基于FX1N的液體混料罐控制系統(tǒng)設(shè)計含3張CAD圖,基于,fx1n,液體,混料罐,控制系統(tǒng),設(shè)計,cad 外文資料翻譯 PLC Studies in China as a Contribution to the Development of International Standards Abstract In the field of PLC, the standardization process on international level is progressing very slowly. The EMC Laboratory of the North China Electric Power University has received the task to develop a measurement method for the field radiated by PLC installations and a standard to be used in the future for the regulation of the PLC deployment. After a short introduction of the standardization process at international level, the paper presents measurements performed at the North China Electric Power University of radiated fields due to PLC. Comparisons of the field with various limits are shown. Finally the paper also presents a review of the regulatory situation on international level. Keywords: PLC, standardization, electromagnetic disturbances. 1. Introduction In the last 6 to 7 years, feasibility studies have been performed in various countries to check the possibility of using the low voltage distribution network to provide data transmission and eventually also telephonic links to individual customers at frequencies up to 30 MHz. This new technology is called Power Line Communication (PLC). This application is particularly interesting for power utilities which, on one side can enter in this way the telecommunication market and use their network for power network data transmission, on the other side can use this technology to control their own network. However, this transmission mode in the frequency band extending from 1.6 to 30 MHz presents various and quite complex EMC problems. The main problem isproduction of disturbances in the network and in the environment. 2. Disturbance sources The sources of disturbance are both radiated and conducted: - the emission of electromagnetic noise which can interfere with radio communications for safety or military use, or disturb the radio amateurs； - conducted differential and common mode currents can penetrate in any equipment connected to the network in which PLC is working. The disturbances have two types of origins: - the signal source asymmetry, due to the coupler asymmetry； - the unbalance of the Low Voltage Distribution Network (LVDN) and as a result an common mode to differential mode conversion. The conversion from differential to common mode due to the network unbalance has been analysed in various paper, as for instance in [1]. Different mitigation solutions have been also been proposed in the literature , but the research work must be further continued. 3. Standardization at international level Concerning EMC problems, at an international level, two types of standards must be developed: - a product standard； - a network standard. 3.1 The product standard The product standard should be an amendment of the CISPR22 standard and is the task of the Subcommittee CISPR. A first idea was to extend the concept of Longitudinal Conversion Loss (LCL) specific for symmetric telecommunication pairs of wire to the non symmetric power network. Measurements performed in various power networks, as those shown in Fig. 1, have given a large spread of LCL values . It was not possible to arrive to a consensus for the concept based on the LCL value, to be used for the calculation of a voltage limit at the ports of the equipment connected to the network, although that this concept has been well-established for the case of telecommunication lines. After about 4 years of work and a