諧波畢業(yè)設計英文文獻翻譯

1、<p><b>　　Harmonics</b></p><p>　　Service reliability and quality of power have become growing concerns for many facility managers, especially with the increasing sensitivity of electronic equ

2、ipment and automated controls. There are several types of voltage fluctuations that can cause problems, including surges and spikes, sags, harmonic distortion, and momentary disruptions. Harmonics can cause sensitive equ

3、ipment to malfunction and other problems, including overheating of transformers and wiring, nuisance breaker trips, and re</p><p>　　What Are Harmonics?</p><p>　　Harmonics are voltage and current

4、 frequencies riding on top of the normal sinusoidal voltage and current waveforms. Usually these harmonic frequencies are in multiples of the fundamental frequency, which is 60 hertz (Hz) in the US and Canada. The most c

5、ommon source of harmonic distortion is electronic equipment using switch-mode power supplies, such as computers, adjustable-speed drives, and high-efficiency electronic light ballasts. </p><p>　　Harmonics ar

6、e created by these “switching loads” (also called “nonlinear loads,” because current does not vary smoothly with voltage as it does with simple resistive and reactive loads): Each time the current is switched on and off,

7、 a current pulse is created. The resulting pulsed waveform is made up of a spectrum of harmonic frequencies, including the 60 Hz fundamental and multiples of it. This voltage distortion typically results from distortion

8、in the current reacting with system impedance. (</p><p>　　Harmonic waveforms are characterized by their amplitude and harmonic number. In the U.S. and Canada, the third harmonic is 180 Hz—or 3 x 60 Hz—and th

9、e fifth harmonic is 300 Hz (5 x 60 Hz). The third harmonic (and multiples of it) is the largest problem in circuits with single-phase loads such as computers and fax machines. Figure 1 shows how the 60-Hz alternating cur

10、rent (AC) voltage waveform changes when harmonics are added. </p><p>　　The Problem with Harmonics</p><p>　　Any distribution circuit serving modern electronic devices will contain some degree of

11、harmonic frequencies. The harmonics do not always cause problems, but the greater the power drawn by these modern devices or other nonlinear loads, the greater the level of voltage distortion. Potential problems (or symp

12、toms of problems) attributed to harmonics include:</p><p>　　Malfunction of sensitive equipment</p><p>　　Random tripping of circuit breakers</p><p>　　Flickering lights</p><

13、;p>　　Very high neutral currents</p><p>　　Overheated phase conductors, panels, and transformers</p><p>　　Premature failure of transformers and uninterruptible power supplies (UPSs)</p>

14、<p>　　Reduced power factor</p><p>　　Reduced system capacity (because harmonics create additional heat, transformers and other distribution equipment cannot carry full rated load)</p><p>　　I

15、dentifying the Problem</p><p>　　Without obvious symptoms such as nuisance breaker trips or overheated transformers, how do you determine whether harmonic current or voltages are a cause for concern? Here are

16、 several suggestions for simple, inexpensive measurements that a facility manager or staff electrician could take, starting at the outlet and moving upstream:</p><p>　　■ Measure the peak and root mean square

17、 (RMS) voltage at a sample of receptacles. The “crest factor” is the ratio of peak to RMS voltage. For a perfectly sinusoidal voltage, the crest factor will be 1.4. Low crest factor is a clear indicator of the presence o

18、f harmonics. Note that these measurements must be performed with a “true RMS” meter—one that doesn’t assume a perfectly sinusoidal waveform.</p><p>　　■ Inspect distribution panels. Remove panel covers and vi

19、sually inspect components for signs of overheating, including discolored or receded insulation or discoloration of terminal screws. If you see any of these symptoms, check that connections are tight (since loose connecti

20、ons could also cause overheating), and compare currents in all conductors to their ratings.</p><p>　　■ Measure phase and neutral currents at the transformer secondary with clamp-on current probes. If no harm

21、onics are being generated, the neutral current of a three-phase distribution system carries only the imbalance of the phase currents. In a well-balanced three-phase distribution system, phase currents will be very simila

22、r, and current in the neutral conductor should be much lower than phase current and far below its rated current capacity. If phase currents are similar and neutral current ex</p><p>　　■Compare transformer te

23、mperature and loading with nameplate temperature rise and capacity ratings. Even lightly loaded transformers can overheat if harmonic current is high. A transformer that is near or over its rated temperature rise but is

24、loaded well below its rated capacity is a clear sign that harmonics are at work. (Many transformers have built-in temperature gauges. If yours does not, infrared thermography can be used to detect overheating.)</p>

