VSC-Based HVDC Power Transmission Systems An Overv_动视

VSC-Based HVDC Power Transmission Systems An Overv

2025-09-25 23:11:46 责编:小OO

VSC-Based HVDC Power Transmission Systems:

An Overview

Nikolas Flourentzou,Student Member,IEEE,Vassilios G.Agelidis,Senior Member,IEEE,

and Georgios D.Demetriades,Member,IEEE

Abstract—The ever increasing progress of high-voltage high-power fully controlled semiconductor technology continues to have a signiﬁcant impact on the development of advanced power elec-tronic apparatus used to support optimized operations and efﬁcient management of electrical grids,which,in many cases,are fully or partially deregulated networks.Developments advance both the HVdc power transmission and theﬂexible ac transmission system technologies.In this paper,an overview of the recent advances in the area of voltage-source converter(VSC)HVdc technology is pro-vided.Selected key multilevel converter topologies are presented. Control and modeling methods are discussed.A list of VSC-based HVdc installations worldwide is included.It is conﬁrmed that the continuous development of power electronics presents cost-effective opportunities for the utilities to exploit,and HVdc re-mains a key technology.In particular,VSC-HVdc can address not only conventional network issues such as bulk power transmission, asynchronous network interconnections,back-to-back ac system linking,and voltage/stability support to mention a few,but also niche markets such as the integration of large-scale renewable en-ergy sources with the grid and most recently large onshore/offshore wind farms.

Index Terms—HVdc circuit breakers(CBs),HVdc converters, HVdc transmission,power electronics,power engineering educa-tion,power systems.

I.I NTRODUCTION

H VDC POWER transmission systems and technologies

associated with theﬂexible ac transmission system (FACTS)continue to advance as they make their way to com-mercial applications[1]–[30].Both HVdc and FACTS systems underwent research and development for many years,and they were based initially on thyristor technology and more recently on fully controlled semiconductors and voltage-source converter (VSC)topologies[1]–[30].The ever increasing penetration of the power electronics technologies into the power systems is mainly due to the continuous progress of the high-voltage high-power fully controlled semiconductors[31]–[36].

The fully controlled semiconductor devices available today for high-voltage high-power converters can be based on either thyristor or transistor technology(see Table I).These devices can be used for a VSC with pulsewidth modulation(PWM)

Manuscript received February13,2008;revised June5,2008and August14, 2008.First published February3,2009;current version published April8,2009. Recommended for publication by Associate Editor J.H.R.Enslin.

N.Flourentzou and V.G.Agelidis are with the School of Electrical and Information Engineering,The University of Sydney,Sydney,N.S.W.2006, Australia(e-mail:nﬂourentzou@ee.usyd.edu.au;v.agelidis@ee.usyd.edu.au).

G.D.Demetriades is with ABB Corporate Research,SE-72178V¨a ster˚a s, Sweden(e-mail:georgios.demetriades@se.abb.com).

Digital Object Identiﬁer10.1109/TPEL.2008.2008441

TABLE I

S UMMARY OF F ULLY C ONTROLLED H IGH-P OWER S

EMICONDUCTORS operating at frequencies higher than the line frequency.These devices are all self-commuted via a gate pulse.

Typically,it is desirable that a VSC application generates PWM waveforms of higher frequency when compared to the thyristor-based systems.However,the operating frequency of these devices is also determined by the switching losses and the design of the heat sink,both of which are related to the power through the component.Switching losses,which are di-rectly linked to high-frequency PWM operation,are one of the most serious and challenging issues that need to be dealt with in VSC-based high-power applications.Other signiﬁcant dis-advantages that occur by operating a VSC at high frequency are the electromagnetic compatibility/electromagnetic interfer-ence(EMC/EMI),transformer insulation stresses,and high-frequency oscillations,which require additionalﬁlters.

HVdc and FACTS systems are important technologies,sup-porting in their own way the modern power systems,which,in many cases,are fully or partially deregulated in several coun-tries[37].In the near future,even higher integration of electrical grids and market-driven developments are expected,as for in-stance,countries in the Middle East,China,India,and South America require infrastructure to power their growth and inter-connection of“island”grids[38]–[43].