whole series of documents at CD (Committee Draft) stage, the concept did not find the requested qualified majority for approval by the CISPR/I/ although that it found majority approval within the working group. It was decided to re-start the work evaluating a new basis. A New Work Item Proposal (NWIP) was prepared by the French national Committee and approved in April 2005 [6]. The work will not be focused any more on the LCL value, but will try to: - describe the typical electricity installations where it is intended to connect PLC equipment； - identify the potentially disturbed services/equipment for each typical section of electricity installations described above； - assess the level of protection currently provided by the CISPR22 for each equipment/service； - set radiated and conducted limits for emissions of each typical section of electricity installation when PLC is operating. The work started in June 2005 and is currently in progress. 3.2 Network standard The European Commission has issued in 2001 the Mandate 313 which gives CENELEC and ETSI the task to develop a standard, to define emission limits for all communication networks including PLC. Different limits have been proposed by various countries (Germany, UK, Norway) and entities (CENELEC, FCC, BBC). The differences between the various proposals were quite large and it was not possible to reach a consensus. A Joint Working Group ETSI/CENELEC has produced several drafts, which have all failed to be approved by the National Committees. 4. PLC activity at the North China Electric Power University 4.1 Mandate given to the EMC Laboratory In China, the Telecommunication Center of the China National Power Grid is supervising the PLC deployment over the whole country as a provider of service, but not as a regulatory authority. The Telecommunication Center has given to the EMC Laboratory of the North China Electric Power University the mandate to develop: - a measurement method for the field； - a standard which should be used in the future as a basis for the regulation of the PLC deployment. These studies are a contribution, together with other research activities in Europe like the European Project OPERA, to the development of international standards. 4.2 Experimental measurements In order to simulate the PLC operation environment, an experimental network was set up. Its structure is presented in Fig. 2. As seen in Fig.2, the field was measured with a loop antenna which gives the magnetic field value. The conversion to electric field was performed by multiplying the measured values by the vacuum impedance (377 ohms). It is clear that in near fields, the value of the vacuum impedance is higher than 377 ohms and a better approach to convert magnetic to electric fields in such configurations is under study. As a pair of PLC modems with rate of 200Mbps being used to download data from internet, the radiated field was also measured and shown in Fig.4. The radiation field was above all of the three limits. The dimensions of the room were 9.45×6.8m. Three power distribution branches have been installed in the test. The first branch supplied three daylight lamps； the second branch a high-powered air conditioning； the third one five household electric appliances, including a refrigerator, a computer, a microwave oven, a washer, and a TV set each of it at distances of 10 meters. PLC signals were coupled at the outlet of the energy meter. A loop antenna was placed 3 meters away from the power line. A PLC router and PLC modems composed of