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基于PSModel的江苏电网机电一电磁混合仿真金梦;李修金;刘一丹;张祥;孙毅;朱鑫要【摘要】江苏电网直流输电发展迅猛,未来将通过直流输电受入大量功率.在电网运行过程中,交流电网故障将通过换流站母线对直流输电运行产生影响,可能造成直流输电发生换相失败等,而目前电力系统稳定分析所采用的机电暂态仿真手段可能无法准确反映该动态过程.文中分别采用机电仿真软件BPA和机电-电磁混合仿真软件PSModel(power system model)2种仿真工具,对比仿真分析和研究了江苏电网交流故障对直流输电运行的影响,相关结论为电网运行分析工作提供建议和参考.【期刊名称】《江苏电机工程》【年(卷),期】2017(036)003【总页数】6页(P7-11,27)【关键词】特高压直流;换相失败;机电仿真;机电-电磁混合仿真【作者】金梦;李修金;刘一丹;张祥;孙毅;朱鑫要【作者单位】国网江苏省电力公司检修分公司江苏南京211102;国网江苏省电力公司检修分公司江苏南京211102;国网江苏省电力公司检修分公司江苏南京211102;国网江苏省电力公司检修分公司江苏南京211102;国网江苏省电力公司检修分公司江苏南京211102;国网江苏省电力公司电力科学研究院,江苏南京211103【正文语种】中文【中图分类】TM721我国能源资源和经济发展严重不匹配，能源资源主要分布在西南和“三北”(东北、华北和西北)地区，负荷中心则主要位于东南沿海地区；为解决电力的远距离输送问题，大容量特高压直流输电在我国电网得到了长足的发展和应用[1-3]。
江苏电网为我国东部的负荷中心，截至2016年，已有±500 kV龙政超高压直流、±800 kV锦苏特高压直流2条直流输电落点，直流受电功率超过10 000 MW[4,5]。
此外，±800 kV雁门关—淮安特高压直流和±800 kV锡盟—泰州特高压直流也均已进入全面建设阶段，将于2017年建成投运，届时江苏电网直流受电功率将超过28 000 MW[6,7]。
1 编制目的为了在工程设计文件中正确使用英文缩写词和理解英文词表达的函义，特编制本文件。
2 适用范围英文缩写词可以在英文注释的专业图纸和设计文件中使用。
中文注释的图纸和文件除特殊情况外一般不采用。
3 注意事项3.1 在绘制工程设计图纸时，英文缩写词一律采用大写字母。
3.2 编制设计标准和设计文件时，除国家、机关、学会、工程单位等名称需采用大写字母的缩写词外，其余均应优先采用小写字母的缩写词，没有小写字母的缩写词时，再采用大写字母的缩写词。
顺序号缩写词英文全文及中文涵义A1 a absorption吸收（作用）2 A ① ammeter安培计、电流计② ampere安培③ assembly装配，组合，成套设备，机组，部件3 AAC acoustical-absorption coefficient吸音系数4 AACC American Automatic Control Council美国自动控制委员会5 A.A.F American Air-Filter Co.美国空气过滤器公司6 AB anchor boltF—A14-96第 2 页共 60 页地脚螺栓7 ABA1 American Boiler & AffiliatedIndustries美国锅炉和附属设备制造厂商协会8 abb abbreviation缩写,简体9 abr abridgement简介、简述10 abs ① absolute绝对的② absorption吸收顺序号缩写词英文全文及中文涵义11 A.B.S American Bureau of Standards美国标准局12 ABS.H absolute humidity绝对湿度13 ABS.T absolute temperature绝对温度14 a.c absorption coefficient吸收系数15 AC ① air condenser空气冷凝器② air cooling空气冷却③ alternating current交流电16 A/C ① air condition (-ing,-ed,-er)空调（机）② air compressorF-A14-96第 3 页共 60 页空气压缩机17 acc accessories附件，零件，附属设备18 ACR automatic controller自动控制器19 ACS automatic control system自动控制系统20 act.std actual standard现行标准21 ACU air-conditioning unit空调机组顺序号缩写词英文全文及中文涵义22 AD ① air duct风道② anemostatic diffuser恒速式散流器23 adj.sp adjustable speed可调速度24 ADP apparatus dew point机器露点25 AESC American Engineering StandardsCommittee美国工程标准委员会26 AEV automatic expansion valve自动膨胀阀27 AF air filter空气过滤器28 AG asbestos gasket石棉垫片29 AGA American Gas AssociationF—A14-96第 4 页共 60 页美国煤气协会30 AGC automatic gauge controller自动测量控制器31 AHU air-handling unit组合式空调机，空气处理机组32 AIR CHG air change(s)换气量，换气次数33 ALM alarm警报器，信号装置，警报顺序号缩写词英文全文及中文涵义34 alt altitude高度，标高35 amb.temp ambient temperature周围温度，室温，环境温度36 AN air natural(cooled)自然通风（冷却）的37 A.N.S.I American National Standards Institute美国国家标准学会38 AO air outlet送风口39 A.P American Patent美国专利40 APCA Air Pollution Control Association美国空气污染控制协会41 APHA American Public Health Association美国公共卫生协会42 appx appendix附录、补遗43 APS accessory power supplyF-A14-96第 5 页共 60 页辅助电源44 ARI Air conditioning and RefrigerationInstitute空调制冷研究所（美）45 AS ① air speed风速② American Standard美国标准顺序号缩写词英文全文及中文涵义46 A.B.C American Standard Association美国标准协会47 ASCE American Society of Civil Engineers美国土木工程师学会48 ASHRAE American Society of HeatingRefrigerating and Air ConditioningEngineers美国供热制冷和空调工程师协会49 ASHVE American Society of Heating andVentilation Engineers美国供暖通风工程师学会（ASHRAE的前身）50 at ① air tight不透气，气密的② atmosphere大气，大气压51 ATS absolute temperature scale绝对温标52 AUTO automatic自动的53 AUX auxiliary辅助的，附件，辅助装置F—A14-96第 6 页共 60 页54 AV angle valve角阀55 av;avg average平均，平均的56 AVD automatic vent damper自动风阀顺序号缩写词英文全文及中文涵义57 a.w.p actual working pressure实际工作压力58 AWT average water temperature平均水温B59 B bolt螺栓60 BAR barometer气压计，气压表61 BAS British Association Standard英国协会标准62 b.c between centers中心间距，轴间63 BESA British Engineering StandardAssociation英国工程标准协会64 BF ① boiler feed锅炉给水② bypass factor旁路系数65 BFP boiler-feed pump锅炉给水泵66 BHN Brinell hardness numberF-A14-96第 7 页共 60 页布氏硬度数67 BHP brake horsepower制动马力，轴功率68 B.I black iron黑铁（皮）顺序号缩写词英文全文及中文涵义69 bibl bibliography书目，文献目录70 BL ① base line基线② base load基本负荷③ boundary line边界线④ battery limits界区71 BLD blind盲板，档板72 BLDG building建筑物73 BLK blank空白，盲板74 BLR boiler锅炉75 B.O.D bottom of duct风道底（标高）76 BOM bill of material材料表，材料单77 B.O.P bottom of pipe管底（标高）F—A14-96第 8 页共 60 页78 B.P ① base plate底板，底座② back pressure背压顺序号缩写词英文全文及中文涵义③ barometric pressure表压力，大气压④ boiler pressure锅炉压力⑤ boiling point沸点⑥ bypass旁路，旁通管⑦ British Patent英国专利79 br branch支线（管）80 BRA British Refrigeration Association英国制冷协会81 BRACA British Refrigeration and AirConditioning Association英国制冷空调协会82 BRKT bracket托架，支架83 BS ① British Atandard英国标准② Bureau of Standard标准局（美）84 BSD Building System Design美国《建筑系统设计》期刊F-A14-96第 9 页共 60 页85 BSI ① British Standards Institution英国标准协会顺序号缩写词英文全文及中文涵义② Building Societies’ Institute建筑学会联合会86 bsmt basement地下室87 BSP British standard pipe英国标准管88 BSS British Standard Specification英国标准规范89 BTUH British thermal units per hour英热单位每小时90 BU bushing内外螺纹接头91 BV ① ball valve球阀② butterfly valve蝶阀92 BW butt weld对焊，对缝焊接C93 C ① centre中心② circuit电路，回路③ close闭合的，关闭，接通④ constant常数F—A14-96第 10 页共 60 页顺序号缩写词英文全文及中文涵义⑤ cycle循环，周期94 CA ① cooled in air风冷的② cold air冷空气，冷风③ compressed air压缩空气95 CAD computer-aided design计算机辅助设计96 cap capacity容量，生产能力97 CAS cast steel铸钢98 cat catalog目录，条目，总目，样本99 CB ① control board控制盘，操纵盘② control button控制按钮③ catch basin集水井，滤污器100 CC cooling cail冷却盘管101 C/C center-to-center中心距102 CCR critical compression ratio临界压缩比顺序号缩写词英文全文及中文涵义103 CD ceiling diffuser吊顶散流器104 CE ① chief engineer总工程师② civil engineering土木工程105 CEM cement lined水泥衬里，水泥抹面106 CENT centrifugal离心（式）的107 CEP condensate extraction pump凝结水排水泵108 cert certificate证明书，合格证109 CF contact factor接触系数110 CFM cubic feet per minute立方英尺每分111 CFS cubic feet per second立方英尺每秒112 CG ceiling grille吊顶风口113 CH chimney烟道114 ch chapter章115 CHAN channel槽钢，通道顺序号缩写词英文全文及中文涵义116 chem chemical化学的117 CHWP chilled water pump冷冻水泵118 CHWR chilled water return冷冻回水119 CHWS chilled water supply冷冻供水120 C.I cast iron铸铁121 circ.pump circulating pump循环水泵122 CIR.WF circulating water flow循环供水123 CIR.WR circulating water return循环回水124 CL ① center line中心线，轴线② class类别，级别125 CLG ceiling吊顶，天花板126 CM colour mark色标127 CN construction north建北128 CO ceiling outlet吊顶送风口顺序号缩写词英文全文及中文涵义129 Co. company公司130 coeff coefficient系数，率131 col column柱，纵行，栏，项目132 COMPR compressor压缩机133 conc concentration浓度134 CONC.DT concrete duct水泥风道135 cond ① condenser冷凝器，电容器② conductivity传导系数③ condens(e)(-ing,-ed,-er)冷凝（器）136 COND.WR vondenser water return冷凝器回水137 COND.WS condenser water supply冷凝器供水138 CONT.V control valve调节阀，控制阀139 Conv convector对流器140 COP ① coefficient of performance（制冷）工作系数，性能系数顺序号缩写词英文全文及中文涵义② center of pipe管中心141 corr correction修正，校正，改正142 CP ① calorific power发热量，热值② Canadion Patent加拿大专利③ check point检测点④ constant pressure恒压，等压143 CPLG coupling联轴节，连接，管箍144 cpm cycles per minute周每分145 c.r. continuous rating连续（额定）功率146 CPG ceiling return grille吊顶回风口147 cr.s. cross section横截面148 CS carbon steel碳钢149 CT cooling tower冷却塔150 CTR cooling tower retun冷却塔回水顺序号缩写词英文全文及中文涵义151 CTS cooling tower supply冷却塔供水152 cu. cubic立方的，三次的153 CU.FT cubic feet立方英尺154 CV ① calorific value热值，发热量② check valve止回阀，逆止阀③ constant volume定风量，定容155 CW ① cold water冷水② cooling water冷却水③ continuous welding连续焊156 CWP cooling water pump冷却水泵157 CWR cooling water return冷却回水158 CWS cooling water supply冷却供水D159 D ① degree度，程度顺序号缩写词英文全文及中文涵义② density密度③ diameter直径④ drop降落，温度降，压力降160 DB.A decibels of sound on an A-scale在A音阶上的分贝音量161 DBT dry bulb temperature干球温度162 DC direct current直流电163 DD dual duct双风管164 def. definition定义165 deg.cent. degree centigrade摄氏度166 deg.F degree fanrenheit华氏度167 deg.K. degree Kelvin开氏度168 DET detail零年，详图169 diag diagram图表，图解，曲线图，示意图170 DIN Deutsche Industrie Norman德国工业标准顺序号缩写词英文全文及中文涵义171 disch discharge排出，流出172 dist distribution分布，分配173 d.l.a. dust lade air含尘空气174 DN ① down下② nominal diameter公称直径175 DP ① dew point露点② differantial pressure压差，压降③ design pressure设计压力④ drain pipe排水管176 DPA days per annum每年日数177 DPT ① dew point temperature露点温度② dew point thermostat露点温控器178 dr. drain泄水，排水179 DS duct shaft竖向结构风道顺序号缩写词英文全文及中文涵义180 DSS The Society of Domestic and SanitaryEngineering Standard美国卫生工程协会标准181 DWG drawing图纸，制图182 DWG.NO drawing number图号183 DX.C direct expansion coil直接膨胀管E184 E east东185 EA exhaust air排风186 EAC electrostatic air cleaner静电滤尘器187 EBP exhaust back pressure排汽背压188 ECS environmental control system环境控制系统189 ED ① edition版本，版次② exhaust duct排风管190 EDP engineering design plan工程设计方案191 EF exhaust fan排风机顺序号缩写词英文全文及中文涵义192 eff efficiency效率193 EG exhaust air grille排风口194 EH exhaust hood排风罩195 EHP elcctric horsepower电功率196 EI ① exhaust inlet排风入口② Engineering Index工程技术文献索引（美）197 EJ expansion joint伸缩器，伸缩缝，补偿器198 EL ① exhaust loss排出损失② expansion line膨胀管199 ELB elbow弯头200 elev elevation标高，海拔，正视图201 EM engineering manual工程手册202 emg emergency事故，紧急情况203 ENCL