侧电流谐波畸变率(THD)分别由补偿前的54.4%、59.2%、65.2%降低至补偿后的2.6%、3.2%、4.4%,证明所提出的检测及控制方法具有实用性和高稳态性,并为以后的研究奠定了基础。
[Abstract]:With the development of modern industry, nonlinear load is widely used. The pollution of harmonic and reactive current to the power network can not be ignored. The birth of active power filter (APF) provides an effective solution to this problem. At present, the application of three-phase three-wire APF is mature. Three-phase four-wire parallel APF has been paid more and more attention because of its ability to compensate harmonics and reactive currents on the network side and the middle line. This paper introduces the development history, research status and basic principle of active power filter. The topology, harmonic detection theory and control theory of three-phase four-wire system are compared and analyzed. Considering the asymmetry of three-phase four-wire system, the zero sequence current exists. Therefore, the traditional harmonic detection algorithm may not be applicable. A new harmonic detection method suitable for three-phase four-wire asymmetric load is adopted in this paper. The inverter only needs to compensate reactive power and harmonic current to reduce the design of DC side capacitance. The comparison of various control methods is carried out in the control algorithm. Finally, the proportional adjustment is combined with the repetitive control theory. The current double loop repetitive control system is designed, which improves the speed and steady-state precision of current loop tracking. In MATLAB/Simulink, the topology model of capacitive midpoint three-phase four-wire active power filter is built. The theoretical feasibility of harmonic detection method and control strategy is verified by modifying simulation parameters and calculating parameters of harmonic detection theory and control strategy obtained by previous analysis. The topology of the selected main circuit is verified by simulation. The DSP chip of TI Company TMS320F2812 is set up as the main control chip of its hardware circuit, which is responsible for data sampling, harmonic detection, current tracking control, PWM duty cycle calculation, system protection and so on. The harmonic distortion rate (THD) of three-phase grid-side current is reduced from 54.42% before compensation to 2.66% and 3.2% after compensation, which proves that the proposed detection and control method has practicability and high steady-state property, and lays a foundation for future research.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713.8;TM761

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