the LAN at nominal rates of 14Mbps, 45Mbps and 200Mbps to simulate the PLC internet access have been used. An example of the radiated electric field measured in the room is presented in Fig.3. When using the PLC modems, besides shutting them down and transferring data with the internet at relatively high rate, there is another possible state: standby. In this state, the PLC modem is powered on, but it isn’t used to transfer data by the customer. The radiated field of a pair of PLC modems with a rate of 45Mbps in standby state was also measured and shown in Fig.5. Compared with the background, it appears that the radiation of the PLC network is significant when the PLC modem is in standby especially from 18MHz to 23MHz. Fig.6 shows the measured radiation fields with different load conditions. The dotted line presents the condition when all household electric appliances were on, and the solid line presents the “off” condition. Fig.6 shows that the radiation fields did not vary significantly when the household electric appliances were “on” and “off”. Another interesting item investigated at the North China Electric Power University EMC Laboratory was the relation between the injected current and the radiation field strength. Generally, if this relation is known and it if is stable enough, then we can assess the emission level to some extent by measuring the injected current. Therefore, the injected current was measured in parallel with the field. Fig.7 shows the relation between the injected current and the radiation field in the frequency domain for the 45Mbps network. A rather good correlation was found except for frequencies in the range of about 16 to 24 MHz. The quantitative transfer relation for a typical network structure is still under investigation. 5. Regulatory approaches for access networks in Europe and USA 5.1 European Union regulation The Communication Committee (COCOM) of the European Commission (EC) has delivered a positive message on the Draft Recommendation on Broadband Communications from 6 April 2005. This recommendation is very similar to the “Report and Order” published by the FCC on October 14, 2004. The main features of this recommendation are: - It requires that Regulatory Authorities should not follow the ex-ante approach for PLC deployment and operation. That means that PLC equipment should have easy market access and that an authorization is only required in case of harmful interference within a specific location at a specific frequency； - the PLC equipment is regarded as a telecommunication equipment and as a consequence should follow the CE certification； - it requires that PLC systems should be installed and operated according to good engineering principles； - it recognizes the right of countries to take special restriction measures if necessary, for instance frequency restrictions in specific areas (military, coast where ship navigation can be affected), or fir frequencies of specific use (fire alarm). Misunderstandings by EU member states are minimized by the recommended permanent dialogue towards the EC. 5.2 USA regulation As an amendment to Part 15 of its rules, the Federal Communication Commission (FCC) has published on 14 October 2004 the “Report and Order”, which defines the BPL (Broadband Power Lines, name of PLC in US) regulation for Access PLC. Access BPL systems will operate on an unlicensed non-interference basis under Part 15 model. This means that the permitted limits are those defined by FCC Part 15, i.e.62 dBμV/m (see Fig. 3) and that