ECFL的批量使用对电网中性线电流的影响

通过对不同厂家，不同型号及国产及进口电子式紧着型荧光灯（ＥＣＦＬ）批量使用民政部的测量，得出：ＥＣＦＬ在遇网上批量使用，对电网的电压谐波影响很小，电网上所测得的电流谐波与单灯测试值基本相等。但在新设计照明电路或同功率替换白炽灯，批量使用ＥＣＦＬ须特别注意，要针对ＥＣＦＬ的不同功率不同电流谐波进行预先计算，以确定电路的合理配置，确保电网质量民民安全。     

DZJ-1F 型电能质量监测仪的研制

控制谐波污染是电网运行的重要任务用微机处理数据监测电网谐波,是目前电能质量控制的先进技术。新型的ＤＺＪ－１Ｆ型微机电能质量监测仪采用８０９８ＣＰＵ,利用时域采样技术,实时对电网三相电压、电流分析计算,完成对电能质量有关参数的监测。当负序电流Ｉ２及（Ｉ２／ＩＮ）＾２·ｔ超出规定极限值时报警。测试结果可通过ＬＣＤ显示,用打印机输出。     

三相单支全控开关高功率因数低谐波整流器的研究进展

在需要采用三相整流器的中大功率场合，可控或不可控整流电路产生的低功率因数高谐波含量电网电流导致了电网电压畸变，增加了配电系统导体，变压器损和中电流。     

基于准比例谐振控制的三相并网逆变器谐波补偿方法研究

针对电网不平衡和畸变条件下,传统并联谐振谐波补偿并不能有效抑制电网谐波引起的参考电流谐波对逆变器输出电流的影响的缺点,提出了一种改进型并联准比例谐振（QPR）谐波补偿方法,有效抑制了电网电压谐波引起的参考电流谐波。仿真结果表明,改进型谐波补偿方法有效地降低了并网电流的总谐波畸变率,提高了逆变并网系统的电能质量。     

高次谐波的探讨与技术处理

随着变流技术的发展，电力拖动系统中大量应用变频器、斩波器、逆变器和软起动器等，这些设备在应用中产生多种高次谐波，导致电网电压电流波形的畸变。当变配电系统中采用并联电容器进行无功补偿时，必须考虑谐波的影响，分析谐波源及可能产生的谐波阶次，采取合理的补偿措施避免发生谐振；当电网中谐波导致的电压电流畸变严重时，就需要进行谐波治理，最终将谐波引发的电压电流畸变限制在许可的范围之内。变配电系统设计运行在恒定频率的正弦波电压电流环境中，当负载中存在非线性负荷时，电网中就会产生高于基波频率的谐波电流，它们与基…     

相间干挠对氧化锌避雷器阻性电流测试波形的影响

介绍使用ＬＣＤ－４型泄漏电流检测仪加示波器，在线检测ＭＯＡ阻性电流波形时，由于存在相间干挠，致使阻性电流波形因所含谐波分量的百分比不同而引起波形畸变的现象。     

电网电压畸变下的级联H桥光伏并网逆变器谐波抑制控制策略

三次谐波补偿策略可有效解决单相级联H桥光伏并网逆变器的功率不平衡问题,但在电网电压畸变下易发生并网电流畸变.针对这一问题,提出一种电流谐波抑制环来消除电网电压畸变所带来的影响,并降低电网电流畸变率.分析了电网电压畸变导致电流畸变的机理原因,在此基础上,提出了将并网电流中的谐波成分作为控制对象,实时反馈至系统中,通过闭环...     