enclosure, enclosed外壳，套，界限，封闭式的顺序号缩写词英文全文及中文涵义204 ENGR engineering工程，设计205 EP ① explosion proof防爆② English Patent英国专利206 EPA Environmental Protection Agency环境保护局（美）207 EPR evaporator pressure regulator蒸发器压力调节器208 ERT electric resistance thermometer电阻温度计209 ESHF effective sensible heat factor有效显热系数210 est estimate估计，预算，概算211 ESV emergency stop valve紧急切断阀212 ET expansion tank膨胀水箱213 ETR evaporator temperature regulator蒸发器温度调节器214 EV ① elevator电梯② expansion valve膨胀阀215 EVAP evaporat(e)(-ing,-ed,-or)蒸发（器）顺序号缩写词英文全文及中文涵义216 exh exhaust排气217 EXIST existing现行的，现有的218 exp expansion膨胀，增大219 ext ① extension伸长，发展，附加物② external外部的，表面的F220 F filter过滤器221 FA fresh air新鲜空气，新风222 FAI fresh air inlet通风孔，新风入口223 FC ① fire control消防② fan coil unit风机盘管224 f.d forced draft强制通风，送风225 FD ① fire damper防火阀② floor drain地漏顺序号缩写词英文全文及中文涵义226 FDF forced-draft-fan送风机227 FDN foundation基础228 FDW feed water供水229 F/F field faricated现场制造230 FG flue gas烟气231 FH fire hydrant消火栓232 fig figure图，插图233 FIN finish完成，成品，加工234 FL ① floor层，地板② full load全负荷，满载235 flg flange法兰，凸缘236 FOB free on board离岸价（船上交货）237 FOR fuel oil return回（燃料）油管238 FOS fuel oil supply供（燃料）油管顺序号缩写词英文全文及中文涵义239 FP fire proof防火，耐火的240 FRP fiber reinforced plastic玻璃钢241 FRT freight运费，货运242 FS forged steel锻钢243 FTG ① fitting配件，管件，装配，组装② footing基础脚，底座脚244 FVD fire volume damper防火调节阀245 FW ① field weld现场焊接② fresh water新鲜水，淡水G246 g gas气体，煤气247 g.a.d general assembly drawing总装配图248 G.B Great Britain大不列颠，英国249 GEN generator发电机，发生器顺序号缩写词英文全文及中文涵义250 GHC greenhouse controller温室控制器251 GHR gross heat rate总热耗252 G.I galvanized iron镀锌薄钢板，白铁皮253 gl glass玻璃，镜254 GLV globe valve截止阀255 gor governor调节器，调速器256 gp gauge pressure表压257 G.P German Patent德国专利258 gr grade级，度，坡度259 grad gradient梯度260 GRD ground地坪261 GRTG grating棚，格栅262 GSHF grand sensible heat factor总显热系数263 GSKT gasket垫片，密封垫顺序号缩写词英文全文及中文涵义264 GTH grand total heat总热量265 GV gate valve闸阀266 GW gross weight总重，毛重H267 H ① hardness硬度，硬性② head高差，压头③ heat热量，加热，热④ heater加热器⑤ height高度⑥ humidity湿度⑦ humidistat恒湿器，湿度调节器268 HA hot air热风269 HC ① heating coil加热盘管② hand control手（动）控制顺序号缩写词英文全文及中文涵义③ hose connection软管连接，软管接头270 hdbk handbook手册271 HDR header集气管，联管箱，顶盖，端板272 HE high efficiency高效273 HH handhole手孔274 HMF humidifier加湿器275 hor horizontal水平的，卧式的276 HP ① horse power马力，功率② high pressure高压277 HPAC Heating Piping & Air Conditioning美国《供热、配管、空气调节》期刊278 HR heat rate热耗率279 HRA heating,refrigerating and air-conditioning供暖制冷和空气调节280 HRD half round diffuser半圆散流器顺序号缩写词英文全文及中文涵义281 HSD high speed duct高速风管282 h/S diagram Enthalpy/Entropy diagram焓熵图，h-S图283 H.T.C heat transfer coefficient传热系数284 HTW high temperature water高温热水285 HV ① heating and ventilation供暖通风② heating value热值286 HVAC heating ventilation,air conditioning供暖通风空气调节287 HVE heating and ventilating engineer暖通工程师288 HW hot water热水289 HWP hot water pump热水泵290 HWR hot water return热水回水管291 HWS hot water supply热水供水管292 HX heat exchanger换热器293 HYDT hydraulic testing水压试验顺序号缩写词英文全文及中文涵义294 I input输入295 IAMAP International Association ofMeteorology and Atmospheric Physics国际气象和大气物理协会296 IBR Institute of Boiler and RadiatorManufacturers锅炉和散热器制造业协会297 ID ① induced draft引风② inside diameter内径298 IDF induced-draft-fan引风机299 IDHA International District HeatingAssociation国际区域供热协会300 IG inlet grille吸风口301 ih indirect heating间接加热302 i.hp indicated horsepower指示功率303 IHVE Institute of Heating and VentilatingEngineers英国暖通工程师学会顺序号缩写词英文全文及中文涵义304 I.I.R International Institute ofRefrigeration国际制冷学会305 IL intensity level声强级306 IME Institytion of Mecnical Engineers机械工程师学会（英）307 ind indicator指示器308 in.H2O inches of water英寸水柱309 ins insulated绝热的，绝缘的310 inst installation安装设备311 INSTR instruction说明书312 INTLK intotlock连锁装置313 INTMT intermittent间歇的314 IO inlet opening吸风口315 IPS iron pipe size铸铁管径316 ISA International StandardizationAssociation国际标准化协会顺序号缩写词英文全文及中文涵义317 ISO International AtandardizationOrganization国际标准化组织318 isoth isothermal等温的319 ISU international standard unit国际标准单位320 IT inlet temperature进口温度321 IU ① induction unit诱导器② international unit国际单位J322 J.E.S.A Japanese Engineering StandardAssociation日本工程标准协会323 JICST Japan Information Center of Science &Technology日本科技情报中心324 JIS Japan Industrial Standard日本工业标准325 jnt joint接头，接合326 JOB.NO job number项目号顺序号缩写词英文全文及中文涵义K327 K heat transfer coefficient传热系数328 KB knee brace斜撑，角撑。
I.J. Engineering and Manufacturing, 2020, 1, 1-11Published Online February 2020 in MECS ()DOI: 10.5815/ijem.2020.01.01Available online at /ijemOptimal Capacity Determination For Electrical DistributionTransformers Based On IEC 60076-7 And Practical Load Data Keyvan Farahzad a, Aliakbar Shahbahrami a, Mani Ashouri b*a Iranian Northern DSO, Nowshahr, Iranb PhD Student at Aalborg University, Aalborg, DenmarkReceived: 24 September 2019; Accepted: 15 October 2019; Published: 08 February 2020AbstractOptimal installation of electrical distribution transformers has always been a challenging task for distribution operator (DSO)s due to load variations, particularly for seasonal loads. Depending on the quality of distribution systems in different regions and countries, a considerable number of installed transformers may be oversized or have capacity lower than critical standard. In this study, IEC 60076-7 is used to calculate the temperature limitations for distribution transformer capacities and determine optimal transformer capacity for an electrical distribution substation based on the critical values and limitations given in the standard. A data logger is installed on the substation and the load data is recorded for one year. Additionally, the impact of different parameters like ambient temperature is investigated for optimal determination of transformer capacity.Index Terms: Distribution Transformer, IEC 60076-7, Capacity Determination, DSO, Practical Load.© 2020 Published by MECS Publisher. Selection and/or peer review under responsibility of the Research Association of Mode rn Education and Computer Science* Corresponding author.E-mail address:2 Optimal Capacity Determination For Electrical Distribution TransformersBased On IEC 60076-7 And Practical Load Data1.IntroductionElectrical distribution systems are of significant importance in the field of power systems and energy due to being the final stage in delivering electrical power to the consumers [1]. In both traditional distribution systems and grids including renewable generation, optimal implementation of the equipment and their operation is one of the important and challenging tasks [2-4]. The distribution system operator (DSO)s always try to keep the electrical distribution system in an optimal shape trying to keep a trade-off between the costs and the quality of the grid [5]. Accordingly, other than different optimization studies in electrical power systems [6-8], there are additional studies like optimal capacity determination for electrical distribution transformers, which helps the DSOs to have a more cost saving grid, while keeping the distribution system in a reliable and high quality condition [9].In seasonal and rural regions, the load in summer seasons is significantly higher than the other periods of the year [10]. Additionally, different parameters like variable ambient temperature have a considerable impact on the needed capacity of electrical distribution transformers. Moreover, depending on the quality of distribution systems in different regions and countries, a considerable number of installed transformers may be oversized or have capacity lower than critical standard. Thereupon, different parameters and limitations should be considered to determine the optimal capacity needed for electrical distribution transformers. IEC 60076-7 is published as a loading guide for mineral-oil-immersed transformers [11]. According to this study, the hotspot temperature of the transformers is calculated for different load intervals and various limitations and thresholds introduced, which can be used to determine the optimal capacity needed for a specific distribution substation. Although several discussion remains in protection and dynamics of the transformers and the system [12], and also the interactions between the distribution system and the HVAC or HVDC grids [13] and the transients injected to the distribution system from the upper grid, this study only focuses on steady-state analysis of the distribution system, doing steady state calculations for optimal capacity determination of distribution transformers [14-15].A practical electrical distribution substation is considered in this study and a data logger is installed in the feeder to accurately record yearly load variations. Different standard distribution capacities are used to calculate the hotspot temperature and