the FCC will ask for a decrease of these limits or mitigation measures only in case of Interference. In addition, in order to achieve this goal the “Report and Order” specifies that the FCC: - can decide that BPL must avoid specific frequencies and can decide to shut down any unit in the case of harmful interference； - establishes “exclusion zones” in locations close to sensitive operations, such as coast guard or radio astronomy stations, within BPL must avoid operating on certain frequencies； - establishes consultation requirements with public safety agencies, federal government sensitive stations and aeronautical stations； - establishes a publicly available Access BPL notification database to facilitate an organized approach to identification and resolution of harmful interference； - changes the equipment authorization for Access BPL systems from verification to certification； - improves measurement procedures for all equipment that use RF energy to communicate over power lines. 6. Conclusion The Power Line Communication represents a very promising technique, permitting to extend internet, voice phone and digital TV everywhere where exists a Low Voltage Distribution Network. However, a few EMC problems should still be solved, in order to avoid disturbances. On international level, the standardization work is progressing very slowly, due to many divergent approaches and lack of some technical solutions. The measurements performed in the experimental network of the EMC.Laboratory of the North China Electric Power University, show that the radiated fields are related with the work state and the transfer rate of the PLC modems. Especially for the higher rate, the radiated fields are beyond limits of NB30, ITU K60 and even FCC Part15. The research work performed in this university, together with studies taking place in other universities in the world, will contribute to a better understanding of the behavior of the reducing the disturbances and to permit the development of standards compatible with the commercial interests and with the protection of consumers. Acknowledgment This work is supported by the National Natural Science Foundation of China (project 60571030). 國際標準的發(fā)展促進國內(nèi)PLC的研究 摘要 在該領(lǐng)域的PLC ，標準化進程，國際一級的進展十分緩慢。 EMC的實驗室，華北電力大學(xué)收到了任務(wù)，制定一個測量方法，為外地輻射裝置用PLC和標準，用于在今后的監(jiān)管的PLC部署。經(jīng)過簡短介紹的標準化進程在國際一級，提出了測量數(shù)據(jù)進行的華北電力大學(xué)的輻射領(lǐng)域，由于PLC的。比較外地的各種限制顯示。最后，文件還提出了審查監(jiān)管情況，國際一級。 關(guān)鍵詞： PLC ，標準化，電磁干擾。 1 .導(dǎo)言 在過去6至7年，可行性研究已經(jīng)完成在不同國家，以檢查是否有可能利用低壓配電網(wǎng)絡(luò)，使數(shù)據(jù)傳輸和電話聯(lián)系，最終也對個人客戶的頻率高達30 MHz的。這一新技術(shù)被稱為電力線通信（ PLC ）的。這種應(yīng)用是特別有趣的是電力，一方可以以這種方式進入電信市場，并利用其網(wǎng)絡(luò)，電力網(wǎng)絡(luò)的數(shù)據(jù)傳輸，另一邊可以使用此技術(shù)來控制自己的網(wǎng)絡(luò)。 然而，這種傳輸模式中頻段從6月1日至30兆赫的各種禮物和相當復(fù)雜的電磁兼容問題。主要的問題isproduction的網(wǎng)絡(luò)中的干擾和環(huán)境。 2 .干擾源 干擾的來源都是輻射，并進行： -排放的電磁噪聲，可干擾無線電通訊的安全或軍事用途，或干擾無線電業(yè)余愛好者； -進行差分和共模電流可以穿透任何設(shè)備連接到網(wǎng)絡(luò)中，公司正在努力。騷亂有兩種類型的來源： -信號源的不對稱，由于耦合不對稱； -不平衡的低壓配電網(wǎng)（ LVDN ） ，因此一個共同的模式，以差模轉(zhuǎn)換。 轉(zhuǎn)換差別的共同模式由于網(wǎng)絡(luò)不平衡分析了各種文件，例如在不同的解決方案已經(jīng)緩解還提議在文獻，但研究工作必須進一步繼續(xù)。 3 .標準化在國際一級 關(guān)于電磁兼容問題，在國際層面上，兩種類型的標準，必須制訂： -產(chǎn)品標準； -網(wǎng)絡(luò)標準。 3.1產(chǎn)品標準 產(chǎn)品標準應(yīng)修改CISPR22標準的任務(wù)是小組委員會的CISP。 第一個想法是的概念擴大縱向轉(zhuǎn)換損耗（柜）具體對稱雙絲電信的非對稱電網(wǎng)。 表現(xiàn)在各種測量電力網(wǎng)絡(luò)，因為這些顯示圖，給予了大量的傳播拼箱值。 這是不可能達成協(xié)商一致的概念基礎(chǔ)上拼箱值，用于計算的電壓限制在港口的設(shè)備連接到網(wǎng)絡(luò)，但這個概念已經(jīng)被確立為案件電信線路。經(jīng)過大約4年的工作和一系列文件光盤（委員會草案）階段，這一概念沒有找到所要求的合格的多數(shù)批準的CISPR /我/雖然，它發(fā)現(xiàn)了多數(shù)人的贊同在工作組內(nèi)。