Modeling, measurement and mitigation of power system harmonics
Modeling, measurement and mitigation of power system harmonics
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DOI：
10.7939/r37x3g
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
A. Nassif
中科院分区：
文献类型：
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作者：
A. Nassif
电力系统的谐波和间谐波是近年来备受关注的电能质量问题。这些现象可能会对电力系统的运行产生几种不利影响。主要的谐波源和间谐波源是基于电力电子技术的装置。电力电子类家用电器是一种新兴的谐波源。这些电器分散在整个低压配电系统中，它们的集体影响可能导致不可接受的电压失真程度。根据家用电器的谐波电流对其进行表征是了解这些设备的影响的重要一步。本文评估了这些装置产生的谐波电流的相对严重程度，以及谐波电流相角差异的影响。通常，提供给每个谐波源的电压已经失真。这种失真会引起谐波电流大小的变化(传统上称为衰减效应)。常用的谐波分析方法不能考虑这种变化，因为它们使用由电源电压指定的典型的谐波电流源模型，该模型具有很小的失真或没有失真。本文对电力电子设备的谐波衰减效应进行了研究。其中一个发现是，在可靠的电压条件下，可以发生谐波放大，而不是衰减。这一发现以前从未出现过。为了将谐波衰减/放大计入家电建模中，提出了一种基于测量的谐波建模技术。减少电力系统中的谐波的最经济和有效的方法之一是使用谐波并联型无源滤波器。这些过滤器可以有多种拓扑。如今，选择这些拓扑是一项取决于过滤器设计者的经验和判断的任务。对常见的滤波器拓扑结构进行了研究，确定了最经济有效的抑制谐波的拓扑结构。由于许多较大的谐波负荷也会产生间谐波，间谐波在当今的中压配电系统中已经很普遍。在知道间谐源位置之前，不能进行缓解。提出了一种间谐源确定方法，并通过仿真和现场测量验证了该方法的有效性。
Power system harmonics and interharmonics are power quality concerns that have received a great deal of attention in recent years. These phenomena can have several adverse effects on power system operation. The main harmonic and interharmonic sources are devices based on power electronics. An emerging class of harmonic sources is comprised of power electronic-based home appliances. These appliances are dispersed throughout the low-voltage distribution system, and their collective impact can result in unacceptable levels of voltage distortion. The characterization of home appliances based on their harmonic currents is an important step toward understanding the impact of these devices. This thesis presents an evaluation of the relative severity of the harmonic currents from these devices, and the impact of the disparity of the harmonic current phase angles. Typically, the voltage supplied to each harmonic source is already distorted. This distortion causes a change of the harmonic current magnitudes (traditionally referred to as the attenuation effect). Common harmonic analysis methods cannot take this variation into account because they use a typical harmonic current source model specified by a supply voltage having little or no distortion. This thesis characterizes the harmonic attenuation effect of power electronic-based appliances. One of the findings is that harmonic amplification, rather than attenuation, can occur under credible voltage conditions. This finding had not been made previously. In order to include the harmonic attenuation/amplification in appliance modeling, a measurement-based harmonic modeling technique is proposed. One of the most economic and effective ways to mitigate harmonics in power systems is through the use of harmonic shunt passive filters. These filters can be of many topologies. Selecting these topologies is a task that, today, depends on the experience and judgment of the filter designer. An investigation is carried out on the common filter topologies, and the most cost-effective topologies for mitigating harmonics are identified. As many of the larger harmonic loads also generate interharmonics, interharmonics have become prevalent in today's medium-voltage distribution system. Mitigation cannot be carried out until the interharmonic-source location is known. A method for interharmonic source determination is proposed and then verified through simulation and field measurement studies.