Today,there are approximately100HVdc installations world-wide(in operation or planned for the very near future)trans-mitting more than80GW of power employing two distinct technologies as follows.

1)Line-commutated current-source converters(CSCs)that

use thyristors(Fig.1,CSC-HVdc):This technology is well established for high power,typically around 1000MW,with the largest project being the Itaipu sys-tem in Brazil at6300MW power level.The longest power transmission in the world will transmit00MW power from the Xiangjiaba hydropower plant to Shang-hai.The2071km line will use800kV HVdc and 1000kV ultrahigh-voltage ac transmission technology

[44].

2)Forced-commutated VSCs that use gate turn-off thyris-

tors(GTOs)or in most industrial cases insulated gate

Fig.1.HVDC system based on CSC technology with

thyristors.

Fig.2.HVDC system based on VSC technology built with IGBTs.

bipolar transistors (IGBTs)(Fig.2,VSC-HVdc):It is well-established technology for medium power levels,thus far,with recent projects ranging around 300–400MW power level (see Table II)[45]–[55].

The CSC-HVdc systems represent mature technology today (i.e.,also referred to as “classic”HVdc),and recently,there have been a number of signiﬁcant advances [56]–[58].It is beyond the scope of this paper to discuss developments associated with the CSC-HVdc that are well documented in [56]–[58].

On the other hand,VSC-HVdc systems represent recent developments in the area of dc power transmission technol-ogy [48].The experience with VSC-HVdc at commercial level scatters over the last 12years [45]–[47],[49]–[55].The breakthrough was made when the world’s ﬁrst VSC-based PWM-controlled HVdc system using IGBTs was installed in March 1997(Hellsj¨o n project,Sweden,3MW,10km distance,±10kV)[46],[47].Since then,more VSC-HVdc systems have been installed worldwide (see Table II)[49]–[55].

The CSCs have the natural ability to withstand short cir-cuits as the dc inductors can assist the limiting of the currents during faulty operating conditions.The VSCs are more vulner-able to line faults,and therefore,cables are more attractive for VSC-HVdc applications.It is worth mentioning relevant de-velopments that led to the success of VSC-HVdc such as the advanced extruded dc cable technologies [59]–[61].Faults on the dc side of VSC-HVdc systems can also be addressed through the use of dc circuit breakers (CBs)[62]–[68].In the event of the loss of a VSC in a multiterminal HVdc,the excess of power can be restricted by the advanced dc voltage controller [69].The objective of this paper is to provide an overview of the HVdc technologies associated with VSC-based systems includ-ing converter topologies.Modeling and control are another area of importance,and recent contributions presented in the techni-cal literature are analyzed brieﬂy.Finally,emerging applications of VSC-HVdc systems and multiterminal dc conﬁgurations that can be used to interconnect large-scale wind energy sources with the grid are discussed.

The paper is organized as follows.Section II provides a sum-mary of the CSC-HVdc system conﬁgurations,which also ap-ply,with some modiﬁcations,to the VSC-HVdc ones as well.

Section III discusses in detail the fundamental concepts as-sociated with the VSC-HVdc system.The various multilevel converter topologies suitable for VSC-HVdc are presented in Section IV.Modeling and control issues are mentioned in Sec-tion V.Technical issues associated with dc faults,dc CBs,and isolation/reconnection of the dc network of multiterminal sys-tems are discussed in Section VI.Emerging applications in-volving the integration of large-scale wind energy systems are presented in Section VII.The various worldwide VSC-HVdc projects are summarized in Section VIII.

II.CSC-HVDC S YSTEM C ONFIGURATIONS

Depending upon the function and location of the converter stations,various conﬁgurations of HVdc systems can be iden-tiﬁed.The ones presented in this section involve CSC-HVdc conﬁgurations but similar types of conﬁgurations exist for VSC-HVdc with or without transformers depending upon the project in question.