25、<p>　　In addition to these simple measurements, many power-monitoring devices are now commercially available from a variety of manufacturers to measure and record harmonic levels. These instruments provide detaile

26、d information on THD, as well as on the intensity of individual harmonic frequencies. After taking the appropriate measurements to determine whether you have high levels of harmonics and, if so, to find the source, you w

27、ill be well-positioned to choose the best solution.</p><p>　　Solutions to Harmonics Problems</p><p>　　The best way to deal with harmonics problems is through prevention: choosing equipment and i

28、nstallation practices that minimize the level of harmonics in any one circuit or portion of a facility. Many power quality problems, including those resulting from harmonics, occur when new equipment is haphazardly added

29、 to older systems. However, even within existing facilities, the problems can often be solved with simple solutions such as fixing poor or nonexistent grounding on individual equipment or </p><p>　　install d

30、evices to attenuate or remove the harmonics. Reinforcing the distribution system means installing double-size neutral wires or installing separate neutral wires for each phase, and/or installing oversized or Krated trans

31、formers, which allow for more heat dissipation. There are also harmonic-rated circuit breakers and panels, which are designed to prevent overheating due to harmonics. This option is generally more suited to new facilitie

32、s, because the costs of retrofitting an existing fa</p><p>　　Passive filters (also called traps) include devices that provide low-impedance paths to divert harmonics to ground and devices that create a highe

33、r-impedance path to discourage the flow of harmonics. Both of these devices, by necessity, change the impedance characteristics of the circuits into which they are inserted. Another weakness of passive harmonic technolog

34、ies is that, as their name implies, they cannot adapt to changes in the electrical systems in which they operate. This means that chan</p><p>　　Active harmonic filters, in contrast, continuously adjust their

35、 behavior in response to the harmonic current content of the monitored circuit, and they will not cause resonance. Like an automatic transmission in a car, active filters are designed to accommodate a full range of expec

36、ted operating conditions upon installation, without requiring further adjustments by the operator.</p><p>　　Isolation transformers are filtering devices that segregate harmonics in the circuit in which they

37、are created, protecting upstream equipment from the effects of harmonics. These transformers do not remove the problem in the circuit generating the harmonics, but they can prevent the harmonics from affecting more sensi

38、tive equipment elsewhere within the facility.</p><p>　　Harmonic mitigating transformers actually do relieve problematic harmonics. HMTs can be quite cost-effective in the right application, because they can

39、both improve reliability and reduce energy costs. The right application includes transformers that are heavily or moderately loaded and where high levels of harmonic currents are present. In addition, HMTs are very effec

40、tive in supporting critical loads that are backed up by a UPS. UPSs and backup generators tend to have high impedance, which res</p><p>　　Because of this, equipment that operates flawlessly when supplied by

41、utility power may malfunction when the backup system engages during a utility outage. Note that some of these power systems have output filters (either passive or active) to control harmonic levels. The presence or absen

42、ce of such filters should be determined before adding an HMT.</p><p>　　The Harmonics Ltd. Harmonic Suppression System is a unique solution for single-phase loads that is designed to suppress the third harmon

43、ic. An HSS is generally more expensive than an HMT, but it is designed to attenuate the harmonics problems throughout the entire distribution system, not just upstream of the transformer. The types of facilities that pre

44、sent the best opportunities for HSS installation are those that place a very high premium on power quality and reliability, such as server farms</p><p>　　Economic Evaluation</p><p>　　Evaluating

45、the life-cycle costs and effectiveness of harmonics mitigation technologies can be very challenging—beyond the expertise of most industrial facility managers. After performing the proper measurement and analysis of the h

46、armonics problem, this type of evaluation requires an analysis of the costs of the harmonics problem (downtime of sensitive equipment, reduced power factor, energy losses or potential energy savings) and the costs of the

47、 solutions. A good place to start in performing t</p><p>　　Additional Resources</p><p>　　Institute of Electrical and Electronics Engineers (IEEE),Standard 519-1992, “IEEE Recommended Practices a

48、nd Requirements for Harmonic Control in Electric Power Systems” (1992), available at www.ieee.org.</p><p>　　Relationship between harmonics and symmetrical components</p><p>　　Abstract New termin

49、ology is introduced to make clear the relationship between harmonics and symmetrical components. Three-phase sets are classified in terms of symmetrical sets and asymmetrical sets. Subclasses are introduced with the name