determine the minimum capacity, which does not exceed the limitation based on the IEC 60076-7 standard. Additionally, the impact of different parameters like the ambient temperature on the optimal determined capacity is investigated and the sensitivity analysis is done for some of the parameters and constants used in the calculation process.The novelty of this paper is to have optimal distribution transformer installations based on IEC 60076-7 instead of installing transformer capacities based on experiment, which leads oversized capacity installations and non-optimal electrical distribution system. According to authors’ knowledge, this method of capacity distribution based on thermal limitations of IEC 60076-7 was not investigated in literature work.The remainder of this paper is organized as follows: Section 2 gives basic definitions and the required explanations. Section 3 explains the calculation process for transformer hotspot temperature based on IEC-60076-7 standard. The whole process and the corresponding constants are given in section 4. Section 5 give the experimental results and discussions are given in section 6. Finally, section 7 concludes the study.Optimal Capacity Determination For Electrical Distribution Transformers 3Based On IEC 60076-7 And Practical Load DataNomenclatureTop oil temperatureAmbient temperatureInitial top-oil temperature riseTop-oil temperature rises in steady state at rated lossLoad factorLoad loss ratio at rated current to no-load loss at rated voltageOil exponential factorWinding exponential factorConstant in the thermal modelTime-constant for oilTime constant for windingsConstant in the thermal modelConstant in the thermal modelHot-spot factor2.Basic definitions based on IEC 60076-7In this section, the basic definitions are given based on IEC 60076-7, which are needed for further analysis of the distribution transformers. Each of the categories has specific constant and parameter values, which are different than other categories.2. 1 Types of transformersAccording to IEC 60076-7, the transformers are categorized into 3 groups based on their size, namely large, medium and small transformers [11]. The definition for the small transformers is a power transformer without attached radiators, external tubes or coolers. This definition is not related to the rating and any transformer with this specification is considered as small transformer. The distribution transformers are also included in this category. Accordingly, the constant and parameter values for the category of small transformers are used in the formulations and calculations.2.2 Types of cyclic loadingsAccording to IEC 60076-7, three cyclic loadings are defined as normal cyclic loading, short-term emergency loading, and long-term emergency loading. According to the standard, loading that a higher ambient temperature with the thermal ageing rate same as the rated load at normal ambient temperature is defined as a normal cyclic loading [11]. The loading in this study is categorized in the normal cyclic loading.3.Calculation of transformer hotspot temperatureIn this section, the calculation method for distribution transformer hotspot temperature is explained. According to IEC 60076-7 there are different methods for determining the hotspot temperature like direct measurement, exponential equations and difference equation method. In this study, exponential equations method is used to determine the hotspot temperature.Transformer top-oil temperature increase and decrease corresponding to the load factor is calculatedusing eq.s (1-2)[11]:4 Optimal Capacity Determination For Electrical Distribution TransformersBased On IEC 60076-7 And Practical Load Data(1)(2)Where, is the top-oil temperature, is the ambient temperature, is initial top-oiltemperature rise, is the steady-state temperature rise, is the load factor, is the ratio of load lossesat rated current to no-load losses at rated voltage, is temperature model constant and is the oil timeconstant.In a specific load factor the hotspot to the top-oil gradient increase is obtained using[11]:(3)Where, and are gradients and will be determined using [11]:(4)(5) In another hand, in the hotspot to the top-oil gradient decrease, equations (4-5) will be changed to[11]:(6)(7) Finally, the hotspot temperature is obtained using [11]:(8) 4.The proposed procedure for Optimal capacity determination based on exponential equations methodThe process of using IEC 60076-7 for determining the optimal capacity is explained in this section. In the first step, the yearly load data for the distribution transformer is imported to MATLAB and the load factor is calculated for each time interval. According to the current limitation from IEC 60076-7, the load must not exceed 1.5 multiples of the transformer rated load. This limitation is the first step of checking the capacities. Then the next step is calculated. Then, Transformer top-oil temperature increase and decrease is calculated using (1-2). In sequence, hotspot to the top-oil gradient increase and decrease is calculated using (3-7). Then, the hotspot temperature in the first interval is calculated using (8). This procedure is repeated for all the time intervals. In this study, standard transformer capacities of 25, 50, 100, 125, 160, 200, 250, 315 and 630 KVA are considered as the steps of the algorithm. Accordingly, the explained procedure is calculated for theOptimal Capacity Determination For Electrical Distribution Transformers 5Based On IEC 60076-7 And Practical Load Dataminimum capacity first. If the limitations are exceeded, the calculations will be repeated for the upper interval, until the optimal capacity is determined. Fig. 1 depicts the flowchart of the whole process.5.Experimental results using practical dataIn this study, a data logger is installed to measure the yearly practical load of a distribution transformer installed on a 20 KV feeder, in the northern region of Iran, named Darvishabad station. The yearly peak load for this transformer was 140.5 KVA, which happened at 25 July 2018. Fig. 2 and 3 depict the yearly load curve, and the load percentage compared to time, for Darvishabad transformer, respectively. According to the Fig. 2, it is clearly obvious that the transformer is installed in a rural area and has seasonal load type, whichFig. 1: Yearly load percentage time diagram for Darvishabad station transformer6 Optimal Capacity Determination For Electrical Distribution TransformersBased On IEC 60076-7 And Practical Load Data5.1 Main simulation resultsAccording to the current limitation from IEC 60076-7, the load must not exceed 1.5 multiples of the transformer rated load. Accordingly, with the peak load of 140.5 KVA, 25 and 50 KVA transformers are not proper choices for the measured load.The yearly load curve is imported to MATLAB and the algorithm is applied to the load curve based on the flowchart given in Fig. 1. Table 1 gives the parameter values used in this study. According to the yearly load curve given in Fig. 2, the hotspot temperature of different transformer capacities is given in Fig. 4.Fig. 2: Yearly load percentage time diagram for Darvishabad transformerFig. 3: Yearly load curve for Darvishabad transformerOptimal Capacity Determination For Electrical Distribution Transformers 7Based On IEC 60076-7 And Practical Load DataFig. 4: Calculated yearly hotspot temperature. (a): 50 KVA transformer, (b): 100 KVA transformer, (c): 125 KVA transformer, (d): 150 KVA transformer.Table 1. Parameter values used in this studyParameter Value Parameter Value1.1 1.0R 5.0 1.014.5 2.04.0 0.8180 1.6According to Fig. 4 (a) and Fig 4 (b), the hotspot temperature has exceeded from the standard limit of 120 ℃, which is given in the IEC 60076-7 standard. Accordingly, the capacities of 50 and 100 KVA cannot be the optimal capacities for this station. Fig. 4 (c) shows that the yearly hotspot temperature has not exceeded the limit of 120 ℃. Accordingly, the capacity of 125 KVA is obtained as the optimal capacity based on IEC 60076-7.8 Optimal Capacity Determination For Electrical Distribution TransformersBased On IEC 60076-7 And Practical Load Data5.2 Sensitivity Analysis to the ambient temperatureIn this section, the hotspot temperature of the transformer is calculated in different ambient temperatures. The ambient temperatures varies from 25 ℃ to 60 ℃. Fig. 5 depicts the hotspot temperature of a 125 KVA capacity distribution transformer installed on Darvishabad station. Considering the optimal capacity of 125 ℃, which was resulted in section 5, Table 2 shows the optimal capacity in different ambient temperatures. According to the Table 2 and Fig. 4, for the temperatures