A.Back-to-Back CSC-HVDC System

In this case,the two converter stations are located at the same site and there is no transmission of power with a dc link over a long distance.A block diagram of a back-to-back CSC-HVdc system with 12-pulse converters is shown in Fig.3.The two ac systems interconnected may have the same or different frequency (asynchronous interconnection).B.Monopolar CSC-HVDC System

In this conﬁguration,two converters are used that are sep-arated by a single pole line,and a positive or a negative dc voltage is used.Many of the cable transmissions with subma-rine connections use a monopolar system.The ground is used to return current.Fig.4shows a block diagram of a monopolar CSC-HVdc system with 12-pulse converters.C.Bipolar CSC-HVDC System

This is the most commonly used conﬁguration of a CSC-HVdc system in applications where overhead lines are used to transmit power.In fact,the bipolar system is two monopolar systems.The advantage of such system is that one pole can continue to transmit power in case the other one is out of service for whatever reason.In other words,each system can operate on its own as an independent system with the earth return.Since one is positive and one is negative,in case that both poles have equal currents,the ground current is zero theoretically,or,in practice,within a difference of 1%.The 12-pulse-based bipolar CSC-HVdc system is depicted in Fig.5.D.Multiterminal CSC-HVDC System

In this conﬁguration,there are more than two sets of convert-ers.A multiterminal CSC-HVdc system with 12-pulse convert-ers per pole is shown in Fig.6.In this case,converters 1and 3can operate as rectiﬁers while converter 2operates as an inverter.Working in the other order,converter 2can operate as a rectiﬁer and converters 1and 3as inverters.By mechanically switching

TABLE II

S UMMARY OF W ORLDWIDE VSC-HVDC P ROJECTS AND T HEIR B ASIC P

ARAMETERS

Fig.3.Back-to-back CSC-HVDC system with 12-pulse

converters.

Fig.4.Monopolar CSC-HVDC system with 12-pulse converters.

the connections of a given converter,other combinations can be achieved.

III.VSC-HVDC F UNDAMENTAL C ONCEPTS

A basic VSC-HVdc system comprises of two converter sta-tions built with VSC topologies (see Fig.2).The simplest VSC topology is the conventional two-level three-phase bridge shown in Fig.7.

Typically,many series-connected IGBTs are used for each semiconductor shown (see Fig.7)in order to deliver a higher blocking voltage capability for the converter,and therefore

in-

Fig.5.Bipolar CSC-HVDC system with one 12-pulse converter per pole.

crease the dc bus voltage level of the HVdc system.It should be noted that an antiparallel diode is also needed in order to ensure the four-quadrant operation of the converter.The dc bus capacitor provides the required storage of the energy so that the power ﬂow can be controlled and offers ﬁltering for the dc harmonics.The VSC-HVdc system can also be built with other VSC topologies.Key topologies are presented in Section IV.The converter is typically controlled through sinusoidal PWM (SPWM),and the harmonics are directly associated with the switching frequency of each converter leg.Fig.8presents the basic waveforms associated with SPWM and the line-to-neutral voltage waveform of the two-level converter (see Fig.7).Each phase leg of the converter is connected through a reactor to the

Fig.6.Multiterminal CSC-HVDC system—parallel

connected.

Fig.7.Conventional three-phase two-level VSC

topology.

Fig.8.Two-level sinusoidal PWM method:reference (sinusoidal)and carrier (triangular)signals and line-to-neutral voltage waveform.

ac system.Filters are also included on the ac side to further reduce the harmonic content ﬂowing into the ac system.

Generalized two ac voltage sources connected via a reactor is shown in Fig.9.Fig.10shows the relative location of the phasors of the two ac sinusoidal quantities and their relationship through the voltage drop across the line reactor (see Fig.9).One voltage is generated by the VSC and the other one is the voltage of the ac system.At the fundamental frequency,the active and reactive powers are deﬁned by the following relationships,assuming that the reactor between the converter and the ac system is ideal (i.e.,lossless):

P =V s sin δ

X L V r

(1)Q =

V s cos δ−V r

X L

V r

(2)

Fig.9.Interconnection of two ac voltage sources through a lossless

reactor.