低压配电室有源滤波器治理可行性分析

<正>变频器等设备的广泛应用产生了大量谐波，造成电流畸变、电压畸变率增大，电能质量变差，出现“电网污染”。为了解决这一问题，低压配电室安装有源滤波器（APF）可以控制谐波污染，提高电网功率因数。消除谐波产生的危害是解决谐波危害、电网污染的有效方法。     

输电网谐波传输特性仿真分析

为研究输电网的谐波传输特性,采用基于等效π模型的输电线谐波模型对输电网谐波电流放大、谐波谐振等现象进行了理论分析。通过对某谐波用户以不同方案接入电网时,其电网侧谐波电流放大倍数、谐波电压畸变率等输电网谐波传输特性指标进行了对比仿真分析,得出了线路长度、系统谐波等值阻抗与谐波电流放大、谐波电压畸变率之间的关系。最后在此基础上提出了谐波用户接入系统的建议。     

ip-iq检测法的单周控制三电平有源电力滤波器

并联型有源电力滤波器APF可以有效补偿由非线性负载产生的谐波和无功功率电流。为了实现单独对谐波分量、无功功率分量进行补偿,或者对谐波和无功功率分量同时进行补偿这些不同的补偿目标,同时为了满足大功率、高电压和输出电流波形畸变小的需要,提出了将中点箝位变换器和ip-iq电流检测法应用于单周控制有源电力滤波器的方法。采用ip-iq电流检测算法可分离出负载电流中的谐波分量、无功功率分量,且电网电压波形畸变不影响检测结果,故可提供不同补偿目标的参考信号。理论推导和仿真结果表明,该法能分别单独补偿谐波分量、无功功率分量,或者同时补偿谐波和无功功率分量,而且电网电压波形畸变不影响补偿效果。通过将ip-iq电流检测法运用于单周控制三电平有源电力滤波器,既实现多种补偿目标,又具有电网电压波形畸变不影响补偿效果、单周控制策略简单、三电平变换器输出电流波形畸变小的优点。     

微汞节能灯技术应用探讨

通过对节能灯汞消耗的研究,提出对现有光源工艺的改进和新工艺的实施方案,并对汞齐原材料控制和生产环境提出要求。倡导电光源从业人员通过践行生产工艺的精细化管理,从源头上减少节能灯的汞使用量,减少对环境的危害。     

The voltage distortion in low-voltage networks caused by compact fluorescent lamps with electronic gear

Commonly used compact fluorescent lamps (CFLs) with electronic gear are characterized by extremely distorted current, with total harmonic distortion (THD) usually exceeding 100%. That is why they cause a significant voltage distortion in electrical installations. The principal goal of this research was to determine their maximum permissible share in the total load installed for commercial customers, at which voltage distortion is still acceptable (according to international standards). An analysis regarding a low-voltage electrical installation of a hotel, representing a typical commercial customer, showed that maximum permissible share should not exceed 10%. As this maximum permissible share could restrict the installment of the intended quantity of CFLs, the costs of two possible solutions for this problem – the use of filters or a new generation of CFLs with a high power factor – are compared.     

小波变换在谐波检测中的应用研究

电网谐波是影响电能质量的重要因素,随着电力电子器件的广泛应用,电网谐波污染问题正日趋严重.因此为了提高电能质量,保证系统的安全运行,必须准确的对谐波进行检测和分析,掌握电力系统中畸变波形含有的谐波,采取相应措施对谐波进行抑制或补偿.将小波变换应用于电力系统谐波检测,选取合适的小波函数,通过MATLAB 仿真,在谐波中提...     

A method and related digital instrument for the measurement of theelectric power quality

The ever increasing number and power of polluting loads (nonlinear, time-variant loads) connected to the electric power network causes a significant distortion in the line current and, as their overall power is no longer negligible with respect to the network power, also some distortion in the line voltage. This causes a deterioration of the electric power quality that may disturb the other connected loads. The availability of an instrument able to quantify the deterioration of the power quality due to the harmonic distortion, to assess whether or not this deterioration is caused by a polluting load connected after the metering section and to quantify the effects of such a load on the power quality therefore represents an important point for the correct operation of the electric power system. This paper proposes a measurement method, based on the evaluation of the harmonic powers, for the identification of the source producing pollution in a three-phase power system. Some parameters are also defined in order to quantify the electric power quality and the deteriorating effects of a polluting load. A digital instrument is also described, realized by means of virtual instrument techniques to implement the proposed method and to verify it experimentally. The measurement accuracy is discussed     