equal or higher than 40 ℃, 125 KVA is not the optimal capacity and the upper standard value, namely 160 KVA transformer will be the optimal distribution capacity for Darvishabad station.Table 2. Optimal transformer capacity based on the ambient temperatureAmbient temperature (℃) 25 30 35 40 45 50 55 60Optimal capacity 25 (KVA) 125 125 125 160 160 160 160 160Fig. 5: Hotspot temperature in different ambient temperatures for 125 KVA transformer. (a): 25 ℃, (b): 30 ℃, (c): 35 ℃, (d): 40 ℃, (e): 45 ℃, (f): 50 ℃, (g): 55 ℃, (h): 60 ℃6.DiscussionAccording to the results given in section 6, with increasing the ambient temperature, the optimal capacity is changed one step above. It should be mentioned that in some case, where the optimal capacity is closer to the yearly peak load, it may stay constant with increase in the ambient temperature. In this study, the yearly ambient temperature is considered to be a constant value. According to IEC 60076-7, the definition of theOptimal Capacity Determination For Electrical Distribution Transformers 9Based On IEC 60076-7 And Practical Load Dataambient temperature is the monthly average temperature of the hottest month. However, to have more accurate results, time-varying ambient temperature can be used. Another important thing to consider is that all of the calculations given in this paper, are done for brand new transformers. For the transformers, which had been commissioned years before and are online for a long period, ageing factors must be considered and correction parameters should be defined. Additionally, there other parameters like outdoor ambient conditions, which may affect the optimal capacity results. Due to lack of a straightforward method for modeling these conditions, they are neglected in this study.7.ConclusionIn this paper, optimal distribution transformer capacity is determined based on IEC 60076-7. The resulted capacities can help keeping the distribution grid in the most optimum condition, removing the redundant installed capacities in the grid. This is achieved by calculating the yearly hotspot temperature of distribution transformers installed in target substations. The yearly load of the specific transformers, are measured using data logger during one full year, and the practical data is imported to the optimization algorithm, which is designed based on IEC 60076-7 equations. The temperature limits have also been taken from IEC 60076-7 to check the validity of different capacities. A sensitivity analysis is done to calculate optimal values in different ambient conditions, It is resulted that in higher ambient conditions, the optimal capacities will change to the upper standard level. Further works, consist of defining time-variable ambient temperature to have more accurate results. The ageing factors must be designed to extend this study to the aged transformers, which are online for a long period.References[1] S. Wang, “Study on the selection method of economical capacity for MV transformers,” in 2012 ChinaInternational Conference on Electricity Distribution, 2012, pp. 1–5.[2] A. Izanlo, S. A. Gholamian, and M. V. 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Hu, “Optimization and modeling of power supplycapability in distribution system based on analyzing interconnections among main transformer,” in 2016 China International Conference on Electricity Distribution (CICED), 2016, pp. 1–5.Optimal Capacity Determination For Electrical Distribution Transformers 11Based On IEC 60076-7 And Practical Load DataAuthors’ ProfilesKeyvan Farahzad received his B.Sc. and M.Sc. from Tehran Polytechnic University inelectrical engineering, Tehran, Iran. He is currently the CEO of Iranian northern DSO. Hehas more than 20 years of experience in electrical distribution system operation andplanning. His current research interests are application of signal processing in electricaldistribution systems, Optimal transformer allocation in distribution systems abd mediumvoltage DC distribution system protection and control.Aliakbar Shahbahrami received his B.Sc. from Tehran Polytechnic University inelectrical engineering and received his Ms.C. from Qazvin University. He is currently thehead of the R&D section in Iranian northern DSO. His research interests are electricaldistribution system planning, optimal distribution system design, Seasonal load analysisand data science.Mani Ashouri received his B.Sc. and M.Sc. from Babol University of technology, Iran.He is currently a Ph.D. student in the Department of Energy Technology, AalborgUniversity, Denmark. He had been working as HVAC protection and relay test engineerduring 2011-2017 in Iranian northern TSO. His main research interests are protection andcontrol of multi-terminal VSC-HVDC and HVAC systems, Electromagnetic transients inelectrical power systems and high voltage cables, power electronic converters used forHVDC transmission and signal processing methods for power system fault analysis.How to cite this paper: Keyvan Farahzad, Aliakbar Shahbahrami, Mani Ashouri. “Optimal Capacity Determination For Electrical Distribution Transformers Based On IEC 60076-7 And Practical Load Data", International Journal of Engineering and Manufacturing(IJEM), Vol.10, No.1, pp.1-11, 2020. DOI:10.5815/ijem.2020.01.01。
H V D C换相失败判据及恢复策略的研究艾 飞,李兴源,李 伟,徐大鹏(四川大学电气信息学院,四川成都610065)摘 要:换相失败是指在换相电压反向之前未能完成换相的故障。
它是高压直流输电系统最常见的动态故障,为保证直流系统运行的安全、稳定性,对换相失败现象进行深入研究是十分必要的。
详细论述了换相失败的判据以及换相失败后应采取的恢复措施,对于保证直流系统稳定运行具有一定的指导意义。
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HVAC系统培训资料GMP增补培训课程空气处理系统HVAC是 Heating Ventilation and Air Conditioning 首字母的缩写,通称为供热,通风和空气调节.空气处理系统目的理解以下内容: 1. 制药行业中空气处理系统的需求和原因;2. 3. 4.空气处理系统的技术要求; 空气处理系统的不同类型; 确认和监控要求.第一部分第3 章第一部分:介绍和概况 1 of 20介绍和概况WHO - EDM第3 章第一部分:介绍和概况2 of 20WHO - EDM空气处理系统影响产品质量的因素:1. 2. 3. 4. 5. 6. 7.空气处理系统影响产品质量的因素已验证工艺程序人员原材料和包装材料已验证的工艺人员程序设备厂房的设计和质量制造环境原材料设备包装材料如果不能充分满足以上因素,将会导致产品质量不合标准.第3 章第一部分:介绍和概况 3 of 20WHO - EDM厂房环境第3 章第一部分:介绍和概况4 of 20WHO - EDM空气处理系统生产环境对于产品质量至关重要:1.空气处理系统什么是污染?污染是:1. 2. 3. 4. 5.照明温度湿度空气流动微生物污染微粒污染不受控制的环境会导致产品质量降级产品污染产品和利润的损失5 of 20WHO - EDM2. 3. 4. 5. 6. 7.所生产的产品以外的其它产品或物质外来产品微粒微生物内毒素 (微生物代谢产物之一)交叉污染是污染的一种特例.第3 章第一部分:介绍和概况 6 of 20WHO - EDM第3 章第一部分:介绍和概况空气处理系统交叉污染(1)什么是交叉污染? 交叉污染的定义: 在生产过程中,一种原材料,中间产品,成品与另外一种原材料或产品之间的污染现象. (世界卫生组织) 附件 1, 术语空气处理系统交叉污染(2)交叉污染的起源?1. 2. 3. 4.空气处理系统和除尘系统设计不当空气处理系统和除尘系统操作或保养不当人员和设备的操作程序不适当设备未充分清洁第3 章第一部分:介绍和概况7 of 20WHO - EDM第3 章第一部分:介绍和概况8 of 20WHO - EDM空气处理系统交叉污染(3)来自环境/操作者自身的污染物污染来自设备的污染物空气处理系统交叉污染(4)可以通过以下方法可将交叉污染降到最少:1. 2. 3. 4.人员的行为规范足够的厂房面积采用密闭式生产系统恰当并且经过验证的清洁方法适当的产品保护正确的气压气流分布10 of 20WHO - EDM来自环境/操作者自身的产品交叉污染来自设备的产品5. 6.第3 章第一部分:介绍和概况9 of 20WHO - EDM第3 章第一部分:介绍和概况空气处理系统保护等级的概念1.空气处理系统确定环境要求帮助防止污染和交叉污染使产品处于最佳的卫生环境重视产品对污染的敏感程度治疗风险生产环境要求其它级洁净等级级 C 洁净等级 A/B 级2. 3. 4.洁净等级 D治疗风险第3 章第一部分:介绍和概况 11 of 20WHO - EDM第3 章第一部分:介绍和概况12 of 20WHO - EDM空气处理系统保护等级几个参数:1.空气处理系统保护等级洁净厂房等级分类: 国际WHO 国家EC,PIC/S,TGA等US FDA ISPE 企业附件1, 17.3, 17.4 附件1, 17.3, 17.4空气洁净度要求 (过滤器类型和位置,空气换气次数,气流形式,差压,微粒和微生物的污染等级) 人流和物流方法生产操作允许的洁净等级建筑物的设计和装饰A,B,C,D A,B,C,D 重要的和受控的 1,2,3级或洁净区等级不尽相同2. 3. 4.第3 章第一部分:介绍和概况13 of 20WHO - EDM第3 章第一部分:介绍和概况14 of 20WHO - EDM空气处理系统保护等级制药设施内的所有运行与洁净厂房的洁净等级是密切相关的,并一起纳入了卫生概念之中. 例如:容器的清洗最终灭菌产品的溶液配置无菌灌装产品的溶液配置容器的去热原处理最终灭菌产品的灌装无菌产品的灌装其它 X X X X X X X空气处理系统保护等级根据洁净厂房的洁净级别要求,必须建立不同的保护等级,其中包括: 工艺操作和洁净级别的关联性在各保护等级区内允许的操作类型洁净厂房的洁净等级A B C D X洁净厂房的洁净级别定义(参数,建筑材料,房间要求,空调系统) 在不同级别的洁净厂房内,人员和物料的要求(服装,培训,物料类型等) 人员和物料入口状态的要求(更衣的步骤)附件 1, 17.3, 17.4, 17.515 of 20WHO - EDM第3 章第一部分:介绍和概况第3 章第一部分:介绍和概况16 of 20WHO - EDM空气处理系统影响保护等级的参数(1)空气处理系统空气处理系统影响保护等级的参数(2)1 2 3 4空气中的微粒数空气中和设备表面上的微生物数量每个房间的换气次数空气流速气流形态过滤器 (类型,位置) 房间之间的差压温湿度18 of 20WHO - EDM送风有确定要求的生产房间排风5 6 7附件 1, 17.48第3 章第一部分:介绍和概况17 of 20WHO - EDM第3 章第一部分:介绍和概况空气处理系统影响保护等级的参数(3)空气处理系统影响保护等级的参数(4)按关键参数定义的洁净厂房等级空气处理系统: 是达到所需参数的主要工具但是仅仅有它还不够完整还必需附加一些措施适当的更衣(衣服的类型,合适的更衣间) 经验证的清洁和消毒处理程序合适的人员和物料传输程序附件 1, 17.10 至 17.16空气处理系统附加措施第3 章第一部分:介绍和概况19 of 20WHO - EDM第3 章第一部分:介绍和概况20 of 20WHO - EDMGMP增补培训课程空气处理系统HVAC是 Heating Ventilation and Air Conditioning 首字母的缩写,通称为供热,通风和空气调节.空气处理系统空气处理系统的目的空气处理系统第二部分第3 章第二部分:构成 21 of 20构成WHO - EDM送风具有规定要求的生产房间排风第3 章第一部分:介绍和概况22 of 20WHO - EDM空气处理系统目的通过以下内容,我们来学习空气处理系统的构成:1. 2. 3. 