Tender for 500 kV transformers and switchgears for Three Gorges Project is ready

AmassivetenderfortansformersandotherequipmentforthegiantThreeGorgesProjectisreadyfordomesticandinternationaltenders.Thenewtenderwillincludefifteen5ookVtransformers,gas-insulatedswitchgearsandotherequipmenttobeusedintheleft-bankpowerhouseoftheproject.ChinaYangtzeDevelopmentCorp.(CTGPC)ThreeGorgesProjectwillinvitetendersforthedeallatethisyearoratthebeginningofnextyear,andwillgiveprioritytothedomesticproductsiftheirqualitycanfullysatisfythedemandsoftheproject.Butsomeequipmentkey,includingla…     

Partial discharge tests——at site for large power transformers

1.IntroductionAn obvious improvement in designing and manufacturingtransformers has been achieved since the application of partial dis-charge (PD) test on power transformers was accepted.ChineseNational Standard has stipulated that PD test is a routine item fortransformers with rated voltage 220 kV and above.Many transform-     

Can fractal techniques be used for impulse fault pattern discrimination in distribution transformers?

Distribution transformers connected to overhead lines are often prone to lightning strikes and resulting winding damage. For assessment of their insulation strength against such impulse stresses they are usually subjected to lightning impulse tests after assembly. In the case of a fault inside the winding, the shape of the winding current changes as compared to that of a healthy winding. The pattern of the fault current depends on the type of fault and its location along the length of the winding. This paper investigates the potential application of fractal techniques for analysis of such fault current patterns. Fractal features such as fractal dimension and lacunarity commonly used for image and pattern recognition have been employed for classification of distribution transformer impulse faults. Simulation results obtained for a range of distribution transformer digital models are presented to illustrate the ability of this approach to classify insulation failures during impulse testing. The proposed tool has been applied for impulse fault analysis of a scaled-down analog model of a 3 MVA transformer. The results promise potential application of this novel technique for impulse fault pattern recognition in distribution transformers.     

Development and Prospect of Installation Technology of Electrical and Mechanical Equipment in Hydropower Construction

The hydropower installed capacity in China exceeded 100GW by the end of 2004. With the development of hydropower construction cause, the contingents of eleetrical and mechanical installation also grew steadily.The installation and debugging techniques made great strides in aspects of different conventional hydrogenerator sets. reversible pumped-storage units and their rotor spiders, runners, bearings, penstocks as well as control equipment, such as computerized governors, intelligent monitoring devices. Major technical innovations were brought about in the electrical and mechanical installation. For an arduous task to construct hydropower projects of over 50 GW confronts hydropower installatinn enterprises at the beginning of 2 I st century, the installation technologies will certainly develop around the projects.     

Travelling wave pilot protection for LCC-HVDC transmission lines based on electronic transformers’ differential output characteristic

Considering travelling wave’s bandwidth which varies from several kilohertz to hundreds of kilohertz, traditional current and voltage transformers cannot transfer whole bandwidth of travelling wave. However, electronic transformers, including Rogowski coil based electronic current transformer and capacitance divided electronic voltage transformer, have much wider bandwidth (up to 500 kHz) which could transfer almost whole bandwidth of travelling wave without distortion. Besides, secondary side’s output of electronic transformer is the differential signal of primary side. So, the integration circuit can be omitted when using differential travelling wave signal directly in protection principle. Traditional travelling protection for high voltage direct current (HVDC) lines is highly affected by grounding resistance. And the backup protection, such as current differential protection, has long operation time. So the paper proposes a novel travelling wave pilot protection based on the differential output signal of electronic transformers. Differential voltage and current travelling wave have axisymmetric relationship when the fault occurs at forward direction. Conversely, differential voltage and current travelling wave almost overlap when the fault occurs at reverse direction. Considering fault direction identification results of two ends, fault section can be determined. Besides, according to amplitude ratio of fault line and normal line, fault line can be selected correctly. The simulation results in PSCAD/EMTDC prove the correctness, sensitivity and reliability.     