Fig.10.Phasor diagram of two ac voltage sources interconnected through a lossless

reactor.

Fig.11.Active–reactive locus diagram of VSC-based power transmission

system.

where δis the phase angle between the voltage phasors V s and V r at the fundamental frequency.

Fig.11shows the entire active–reactive power area where the VSC can be operated with 1.0per unit (p.u.)value being the megavolt amperes rating of each converter (assuming that the HVdc operates in ideal conditions).The use of VSC as opposed to a line-commutated CSC offers the following advantages.1)Avoidance of commutation failures due to disturbances in the ac network.

2)Independent control of the reactive and active power con-sumed or generated by the converter.

3)Possibility to connect the VSC-HVdc system to a “weak”ac network or even to one where no generation source is available,and naturally,the short-circuit level is very low.4)Faster dynamic response due to higher PWM than the fundamental switching frequency (phase-controlled)op-eration,which further results in reduced need for ﬁltering,and hence smaller ﬁlter size.

5)No need of transformers to assist the commutation process of the converter’s fully controlled semiconductors.

Fig.12.NPC phase

leg.

Fig.13.Five-level FC VSC phase leg.

IV .VSC-HVDC M ULTILEVEL T OPOLOGIES

In this section,different selected VSC topologies suitable for the implementation of a VSC-HVdc system are discussed.Multilevel converters extend the well-known advantages of low-and medium-power PWM converter technology into the high-power applications suitable for high-voltage high-power adjustable-speed drives and large converters for power sys-tems through VSC-based FACTS and HVdc power transmission [70]–[86].

There are numerous multilevel solid-state converter topolo-gies reported in the technical literature [74].However,there are two distinct topologies,namely,the diode-clamped neutral-point-clamped (NPC)converter (see Fig.12)[70]and the ﬂying capacitor (FC)converter (see Fig.13)[71],[72].For clarity purposes,three-level and ﬁve-level PWM voltage waveforms on the line-to-neutral basis are shown in Figs.14and 15,respectively.

Contributions for selected topologies that can be used to build an HVdc system were made in numerous technical pa-pers and are not limited to [78]–[102].Speciﬁcally,PWM-controlled HVdc concepts based on the three-phase two-level converter were reported using GTOs in [87].A similar sys-tem was developed and reported using IGBTs and DSP

con-

Fig.14.Three-level PWM line-to-neutral voltage

waveform.

Fig.15.Five-level PWM line-to-neutral voltage

waveform.

Fig.16.Module-multilevel converter topology.(a)Structure of the submodule (SM).(b)Phase leg.

trol in [93].Using modular approach and phase-shifted SPWM concepts,a number of advantages can be gained as far as the harmonic performance of the overall VSC-HVdc system is con-cerned [88],[],[91],[101].The modular multilevel converter using half-bridge cascaded connections [see Fig.16(a)]that seems to be more suitable for different number of voltage levels [see Fig.16(b)]is presented in [81]and examined for HVdc applications [82],[83].The diode-clamped NPC topology was studied in [90]for an HVdc system in its three-level version (see Fig.12).The beneﬁts of using such a system were brought out;however,the converter has signiﬁcant challenges with volt-age balancing across the various dc bus capacitors,in addition to the uneven loss distribution between the devices.An actively clamped topology that is able to offer a solution to the loss distri-bution problem of the NPC was introduced in [78]and is called active NPC (ANPC)converter (see Fig.17).This topology is an attractive solution for HVdc applications.

A VSC-HVdc system based on the ﬁve-level PWM FC topol-ogy was studied in [92](see Fig.13).The three basic topologies,namely the two-level converter (see Fig.7),the NPC converter

Fig.17.ANPC phase

leg.

Fig.18.Hybrid CSC-based HVDC combined with VSC-based STATCOM

[94].

