Stationary-Frame Generalized Integrators for Current Control of Active Power Filters With Zero
Steady-State Error for Current Harmonics
of Concern Under Unbalanced and
Distorted Operating Conditions
Xiaoming Yuan,Senior Member,IEEE,Willi Merk,Herbert Stemmler,and Jost Allmeling
Abstract—The paper proposes the concepts of integrators for sinusoidal signals.A proportional-integral(PI)current controller using stationary-frame generalized integrators is applied for cur-rent control of active power filters.Zero steady-state error for the concerned current harmonics is realized,with reduced computa-tion,under unbalanced utility or load conditions.Designing of the PI constants,digital realization of the generalized integrators,as well as compensation of the computation delay are studied.Exten-sive test results from a10-kW prototype are demonstrated. Index Terms—Active power filter,current control,generalized integrator,resonator.
I.I NTRODUCTION
R ESEARCH on current control for power converters has been one of the most intensive activities recently[1]. When the reference current is a direct signal,as in the dc motor drive,zero steady-state error can be secured by using a conventional proportional-integral(PI)controller.When the reference current is a sinusoidal signal,as in the ac motor drive,however,straightforward use of the conventional PI controller would lead to steady-state error due to finite gain at the operating frequency.A synchronous-frame PI controller was then proposed which guarantees zero steady-state error in a balanced system[2],[3].For an unbalanced system,a second reference frame rotating in the opposite direction would also be needed[4],[5]in order that the negative sequence component is tracked with zero steady-state error.
When the reference current is a nonsinusoidal signal,as in active power filters,a hysteresis or predictive controller is often
Paper IPCSD01-081,presented at the2000Industry Applications Society An-nual Meeting,Rome,Italy,October8–12,and approved for publication in the IEEE T RANSACTIONS ON I NDUSTRY A PPLICATIONS by the Industrial Power Con-verter Committee of the IEEE Industry Applications Society.Manuscript sub-mitted for review April1,2000and released for publication November13,2001. X.Yuan is with General Electric Corporate R&D-Shanghai,200233 Shanghai,China(e-mail:xiaoming.yuan@https://www.doczj.com/doc/757932411.html,).
W.Merk is with the Electrical Engineering Department,Burgdorf School of Engineering,University of Applied Sciences Bern,3400Burgdorf,Switzerland (e-mail:willi.merk@isburg.ch).
H.Stemmler and J.Allmeling are with the Power Electronics and Electrometrology Laboratory,Swiss Federal Institute of Technology Zurich,ETH-Zentrum/ETL,CH-8092Zurich,Switzerland(e-mail: stemmler@lem.ee.ethz.ch).
Publisher Item Identifier S0093-9994(02)02666-X.deemed a viable solution[6].While the hysteresis controller is simple and robust,it has major drawbacks in variable switching rate,current error of twice the hysteresis band,and high-fre-quency limit-cycle operation[1].Performance of the predictive controller,on the other hand,is subject to accuracy of the plant model as well as accuracy of the reference current prediction [7],[8].
Recent contributions have been applying the synchronous-frame PI controller for current control of active power filters[9], [10].The limitation consists of significant computation arising from the need for multiple reference frames.To deal with unbal-anced conditions,the number of reference frames and therefore the computation must be doubled.
Revisiting the adaptive filter technique[11],which was re-cently introduced to converter control[12],[13],the core of the filter is really an indirectly implemented integrator for a single sinusoidal signal.Direct realization of the integrator allowing for reduction of computation was already detailed in[14].The direct realization was also used in[15]for reference current prediction in a synchronous frame dead-beat controlled active power filter.
From the stationary-frame equivalent transfer matrix given in [2],a synchronous-frame PI controller,without regard to the PI, can be deemed an indirectly implemented integrator,however, only for a positive sequence sinusoidal signal.Directly imple-menting the transfer matrix shall reduce the computation.The present paper will further prove that,without the cross-coupling terms[16]–[18],the new transfer matrix will represent an inte-grator for either balanced or unbalanced sinusoidal signals. The paper proposes the concept of integrators for sinusoidal signals.The concepts of ideal integrator for a single sinusoidal signal and a stationary-frame ideal integrator for positive or neg-ative sequence sinusoidal signals are explored.The concepts of generalized integrator for a single sinusoidal signal and sta-tionary-frame generalized integrator for balanced or unbalanced sinusoidal signal are also clarified.
The paper will further report a PI current controller using the stationary-frame generalized integrators for current control of active power filters.Designing the PI constants,digital re-alization of the generalized integrators,as well as compensa-tion of the computation delay will be studied.The instanta-
0096-9994/02$17.00?2002IEEE
neous-reactive-power(IRP)theory[19]will be used for refer-ence current generation.The problem in IRP related to nonideal point-of-common-coupling(PCC)voltage will be resolved by using a sequence filter.
II.S TATIONARY-F RAME I DEAL I NTEGRATOR AND THE S TATIONARY-F RAME G ENERALIZED I NTEGRATOR
A.Ideal Integrator for a Single Sinusoidal Signal and the Stationary-Frame Ideal Integrator
Similar to the direct signal case,for a sinusoidal
signal
.Defining further an auxiliary
signal
(2)
is the resonant fre-
quency of the integrator corresponding to the signal frequency.
Notice that,for an input signal with frequency deviation
of
-axis signal and
the
-axis
and
the
-axis signal
by90degrees,as in a positive sequence system[2],[3],a
positive sequence ideal integrator can be established as shown
in Fig.2(a).However,for a system where
the
-axis signal by90degrees,as in a negative
sequence system,the signs for the cross-coupling terms must
be exchanged to build a negative sequence ideal integrator,as
shown in Fig.2(b).Fig.2(c)corresponds to positive sequence
signal passing through the negative sequence ideal integrator,
while Fig.2(d)corresponds to a negative sequence signal
passing through the positive sequence ideal integrator,each
producing negligible output.