A Brief Introduction to the Key National Disciplines of College of Electrical and Electronic Engineering of Huazhong University of Science and Technology

The electrical engineering discipline of HUST is amongthe first batch of disciplines approved by the Academic DegreeEvaluating Committee of the State Council of China as entitledto confer the mastership and the doctorate (1981), the firstbatch of postdoctoral programs (1985), and the first batch ofdisciplines entitled to award the doctorate in top level discipline(1996). The electrical machinery and electrical apparatus discipline,and the power system and its automation discipline were elected asthe key national disciplines January 2002. Also, the electrical amchinery discipline is one of the original two key nationaldisciplines, and its Electrical Machinery State SpecializedLaboratory is the only state key laboratory in this field.     

Practice and Development of Environmental Impact Assessment

Environmentalimpactassessment(EIA)ofthermalpowerprojecthasbeencarriedoutfor20yearssinceEIAsystemwassetupin1979inChina.Inthebeginning,theairenvironmentalimpactwastakenastheprincipalitemofEIA.Now,ithasinvolvedtoassesscomprehensivelytheair,water,noise,solidwastematter(ashandslag)environmentalimpactriskanalysis,pollutantsemissionquantitycontrolcleanproduction,waterandsoilpreservation,environmentalmanagementandmonitoringplanpublicparticipationetc.Somenewassessmentfieldsuchastransmissionandsubst…     

Past, Present and Future of PXI

Since its first introduction more than 25 years ago, the concept of Virtual Instrumentation has now been widely adopted in automated test and measurement industry. Virtual Instrumentation allows users to create a user-defined system by combining modular h…     

Informatization of Power Plant and Its Implementation

This paper presents the working procedure of power generating enterprises and explains the framework of an e-power-plant and its information system, puts forward the guideline and the general goal of informatization construction while focusing on the construction goal in the applied system, the implementing strategy, the project management and organization.     

Reform and Development of China''''s Power Industry

Mr.Chairman,LadiesandGentlemen:ItismygreatpleasuretobeinvitedtoparticipateintheChinaPowerForum's97jointlysponsoredbyChinaElectricityCouncil,PanwellConferences&ExhibitionsandSingaporePublishingGroup.OnbehalfoftheMinistryofElectricPowerofChina,Iampleasedtohavethisopportunitytodiscussthereformanddevelopmentofpowerindustrywithnewfriendsandoldacquaintancesfromtheelectricitycommunityworldwide.IwouldliketobriefyouhereonStatePowerCorporationofChinaandthepolicyonutilizationofforeigncapitalinC…     

Achievements and Prospects of China's Hydropower Generation

<正>Outstanding achievements The scale of hydropower development continuously expanding to a new level As a type of clean and renewable energy     

Construction and commissioning news of key projects

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Practical application of the benchmarking technique to increase reliability and efficiency of power installations and main heat-mechaniс equipment of thermal power plants

Data on the comparative analysis variants of the quality of power installations (benchmarking) applied in the power industry is systematized. It is shown that the most efficient variant of implementation of the benchmarking technique is the analysis of statistical distributions of the indicators in the composed homogenous group of the uniform power installations. The benchmarking technique aimed at revealing the available reserves on improvement of the reliability and heat efficiency indicators of the power installations of the thermal power plants is developed in the furtherance of this approach. The technique provides a possibility of reliable comparison of the quality of the power installations in their homogenous group limited by the number and adoption of the adequate decision on improving some or other technical characteristics of this power installation. The technique provides structuring of the list of the comparison indicators and internal factors affecting them represented according to the requirements of the sectoral standards and taking into account the price formation characteristics in the Russian power industry. The mentioned structuring ensures traceability of the reasons of deviation of the internal influencing factors from the specified values. The starting point for further detail analysis of the delay of the certain power installation indicators from the best practice expressed in the specific money equivalent is positioning of this power installation on distribution of the key indicator being a convolution of the comparison indicators. The distribution of the key indicator is simulated by the Monte-Carlo method after receiving the actual distributions of the comparison indicators: specific lost profit due to the short supply of electric energy and short delivery of power, specific cost of losses due to the nonoptimal expenditures for repairs, and specific cost of excess fuel equivalent consumption. The quality loss indicators are developed facilitating the analysis of the benchmarking results permitting to represent the quality loss of this power installation in the form of the difference between the actual value of the key indicator or comparison indicator and the best quartile of the existing distribution. The uncertainty of the obtained values of the quality loss indicators was evaluated by transforming the standard uncertainties of the input values into the expanded uncertainties of the output values with the confidence level of 95%. The efficiency of the technique is demonstrated in terms of benchmarking of the main thermal and mechanical equipment of the extraction power-generating units T-250 and power installations of the thermal power plants with the main steam pressure 130 atm.     