50、s symmetrical balanced sets, symmetrical unbalanced sets, asymmetrical balanced sets and asymmetrical unbalanced sets to show that a threephase set can resolve to either one, two or three symmetrical component sets. The

51、results from four case studies show that </p><p>　　Keywords asymmetrical sets; harmonic flows; harmonic sources; symmetrical component sets; symmetrical sets</p><p>　　Any periodic wave shape can

52、 be broken down into or analysed as a fundamental</p><p>　　wave and a series of harmonics.</p><p>　　Three-phase harmonic analysis requires a clear understanding of the relationship between symme

53、trical component injections from harmonic sources (e.g. adjustable speed drives, ASDs) and their relationship to harmonic flows (symmetrical components) arising from the application of a harmonic source to a linear syste

54、m.</p><p>　　Alimited number of references contain brief information concerning harmonics and symmetrical components. Reference 1, provides a paragraph on this topic and uses the heading ‘Relationship between

55、 Harmonics and Symmetrical Components’.It includes a table that is supported by a brief explanatory paragraph. The table expresses harmonics in terms of positive, negative and zero sequences. It states that these sequenc

56、es are for harmonics in balanced three-phase systems. The heading refers to symmetric</p><p>　　(a)Do symmetrical components (especially zero sequence), in the classical sense,</p><p>　　apply in

57、balanced as well as unbalanced non-sinusoidal systems and is this a</p><p>　　break from tradition?</p><p>　　(b)What do the terms, symmetrical, asymmetrical, balanced, unbalanced and </p>

58、<p>　　symmetrical components mean?</p><p>　　(c)What are the conditions under which a system must operate so that harmonics</p><p>　　resolve to positive, negative and zero sequences and is t

59、he table given in </p><p>　　Ref. 1 correct?</p><p>　　The terminology used is found inadequate for describing non-sinusoidal systems.</p><p>　　There is thus a need to introduce a thr

60、ee-phase terminology that will show the relationship and make the comparison between injections (currents) and harmonic flows (voltages and currents) meaningful.</p><p>　　References 3 provides the basis for

61、the solution by providing definitions for ‘threephase sets’, ‘symmetrical sets’and ‘symmetrical component sets’.</p><p>　　The purpose of this paper is to introduce an approach to harmonic analysis </p>

62、<p>　　based on the classification of three-phase sets and to make to comparison between injections from harmonic sources and corresponding harmonic flows quantifiable by expressing the results in terms of the numb

63、er of symmetrical component sets found.</p><p>　　Harmonic flows and their resolution to symmetrical components depends upon the magnitudes and phase sequences of the injections from a harmonic source, on the

64、 system’s sequence impedances, on three- and four-wire connections and on whether the customer’s linear load on the system is balanced or unbalanced. Therefore, what is injected in terms of symmetrical component sets by

65、a harmonic source is not necessarily received by the system, i.e. the harmonic flows may resolve to one, two or three symm</p><p>　　Four case studies are reported and they show a novel method for teaching th

66、e flow of power system harmonics. It is important to use case studies as part of one’s teaching as they link learning to concepts and improve understanding. They show how the method of symmetrical components can be exten

67、ded to a system’s response to harmonic flows. When taught as a group, the four case studies improve cognitive skills by showing that the symmetrical component responses under unbalanced situations are diff</p><

68、;p>　　IEEE TRANSACTIONS ON POWER ELECTRONICS VOL.19,NO.3,MAY2004</p><p><b>　　諧波</b></p><p>　　服務的可靠性和電能質量已成為越來越多設施經(jīng)理的關注，尤其是隨著電子設備和自動化控制靈敏度提高了很多。有幾種類型的電壓波動可能導致問題，包括浪涌和尖峰，凹陷，諧波失真，一時中斷

69、。諧波可能導致敏感的設備出現(xiàn)故障和其他問題，包括變壓器、線路和斷路器過熱傳輸滋擾，并降低功率因數(shù)。</p><p><b>　　什么是諧波？</b></p><p>　　諧波電壓和電流的頻率在正常正弦電壓和電流波形時為最佳。通常，這些諧波頻率是基本頻率，這里是60赫茲，在美國和加拿大（赫茲）的倍數(shù)。諧波失真的最常見的來源是使用電子設備開關電源，如電腦，調速器，以及高效