這是決定重新開始新的工作評價的基礎(chǔ)。 一項新的工作項目提案（ NWIP ）是由法國國家委員會，并核準于2005年4月這項工作將無法集中更多的拼箱價值，但將努力： -描述了典型的電力設(shè)施的地方是連接PLC設(shè)備； -確定潛在的不安服務(wù)/設(shè)備為每個典型部分電力設(shè)施上文所述； -評估的保護水平，目前提供的CISPR22為每個設(shè)備/服務(wù)； -建立輻射和排放量進行限制，每一個典型的電力安裝一節(jié)時， PLC的運行。 這項工作開始于2005年6月，目前正在取得進展。 3.2網(wǎng)絡(luò)標準 歐盟委員會已經(jīng)于2001年發(fā)布的任務(wù)313使CENELEC和ETSI的任務(wù)是制定標準，確定排放限值的所有通信網(wǎng)絡(luò)，包括PLC的不同的限制提出了不同的國家（德國，英國，挪威）和實體（ CENELEC ，催化裂化，英國廣播公司） 。之間的分歧的各種建議是相當大，因此無法達成共識。 聯(lián)合工作組的ETSI / CENELEC編制了若干草案，這都沒有得到批準的全國委員會。 4 . PLC的活動在華北電力大學(xué) 4.1授權(quán)的電磁兼容實驗室 在我國，電信中心，中國國家電網(wǎng)公司是監(jiān)督部署對整個國家作為一個供應(yīng)商的服務(wù)，而不是作為一個監(jiān)管機構(gòu)。電信中心已考慮到電磁兼容實驗室的華北電力大學(xué)開發(fā)的任務(wù)： -一種測量方法的領(lǐng)域； -一個標準的，應(yīng)在將來使用，以此為基礎(chǔ)的PLC部署。 這些研究的貢獻，連同其他研究活動在歐洲象歐洲項目歌劇，向國際標準的發(fā)展。 4.2實驗測量 為了模擬PLC的經(jīng)營環(huán)境，實驗網(wǎng)絡(luò)正式成立。其結(jié)構(gòu)如圖2 ，實地測量的環(huán)形天線使磁場價值。轉(zhuǎn)換電場是由乘以測量值的真空阻抗（ 377歐姆） 。顯然，在不久的領(lǐng)域，其價值的真空阻抗高于377歐姆和更好的方法來轉(zhuǎn)換磁場對電場在這種配置目前正在研究。 作為一個對PLC的調(diào)制解調(diào)器的速度200Mbps被用來從互聯(lián)網(wǎng)下載數(shù)據(jù)的輻射場也是衡量和顯示在圖4 。輻射場是最重要的三個限制的尺寸為9.45 ×房間六點八米，三峽電力分配部門已經(jīng)安裝測試。第一個分支提供三個日光燈；第二處高功率的空調(diào)；第三個五年家用電器，包括冰箱，電腦，微波爐，洗衣機和一臺電視機，在每一個距離10米。 PLC的信號，再加上出口的電能表。循環(huán)天線被置于3米遠離電力線。 PLC與PLC調(diào)制解調(diào)器路由器組成的局域網(wǎng)的名義利率14Mbps ， 45Mbps和200Mbps模擬PLC的互聯(lián)網(wǎng)接入已經(jīng)使用。一個例子輻射電場測量室介紹圖。 當使用的PLC調(diào)制解調(diào)器，除了關(guān)閉他們失望和傳輸數(shù)據(jù)與互聯(lián)網(wǎng)在相對較高的利率，還有一個可能的狀態(tài)：待命。在此狀態(tài)下， PLC的調(diào)制解調(diào)器的電源，但它不是用來傳輸數(shù)據(jù)的客戶。輻射場對PLC的調(diào)制解調(diào)器的速度45Mbps在待機狀態(tài)也是衡量和圖5所示。與背景，似乎輻射的PLC網(wǎng)絡(luò)具有重要意義時， PLC的調(diào)制解調(diào)器在待機特別是從達18MHz到23MHz 。 圖6顯示了測量輻射領(lǐng)域不同負載條件下。虛線提出的條件時，所有的家用電器上，而實線介紹了“關(guān)閉”狀態(tài)。圖6表明，沒有輻射領(lǐng)域差別很大時，家電是“上”和“關(guān)閉” 。 另一個令人感興趣的項目調(diào)查，在華北電力大學(xué)電磁兼容實驗室是關(guān)系注入電流和電場強度的輻射。一般來說，如果這種關(guān)系是已知的和穩(wěn)定的，如果是不夠的，那么我們可以評估排放水平在一定程度上通過測量注入電流。因此，注入電流測量平行與外地。圖7顯示之間的關(guān)系注入電流和輻射場的頻域的45Mbps網(wǎng)絡(luò)。一個比較良好的相關(guān)性，發(fā)現(xiàn)除了頻率范圍約16至24兆赫。轉(zhuǎn)讓的數(shù)量關(guān)系的一個典型的網(wǎng)絡(luò)結(jié)構(gòu)仍在調(diào)查之中。 5 .管理辦法的接入網(wǎng)絡(luò)在歐洲和美國 5月1日歐洲聯(lián)盟條例通信委員會（巴統(tǒng)）的歐洲委員會（ EC ）帶來了一個積極的信息對建議草案的寬帶通信從2005年4月6日。這項建議是非常類似的報告“和秩序”出版由FCC于2004年10月14號。主要特點，這一建議是： -它要求監(jiān)管當局不應(yīng)按照事前辦法PLC的部署和行動。這意味著，公司設(shè)備應(yīng)具有方便的市場準入，并授權(quán)只須在案件內(nèi)的有害干擾的具體位置在特定的頻率； -的PLC設(shè)備被視為電信設(shè)備，因此應(yīng)遵循CE認證； -它要求PLC系統(tǒng)應(yīng)安裝和操作按照良好的工程原則； -它承認各國有權(quán)采取特別限制措施，如果有必要，例如頻率限制在特定領(lǐng)域（軍事，海岸船舶航行可能受到影響） ，或飛行情報區(qū)的具體使用頻率（火災(zāi)報警） ，誤解了歐盟成員國盡量減少長期對話的建議對歐共體。 5.2美國監(jiān)管 作為修正案的第15部分的規(guī)定，聯(lián)邦通訊委員會（ FCC ）發(fā)表了關(guān)于2004年10月14 “報告和秩序” ，它確定了電力線寬帶（寬帶電力線，名稱的PLC在美國）規(guī)例獲取PLC的。 電力線寬帶接入系統(tǒng)將在一間無牌經(jīng)營不干預(yù)的基礎(chǔ)上根據(jù)15模型。這就是說，允許限額所規(guī)定的FCC Part 15的， ie62 dBμV /平方米（見圖3） ，并要求聯(lián)邦通信委員會將減少或減輕這些限制措施只能在案件干涉。 此外，為了實現(xiàn)這一目標“報告和秩序”中指定的催化裂化： -可以決定BPL公司必須避免特定頻率和可以決定關(guān)閉任何單位的情況下有害干擾； -建立“禁區(qū)”的地點接近敏感的業(yè)務(wù)，如海岸警衛(wèi)隊或射電天文站，必須避免在電力線寬帶業(yè)務(wù)在某些頻率； -建立磋商要求公眾安全機構(gòu)，聯(lián)邦政府的敏感和航空站； -建立了一個公開的訪問BPL的通知數(shù)據(jù)庫，以促進一個有組織的方法來識別和解決有害干擾； -改變了設(shè)備的授權(quán)，電力線寬帶接入系統(tǒng)核查驗證； -提高了測量程序，對所有設(shè)備的能源使用射頻通訊電力線路上。 6 .結(jié)論 電力線通訊是一個非常有前景的技術(shù)，允許延長互聯(lián)網(wǎng)，語音電話和數(shù)字電視在世界各地存在著一種低壓配電網(wǎng)。但是，有少數(shù)的EMC問題，仍然應(yīng)該得到解決，以避免干擾。在國際一級，標準化工作進展非常慢慢地，由于許多不同的辦法和缺乏一些技術(shù)解決方案。測量完成實驗網(wǎng)絡(luò)的EMC實驗室華北電力大學(xué)，表明，輻射相關(guān)領(lǐng)域的工作狀態(tài)和傳輸速率的PLC調(diào)制解調(diào)器。特別是較高的利率，輻射領(lǐng)域超出限度NB30 ，國際電聯(lián)K60 ，甚至催化裂化Part15 。這項研究工作在這所大學(xué)，研究一起發(fā)生在其他大學(xué)在世界上，將有助于更好地理解的行為減少了干擾，并允許制定標準兼容的商業(yè)利益與保護消費者的利益。 致謝 這項工作得到了國家自然科學(xué)基金資助項目（項目六千零五十七點一零三萬） 。