(see Fig.12),and the FC converter (see Fig.13),were com-pared for the HVdc system in [84].A hybrid system is proposed in [94]as a way to exploit the beneﬁts of more than one technol-ogy,i.e.,the advantages of CSC-based HVdc and VSC-based static synchronous compensator (STATCOM)used as a static compensator for the connection of two ac systems when there is no synchronous generation to a main grid.The proposed system is shown in Fig.18.The system studied through simulations combines the robust performance and relatively lower capital cost due to the low frequency switching with the fast dynamic response of a PWM-controlled VSC STATCOM.The power level of the STATCOM is not as high as the power level of the CSC-based HVdc.The multilevel FC topology and its opera-tion under fault ac conditions were discussed in [96]and [97].The control of the FC VSC-based HVdc system by selective har-monic elimination (SHE)PWM,hybrid SHE-PWM,and SPWM strategies was presented in [95]and [102].Advances of SHE-PWM techniques that result in a reduced switching frequency were discussed in [103]and [104].Space vector modulation (SVM)methods are also investigated to minimize the switching losses [91],[101].Recently,VSC transmission topologies based on the multilevel current/voltage reinjection concept have been reported in [79],[80],and [98]–[100].The conﬁguration in [85]generates multilevel voltage waveforms with about 5%of total harmonic distortion under the fundamental switching frequency for the main bridges and six times the fundamental switching

frequency for the reinjection bridge without the assistance of ﬁlters or PWM.Another multilevel conﬁguration that is suited for high-voltage ratings is proposed in [79]and [80].

V .M ODELING AND C ONTROL

The large number of technical papers associated with VSC-HVdc systems,in the area of modeling and control,is not limited to [105]–[111].A dc bus voltage control system using equivalent continuous-time state-space average modeling was presented in [105].It is shown in [106]that including a back-to-back VSC-HVdc system at the midpoint of a transmission line can increase the transmissibility of the line by a factor of 1.68.It is shown in [107]that the VSC-HVdc system can be operated as a static synchronous series compensator (SSSC).Recently,a control system for the VSC-HVdc during island operation and under three-phase balanced faults was investigated in [108],and it has been found that the current limit of the converters has a signiﬁcant inﬂuence on the dynamic response of the system.Finally,a dynamic model for a back-to-back HVdc system based on the three-level NPC topology was presented in [109].

VI.HVDC CB S

The availability of dc CBs is limited.DC CBs are commonly used in traction applications [62]–[67]but the voltage and cur-rent ratings of these devices are considerably lower than what would be required in HVdc and multiterminal applications.The use of the dc CBs is feasible if a number of breakers are con-nected in series.Series connection of the dc breakers implies that all breakers should commutate simultaneously.Any time delays or breaker mismatching will result in breaker failure.A plethora of publications exists in the literature concern-ing mechanical,solid-state,and hybrid ac CBs.On the other hand,only a few scientiﬁc publications are available studying the feasibility of different solutions concerning dc CBs.The different dc CBs topologies can be divided into three categories as follows.

1)A conﬁguration employing a conventional ac CB and:

a)a charged capacitor in parallel with the breaker;b)a resonance circuit is connected in parallel with the breaker.

2)A solid-state CB that can consist of:

a)a controllable device such as IGBT,integrated gate commutated thyristor (IGCT),GTO,with an an-tiparallel diode;

b)a bidirectional switch that consists of controllable devices and diodes.

3)A hybrid dc CB where a solid-state breaker,uni-or bidi-rectional conﬁguration,is connected in parallel with a conventional ac CB.

During a dc fault,the antiparallel diodes of the three legs of the converter conduct as a rectiﬁer to feed the fault.The fault can be cleared either by ac CBs without protecting the VSC or by breakers at the dc side.Two IGBT CBs (IGBT-CBs)are required for each converter of a two-terminal VSC-based HVdc system.For a multiterminal system,the IGBT-CBs can

Fig.19.Five-terminal VSC-HVDC system[112].

be placed between each VSC and the dc network or at each end of a dc branch line[68].