Current Situation and Development of Cogeneration in China

1. The Power Industry and Cogeneration in China 1.1 The Power Industry in China The power industry has developed rapidly in China in recent decades. In 1994, total electricity generation was 927.8 TWh and the total installed capacity was 199.80 GW. It is broken down as follows: hydropower 49.0 GW. 24.5 %; thermal power 148.73 GW, 74.4c/c: and nuclear power 2.1 GW, 0.7%.     

The Intranet of NARI and Its Application Development

1.IntroductionWiththecobingofinformahontechnologyera,itbecomesanimportantcriterionofevaluatingacountry,abranchandacorPOrahontodevelopandamplementinformahontechniques.NARIgrouP,asatoppingcolorationofscienhficresearchandequipmentmanufactUreofelectricPOwersysteminChina,keepsaheadalltheWhileintheprocesstowardsinformahonnetWorkthroughtheactiVedevelopmentandresearchofcomputernetWorkanditsaPPlicahontechniques.Fromthelaterhalfof1996,thetechniciansofNAKIwereorganizedtobuildtheNARIIntranetandd…     

Past, present and future of fuel cells

Ｉｎ 18 3 9,Ｇｒｏｖｅ[1] ｐｕｂｌｉｓｈｅｄｈｉｓｓｔｕｄｉｅｓｏｎｔｈｅｇｅｎｅｒａｔｉｏｎｏｆｅｌｅｃｔｒｉｃｉｔｙｂｙｃｏｎｎｅｃｔｉｎｇｔｗｏｐａｒｔｉａｌｌｙｉｍｍｅｒｓｅｄｐｌａｔｉｎｕｍｆｏｉｌｓｉｎｓｕｌｐｈｕｒｉｃａｃｉｄａｎｄｆｅｅｄｉｎｇｈｙｄｒｏｇｅｎａｎｄｏｘｙｇｅｎｓｅｐａｒａｔｅｌｙｔｏｔｈｅｅｌｅｃｔｒｏｄｅｓ .Ｔｈｅｂａｓｉｃｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｒｅａｃｔｉｏｎｗａｓｓｉｍｐｌｅ :Ａｎｏｄｉｃｒｅａｃｔｉｏｎ :Ｈ2 2Ｈ+ + 2ｅ-Ｃａｔｈｏｄｉｃｒｅａｃｔ…     

Energy and water saving of thermal power plant

The average coal consumption of thermal power plants inShandong Provincial Grid was reduced from 449 g(standardcoal)/kWh in 1979 to 389 g(standard coal)/kWh in 1989,as inrecent ten years,the thermal power plants of Shandong Provinceadopted the method of constructing large scale generating units andimproving the economic performance of old generation units,mean-while the other technical and economical targets also were improvedsignificantly.For instance,the electric energy consumption rate of     

Status and Functions of Regional Power Grid Corporations

In line with power institutional reform and formation of the state power grid, status and roles of regional power grid corporations experienced several variations and are now being incessantly marginalized and weakened. The reform of turning regional grid corporations into regional headquarters of State Grid Corporation may be a better choice beneficial to group operation, intensive development and precise management. This article can be regarded as the author＇s personal opinion.     

I Ching and Two of Its English Versions

I Ching, the essence of Chinese culture, has a history of three thousand years. It embodies a kind of philosophy, wisdom, even a kind of science, and greatly influences Chinese civilization. However, for its special style and abstract content, I Ching＇s meaning is far to reach, especially for foreigners. This paper is going to compare two well-known English editions t~om the aspects of comprehension, wording and expression. The author attempts to primarily probe into the practice and skills of the translation of I Ching.