B.Generalized Integrator for a Single Sinusoidal Signal and
the Stationary-Frame Generalized Integrator
Consider then the generalized integrator for a single sinu-
soidal signal[15],[17],[18],as shown in Fig.4(a).The in-
tegrator output contains not only the integration of the input,
but also an additional negligible component.The corresponding
stationary-frame generalized integrator is shown in Fig.
4(b),
Fig.1.(a)An ideal integrator for a single sinusoidal signal.(b)Sinusoidal
signal with frequency deviation of1!passing through the ideal integrator for
a single sinusoidal.(c)The corresponding stationary-frame ideal integrator.
which works without regard to the sequence between
the
-axis signal.
Observing that the stationary-frame generalized integrator in
Fig.4(b)is the superposition of the positive sequence ideal in-
tegrator in Fig.2(a)and the negative sequence ideal integrator
in Fig.2(b),the cross-coupling terms in one are canceled by
the corresponding terms in the other.Observe further that the
output of an ideal integrator of a given sequence resulting from
the signal of the opposite sequence is negligible.Then a typ-
ical converter current control system using the stationary-frame
generalized integrator[17],as shown in Fig.5(a),can be de-
composed into a positive sequence signal system and a negative
sequence signal system,as shown in Fig.5(b)/(d)and(c)/(e),re-
spectively.Similarly,looking from a counter-clockwise or a
clockwise
reference frame,the
equivalents of Fig.2(a)and(c)can be represented by Fig.3(a)
and(c),respectively[18].Meanwhile,in a clockwise
rotating
is the converter voltage gain,
and
YUAN et al.:STATIONARY-FRAME GENERALIZED INTEGRATORS FOR CURRENT CONTROL OF ACTIVE POWER FILTERS
525
Fig.2.(a)Positive sequence signal passing through a positive sequence ideal integrator.(b)Negative sequence signal passing through a negative sequence ideal integrator.(c)Positive sequence signal passing through a negative sequence ideal integrator.(d)Negative sequence signal passing through a positive sequence ideal integrator.
III.C URRENT C ONTROL OF A CTIVE P OWER F ILTERS U SING S TATIONARY-F RAME G ENERALIZED I NTEGRATORS
A.PI Current Controller for Active Power Filters Using the Stationary-Frame Generalized Integrators
In the case of current control for active power filters,the current error signal is nonsinusoidal which contains
multiple Fig.3.(a)Positive sequence ideal integrator equivalent and(c)negative sequence ideal integrator equivalent in the counter-clockwise(!)rotating reference frame.(b)Negative sequence ideal integrator equivalent and(d) positive sequence ideal integrator equivalent in the clockwise(0!)rotating reference
frame.
Fig. 4.(a)The generalized integrator for a single sinusoidal signal [17].(b)The corresponding stationary-frame generalized integrator.The stationary-frame generalized integrator works without regard to the sequence between the -axis signal and the -axis signal.
current harmonics.For each current harmonic of concern,a corresponding stationary-frame generalized integrator must be
526IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS,VOL.38,NO.2,MARCH/APRIL2002
Fig.5.(a)Typical converter current control system using the stationary frame generalized integrator.(b)Stationary-frame positive sequence signal system decomposition with the original input.(c)Stationary-frame negative sequence signal system decomposition with the original input.(d)Stationary-frame positive sequence signal system decomposition with the positive sequence input.(e)Stationary-frame negative sequence signal system decomposition with the negative sequence input.(f)Stationary-frame positive sequence signal system equivalent in the counter-clockwise rotating reference frame.(g)Stationary-frame negative sequence signal system equivalent in the clockwise rotating reference frame.
YUAN et al.:STATIONARY-FRAME GENERALIZED INTEGRATORS FOR CURRENT CONTROL OF ACTIVE POWER FILTERS527
Fig.6.PI current controller for active power filters using the stationary-frame
generalized integrators.
installed.When multiple current harmonics are of concern,the
corresponding multiple integrators can be installed as shown in
Fig.6.Resonant frequencies of the stationary-frame generalized integratorscorrespondtothefrequenciesoftheconcernedcurrent
harmonics.
B.Current Control System for Active Power Filters Using the
Proposed PI Current Controller
Fig.7(a)shows a typical shunt active power filter
system.A voltage source inverter
.
in Fig.8
controls the bandwidth and the response speed of the filter and
will not be detailed.
D.Identifying the Control Loops in the Control System
The current control system given in Fig.7(b)contains the
following control loops:
528IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS,VOL.38,NO.2,MARCH/APRIL
2002
Fig.9.Magnitude and phase characteristics of the open-loop transfer function of the fast utility current control loop when the 5th,7th,11th,and 13th harmonics are concerned.Proportional constant
K
=0,(b)K
=4:8.
1)Fast Utility Current Control Loop:This loop has an input
of the utility current reference
,an output of the utility current
,with a perturbation from the utility
voltage
.As this is the fastest loop in the system,the utility current reference is assumed independent of the remaining system.
2)Slow DC-Link Voltage Control Loop:This loop has an
input of the dc-link voltage
reference
,and an output of the inverter dc-link voltage.The loop is always made decoupled from first loop,by setting properly the cut-off frequencies of the low-pass filters in the dc-link voltage measurement,as well as well as in the IRP
[19].
Fig.10.Spectrum of the load current (phase B).