When IGBT-CBs are placed between each VSC and the dc network,mechanical switches are placed at each end of a dc branch line.During dc fault,the VSCs are isolated from the dc network by blocking of IGBT-CBs and give sufﬁcient time for the arc to deionize.For a temporary fault,the system can be restored by unblocking of IGBT-CBs.If there is a permanent fault,the mechanical switches can be opened to isolate the fault, and then unblock the breakers to resume operation[68].

An alternative method that may imply higher cost is to place the IGBT-CBs at each end of a dc branch line.Therefore,the dc fault can be isolated from the VSCs directly,without the need of extinguishing of the fault current.

VII.E MERGING A PPLICATIONS

VSC-HVdc can be effectively used in a number of key areas as follows[45]–[55]:

1)small,isolated remote loads;

2)power supply to islands;

3)infeed to city centers;

4)remote small-scale generation;

5)offshore generation and deep-sea crossings;

6)multiterminal systems.

As a way of example,aﬁve-terminal VSC-HVdc[112]and a multiterminal conﬁguration[113]are shown in Figs.19and20, respectively.

From the technology point of view,wind farms and offshore wind farms in particular are well suited for VSC-HVdc applica-tion[114],[115].The discussion continues as to whether the dc is more cost-effective to the ac counterpart as a means to connect wind farms with the main grid[116].Evaluation of grid connect-ing offshore wind farms through a dc link and their technical and economic analyses are recently presented in[117].The oppor-tunity to use dc systems based on permanent-magnet generators and medium-frequency transformers,as opposed to50/60Hz generators and transformers,has been presented offering more compact and light solution for offshore wind farms[128]. Multiterminal dc systems have been studied for wind farms and work is reported in[112],[118],and[119].

Fig.21presents a scenario of three wind generators connected through dc into a multiterminal grid through a VSC

connection,Fig.20.Single-line multiterminal VSC-HVDC system

[113].

Fig.21.Four-terminal PWM VSC-based HVDC system for wind tur-bines/wind parks

[118].

Fig.22.Single-line diagram of wind farm integration using VSC transmission based on the three-level NPC converter[120].

and a single VSC-HVdc transmits the power and/or connects the entire farm with the grid.

The use of doubly fed induction generators(DFIGs)for wind farm development and the relation to an HVdc interconnection and coordinated control is one of the most current research de-velopments in theﬁeld[120]–[127].Fig.22shows the diagram of a DFIG-based wind farm integration using the VSC-HVdc transmission system[120].

The proliferation of power electronics technologies over past two decades has forced theﬁeld to reevaluate the potential of renewable energy and dc distribution grids.Recent develop-ments include a low-voltage dc industrial power distribution system without a central control unit[129],a study of the impact of power quality and distributed generation based on the low-voltage dc distribution system[130],and analysis of

power systems for dc distribution[131].Analysis of the ef-ﬁciency of low-and medium-voltage dc distribution systems conﬁrms the beneﬁts of considering dc[132].Theoretical stud-ies of feasibility that included new storage technologies based on superconductivity[133]and commercial facilities based on dc were also conceptually considered[134].

VIII.VSC-HVDC I NSTALLATIONS

In this section,the various projects worldwide where VSC-based HVdc systems have been successfully exploited are dis-cussed.The projects are summarized in Table II.They involve back-to-back systems(Eagle Pass,USA),wind energy applica-tions(Gotland,Sweden,and NORD E.ON1,Germany),two controlled asynchronous connections for trading of electricity (MurrayLink and DirectLink,Australia),power enhancement (CrossSound link,USA,and Caprivi link,Namibia),and the powering of offshore platforms(Troll A and Valhall,Norway). It should be noted that the dc voltage has reached350kV and the largest system is at400MW,making the VSC-HVdc a well-established technology in the medium power levels.Irrespective of how challenging the applications are,the VSC-HVdc tech-nology remains competitive and assists utilities worldwide in order to deliver efﬁcient,reliable,economic,and(where possi-ble)renewable energy to customers.