排风空气处理系统主要的子系统熟悉系统构成了解它们的功能知道可能的问题空气处理单元补充新风+ 生产房间末端空气处理生产房间第3 章第一部分:介绍和概况23 of 20WHO - EDM第3 章第一部分:介绍和概况24 of 20WHO - EDM空气处理系统构造概况排风格栅消音器流量控制器风机过滤器空气处理系统构件(1)防水百叶风口防止昆虫,树叶,灰尘和雨水进入降低空气循环/气流产生的噪声自动调整风量(根据昼夜,压力等来控制) 固定的风量调节阀防水百叶风口控制风阀加热器消声器末端过滤器+预过滤器加湿器流量控制器控制风阀冷盘管及二级过滤器挡水板热盘管再循环空气生产房间第3 章第一部分:介绍和概况25 of 20WHO - EDM第3 章第一部分:介绍和概况26 of 20WHO - EDM空气处理系统构件(2)加热单元制冷单元/ 除湿器加湿器过滤器风管加热空气到适当温度冷却空气到要求的温度或除去空气中的水分流速控制器控制风阀加湿器如果空气湿度太低,将空气加到适当湿度冷盘管除去预定尺寸的颗粒和/或微生物过滤器输送空气风管27 of 20WHO - EDM空气处理系统部件常出现的问题堵塞调节不良,压差系统不正常水/汽质量不好/排水不畅不能去除空气露水/排水不畅选用等级不正确/损坏/安装不当不适当的材料/内部保温处的泄漏第3 章第一部分:介绍和概况第3 章第一部分:介绍和概况28 of 20WHO - EDM空气处理系统空气类型粒子数 / 立方米空气处理系统国际洁净区级别比较US 209D 英制≥ 0 .5 m 1 3 ,5 10 35 100 353 1 .0 0 0 3 .5 3 0 US 209E 1992 公制欧盟 cG M P 附件 I 1997 德国 VDI 2083 1990 英国 BS 5295 1989 日本 J IS B 9920 1989 IS O 1 4 6 4 4 -10 1 10 100 M M M M M M 1 1 .5 2 2 .5 3 3 .5 1 2 A, BA= 单向流 B= 乱流2 3 4 E or F 52 3 4 5新风 (补充新风)送风+排风3生产房间回风再循环1 0 .0 0 0 3 5 .3 0 0 1 0 0 .0 0 0 3 5 3 .0 0 0 1 .0 0 0 .0 0 0 3 .5 3 0 .0 0 0 1 0 .0 0 0 .0 0 01 .0 0 0 1 0 .0 0 0 1 0 0 .0 0 0M M M M M M M4 4 .5 5 5 .56 6 .5 74 C D5 6G or H J K6 7 86 7 8第3 章第一部分:介绍和概况29 of 20WHO - EDM第3 章第一部分:介绍和概况30 of 20WHO - EDM空气处理系统过滤器分类标准空气过滤器气溶胶测试F9空气处理系统过滤器的分类(按照过滤效率划分)平均效率整体效率捕获率% 穿透率85 95 99.5 99.95 99.995 0.15 0.05 5x10-3 5x10-4 5x10-5 97.5 99.75 99.975 25x10-3 25x10-4 25x10-5 最大捕捉率逐点效率效率穿透率初效Dp > 10 m中效10 m > Dp > 1 m高效Dp < 1 m超高效H11 H12G1 - G4F5 - F9H 11 - 13U 14- 17H13 U14EN 779 标准EN 1822 标准第3 章第一部分:介绍和概况31 of 20WHO - EDM第3 章第一部分:介绍和概况32 of 20WHO - EDM空气处理系统加湿器高效/第三级过滤器空气处理系统消音器加热和冷却单元初效平板式过滤器中效/第二级过滤器第3 章第一部分:介绍和概况 33 of 20 WHO - EDM第3 章第一部分:介绍和概况34 of 20WHO - EDM空气处理系统1 2空气处理系统带终端过滤器的漩流型散流器空气流量调节阀潮湿的房间空气吸附轮干空气AHU风机的变速控制器3 4再生空气潮湿的房间空气过滤器压差表空气加热器除湿机第3 章第一部分:介绍和概况 35 of 20空气处理单元WHO - EDM1 2 3 4过滤器固定框架通风口通风口大小调节螺丝36 of 20WHO - EDM第3 章第一部分:介绍和概况空气处理系统办公用柯恩达效应散流器漩流散流器空气处理系统房间压力调整-压差概念减少诱导气流诱导房间空气与送风混合回风回风回风回风房间压力表高诱导办公型散流器 (避免)第3 章第一部分:介绍和概况 37 of 20 低诱导漩流型散流器 (首选)WHO - EDM房间压力表面板附录 1, 17.26第3 章第一部分:介绍和概况 38 of 20 WHO - EDM空气处理系统注射剂压力梯度的设置以防止微粒和微生物的进入1#房间1#房间30 Pa 60 Pa空气处理系统固体制剂压力梯度的设置以防止交叉污染2#房间15 Pa3#房间15 Pa2#房间3#房间45 Pa15 PaLFD气闸室45 Pa气闸室B C气闸室气闸室气闸室30 Pa15 Pa 30 PaD过道气闸室0 PaE0 Pa 15 Pa过道备注:房门开启方向与压差有关附件1, 17.24, 17.25WHO - EDM备注: 房门开启方向与压差有关第3 章第一部分:介绍和概况39 of 20第3 章第一部分:介绍和概况40 of 20WHO - EDMHongwu Guo: Hongwu Guo: Hongwu Guo: Hongwu Guo:GMP增补培训课程空气处理系统Hongwu Guo: Hongwu Guo:空气处理系统空气处理系统特性在下面内容中,我们将学习空气处理系统的一些要点: 乱流和单向流过滤器位置空气再循环与新风回风系统(位置) 正压要求HVAC是英文 Heating Ventilation and Air Conditioning 首字母的缩写, 通称为供热,通风和空气调节.第三部分第3 章第三部分:设计,确认和维护设计,确认和维护41 of 27WHO - EDM第3 章第一部分:介绍和概况42 of 20WHO - EDM空气处理系统气流组织方式(1)乱流稀释玷污的空气单向流/层流置换玷污的空气空气处理系统气流组织方式(2)净化空气进入生产房间或覆盖生产过程时可以是: 乱流单向流(层流) GMP方面经济方面新技术:隔离器技术0,30 m/s附件 1, 17.3第3 章第一部分:介绍和概况 43 of 20WHO - EDM附件 1, 17.3, 17.4第3 章第一部分:介绍和概况 44 of 20 WHO - EDM空气处理系统气流组织方式(3)预过滤器附件 1, 17.3空气处理系统气流组织方式(4)工作台(垂直层流) 通风柜吊顶安装空气处理单元主过滤器123乱流单向流乱流第3 章第一部分:介绍和概况45 of 20WHO - EDM第3 章第一部分:介绍和概况46 of 20WHO - EDM空气处理系统过滤器安装位置(1)空气处理单元内安装的末道过滤器终端过滤器高效过滤器空气处理系统过滤器安装位置(2)预过滤器空气处理单元主过滤器 +1生产房间高效过滤器生产房间吊顶排风口 2 3低位排风口第3 章第一部分:介绍和概况 47 of 20WHO - EDM第3 章第一部分:介绍和概况48 of 20WHO - EDM空气处理系统过滤器安装位置(3)空气处理单元预过滤器终过滤器空气处理系统空气再循环送入生产房间的净化空气可以被: 100% 排放一定比例再循环GMP方面经济方面附件 1, 15.10, 17.24149 of 202WHO - EDM第3 章第一部分:介绍和概况第3 章第一部分:介绍和概况50 of 20空气处理系统100%新风通风系统(无空气再循环)排风机组清洗设备(可选) 排风机组空气处理系统再循环风+新风的通风系统W中央空气处理机组生产车间中央空气处理机组附件 1, 17.24第3 章第一部分:介绍和概况 51 of 20WHO - EDM回风第3 章第一部分:介绍和概况 52 of 20WHO - EDM空气处理系统状态定义空态空气空气处理系统确认/验证要点动态好的设计是基本的,但是还必须补充以下部分:空气静态空气空气处理系统确认生产过程验证维护和周期性再验证足够的支持文档第3 章第一部分:介绍和概况53 of 20第3 章第一部分:介绍和概况54 of 20WHO - EDM空气处理系统(OQ,PQ)确认(1)测试过滤器压差房间压差气流速率/均匀性流量 / 总量平行性气流形态 IQ 测试未在此提及 2 N/A 2, 3 2 2 2 单向流 / LAF 2 2, 3 可选 2 N/A 3 1 = 空态 (执行IQ) 2 = 静态 (执行OQ) 3 = 动态 (执行PQ) 恢复时间房间级别 (空气微粒) 温度湿度测试乱流/ 混合流描述空气处理系统(OQ,PQ)确认(2)单向流 / LAF N/A 2 N/A 2乱流/ 混合流 1 = 空态 (执行IQ) 2 = 静态 (执行OQ) 3 = 动态 (执行PQ)描述2,3 2,3附件 1, 17. 4附件 1, 17. 4IQ 测试未在本页中提及第3 章第一部分:介绍和概况55 of 20WHO - EDM第3 章第一部分:介绍和概况56 of 20WHO - EDM空气处理系统微生物验证1. 2. 3.空气处理系统洁净室监控程序(1)洁净室要监测微生物和空气微粒行动限定义洁净区域报警/行动界限确定和标记采样点定义运输,储存和培养条件行动限报警限报警限空气请考虑此问题:"何为报警和行动界限, 如果这些限制点被超过要采取哪些行动? "设计条件正常运行范围运行范围-经验证的可接受标准采样点第3 章第一部分:介绍和概况57 of 20WHO - EDM第3 章第一部分:介绍和概况58 of 20WHO - EDM空气处理系统洁净室监控程序(2)日常的检测程序是质量保证的一部分附加的监控和行动条件1. 2. 3. 4.空气处理系统洁净室维护程序(1)证明持续符合的测试时间表测试参数微粒计数测试洁净度 A, B <= ISO 5 C, D > ISO 5 所有级别所有级别最大时间间隔 6月 12 月 12 月 12 月测试程序 ISO 14644 -1 附录 A ISO 14644 -1 附录 A ISO 14644 -1 附录 B5 ISO 14644 -1 附录 B4停机过滤器元件更换空调系统维护超过既定的界限压差测试空气流量测试附件 1, 17.37第3 章第一部分:介绍和概况59 of 20WHO - EDM第3 章第一部分:介绍和概况60 of 20WHO - EDM空气处理系统洁净室维护程序(2)附加可选测试时间表测试参数已安装过滤器的泄漏测试密闭性泄漏测试恢复气流可视化测试洁净度所有级别所有级别所有级别所有级别最大间隔 24 月 24 月 24 月 24 月测试程序 ISO 14644-1 附录 B6 ISO 14644-1 附录 B4 ISO 14644-1 附录 B13 ISO 14644-1 附录 B7空气处理系统文件要求安装和功能描述技术规范明细操作程序性能控制手册维修手册和档案维护记录人员培训 (计划和记录)第3 章第一部分:介绍和概况61 of 20WHO - EDM第3 章第一部分:介绍和概况62 of 20WHO - EDM空气处理系统检查空气处理设备1.空气处理系统结论空气处理系统: 在制药质量方面扮演主要角色必须有专业人员进行合理设计必须作为重要系统对待检查设计文件,包括:安装和功能描述要求的详细说明2. 3. 4. 5. 6. 7. 8.操作程序维修手册维修记录培训日志环境记录数值超限后的纠偏行动讨论巡视整个工厂63 of 20WHO - EDM第3 章第一部分:介绍和概况第3 章第一部分:介绍和概况64 of 20WHO - EDM空气处理系统进一步行动完成了一系列的解释,现在要做的是: 小组讨论,做一个简单练习测验气闸室1 风淋室仓库取样间空气处理系统小组讨论服务走廊(包含真空和RO水供应)气闸室2称重间压片间1压片间2液体混合间软胶囊包装级区走廊应急出口男更衣室2 无菌滴眼液配料和无菌灌装女更衣室2 已包装产品隔离间滴眼液 2级人员入口内外包装气闸室3设备清洗间男更衣室1女更衣室1气闸室4服务间第3 章第一部分:介绍和概况65 of 20WHO - EDM第3 章第一部分:介绍和概况66 of 20WHO - EDM空气处理系统小组讨论–调整后的平面布局20Pa取样室0Pa 30Pa服务走廊(包含真空和RO水供应) 30Pa风淋室20Pa 10Pa称量间传递间20Pa 30Pa仓库0Pa物料缓冲1ISO 9级或 E级区物料缓冲2压片间115Pa压片间215Pa液体混合间30Pa软胶囊包装气闸室15Pa 30Pa级区走廊应急出口人员缓冲物料缓冲340Pa 40Pa20Pa20Pa男更衣室2女更衣室210Pa无菌滴眼液配料和无菌灌装10Pa 10Pa 60Pa已包装产品隔离间外包装20Pa内包装30Pa15Pa物料缓冲450Pa更衣室50Pa设备清洗间男更衣室1女更衣室1气闸室0Pa服务间0Pa0Pa第3 章第一部分:介绍和概况67 of 20WHO - EDM。
电力行业词汇---输电系统(续之交流输电、直流输电和灵活交流输电2.6 交流输电、直流输电和灵活交流输电2.6.1 背靠背直流输电系统Back-to-back HVDC transmission system输电线路长度为零的直流输电系统。
2.6.2 背靠背直流输电系统控制Control of back-to-back HVDC transmission system2.6.3 并联补偿Shunt compensationParallel compensation2.6.4 长线路Long line2.6.5超高压交流输电线路EHV AC power transmission line2.6.6 超高压输电线路EHV power transmission line2.6.7超高压直流输电线路EHVDC power transmission line2.6.8 串联补偿Series compensation2.6.9串联电容补偿Series capacitor compensation2.6.10 单回路输电Single-circuit power transmission2.6.11 单相输电Single-phase power transmission2.6.12 地下交流输电Underground AC power transmission2.6.13 地下输电Underground power transmission2.6.14地下直流输电Underground DC power transmission2.6.15 电力系统联络线Power system tie line2.6.16 端对端直流输电系统End to end HVDC power transmission system2.6.17 短线路Short line2.6.18 多端控制Multiterminal control对含有三个以上换流站的直流输电系统的控制。
2019版绿色建筑评价标准暖通专业相关条文解析成维川中通服咨询设计研究院有限公司摘要：《绿色建筑评价标准》（GB/T 50378-2019）已经于2019年8月1日正式执行，与前一版相比，该版本产生了许多变化，提高了许多要求，增加了许多难度，相关从业人员应当认真学习掌握。
对于暖通设计人员来说，应当加强该标准中暖通专业相关条文的学习，加强与其他各专业的沟通与协作，在被动节能、主动节能、室内空气质量控制、室内外热湿环境控制等方面，多进行一些思考，为我国绿色建筑的高质量发展做出应有的贡献。
关键词：绿色建筑评价标准新标准老标准暖通Analysis of HVAC Relevant Provisions in Assessment Standard for Green Building of 2019EditionCHENG Wei-chuanChina Information Consulting &Designing Institute Co.,Ltd.Abstract:“Assessment Standard for Green Building ”(GB/T 50378-2019)has been implemented on August 1,paring to previous revision,this revision has numerous updates with both design criteria and difficulties increased significantly,which means relevant practitioners should learn and master it seriously.For HVAC designers,it is required to strengthen learning of HVAC relevant provisions in this standard,to strengthen communication and cooperation with other disciplines,and to consider further more in aspects of passive energy saving,active energy saving,indoor air quality control and indoor/outdoor thermal-humidity environment control etc.so as to make new contributions to the high-quality development of green buildings in China.Keywords:green building,assessment standard,old standard,new standard,HVAC收稿日期：2019-12-15作者简介：成维川（1984~），男，硕士，高工；南京市建邺区楠溪江东街58号（210019）；E-mail:***************0引言《绿色建筑评价标准》（GB/T 50378）[1-3]于2006年颁布了第一版，于2014年进行了第一次修改颁布了第二版（以下简称“老标准”），于2019年进行了第二次修改颁布了第三版（以下简称“新标准”），经历了“三版两修”[4]。
Loss Evaluation of HVAC and HVDC Transmission Solutions for Large Offshore Wind FarmsN. Barberis Negra1, J. Todorovic2 and T. Ackermann3Abstract - This paper presents a comparison of transmission system losses in percent for wind farm power production. Three technical solutions are analyzed, i.e. HVAC, HVDC Line Commutated Converter (LCC) and HVDC Voltage Source Converter (VSC). The losses for each technology are calculated for different size of the wind farm, various distances to shore. In addition, solutions with combinations of two and the three are analyzed and compared. From these analyses further analysis regarding reliability and economical issues can be considered in order to define best solutions for wind power transmission.Index terms – Aggregated Model, HVAC, HVDC, LCC, “MW-km” Plane, Offshore Wind Farm, Percent Losses, VSC.I.I NTRODUCTIONToday’s installed offshore wind farms have relatively smaller rated powers and are placed at shorter distances from shore than future planned projects [1]. According to European Wind Energy Association (EWEA) predictions [2], in EU-15 by 2010, 10000 MW of offshore wind farms will be installed. On the one hand, offshore locations have better wind conditions than onshore ones: this means higher energy output. On the other hand, longer transmission distances lead to higher investment costs as well as higher energy losses [3].All currently (early 2004) existing