节点文献
单相统一电能质量控制器中检测与控制方法的研究
The Study of Detection and Control Methods in Single-unity Power Quality Conditioner
【作者】 李波;
【导师】 黄纯;
【作者基本信息】 湖南大学 , 电力系统及其自动化, 2009, 硕士
【摘要】 作为现代社会的主要能源,电能在各行各业中有着广泛的应用,电能质量的优劣关系到国民经济的总体效益。统一电能质量控制器(UPQC)是用户电力技术发展的最新趋势之一,它集电压补偿装置、电流补偿装置和储能装置于一体,统一实现多重电能质量调节功能,具有广阔的发展前景。本文介绍了统一电能质量控制器的基本拓扑结构,并针对它的两个重要部分——控制和检测部分,进行了较为详细的研究和探讨。在控制部分,通过对有源电力滤波器的研究,总结了有源电力滤波器的直接补偿控制策略,指出了各自的优缺点,选取了定时控制的瞬时值比较方式作为UPQC的控制方法。快速、准确的检测出谐波信号是实现补偿目标的关键。在检测部分,分析有源电力滤波器中谐波检测方法,总结了基于瞬时无功功率理论的改进型谐波检测算法,在此基础上提出了一种改进的单相谐波检测算法。该算法根据电网谐波以奇次为主的特点,构建虚拟的两相,通过一定的延时消除三次谐波的影响,在不增加滤波器阶数的前提下,提高低通滤波器的截止频率,以降低总体的延时时间,在各种典型的复杂谐波状况下仿真证明了该方法的可行性。最后,本文参照相关文献中提出的单相统一电能质量控制器的模型,分析了它的工作过程,构建了单相统一电能质量控制器的Maltlab/Simulink仿真模型,使用提出的检测算法,对来自负载侧和电源侧的各种电能质量现象进行了仿真,仿真结果表明,UPQC能够有效解决多种电能质量问题。
【Abstract】 As the main energy of the modern society, electrical power is applied in all aspects of life, and electrical power quality is related with national economy. Unified Power Quality Controller (UPQC) is one of the development trends of Custom Power, which combines the functions of voltage compensator, current compensator and energy storage. Multiple power quality regulation functions are implemented in UPQC simultaneously. It must have a prospective future.At first, the topology and the function of UPQC are explained in the paper. Then the detection method and the control strategy, which are the important parts affecting the compensation effect of the UPQC, are discussed and investigated in detail in the papers. For the control strategy, through the study of active power filter, this paper summarizes the active power filter control strategy of direct compensation, points out the advantages and disadvantages of each, and selects the timer-control hysteretic pulse wide modulation control method for the control method UPQC.Quickly and accurately detecting the harmonic signal from the target is the key to achieve the goal of compensation. In the basis of the APF detecting method, this paper summarizes the harmonics detecting methods based on the instantaneous reactive power, and an improved harmonic detection algorithm in single-phase circuit based on the instantaneous reactive is proposed, in which a time-delay circuit is used to reducing the delay-time of the lower-pass filter. The influence of the third harmonic would be clear by the time-delay circuit, so the total delay-time of the improver method is shorter. Theoretical analysis and simulation experiment prove that the proposed harmonic current detection algorithm is correct and effective.In the basis of the above, this paper makes reference to the literature of single-unity power quality conditioner of the model, analys the course of its work, and builds a simulation model at Matlab/Simulink. Through a variety of issues of power quality compensation simulation to verify the feasibility of the algorithm.