3)Slow Utility Current Control Loop (Spontaneous):This
loop has an input of the utility
voltage
,and an output of the utility current
.Different from the first loop,this loop involves also the second loop.Details of this loop will be left for a future report.E.Designing the PI
Constants
YUAN et al.:STATIONARY-FRAME GENERALIZED INTEGRATORS FOR CURRENT CONTROL OF ACTIVE POWER FILTERS529
Fig.11.Experimental waveforms(phase B)of the PCC voltage,load current,inverter current,and utility current as well as the utility current spectrum in the cases of:(a),(b)no integrators is used;(c),(d)1st,5th,and7th integrators are used;(e),(f)1st,5th,7th,11th,and13th integrators are used;and(g),(h)1st,5th, 7th,11th,13th,17th,and19th integrators are used.
F.Digital Implementation of the Generalized Integrators and
Compensation of the Computation Delay
For digital implementation,the following discrete forms of
the relevant algorithms are used(sampling time
530IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS,VOL.38,NO.2,MARCH/APRIL 2002
Rather than reference current prediction,this paper uses a compromising scheme predicting only the harmonic compo-nents of the concerned frequencies in the modulating signal.As the output of each generalized integrator is always sinusoidal,it is thus easy to predict this output by moving the zero of the transfer function in
the
V .A brake-chopper is connected to each
of the two dc-link capacitor banks.Each capacitor bank con-sists of four
680-
mH.A diode rectifier with an
inductor
at the dcside is used to simulate a
current source type load [24].No ripple filter is installed at the moment.
The PI current controller proposed in Fig.6is used with the
PI
constants
.A conventional PI con-troller for direct signal with a proportional constant of 4and an integral constant of 4is used for dc voltage control.Before the dc voltage controller is a first-order low-pass filter with a cut-off frequency of 125rad/s.A fifth-order Butterworth low-pass filter with a cut-off frequency of 125rad/s is used in the IRP.Con-
stant
S.
Fig.12.Experimental waveforms (phase B)of the PCC voltage,load current,inverter current,and utility current when R =39 .The sequence filter is not
used.
Fig.13.Experimental waveforms (phase B)of the PCC voltage,load current,inverter current,and utility current when the wire of phase A of the load is open.
It is also noticed that an additional controller for the neutral potential of the NPC inverter used as an active power filter is also implemented,which will not be detailed.B.Experimental Results
Fig.10shows the spectrum of the load current,and Fig.11shows the experimental waveforms of the PCC voltage,load current,inverter current,and utility current as well as the utility current spectrum in cases when different current harmonics are concerned.When only proportion is used,as shown in Fig.11(a)and (b),very limited reduction of the load current harmonics is obtained.On the other hand,when a specific current harmonic is the focus and the corresponding integrator is installed,this specific current harmonic will disappear from the utility current spectrum,as demonstrated in Fig.11(c)–(h).Effectiveness of the proposed PI current controller in ensuring zero steady-state error for the concerned current harmonics is verified.The re-sults also show a very desirable feature in selective harmonic elimination [25]for reducing the inverter rating while fulfilling the relevant harmonics standard.
Fig.12shows the PCC voltage,load current,inverter cur-rent,and utility current when the sequence filter is not used
and
YUAN et al.:STATIONARY-FRAME GENERALIZED INTEGRATORS FOR CURRENT CONTROL OF ACTIVE POWER FILTERS
531
Fig.14.Experimental waveforms(phase B)of the PCC voltage,load current, inverter current,and utility current during:(a)no-load to full-load and(b) full-load to no-load step change conditions.In either case,the transient lasts for about10mS.
load unbalance conditions.The wire of phase A of the load is open,representing an extreme unbalance of the load.It is observed that the utility current is still sinusoidal.The operation of the stationary-frame generalized integrator under unbalanced conditions is verified.
Fig.14shows the PCC voltage,load current,inverter current, and utility current under load transient conditions.The transient in either case lasts for about10mS.
V.C ONCLUSION
1)The concepts of integrators for sinusoidal signals offer
novel means for designing a converter control system in-volving nondirect signals.
2)The PI current controller using the stationary-frame gen-
eralized integrators ensures zero steady-state error for the current harmonics of concern with reduced computation.
3)The sequence filter based on the positive sequence ideal
integrator resolves the problems of the IRP under dis-torted or unbalanced PCC voltage conditions.
4)The PI current controller using the stationary-frame gen-
eralized integrators can work under either balanced or un-balanced operation conditions.
A CKNOWLEDGMENT
The authors would like to acknowledge advice from P.Daehler,G.Linhofer,Dr.P.Steimer of ABB Industrie AG, M.Rahmani,Dr.D.Westermann of ABB High V oltage Tech-nologies,Ltd.,and Dr.T.Aschwanden of BKW,Switzerland.
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2002
Xiaoming Yuan(S’97–M’99–SM’01)received the
B.Eng.degree from Shandong University,China,
the M.Eng.degree from Zhejiang University,China,
and the Ph.D.degree from Federal University of
Santa Catarina,Brazil,in1986,1993,and1998
respectively,all in electrical engineering.
He was with Qilu Petrochemical Corporation,
China,from1986to1990,where he was involved
in the commissioning and testing of relaying and au-
tomation devices in power systems,adjustable speed
drives,and high-power UPS systems.From1998to 2001,he was a Project Engineer at the Swiss Federal Institute of Technology Zurich,Switzerland,where he worked on flexible-ac-transmission-systems (FACTS)and power quality.Since February2001,he has been with GE Cor-porate R&D and is Manager of the Low Power Electronics Laboratory based in Shanghai,China.His research interests are power electronics converters, controls,and the applications.
Dr.Yuan received the first prize paper award from the Industrial Power Con-
verter Committee of the IEEE Industry Applications Society in
1999.