offshore wind farms are connected to shore by HVAC cables and only two of them have offshore substations [1]. For large wind farms, with hundreds MW of rated power, and long distances to shore, offshore substations would be necessary for either stepping up the voltage level (HVAC) or for converting the power to HVDC. [3].Connection of such large offshore wind farms impose a challenging task for connection designers. Choice of a proper transmission system, either HVAC or HVDC, can be a decisive part of the overall project feasibility. Small differences in transmission losses between two solutions could cause large differences in energy output over a project time of 20 years.In this paper system transmission losses for three different transmission systems, i.e. HVAC, HVDC Line Commutated Converter (LCC) and HVDC Voltage Source Converter (VSC) are compared for a 500 MW and a 1000 MW wind farm with 1 N. Barberis Negra has recently received his Master’s degree from the Politecnico of Turin, Italy, Department of Electrical Engeneering (nicola.barberis@libero.it)2 J. Todorovic is with Power Transmission Company "ELEKTROPRENOS", Banja Luka, Bosnia and Herzegovina (E-mail: todorovicjovan@)3 T. Ackermann is with the Royal Institute of Technology, Teknikringen 33, 10044 Stockholm, Sweden. (E-mail: Thomas.Ackermann@) different distance to shore (up to 200 km) at an average wind speed in the area of 9 m/s. The transmission system losses are calculated as percentage of losses of the annual wind farm production. It is assumed that the wind farm has a availability of 100 %.Further analyses with different size of the wind farm (400 up to 1000 MW), different average wind speed in the area (8 up to 11 m/s) and different distances from shore (up to 300 km) are performed and presented in [5] and [6].II.A GGREGATED WIND FARM M ODEL In order to evaluate losses in a transmission system for wind power, it is necessary to define the input power into the transmission system. Thus an aggregated model based on Holttinne and Norgaard ([7]) has been considered.Input data for the model are:-Wind farm size of 500 or 1000 MW;-Standard 5 MW wind turbine;-Wind speed in the area with average wind speed of 9 m/s represented by Rayleigh distribution;-Dimension D of the wind farm equal to 25 for 500 MW and 50 km for 1000 MW (front side in respect tothe direction of the wind)([3]);-Turbulence intensity I equal to 10 %;Figure 1. Comparison between a single wind turbine power curve and the wind farm power curve for a 1000 MW wind farm and an average wind speed in the area of 9 m/s.Considering a variation of the wind in the site where the wind farm is installed of ± 5 m/s, it is possible to obtain thepower curve of the wind farm. In Figure 1 the power curve for the wind farm as well as for a single 5 MW wind turbine are compared.In Figure 2 it is possible to observe the duration curve for the 1000 MW wind farm compared with durations curve fordifferent average wind speed in the area (8, 10 and 11 m/s).Figure 2. Duration curve of a 1000 MW wind farm with different average wind speeds in the areaFrom Figure 2 it is possible to observe that increasing the average wind speed in the area, the rated power can be generated for longer period of time. At 11 m/s rated power is generated for almost 40 % of the time and this value is almost the double than the time for 9 m/s.III. HVAC T RANSMISSION S YSTEMThe production of large amounts of reactive power can be considered the main limiting factor of HVAC cable utilization in transmission systems for long distances. A comparison of the transmission capacity of cables with different voltage levels (132 kV, 220 kV and 400 kV) and different compensation solutions (only onshore or at both ends) is presented in Figure 3. Cables’ limits, as maximal permissible current, voltage swing of receiving end between no-load and full load (< 10%) and phase variation (< 30o ) should not be exceeded, according to Brakelmann in [8]. For these cables, the maximal current is the only limit that is reached, while the other two are not critical constraints.The critical distance is achieved when half of the reactive current produced by the cable reaches nominal current at the end of one cable. In that case, there is not any transmission capacity left for active power flow. For the considered cables, the critical distances are:− L max,132KV = 370 km − L max,220KV = 281 km − L max,400KV = 202 kmFigure 3. Limits of cables transmission capacity for three voltage levels, 132 KV, 220 KV and 400 KVA. Components of the transmission systemSince, the voltage level within an offshore wind farm grid is typically in the range of 30 KV – 36 KV, an offshore substation is necessary to step up the voltage to the transmission level.A HVAC transmission system used for connection of large offshore wind farms to the onshore grid contains:− HVAC submarine transmission cable(s) − Offshore transformer(s)− Compensation units, TCR (Thyristor ControlledReactors), both onshore and offshore− Onshore transformer(s), depending on a grid voltageThese components provide the transmission from an offshore collection point of the wind turbines’ power (offshore substation) to a grid connection point placed onshore. B. Loss calculations3.2.1) Models and assumptionsCable loss calculations are performed based on Brakelmann [9]. Loss alculations take into account the current distribution along cable line and temperature dependence.For 132 KV and 220 KV voltage transmission levels, three core XLPE insulated submarine cables are used while for 400 KV level three single core XLPE submarine cables are considered in trefoil formation. Cable characteristics are tabulated in Table I .According to Brakelmann in [9], the cable losses per unit length are calculated as()'2''max'D NDP II P PP +⋅⎟⎟⎠⎞⎜⎜⎝⎛⋅−=θυ (1)where P’max are the nominal total cable losses, P’D are the dielectric losses, per core, I is load current, I N is the nominal current, υθ is the temperature correction coefficient that is calculated as:⎥⎥⎦⎤⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛−⋅∆⋅+=2max 1N T I I c c θαυααθ (2)where αT is the temperature coefficient of the conductor resistivity [1/o K], c α is the constant, i.e. c α = 1 - αT .(20 o C-θamb ), ∆θmax is the maximal temperature rise, i.e. 90-15=75 o C, the ambient temperature is supposed to be θamb =15 o C. T ABLE ICABLES ’ PARAMETERS AND MAIN CHARACTERISTICSSince the cable current along the cable route is not constant for a specific load but depends on its position along a route, i.e. I=f(x), in order to calculate cable losses the following integral has to be solved()()D lx N loP dx x x I I l P P '0220max ''+⋅⋅⋅⋅=∫=θυ (3)Solving integral (3) for length l o , the cable losses per unit length are obtained. Multiplying the integral with actual cable length l o , the cable losses in W are achieved. This method provides accurate calculation of cables losses [9].In order to calculate transformer losses, equivalent parameters like R fe , representing iron losses, and R cu , representing copper losses, are defined. These data are obtained from nominal transformer losses data ([12], [13] and [14]). Since, TCRs are used as compensation units, it is assumed that they have the same no load losses as an equivalent transformer with the same VA rating and half of load losses of an equivalent transformer with the same VA rating [10].3.2.2) ResultsSystem losses for average wind speed of 9 m/s, for three transmission voltage levels (132 KV, 220 KV and 400 KV) and for two wind farm configurations of 500 MW and 1000 MW are presented in Table II and Table III , respectively. Transmission system losses l % have been calculated as ah p P a h p P l Nii i gen Ni i i lost ⋅⋅⎟⎠⎞⎜⎝⎛⋅⋅⋅⎟⎠⎞⎜⎝⎛⋅=∑∑,,% (4)where P lost,i is the power lost by the transmission system at wind speed i, P gen,i is the power generated by the wind farm at wind speed I, N is the number of wind speed class consideredfor the model, p iis the probability to have a certain windspeed i and it is obtained by the Rayleigh distribution, h is the number of hours in a year, a is the availability of the wind park. TABLE IIT RANSMISSION L OSSES OF A 500 MW WIND FARM , WITH 9 M /S OF AVERAGEWIND SPEED IN THE AREA IN% OF A NNUAL W IND F ARM P RODUCTION .Shaded cells in Table II represents the best transmission solutions with the lowest losses, while number of cables indicates number of cables required for that chosen solution. In the 132 KV column, number of cables presents the number of cables required for the 200 km.Within the loss calculations, a new cable is added to the wind farm when the transmission system requires more capacity (depending