70、率的電子燈用鎮(zhèn)流器。</p><p>　　諧波也造成了這些“開關負載”（也稱為“非線性負載”，因為目前不隨電壓變化，因為它是簡單的電阻和負荷的反應）：每次電流接通和關斷時間使電流脈沖產(chǎn)生。由此產(chǎn)生的脈沖波形組成的諧波頻率頻譜，包括60赫茲和它的倍數(shù)。從這個電壓畸變到失真，結果目前通常反應在系統(tǒng)阻抗。（阻抗是完全對立的措施—電阻，電容和電感—交變電流。）在更高頻率的波形，統(tǒng)稱為總諧波失真（THD），不執(zhí)行任何有用的

71、工作，也可以成為重要的滋擾。</p><p>　　諧波波形的特點是其振幅和諧波級次。在美國和加拿大，三次諧波為180赫茲或3 × 60赫茲和第五次諧波為300赫茲（5 × 60赫茲）。第三諧波（和它的倍數(shù)）是在單相負載電路的最大問題例如電腦和傳真。圖1顯示了60赫茲交流電（AC）電壓諧波時添加波形變化。</p><p>　　圖1：在正常的電壓或電流波形的諧波的影響 &l

72、t;/p><p>　　合并后的波形顯示加入到諧波結果 </p><p><b>　　基本的</b></p><p><b>　　聯(lián)合波形</b></p><p>　　第5第7第11和第13諧波</p><p><b>　　振幅</b></p>

73、<p><b>　　第一階段（度）</b></p><p><b>　　諧波的相關問題</b></p><p>　　任何配電線路服務在現(xiàn)代電子設備都存在某種程度的諧波頻率。諧波并不總是導致問題，但是這些現(xiàn)代設備或其他非線性負載的功率越大，電壓失真的程度就越厲害。由于諧波的潛在問題（或者癥狀）包括：</p><p>

74、;<b>　　■敏感設備故障</b></p><p><b>　　■隨機斷路器跳閘</b></p><p><b>　　■閃爍燈</b></p><p><b>　　■非常高的中性電流</b></p><p>　　■過熱相導體，面板，變壓器</p&g

75、t;<p>　　■過早失效的變壓器，不間斷電源（UPS）</p><p><b>　　■降低功率因數(shù)</b></p><p>　　■降低系統(tǒng)的能力（因為諧波創(chuàng)造更多的熱量，變壓器和其他配電設備不能進行全額定負載）</p><p><b>　　辨別問題</b></p><p>　　沒有明

76、顯癥狀例如斷路器和變壓器過熱的滋擾，你如何確定引起諧波電流或電壓的原因是值得關注？下面是簡單的幾點建議，設施經(jīng)理或職員可以采取比較便宜電工測量，從插座向上檢查：</p><p>　　■測量峰值和均方根（RMS）的一個樣本的容器電壓。這“波峰因素”就是峰值比電壓。對于一個完全正弦電壓，波峰因素將是1.4倍低波峰因素是諧波的存在明確的指標。請注意，這些測量必須用“真有效值”米——并不假設完全正弦波。</p>

77、;<p>　　■檢查配電板。移開面板覆蓋 及用眼睛檢查有過熱跡象的組成部分，包括變色或消退絕緣端子螺絲。如果你看見任何的這些特征，檢查連接緊張（因為松散的連接也可導致過熱），并比較各導體電流的評級。</p><p>　　■測量階段用嵌入的探頭間接對不帶電的互感器進行測量。如果沒有諧波生成，中性線的三相配電系統(tǒng)目前只有相電流的不平衡。在一個均衡的三相配電系統(tǒng)，相電流將非常相似，而在中性導體電

78、流應遠低于目前的階段，遠遠低于其額定電流容量。如果相電流類似，中性線的電流大幅度的不平衡，諧波存在。如果中性電流超過百分之七十的額定值，你需要來解決問題。</p><p>　　■比較變壓器溫度和溫度的上升和銘牌額定容量負荷。如果諧波電流高，即使是輕負載變壓器也會過熱。變壓器是接近或超過其額定溫度上升，但遠低于其額定容量裝載是一個明顯的跡象，表明諧波在工作。（許多變壓器有內(nèi)置的溫度傳感器, 如果你沒有諧波，紅外熱像

79、儀可以用來檢測過熱。）</p><p>　　除了這些簡單的測量，有很多電力監(jiān)控設備，現(xiàn)在市面上的生產(chǎn)廠家制造了各種測量和記錄諧波等級的儀器。這些儀器為總諧波失真提供詳細資料，以及關于個別諧波頻率的強度。之后采取適當?shù)臏y量以確定是否有高水平的諧波，如果有的話，要查找原因，您需要做好充分準備，選擇最佳的解決方案。</p><p><b>　　諧波問題的解決方案</b>&l