Willi Merk was born near Schaffhausen,Switzer-land,in1945.He completed his studies in electrical engineering at the University of Applied Sciences in Winterthur in1969.
He joined with Brown Boveri&Cie,Baden,a former Asea Brown Boveri Company.From1972 until1981,he was a leading engineer in HVDC valve design.Since1982,he has been a Lecturer at the University of Applied Sciences Berne,Switzerland, for control systems,digital signal processing,and industrial
electronics.
Herbert Stemmler received the Dipl.-Ing.degree
in automation from the Techniche Hochschule
in Darmsdadt,Germany,in1961and the Ph.D.
degree in power electronics from the Technische
Hochschule in Aachen,Germany,in1971.
He worked with Brown Bovery and ASEA-Brown
Bovery in Baden,Switzerland,from1961to1991,
in the field of power electronics.From1971to1991,
he was head of the department for development,engi-
neering,test,and commissioning of large power elec-
tronics systems.In1987he was appointed Vice-Pres-ident of this department.During these years,he worked with converter and in-verter locomotives,50–162/3Hz interties,all kinds of large ac drives,reactive power compensators,HVDC transmissions,low-power electronics,and stan-dardized and tailor-made electronic control units.Since1991,he has been Pro-fessor of Power Electronics at the Swiss Federal Institute of Technology Zurich, Switzerland,and Head of the Power Electronics and Electrometrology Labo-ratory.At the time of this writing,15doctoral projects have been completed and7projects ongoing in traction,motor drives,flexible-ac-transmission-sys-tems(FACTS),solar energy systems,uninterruptable power supplies,matrix converters,and fuel cell
vehicles.
Jost Allmeling was born in Hamburg,Germany,in
1972.He received the Dipl.-Ing.degree in electrical
engineering from the University of Technology
(RWTH)Aachen,Germany,in1996and the
Ph.D.degree from the Swiss Federal Institute of
Technology(ETH)Zurich,Switzerland,in2001.
Since1996,he has been employed as a Research
Assistant at the Power Electronics Laboratory and the
Power Systems Laboratory of ETH Zurich.His main
research interests are active filters for the medium
voltage grid and the simulation of power electronics systems.
Dr.Allmeling was awarded a second prize in1992in the nationwide youth research competition Jugend-forscht having investigated the security of smart-cards.
The speaker, on the topic of ___________________, effectively casts doubt on the passage, providing the opposite evidence concerning/ about influences on/from ____________________. Firstly, _____听力结果______. Despite the content from passage that ____阅读结果____, the speaker provides an alternative explanation that ___听力内容_2句_. From this case, the speaker questions the validity of the passage. Secondly, ____听力结果_____. According to the lecture, ____听力内容2句__________. Such information directly challenges the position of the passage that ____阅读结果____. Thirdly, ____听力结果___. The passage states that ___阅读结果____. However, the speaker denies this point and gives the proof that ___听力内容2句______. This is another case where the content from the passage is totally groundless. Fourthly, 听力结果 . The passage states that 阅读结果, which is actually questioned by the speaker, who proposes the proof that 听力内容2句. Therefore, the side of the passage is overthrown by listening material.
Chapter4 Introduction to Analysis-of-Variance Procedures Chapter T able of Contents 52Chapter4.Introduction to Analysis-of-Variance Procedures SAS OnlineDoc?:Version8 Chapter4 Introduction to Analysis-of-Variance Procedures 54Chapter4.Introduction to Analysis-of-Variance Procedures The following section presents an overview of some of the fundamental features of analysis of variance.Subsequent sections describe how this analysis is performed with procedures in SAS/STAT software.For more detail,see the chapters for the individual procedures.Additional sources are described in the“References”section on page61. De?nitions Analysis of variance(ANOV Ais a technique for analyzing experimental data in which one or more response(or dependent or simply Yvariables are measured un-der various conditions identi?ed by one or more classi?cation variables.The com-binations of levels for the classi?cation variables form the cells of the experimental design for the data.For example,an experiment may measure weight change(the dependent variablefor men and women who participated in three different weight-loss programs.The six cells of the design are formed by the six combinations of sex (men,womenand program(A,B,C.
2019年托福核心词汇：integrated什么意思(附翻译 及例句) integrated英[ntgretd] 美[ntɡretd] adj.完整的;整体的;结合的;(各组成部分)和谐的 v.使一体化( integrate的过去式和过去分词 );使整合;使完整;使结合成为整体 综合;内建;一体的;完全的 双语例句 1 . He thinks we are living in a fully integrated, supportive society. 他认为我们生活在一个完全和谐、相互扶持的社会里。 来自柯林斯例句 2 . There is, he said, a lack of an integrated national transport policy. 他指出，当前缺乏一个统一的全国交通运输政策。 来自柯林斯例句 3 . We believe that pupils of integrated schools will have more tolerant attitudes. 我们相信在取消种族隔离的学校就读的学生会有更宽容的态度。 来自柯林斯例句 4 . This computer program can be integrated with existing programs.