on the wind speed). The same approach applies for the Table III .TABLE IIIT RANSMISSION L OSSES OF A 1000 MW WIND FARM , WITH9 M /S OF AVERAGEWIND SPEED IN THE AREA IN % OF A NNUAL W IND F ARM P RODUCTION .Figure 4 shows the participation of each transmission component in the total transmission losses for a 500 MW wind farm at 100 km from the shore using a 132 kV cable. It can be seen that cable losses represent by far the largest share of the total transmission losses. Thus, in order to decrease the total transmission losses, the transmission designers should payspecial attention on cable selection.From Table II and Table III , it can be seen that only 220 KV and 400 KV solutions are considered. However, these two submarine XLPE cable designs are still under development [11]. Especially the 400 KV XLPE submarine cable is available for short lengths without appropriate joint andsplices for longer lengths. Considering distances longer than200 km, 132 KV solutions prevail [5], since at such long distances, 220 KV and 400 KV cables generate large amountsof reactive power.Figure.4. Participation of each transmission component in total transmissionlosses for 500 MW wind farm, 9 m/s of average wind speed, at 100 km transmission distance, 3 three–core 132 KV submarine cables [5]IV. HVDC S YSTEM WITH L INE C OMMUTATED C ONVERTER Line Commutated Converter (LCC) devices have been installed in many bulk power transmission systems over long distances both on land and submarine all around the world, see [16] and [17]. A draw back of this transmission solution is the required reactive power to the thyristor valves in the converter and may be the generation of harmonics in the circuit [16].A. Components of the transmission systemMain components of the transmission system based on LCC devices are:- AC and DC filters; - Converter transformer;- Converter based on thyristor valves;- Smoothing reactor- Capacitor banks or STATCOM;- DC cable and return path;- Auxiliary power set- Protection and control devices (i.e.: cooling devices,surge arrester).All these components are considered in the following losscalculations, except the STATCOM: The influence of the STATCOM on total losses we would like to refer to [15].B. Loss calculations4.2.1) Models and assumptions In order to calculate transmission losses for different wind farm sizes, data from existing HVDC LCC installations are considered, see also [16] and [17]. Converter stations have been built in sizes of 250 MW,440 MW, 500 MW and 600 MW. Losses vary typically with alinear trend between 0,11% (no load) and 0,7% (rated power) of the rated power [16]. Both monopolar and bipolar solutions are considered depending on the number of converter stations and on the size of the wind farm. Cable models are based on Brakelmann’s theory [8] andmodels take into account variations of temperature in the cable in order to obtain more realistic results. In Table IV , solutions chosen for cables are presented: all the configurations are based on mass impregnated solution with conductors made of copper.Lost power P cab in the cable is calculated with formulae:θv I I P P NL cab ⋅⋅=22max '(5) cable N m L l I c R P ⋅⋅⋅=20max ' (6)()201max 20−+∆⋅+=U L m c θθα (7) ()U c θαα−⋅−=20120 (8)⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛−∆⋅+=2max 201NL I Ic c v θαααθ (9)where R 0 is the DC resistance of the conductor at 20 °C per unit length ([18] and [19]), α20 is the constant mass temperature coefficient at 20 °C ([18] and [19]), is the lost power in the cable at its maximum operating temperature, max 'L P max L θ∆= 55°C is the maximum operating temperature of theinsulator, θU = 15° C is the ambient temperature, I N is thenominal current of the cable, I is the current flowing into thecable and l cable is the length of the cable used for the transmission. T ABLE IVC ABLES DATA FOR THE MODEL COMPILED AND CALCULATED FROM [8], [17], [18] AND [19].When more than one converter station is used for the transmission, the total power is split between the differentconverter station depending on the configuration that gives the lowest total losses. Converter stations are shut down when low power isgenerated in the wind farm: in these conditions, only the losses of protection and control devices are considered and these devices are supplied by the auxiliary power set.4.2.2) Results Three different layouts are considered for 500 MW wind farm and four for 1000 MW wind farm: these configurations are shown in Table V with the system losses of each system.Transmission system losses l % have been calculated with (4) and data from Table IV .T ABLE V T RANSMISSION L OSSES FOR DIFFERENT CONVERTER STATION LAYOUTS WITH9 M /S OF AVERGAE WIND SPEED IN THE AREA IN % OF A NNUAL W IND F ARMP RODUCTION .The grey marked cells in Table V, represent the configuration with the lowest losses..For some configurations, participation of each componentin the system losses of the system is shown in Figure 5.Fig.ure 5. Loss Participation to the overall system losses from data in Table V.Converter stations are responsible for the highest share of the overall system losses; participation of the cable increases with lengths.V. HVDC S YSTEM WITH V OLTAGE OURCE C ONVERTERVoltage Source Converter (VSC) devices have beeninstalled until today in some bulk power transmission systemsover long distances both on land and submarine all around theworld. This solution is newer than the previous one and relevant projects have been installed only from 1997 [17]. On the one hand, these solutions might supply and absorb reactivepower to the system and help to may help to support powersystem stability; on the other hand losses are higher and line to ground faults can be problematic. A. Components of the transmission system Main components of the transmission system based onVSC devices are:- VSC converter station circuit breaker - System side harmonic filter- Interface transformer- Converter side harmonic filter - VSC unit- VSC dc capacitor - DC harmonic filter - DC reactor - DC cable or overhead transmission line - Auxiliary power set All these components are considered in the following loss calculation, except the auxiliary power set due to lack of information about its losses. B. Loss calculations5.2.1) Models and assumptionsIn order to calculate system losses for different wind farm sizes, and due to lack of data from manufactures, data are mainly used from installed projects. For instance, system loss data are extracted from installed projects such as the Cross Sound Cable [21] and the Murray Link Project [22]. By calculating the transmission losses of those projects, see [9], it is possible to calculate the losses for the total converter station (350 MW and 220 MW). In general, the idea is to divide the total system losses into three components (2 stations + the cable) in order to use the data for further calculations.Considering the system represented in Figure. 6, that is valid for both HVDC transmission solutions,Figure 6. System block diagramand assuming the percent losses x S equal in both converter stations, it’s possible to obtain()in S P x P ⋅−=11 (10) 21221⎟⎟⎠⎞⎜⎜⎝⎛⋅=⋅=−=C C V P R I R P P P (11) ()21P x P S out −= (12) where V C is the rated voltage of the cable and I is the currentflowing in it. Defining then equation()()0112232=+−−−out in S in S CP P x P x V R(13)it is possible to calculate the value x S since all the other parameters are known. In order to consider the temperature dependence of the resistance, it is possible to follow the procedure shown by Brakelmann ([9]) for an AC cable, taking into account the DCnature of our system (equations (6)-(9)). it is thus possible tocalculate the resistance of the cable as2max 'NL I vP R θ⋅= (14) Since the data for the cable provide only the input and the output power for the whole transmission system, it is necessary to solve the calculations in a loop with (6) – (9), (13) and (14) in order to obtain the value of the current that flows into the cable and thus calculate the resistance. In each step the values for I and R are improved and the loop stops when the difference between R:s at (k-1) and (k) is lower than 0,0001. Manufactures are working on larger converter station ratings; however, no detailed data are publicly available for those new converter stations. Hence, the losses for a 500 MW converter station are estimated from the losses of a 350 MW converter station.Again, for the loss calculations of the cable Brakelmann’s theory [9] is used and the model takes into account variations of temperature in the cable in order to obtain more realistic results. In Table VI , solutions chosen for cables are presented: all