采用Meyer小波变换的电能质量扰动信号的检测与时频分析

论述了小波多分辩率信号分解,提出了采用基于小波多分辩分解的电能质量几种暂态干扰检测和时频分析。并用Meyer小波对暂态振荡、暂态脉冲、电压跌落、电压上升、电压中断、短时间谐波失真、暂态谐波失真和电压瞬变等电能质量干扰的检测进行了仿真实验,结果表明所提出的Meyer小波在时域和频域上都具有良好的检测性能,适合于短暂瞬变信号的检测与分析,并可用于其他时变的非平稳信号处理。     

英国电气协会工程导则G5/4评述

电力系统谐波标准是电能质量最重要标准之一。英国工程导则G5/3,即《英国供电系统中谐波的限制》,对世界上许多国家,包括我国的谐波标准产生深远影响。本文评述英国电气协会2001年颁布的G5/4工程导则,即《英国谐波电压畸变和非线性设备接入输电系统和配电网的规划值》为我国修订谐波国标GB/T14549—199《3电能质量—公用电网谐波》提供参考依据。     

Influence of electric power distribution system design on harmonic propagation

The impact of the design parameters of electric power distribution systems on the propagation of harmonic distortion is investigated. This conceptual study is based on simulations on a generalized distribution system model, and leads to an increased insight in the mechanisms of the generation and propagation of voltage distortion. Moreover, analytical expressions are presented that predict the impact of changing design parameters on voltage distortion.     

电气化铁路对沿线电力系统电能质量的影响研究

通过对不同方式下电气化铁路产生的负序和谐波及电压波动的仿真分析,准确地计算得到了电气化铁路引起系统公共连接点三相不平衡度和总谐波畸变率以及电压波动值,并进一步分析了产生负序和谐波的原因.为改善由于电气化铁路引起的电网电能质量问题提出了一些建议性的措施,并讨论了电气化铁路对其并网点风电机组的影响.     

Converter-connected distributed generation units with integrated harmonic voltage damping and harmonic current compensation function

The steadily growing share of converter-connected distributed generators, combined with a large amount of nonlinear and unbalanced loads connected to the electric power system, has led to a degraded power quality. Both harmonic voltage and harmonic current distortion may cause many unfavourable effects on the power system. However, the converter-connected distributed generators can be redesigned to have a positive effect on the distortion of the grid voltage. Two different approaches can be discerned. At the one hand, distributed generation units can be controlled to synthesize a resistive load for harmonic voltage components. This approach is called harmonic voltage damping. At the other hand, if the polluting current of an adjacent nonlinear load is measured and added to the control loop, the converter-connected distributed generator is able to compensate all harmonic current components of the nonlinear load. This approach is referred to as harmonic current compensation. In this paper, a control strategy for a converter-connected distributed generator is extended with a harmonic voltage damping function and a harmonic current compensation function. Experimental tests show that the voltage distortion of the grid voltage can be significantly improved.     

电动汽车充电站仿真模型及其对电网谐波影响

电动汽车的普及与推广将引致对大功率充电设备的大量需求,采用现代电力电子技术的大功率充电机是高度非线性的用电设备,对电网产生的谐波影响不容忽视。其产生的谐波主要来自充电机的整流装置,基于此,论文从适应于大量电动汽车充电需求的合理充电技术和合理充电规模问题出发,分别建立单台充电机和充电站仿真模型,仿真分析单台和多台充电机工作时对电网电能质量的影响,重点研究各次谐波电流含有率、电流总谐波畸变率和功率因数随电动汽车充电功率的变化规律及其随充电机台数增加的变化规律。仿真结果表明:大功率充电时,随着充电机台数的增加,各次谐波电流含有率呈减小的趋势,小功率充电时,随着充电机台数的增加,各次谐波含有率变化较平缓;电流总谐波畸变率随充电功率的增大和充电机台数的增加呈减小趋势,而功率因数的变化则由充电功率与充电机数目的耦合机制决定。