这套计算机程序能够与现有的程序整合在一起. 来自《简明英汉词典》 5 . They soon became fully integrated into the local community. 他们很快就完全融入了当地人的圈子. 来自《简明英汉词典》 网络释义 -integrated 1 . 综合 integratedcircuitintegrated完整 , 整体 , 综合circuit 电路 , 联盟 , 轮演系统的戏院 , 线路 , 巡回 , 巡回裁判 , 巡回裁判区. 2 . 内建 图文 2.内建 AC'97 Digital Audio controller integrated. 系统BIOS 1. 配备SoftMenu III功能,以软体程式取代传统调整DIP Switches来设定CPU 2.支持随插即用(Plug. 3 . 一体的 Dongguan Tianxing Technology Co . , Ltd. is a and development , production , sales and service for the integratedenterprise , honesty , innovation and quality to win customer's trust and support .东莞市天兴科技有限公司是集研发、生产、销售、服务为一体的企业，以诚信、创新和优质服务赢得客户的信任与支持。 4 . 完全的
EXERCISES 一、想一想，你能写出下面这些户外活动的名称吗？ 1. _____________ 2. _____________ 3. _____________ 4. _____________ 5. _____________ 6. _____________ 二、选择填空。 ( )1. The bag is too heavy. Tom, can you ________ it for me? A. make B. carry C. bring D. clean ( )2. ________! It’s time for us to watch the football game on TV. A. Pick up B. Stand up C. Hurry up D. Come up ( )3.I’m feeling very ________. I want to have a good sleep. A. hungry B. tired C. happy D. excited ( )4. — Where you go? —I went to the beach. A. are B. were C. do D. did ( )5. Let’s go for a picnic. You’d better _____ the orange juice _____ you. A. to take, with B. to take, for C. take, with D. take, for ( )6. —I heard someone screaming just now. — Me too. _______ A. It sounds nice. B. What bout you? C. He’s happy. D. What happened? 三、根据句意、首字母或中英文提示补全单词，使句子完整、正确。 1.—What does Simon often _________ (抱怨) about? —Too much homework. 2.Don’t stay at home all day. You should do some o________ sports.
pertain to(有关) vase（花瓶）obstruct（妨碍） distribution（分布）stretcher s（绷画布的框子）canvas（油画布）taut（拉紧的）deteriorate （弄坏）intrude（把观点加于他人）aesthetic（艺术的） porpoise s（海豚）affinities（亲密关系）otter s（水獭）pinniped s（鳍足动物）limb s （肢）transitional（过渡产物） embed ded（埋进，嵌入）skull（头骨）, bred（生育breed）vestigial（发育不全的）locomotion（移动） vegetation（植被）deterioration（变质，恶化）margin s（边缘）devoid（缺少）susceptible （易受……影响）trampling（踩踏）pulverization（粉碎）rigorously（严峻的） projected(投影) parlor（客厅）arcade s（拱廊）makeshift（暂时的） spectacle s（表演，场面）vaudeville（轻喜剧）minstrel（音乐家）spectator s（观众）manipulation（操作） strip s（长条）celluloid（〔美俚〕电影(胶片)）minuscule（极小的） inborn（天生的）offshoot（分支）outwit（哄骗） gratify（使满足）repress（抑制）steam（怒气）analogy（比拟学）Cognitive（有认识力的）distort（歪曲，扭曲）purging(变清净) apprentice s(学徒) craftsmanship（工匠）necessitate d（使……成为必需）regiment ed （有组织的）discard（放弃）alert（机警的）momentum（势头，契机）spearhead ed（带领，当……的先锋） courtship（求偶）hydrodynamic（流体动力学）sleek（光滑的）compact（结实的）flush with（同高的）protrude（使突出）slick（光滑的）fin s（鳍）stiff（僵直的）contour s （轮廓）retract（缩回）gear（齿轮）sophisticated（尖端的）supersonic（超音速的）keel s（龙骨脊）coarse（粗糙的）buoyant（会浮的）. slits（裂缝）thrust（猛推）glide（滑行）propulsion（推进）aristocrat s(贵族)manipulate d （操纵）sap ped（削弱）speculation（投机）agrarian（农业的） humanitarian（人道主义者）disproportionate（不匀称的）surpluse s（剩余）alienated （脱离）semisubsistence（半生存）languishing（日渐衰弱的） despondent（垂头丧气的）hostile（有敌意的）concur with（同意）hypothesis（前提；假说）arousal（激励；觉醒）stiffen ing（使紧绷） terrain(岩层)epitome（缩影）plateau(高原). margin s(边缘)fracture(使破裂，使折断) seeps(漏出) debris(碎片，岩屑) splitting(裂开) meteoric（大气的）soak ed（浸，弄湿）pebbles（细砂）unconsolidated（不坚固的）gravel（砂石）laden（装着货的）fanwise（呈扇形的）pores（细孔）plugged（塞子）cementing（胶状）percolating（滤过）solidified（使凝固，使结晶）permeability（透出量，渗透性）cavities（穴）crevices（裂缝）clinging（贴着） champion ed(主张)perceived（领悟）attributes（归因于）sophisticated（非自然的；富有经验的；复杂的；理智上吸引人的）modify（变更，调节）elaborated（详尽阐述）pantomime （哑剧表演，手势）impersonation（扮演）virtuosity（艺术上的熟练技巧）antecedents（先例）ritual（仪式）objectify（体现）penchant（倾向，嗜好）detached （分开）deviations（脱离）