the configurations are based on PE solution, conductors are made of copper and rated voltage is 150 kV. The same approach described with (5) – (9) is used in the calculations for this transmission system.When more than one converter station system is considered for the transmission, the division of the power into each station depends on the configuration that gives lowest overall transmission system losses. T ABLE VIC ABLES DATA FOR THE VSC MODEL COMPILED AND CALCULATED FROM [9],[17], [18] AND [19].Converter stations are shut down when power production inthe wind farm is lower than transmission system losses: in these conditions, only the losses of protection and control systems are considered and these devices are supplied by the auxiliary power set. However, due to lack of information, these losses are neglected.5.2.2) Results Three different layouts are considered for 500 MW wind farm and four for 1000 MW wind farm: these configurations are shown in Table VII with the percent losses of each system. T ABLE VIIT RANSMISSION L OSSES FOR DIFFERENT CONVERTER STATION LAYOUTS WITH 9 M /S OF AVERGAE WIND SPEED IN THE AREA IN % OF A NNUAL W IND F ARMP RODUCTIONTransmission system losses l % have been calculated with (4) and data from Table VI . Figure 7. Loss Participation to the overall system from data in Table VII, VSC system.The grey cells in Table VII represent the configuration with the lowest losses.. For some configurations, participation of each component in the system losses of the system is shown in Figure 7. It can be seen that converter stations contribute most to the overall system losses,; participation of the cable increases with lengths.VI. C OMPARISON OF D IFFERENT S OLUTIONSIn this section a comparison of the different transmission system is presented. Table VIII shows a comparison of the three transmission systems considering current installed technology and main components.T ABLE VIIIC OMPARISON HVAC-HVDC TRANSMISSION SYSTEM ([1]-[6], [23])HVACHVDC LCCHVDC VSCMaximum available capacity per system 800 MW at 400 kV 380 MW at 220 kV 220 MW at 132 kV all up to 100 km Up to 600 MW (submarine transmission)Up to 350 MW installed 500 MW announcedVoltage level 132 kV installed 220 and 400 kV under development Up to ± 500 kV Up to ± 150 kVOffshore Installed Projects Many small installation (Table1.5 in [6])Not yet installed Only test projectsBlack start capability Yes No YesTechnical capability for network support No, SVC are required to supply reactivepowerNo, capacitorbanks or Statcom are required to supply reactive power to the valvesYes, reactive power can be generated or absorbed by the VSC devicesOffshore station in operation Yes NoNo, butannouncedDecoupling of connected networks No Yes Yes Cable modelResistances, capacitance and induction Resistance Resistance Requirements for ancillary service Not necessaryYes for low wind speeds conditionsYes for low wind speeds conditionsSpace requirements offshore substationSmallest size Biggest size Medium size Installation costsSmall for station (only transformer) High cost for cableHigh cost for station (transformer, filters, capacitors banks, thyristor valves…) Low costs forcableStation 30-40 % more expensive than LCC solution (IGBT more expensive than thyristor valves) Cable more expensive thanLCCFrom results in sections III, IV and V, the AC solution provides the lowest losses for a distance of 50 km from shore, while for 100, 150 and 200 km from the shore the HVDC LCC solution has lowest transmission losses (Table IX and Table X ). In the tables, ‘Config.’ stands for the rated power and the voltage level (between breakers) of the transmission for the HVAC system and the rated power of the converter station for the two HVDC solutions and ‘Nr Cables’ the number of cable requires for the transmission. In Figure 8 it is possible to observe loss comparison results of all three transmission systems (HVAC, HVDC LCC and HVDC VSC) for 400 up to 1000 MW wind farm at 0 up to 300 km from the shore. T ABLE IXL OSS COMPARISON FOR 500 MW WIND FARM AT 9 M /S AVERAGE WIND SPEEDIN THE AREA (CS = C ONVERTER S TATION ).T ABLE XL OSS COMPARISON FOR 1000 MW WIND FARM AT 9 M /S AVERAGE WIND SPEEDIN THE AREA (CS = C ONVERTER S TATION ).Figure 8. “MW-km ” plane, comparison HVAC-HVDC LCC for different wind farm size (400-1000 MW) and different distances to shore (0-300 km) for average wind speed of 9 m/s. Figure 8 s hows that an HVAC system leads to the lowest transmission system losses for a distance of up to 55-70 km (depending on the size of the wind farm). For a longer distances HVDC LCC becomes the solution with lowestlosses.. Dash-dotted lines in Figure 8 shows the 1, 1,6 and 2 %loss line depending on wind farm sizes and distances. Observing these lines it can be seen that in the AC-area, losses do not vary so much and they remain nearly constant for increasing wind farm capacity and almost constant distances to shore. In the LCC-area instead loss vary much more with changing wind farm size and distance: this behaviour is caused by the configuration chosen for the transmission of the power with the LCC system. In fact for each wind farm size a different combination of converter stations is considered and thus losses are only partly correlated between each other.bination of two transmission systems.In some cases it might be benefitical to combine different transmission solutions in order to obtain a wider overview of possible solution and to improve some features of the system (reliability, stability, etc.). For example a HVDC VSCtransmission system, might be useful to improve the stability of the system since it can control the generation and absorption of reactive power in the system.Configurations are defined according to the current technology and data for the components are taken from the previous sections. When a combination is chosen, it is assumed that the system with highest losses is the main transmission component and the lowest one is installed with lower transmitted power in order to decrease the total system losses. When instead system losses of both systems are close, it is assumed that both transmission systems transmit the same amount of power. When HVDC VSC solution is considered, some limitations in the possible combinations must be considered due to the small range of rated power of the converter station (on the market are only available a 220 and a 350 MW converter station).Results are presented in Table XII and Table XIII: in row ‘Config’ the rated power of the relative transmission system isT ABLE XIIC OMPARISON OF COMBINED TRANSMISSION SOLUTIONS LOSSES FOR A 500MW WIND FARM AT 9 M/S AVERAGE WIND SPEEDpointed (in brackets: the voltage level of the HVAC system), in ‘Nr Cables’ the number of cables necessary for each transmission system and ‘at x km’ system losses are shown. In the tables, symbol ‘+’ divides the kind of system used for the transmission.From the tables it can be seen that the combination of two different transmission systems never improves the system losses compared to configurations with a single transmission system. However system losses of the system with highest losses decrease with the combination with another system. For example a HVDC VSC system has losses of 4,05% (Table IX) if it operates alone at 50 km from the shore, but its losses could be decrease up to 2% if it is combined with a HVAC transmission system.T ABLE XIIIC OMPARISON OF COMBINED TRANSMISSION SOLUTIONS LOSSES FOR A 1000MW WIND FARM AT 9 M/S AVERAGE WIND SPEEDbination of three transmission systemsLarge wind farms (up to 1000 MW) are supposed to be installed in a wide offshore area. Large offshore wind turbines (5 MW) could be placed at distance of 1 km from each other.Such large wind farms might have different distances to shore and different grid connection’s conditions. One example of such wind farm configuration is presented in Figure 9. From the considered 1000 MW wind farm, power can be transmitted by three different transmission systems, characterized by different distances from shore and different grid strengths at the onshore connection point.The AC system might be used at short distances with small amount of transmitted power and connected to a weak grid. The HVDC VSC system might has the best stability possibilities and it might be connected to a medium-strong grid with transmission of a larger amount of power. HVDC LCC solution has lowest transmission losses and thus it is used for transmission of large amount of power at long distance from a strong grid connection point.Three cases of power distributions among transmission systems, for 9 m/s of average wind speed, are considered:。