IX.C ONCLUSION

In this paper,recent advances of the VSC-based HVdc tech-nology are presented.The development of high-voltage high-power semiconductors have successfully assisted utilities to ex-ploit the beneﬁts of the four-quadrant static converter interlink-ing two ac systems through HVdc with a number of key ben-eﬁts,namely independent control of active and reactive power through the PWM control of the converter,fast dynamic re-sponse,and possibility to connect ac island with no synchronous generation in the grid.It is conﬁrmed that developments associ-ated with VSC-based HVdc technology have delivered systems at voltage levels up to350kV and power levels up to400MW. VSC-HVdc undoubtedly will continue to provide solutions in many areas of the power systems where installations necessitate proven solutions.

R EFERENCES

[1]L.Gyugyi,“Reactive power generation and control by thyristor circuits,”

IEEE Trans.Ind.Appl.,vol.IA-15,no.5,pp.521–532,Sep./Oct.1979.

[2]L.Gyugyi,“Control of shunt compensation with reference to new design

concepts,”Proc.Inst.Electr.Eng.,Part C:Gener.,Transmiss.Distrib., vol.128,no.6,pp.374–381,1981.

[3]L.Gyugyi,“Power electronics in electric utilities:Static V AR compen-

sators,”Proc.IEEE,vol.76,no.4,pp.483–494,Apr.1988.

[4]N.G.Hingorani,“Power electronics in electric utilities:Role of power

electronics in future power systems,”Proc.IEEE,vol.76,no.4,pp.481–482,Apr.1988.

[5]K.R.Padiyar,HVDC Power Transmission Systems:Technology and

System Interactions.New York/Chichester,U.K.:Wiley,1990. [6]N.G.Hingorani,“FACTS-ﬂexible AC transmission system,”in Proc.

Inst.Electr.Eng.Conf.Publ.,1991,pp.1–7.

[7]L.Gyugyi,“Uniﬁed power-ﬂow control concept forﬂexible AC trans-

mission systems,”Proc.Inst.Electr.Eng.Part C:Gener.,Transmiss.

Distrib.,vol.139,no.4,pp.323–331,1992.

[8]N.G.Hingorani,“Flexible AC transmission,”IEEE Spectr.,vol.30,

no.4,pp.40–45,Apr.1993.

[9]L.Gyugyi,“Dynamic compensation of AC transmission lines by solid-

state synchronous voltage sources,”IEEE Trans.Power Del.,vol.9, no.2,pp.904–911,Apr.1994.

[10]N.G.Hingorani,“FACTS technology and opportunities,”in Proc.Inst.

Electr.Eng.Colloq.Flexible AC Transmiss.Syst.(FACTS)—Key In-creased Utilisation Power Syst.,1994,pp.4/1–4/10,(Dig.No.1994/005).

[11]N.G.Hingorani,“Future role of power electronics in power systems,”in

Proc.1995Int.Symp.Power Semicond.Devices ICs,Yokohama,Japan, 1995,pp.13–15.

[12]N.G.Hingorani,“High-voltage DC transmission:A power electronics

workhorse,”IEEE Spectr.,vol.33,no.4,pp.63–72,Apr.1996. [13]J.Arrillaga,High Voltage Direct Current Transmission.London,U.K.:

Inst.Electr.Eng.,1998.

[14] E.I.Carroll,“Power electronics for very high power applications,”

in Proc.7th Int.Conf.Power Electron.Variable Speed Drives,1998, pp.218–223,(Inst.Electr.Eng.Conf.Publ.No.456).

[15]R.Grunbaum,M.Noroozian,and B.Thorvaldsson,“FACTS—Powerful

systems forﬂexible power transmission,”ABB Rev.,vol.5,pp.4–17, 1999.

[16]Y.H.Song and A.Johns,Flexible AC Transmission Systems(FACTS).

London,U.K.:Inst.Electr.Eng.,1999.

[17]N.G.Hingorani and L.Gyugyi,Understanding FACTS:Concepts and

Technology of Flexible AC Transmission Systems.New York:IEEE Press,2000.