教好Integrated skills板块应把握的要点 众所周知，初中英语每个单元基本上由九个板块构成，分别是Comic strip、Welcome to the unit、Reading、V ocabulary、Grammar、Integrated skills、Study skills/Pronunciation、Main task 和Checkout。其中普遍认为比较难上的板块为“Integrated skills”。老师们总感觉没什么东西可讲，上亦可不上亦可。对于Integrated skills这一课时而言，教材编排肯定有编排者的意图，那就要求我们一定要从课改的高度，认真思考，从教学实际出发来探究Integrated skills在一个单元中的位置、作用及如何上好Integrated skills。 一、Integrated skills在单元中的定位思考 每个单元都围绕一个中心任务展开，每个单元的9个板块都是围绕解决这个中心任务的，因此各个板块之间都有着内在的联系，应该整体进行教学安排。总体上看，我们发现每个单元以main task为主导，topic为主线，把各个板块联在一起。 以8A Unit 4 Wild animals为例，看它是怎样安排话题层层推进的。本单元的中心任务是：write an article about a kind of wild animal.让学生明白：保护动物就是保护人类。当学生希望自己去描写动物的时候，会缺少词汇和表达方式，这就有了下面的V ocabulary 和Grammar。然后Integrated skills在前面语言学习和语法训练的基础上，培养学生综合运用英语的能力，即通过听说为先导，在原来的学习的基础上拓展学生的知识面，去了解老虎、狼等其他动物外貌、习性、面临的危险及保护措施。训练到此，学生应该能比较轻松地完成Main task，即再次通过熊猫相关知识学习，知道如何描述动物的外形特征、生活习性及具体面临的危险，从而能写出一篇关于动物保护方面的文章。 通过一个具体单元各个板块的描述，我们不难发现Integrated skills在一个单元中扮演着重要的角色，起到了承上启下的作用。Integrated skills首先是对前面学习任务的完成能力的检验和所学知识的复习，能否综合运用Reading中的句型，能否正确使用所学词汇，能否正确模仿在Grammar中学习的语言知识，在Integrated skills课中均能得到反馈体现，其次也为学生能否真正在学完一个单元后顺利完成中心任务打好基础。 二、Integrated skills在单元中的作用 1 充分开发综合运用语言的目标功能 Integrated skills教学任务的编排语言难度适中，听力内容、阅读内容和填写内容均是围绕同一个话题，相同话题的材料不断的通过听、读、写的形式来培养学生理解、处理、判断、回应各类信息的能力。因此我们不难看出Integrated skills板块的教学是以侧重听、说、读、写的教学而达到学生综合运用语言的培养目标的。这一培养目标是否成功，关键在于教师如何处理好听、说、读、写的关系，如何合理的分配时间，否则，这部分教学的作用将被削弱或本末倒置，顾此失彼。这就要求我们要改变思维方式，重新审视教学的各个环节，在寻找更合理、更有效的教学方法上下功夫。 2 充分调动话题的任务功能 Integrated skills的材料总是紧扣每个单元的主题。教师应该在教学过程中注重“利用背景资料导入话题，利用学生已有知识激活话题，通过描述图片深入话题，借助多媒体拓展话题。”不仅如此，由于有了听说填写的铺垫，信息的积累，充分利用说、写、调查、游戏等活动调动话题的任务功能是非常有必要的。新课程要求我们在教学中遵循新教材编写的原则：以话题为主线，通过话题引出语言功能，并在完成任务的过程中贯穿语言功能。学生在综合技能的培训当中，坚持以一个话题为立足点，完成一个到两个学习的任务不仅可以使他们把语言及其相关的因素融入学习，全面投入，学用结合，更可以培养学生掌握多种学习策略，使学习的方式多样化，为他们的终身学习打下基础。 三、Integrated skills的教学探究 1.Integrated skills的处理
初中英语Integrated Skills教案 I. Aim: To get specific information from a listening material; To talk about a friend. To talk about future plans II. Teachi ng procedures: Revision 1. We have learnt a lot about different outdoor activities. What are they? (swimming, hiking, campi ng, diving, cycling, skiing…) What do you like doing? What would you like to do when you grow up? (Ask t wo pairs to talk about what they have learnt in the last lesson. The other students will listen to them and try to write down their answers in the proper boxes, e.g.) S1 S2 S3 S4 I like… I would like to… If they can’t, teachers can give them an example (I like hiking best because I think it is very interesting and it’s good for our health. I also like swimming and diving. But I am not good at swimming. So I dare not to swim or dive in the water. In the future, I would like to have a swimming lesson and try to dive in the sea. I don’t like cycling at all. But I must ride a bike every day, or I will have to spend too much time on buses. I would like to drive a car in the future if I can.) 2. Ask Ss to share their answers with each other to see if they have got the right ones. 3. Ask Ss some questions about the table, e.g.: What does … like doing? What would … like to do in the future?
Unit 7 Integrated Skills 一、预习课本，回答以下问题.。 (1) How does UNICEF raise money? _______________________________________________ (2) What does UNICEF do for poor children? _______________________________________________ (3) What is UNICEF? _______________________________________________ (4) When was it set up? _______________________________________________ (5) Why was it set up? _______________________________________________ (6) What changed children’s lives at that time? _______________________________________________ (7) How many countries and areas does UNICEF work in? _______________________________________________ 二、英汉互译 1.The United Nations 2. Because of the war 3.为贫困儿童提供基础教育 4 防止他们得病5.这种药一天吃三次 6 as a volunteer 7.Have a check 8 组织其他的活动 三、根据汉语提示完成单词。 UNICEF is __________(部分) of the United States. A lot of things are sold in Oxfam shops, _________ (包括) books. Those __________(病人) must be taken good care of. Thank you for ___________(提供) me with some water. Mr Green looks _________(苍白). What’s the matter? 四、根据speak up 内容编写新的对话。
集成电路设计实习Integrated Circuits Design Labs I t t d Ci it D i L b 单元实验一（第一次课） 基本门电路设计－－电路仿真 2006-2007 Institute of Microelectronics Peking University
实验内容 z实验内容： z完成CMOS反相器的电路设计 z实验目的 z掌握基本门电路的设计方法 z熟悉Cadence的设计数据管理结构，以及定制设计的原理图输入、电路仿真、版图设计、版图验证工具的使用 z提示： z电路结构和优化设计可以参考《CMOS VLSI分析与设计》 Institute of Microelectronics, Peking University集成电路设计实习－单元实验一Page2