80、t;/p><p>　　最好的處理諧波的方法是通過預防：選擇設備及安裝方法，盡量減少諧波在任何一個電路或部分設施的等級。許多電能質量問題，其中包括因諧波造成的，它發(fā)生在新設備隨意添加到就系統(tǒng)中。然而，即使在現(xiàn)有的設施，這些問題通?？梢杂煤唵蔚慕鉀Q方案，解決例如確定劣質或不存在的個別設備或整個基礎設施，需要在分支電路之間移除一些負載，或增加額外的電路，以幫助隔離引起的諧波失真的敏感設備。如果措施解決不了這些簡單的問題，有

81、兩種基本選擇：加強分散系統(tǒng)承受的諧波或者安裝設備，減輕或消除諧波。加強分散意味著安裝雙尺寸中性線或分割每一階段單獨中性線，和/或安裝特大型或Krated變壓器，使得允許有更大的散熱量。還有諧波級斷路器和儀表盤，其目的是防止由于諧波導致過熱。此選擇通常更適合于新的設施，由于改型目前的設備的花費同樣是值得注意的。減少諧波的策略，從廉價到昂貴，包括無源諧波濾波器，隔離變壓器，諧波（HMTs）減輕變壓器，由諧波有限公司提供的諧波抑制系統(tǒng)（高速鋼

82、），和有源濾波器（見表1）。</p><p><b>　　表1：解決諧波問題</b></p><p>　　這里有從利弊正反兩方面解決諧波。這里列出了大致的解決辦法，以便從便宜的到昂貴的。</p><p>　　初始成本。雖然他們是最昂貴的辦法，但減輕變壓器諧波和諧波抑制系統(tǒng)可以非常經(jīng)濟。</p><p><b>

83、　　正確有效的運用</b></p><p>　　解決辦法 最好的應用程序 注釋</p><p>　　注：kVA = kilovol。所有費用列出美元 來源：普氏</p><p>　　無源濾波器（也稱為陷阱）

84、，包括設備提供低阻抗路徑轉移到地面和設備設備提供了較高的阻抗路徑阻止諧波流。這兩種設備的必要性，改變他們在其中插入電路的阻抗特性。另一種被動諧波技術的缺點是，顧名思義，他們無法適應其運行電力系統(tǒng)的變化。這意味著改變電力系統(tǒng)（例如增加或去除功率因數(shù)校正電容器或更多的非線性負載）此外可能導致他們超負荷或引起“共振”，這實際上可以放大而不是減少諧波。</p><p>　　相反有源諧波濾波器不斷調整響應監(jiān)測到的諧波電流的

85、大小，他們會不會引起共鳴。就像在汽車自動變速器，有源濾波器的設計，以適應在安裝時預期的運行條件齊全，而無需操作員進一步調整。</p><p>　　隔離變壓器隔離過濾設備，在其中隔離線路產(chǎn)生的諧波，保護上級設備免受諧波的影響。</p><p>　　這些變壓器不消除電路產(chǎn)生的諧波問題，但可以防止影響到設施內(nèi)的其他地方更敏感的設備的諧波。</p><p>　　諧波能減緩解

86、壓器實際上是減少諧波問題。HMTs的正確應用可以帶來成本效益，因為它們既可以提高可靠性和降低能源成本。正確的應用包括那些重度，中度加載和那些諧波電流水平很高的地方。此外，HMTs是非常有效的支持臨界負荷，他備份了UPS。UPS和備用發(fā)電機傾向于采用高阻抗，導致非線性負載的高電壓畸變。正因為如此設備運行完美，當電力供應、公用事業(yè)可能故障時 備份系統(tǒng)會在從事一種實用的工具中斷。請注意，這些電力系統(tǒng)的一些輸出濾波器（或主動或被動）控

87、制諧波的等級。是否存在這種過濾器的情況在決定之前，應增加一個HMT的。</p><p>　　諧波的諧波有限公司。抑制系統(tǒng)是一種單相，旨在抑制三次諧波負載獨特的解決方案。通常一個HSS價格比HMT貴，但它的目的是削弱整個配電系統(tǒng)的諧波問題，而不僅僅是上游變壓器。目前的設施，安裝了高速鋼的最有利的場合是那些地方對電力質量和可靠性要求很高的地方，如服務器場，電臺和電視演播室，和醫(yī)院。</p><p&