反相器的设计 z设计目的：基于csmc05工艺，完成一个具有逻辑反相功能的电路z设计要求： z1、反相器的逻辑阈值在Vdd/2附近，即噪声容限最大 z2、反相器的版图高度限制为24微米，电源和地线宽度各为2微米 z3、反相器宽度限制为mos器件不折栅 z4、为了给顶层设计留出更多的布线资源，版图中只能使用金属1 和多晶硅作为互连线，输入，输出和电源、地线等pin脚必须使用 金属1 z5、版图满足设计规则要求，并通过LVS检查 z6、为了满足以后复杂门电路设计的需要，要求反相器版图满足上、下、左、右并置排列的时候不违反设计规则 Institute of Microelectronics, Peking University集成电路设计实习－单元实验一Page3
Generalized Hough Transform (GHT) (Ballard and Brown, section 4.3.4, Sonka et al., section 5.2.6) -The Hough transform was initially developed to detect analytically de?ned shapes (e.g., lines, circles, ellipses etc.). -The generalized Hough transform can be used to detect arbitrary shapes (i.e., shapes having no simple analytical form). -It requires the complete speci?cation of the exact shape of the target object.? Special case: ?xed orientation and size y x =x c +x ′or x c =x ?x ′y =y c +y ′or y c =y ?y ′ cos (π?α)=y ′r or y ′=rcos (π?α)=?rsin (α)sin (π?α)=x ′r or x ′=rsin (π?α)=?rcos (α)
-Combining the above equations we have: x c=x+rcos(α) y c=y+rsin(α) Preprocessing step (1) Pick a reference point (e.g.,(x c,y c)) (2) Draw a line from the reference point to the boundary. (3) Computeφ(i.e., perpendicular to gradient’s direction). (4) Store the reference point(x c,y c)as a function ofφ(i.e., build the R-table) φ1:(r11,α11),(r12,α12),... φ2:(r21,α21),(r22,α22),... φn:(r n1,αn1),(r n2,αn2),... -The R-table allows us to use the contour edge points and gradient angle to recompute the location of the reference point. Note:we need to build a separate R-table for each different object.
Integrated Circuits集成电路 The Integrated Circuit Digital logic and electronic circuits derive their functionality from electronic switches called transistor. （数字逻辑和电子电路由称为晶体管的电子开关得到它们的（各种）功能。）Roughly speaking, the transistor can be likened to an electronically controlled valve whereby ener gy applied to one connection of the valve enables energy to flow between two other connections .By combining multiple transistors, digital logic building blocks such as AND gates and flip-flops ar e formed. Transistors, in turn, are made from semiconductors. （粗略地说，晶体管好似一种电子控制阀，由此加在阀一端的能量可以使能量在另外两个连接端之间流动。通过多个晶体管的组合就可以构成数字逻辑模块，如与门和触发电路等。而晶体管是由半导体构成的。）Consult a periodic table of elements in a college chemistry textbook, and you will locate semicon ductors as a group of elements separating the metals and nonmetals.They are called semiconduct ors because of their ability to behave as both metals and nonmetals.（查阅大学化学书中的元素周期表，你会查到半导体是介于金属与非金属之间的一类元素。它们之所以被叫做半导体是由于它们表现出来的性质类似于金属和非金属。）A semiconductor can be made to conduct electricity like a metal or to insulate as a nonmetal doe s. These differing electrical properties can be accurately controlled by mixing the semiconductor with small amounts of other elements. This mixing is called doping.（可使半导体像金属那样导电，或者像非金属那样绝缘。通过半导体和少量其它元素的混合可以精确地控制这些不同的电特性。这种混合技术称之为“半导体掺杂”。）A semiconductor can be doped to contain more electrons (N-type) or fewer electrons (P-type). Ex amples of commonly used semiconductors are silicon and germanium. Phosphorous and boron ar e two elements that are used to dope N-type and P-type silicon, respectively. （半导体通过掺杂可以包含更多的电子（N型）或更少的电子（P型）。常用的半导体是硅和锗，N型硅半导体掺入磷元素，而P型硅半导体掺入硼元素。） A transistor is constructed by creating a sandwich of differently doped semiconductor layers. The two most common types of transistors, the bipolar-junction transistor (BJT) and the field-ef fect transistor (FET) are schematically illustrated.This figure shows both the silicon structures of th ese elements and their graphical symbolic representation as would be seen in a circuit diagram. The BJT shown is an NPN transistor, because it is composed of a sandwich of N-P-N doped silicon.（不同掺杂的半导体层形成的三明治状夹层结构可以构成一个晶体管，最常见的两类晶体管是双极型晶体管（BJT）和场效应晶体管（FET），这些晶体管的硅结构，以及它们用于电路图中的符号。BJT是NPN型晶体管，因为由N—P—N掺杂硅三层构成。）When a small current is injected into the base terminal, a larger current is enabled to flow from t he collector to the emitter.The FET shown is an N-channel FET, which is composed of two N-type r egions separated by a P-type substrate. When a voltage is applied to the insulated gate terminal, a current is enabled to flow from the drain to the source. It is called N-channel, because the gate
VMware Integrated OpenStack 试用实验 一、实验环境介绍 1、VSphere群集：实验环境从自家数据中心选取一个刀箱 部分主机作为实验环境，建立两个群集，群集m620作 为VMware Integrated OpenStack（以下简称VIO）运 行环境，群集m610作为租户资源。每个群集含3-5台 物理主机，内存128G，双路CPU。 实际如果将VIO用于生产（目前1.0版本有诸多问题， 不建议），建议使用独立群集，区分当前VSPHERE数据 中心。 本次实验采用vsphere 6.0，客户端试用Web Client。 2、网络：VIO要求使用VMWARE分布式交换机DVS，实 验环境建立3个分布式交换机，分别对应管理网络，业 务网络，ISCSI网络，每个交换机绑定2块万兆物理网卡； 其中业务网络和管理网络采用动态链路聚合，ISCSI网络 采用多路径，物理交换机和存储网络开启DCBX。 划分一个24位网络用于租户网络测试。 有条件的应该采用NSX为最佳。 注意：将用于租户的测试网络的分布式交换机需要命名为 “dvs”，否则会有建立租户网络失败的情况。楼主也是 经过多次测试，经查阅VIO官方博客，发现确实存在这 个现象。
地址规划： Vcenter:192.168.10.95/24 VIO management-server:192.168.10.188/24 VIO 组件地址范围：192.168.10.50-192.168.10.69（至 少需要18个） VIO 组件发布地址：10.52.3.11-15/24，对外服务虚拟 IP:10.52.3.16/24 VIO 组户网络：10.52.2.0/24 3、存储：数据中心划取2个LUN，大小分别位200G。分 别挂载为“openstack-vio-vm””openstack-vio-image“， 分别用于存放租户虚拟机云硬盘和镜像。 二、实验步骤 1、部署vshper环境（略） 群集部署
SPSS详细操作：广义估计方程 SPSS详细操作：广义估计方程 2017-03-18 17:40一、问题与数据 在临床研究中，经常会比较两种治疗方式对患者结局的影响，并且多次测量结局。例如，为了研究两种降压药物对血压的控制效果是否存在差异，研究者会对两个人群服药后在不同时间点记录血压值，然后评价降压效果。或者对两组动物分别施加两种干预，连续记录多个时间点的结局，然后比较两种干预的效果。 这种设计可以用如下示意图表示： 另外，有时研究只需要收集一个时间点的数据，但是一个研究对象会提供多个部位的数据点。例如，研究者想评价冠心病患者在冠脉搭桥术后应用阿司匹林是否可以有效降低患 者血管的再堵塞，评价的方法是术后1年做冠脉造影观察血管是否堵塞，但是每个患者可能会在同一次手术中对多条冠状动脉血管进行搭桥，因此有的患者可能会贡献多组数据。这种设计可以用如下示意图表示：
以上两种设计，不管是临床试验还是动物试验都非常常见，它的特点在于数据间非独立，同一个体间数据具有相关性。对于这样的设计类型，该如何分析呢？ 今天我们来介绍另外一种非常好的方法——广义估计方程（GEE）。GEE既可以处理连续型结局变量也可以处理分类型结局变量，它实际上代表了一种模型类别，即在传统模型的基础上对相关性数据进行了校正，可以拟合Logistic回归、泊松回归、Probit回归、一般线性回归等广义线性模型。 本文将以阿司匹林预防冠脉搭桥后血管再堵塞为例介绍运 用SPSS进行GEE的操作方法。以下为数据格式： 表1. 数据格式 每名患者贡献数据量不等。如编号为1的患者只对一根血管进行了搭桥手术，编号为2的患者则有两根血管进行搭桥手术。 表2. 变量赋值 （注：本例中数据纯属虚构，分析结果不能产生任何结论。性别为待调整变量。） 二、SPSS分析方法 1. 数据录入SPSS 首先在SPSS变量视图（Variable View）中新建上述表2中
7B Unit one Grammar-Integrated skills 一，所给词的适当形式 1. We celebrated Thanksgiving Day on the ________(four) of November. 2. December is the _______(twelve) month of the year. 3. Our flat is on the ________(twenty) floor. 4. –what’s the date today? ---- it’s March the ______(eight), women’s Day. 5. There is a sofa in their ______ (sit) room. 6. We can see a lot of ________ (shelf) in the room. 7. Today we will learn the __________(21)lesson. 8.We can visit the Palace Museum on Saturday, the _________(19)of May. 9.In his __________(50), he owns anew car. 10. He is always the ________(one) to come to school. 11. There are ________ (千) of children in the park. 12. The old man dies after his ________ (90) birthday。 13. In the library, there are 20 ________(千)books。 二，词汇 1. Her telephone n_______ is 5551721. 2. your house is _______ (not the same)from the flat in Nanjing. 3. They stay at home and watch v_______ all day. 4. If you have something to tell him. You can ________ (telephone) him. 5. In the game, Daniel gets _________ (99) points. 6.how do we read 1,567,349?______________________ _________ 7. The CN tower is 1,815________ (foot) tall. 9. The d______ room is the _______ (good) place to chat and watch TV. 10. She is selfish(自私)。She doesn’t like s_______(分享) things with others. 11. I am the o_______ of the house. 三，选择题 1. – hello，this is Wendy. Can I speak to Mary? -- Yes, ______. A Mary is me B Mary, please C My name is Mary. D this is Mary speaking. 2. Thanks for your coffee, I am afraid I have to go.--- OK, ________. A Go slowly. B All right C Sounds great . D No problem 3. Today is my mother’s _________ birthday. A fourteen B fourteenth C forty D fortieth 4. How many workers are there in your factory? --- there are two _________. A hundreds B hundred C hundred of D hundreds of 5. I was 8 years old when my father was 31. This year my father is twice my age. How old am I? A 21 B 22 C 23 D24 6. Both of the two rulers are broken. I want to buy a ________ one. A three B third C fourth D 1 7. That big garden is full ______ flowers. It _______ beautiful. A with, look B of, looking C of, looks D with, looks 8. We have a bathroom ________ two showers. A of B with C has D about 9. I like sleeping late _________ every Sunday morning. A in B on C at D / 10. I will call you when she ________ back. A will come B come C comes D is coming _____ ______ _____ _______ _______ _____ ______ _____ _______ _______