88、gt;<b>　　經(jīng)濟評價</b></p><p>　　評價生命周期成本和諧波緩解技術的有效性是非常具有挑戰(zhàn)性的，超出了大多數(shù)工業(yè)設施管理人員的專業(yè)知識。在執(zhí)行了正確的測量和諧波問題的分析，這種類型的評估需要對諧波問題的成本分析（敏感設備的停機時間，降低功率因數(shù)，能量損失或潛在的能源節(jié)約）和解決方案的成本。一個好的地方執(zhí)行這種類型的分析是請當?shù)氐墓彩聵I(yè)或提供電力援助。許多公用事業(yè)提供自己的

89、電能質量服務或減輕你可以參考外部電源提供優(yōu)質服務。</p><p><b>　　其他資源</b></p><p>　　電氣與電子工程師協(xié)會（IEEE），標準519-1992，“電機及電子學工程師聯(lián)合會建議措施和控制要求諧波在電力系統(tǒng)”（1992年），在www.ieee.org可用。</p><p>　　諧波和對稱分量之間的關系</p>

90、;<p>　　摘要 ：了新的術語，明確了對稱與諧波成分的關系。三相對稱集和不對稱集集合的分類。子介紹，名稱分別為對稱平衡臺，套對稱不平衡，不對稱平衡集和不平衡不對稱套表明，三相集可以解決的任何一個，兩個或三個對稱組件集。從四個案例研究的結果表明，這些子類和他們的解釋的對稱分量有助于理解有諧波分析的系統(tǒng)平衡和不平衡諧波源和負載。</p><p>　　關鍵字：非對稱集;諧波流動;諧波源;對稱分量套;對稱

91、套。</p><p>　　任何周期波的形狀可以分解成或作為基波和諧波一系列的分析。</p><p>　　三相諧波分析，需要對諧波源之間，對稱分量輸入關系有清楚的了解（如調速，ASD負載）及其關系（對稱分量）從一個諧波源應用程序所產(chǎn)生的線性系統(tǒng)諧波流動。</p><p>　　引用數(shù)量有限的簡要信息包含關于諧波及對稱分量。參考文獻1，提供了關于這一主題的段落，并使用與諧

92、波及標題'關系對稱分量'。它包括一個由一個簡短的解釋性段落，支持表。表中的術語表達了積極的諧波，負，零序列。這些序列在平衡的三相系統(tǒng)諧波。指的標題，而對稱的部分內(nèi)容是指平衡三相系統(tǒng)。這就是異常。從本質上講，（特別是埃羅序列）對稱分量只適用于非平衡系統(tǒng)。下面的問題閱讀一段后參考。</p><p>　　是否對稱分量（特別是零序）在傳統(tǒng)意義上，適用于均衡和不平衡非正弦系統(tǒng)，這是從打破傳統(tǒng)？</p&

93、gt;<p>　　什么條件，對稱，非對稱，平衡，非平衡和對稱的部件是什么意思？</p><p>　　什么條件下運作的系統(tǒng)以便諧解決正序 負序，零序列，并給出了參考表。 1，正確嗎？</p><p>　　所使用的術語描述，發(fā)現(xiàn)非正弦系統(tǒng)的不足。因此，有必要制定三階段的術語，將顯示的關系，并與輸入（電流）和諧波流動（電壓和電流）有意義的比較。</p><p&g

94、t;　　參考資料3提供了提供'定義為解決方案的基礎'三相套，'對稱設置'和'對稱分量集'。</p><p>　　本文件的目的是引入到諧波分析的三相集分類的方法，并要通過表達的對稱分量套數(shù)量的結果，輸入之間的比較，從諧波源和相應的量化的諧波流動創(chuàng)立。</p><p>　　諧波流動及其決議對稱分量取決于程度及注射相序列，從諧波源，對系統(tǒng)的序列阻抗

95、，在三分線和四線連接的用戶是否對系統(tǒng)非線性負載平衡或不平衡。因此，什么是在對稱分量集合的輸入一諧波源不一定是收到系統(tǒng)，即諧波流入可能會解決一，兩個或三個對稱套，這取決于三個類型相集發(fā)現(xiàn)。因此，任何三相諧波可能部分組成對稱分量的任何一組。</p><p>　　四個案研究報告，他們顯示出對教學的電力系統(tǒng)諧波流量的新方法。重要的是，作為一個人的教學案例研究的一部分，他們的聯(lián)系學習觀念，提高認識。它們表明如何對稱分量的方