[18] D.Povh,“Use of HVDC and FACTS,”Proc.IEEE,vol.88,no.2,

pp.235–245,Feb.2000.

[19]H.Akagi,“Large static converters for industry and utility applications,”

Proc.IEEE,vol.,no.6,pp.976–983,Jun.2001.

[20]N.G.Hingorani,“Future directions for power electronics,”in Proc.

IEEE/PES Transmiss.Distrib.Conf.Expo.,2001,pp.1180–1181. [21] E.Acha,V.G.Agelidis,O.Anaya-Lara,and T.J.E.Miller,Power

Electronic Control in Electrical Systems,1st ed.Oxford,U.K.:Newnes, 2002.

[22] A.A.Edris,S.Zelingher,L.Gyugyi,and L.J.Kovalsky,“Squeezing

more power from the grid,”IEEE Power Eng.Rev.,vol.22,no.6,pp.4–6, Jun.2002.

[23]R.M.Mathur and R.K.Varma,Thyristor-Based Facts Controllers for

Electrical Transmission Systems.Piscataway,NJ/New York:IEEE Press/Wiley,2002.

[24]V.K.Sood,HVDC and FACTS Controllers:Applications of Static Con-

verters in Power Systems.Boston,MA:Kluwer,2004.

[25]T.Ackermann,Wind Power in Power Systems.Chichester,U.K.:Wi-

ley,2005.

[26]V.G.Agelidis,G.D.Demetriades,and N.Flourentzou,“Recent advances

in high-voltage direct-current power transmission systems,”in Proc.

IEEE Int.Conf.Ind.Technol.(ICIT2006),pp.206–213.

[27]M.P.Bahrman and B.K.Johnson,“The ABCs of HVDC transmission

technologies,”IEEE Power Energy Mag.,vol.5,no.2,pp.32–44, Mar./Apr.2007.

[28]R.K.Varma,W.Litzenberger,S.Auddy,and D.Patel,“Bibliography of

HVDC transmission:2001–2003part I IEEE working group report,”in Proc.IEEE Power Eng.Soc.Gen.Meeting,2007,pp.1–8.

[29]R.K.Varma,W.Litzenberger,and J.Berge,“Bibliography of FACTS:

2001—Part II IEEE working group report,”in Proc.IEEE Power Eng.

Soc.Gen.Meeting,2007,pp.1–6.

[30]J.Arrillaga,Y.H.Liu,and N.R.Watson,Flexible Power Transmission:

The HVDC Options.Chichester,U.K.:Wiley,2007.

[31]P.K.Steimer,H.E.Gruening,J.Werninger,E.Carroll,S.Klaka,and

S.Linder,“IGCT—A new emerging technology for high power,low cost inverters,”IEEE Ind.Appl.Mag.,vol.5,no.4,pp.12–18,Jul./Aug.

1999.

[32]P.Steimer,O.Apeldoorn,E.Carroll,and A.Nagel,“IGCT technology

baseline and future opportunities,”in Proc.IEEE Transmiss.Distrib.

Conf.Expo.,2001,pp.1182–1187.

[33] E.Carroll and J.Siefken,“IGCTs:Moving on the right track,”in Proc.

Power Electron.Technol.,2002,vol.V.26,pp.16–18.

[34]S.Gunturi,J.Assal,D.Schneider,and S.Eicher,“Innovative metal sys-

tem for IGBT press pack modules,”in Proc.IEEE Int.Symp.Power Semicond.Devices ICs(ISPSD),Cambridge,U.K.,2003,pp.110–113.

[35] A.Kopta,M.Rahimo,U.Schlabach,D.Schneider,E.Carroll,and S.Lin-

der,“A6.5kV IGBT module with very high safe operating area,”in Proc.

40th IAS Annu.Meeting Ind.Appl.Conf.,2005,pp.794–798.[36]S.Gunturi and D.Schneider,“On the operation of a press pack IGBT

module under short circuit conditions,”IEEE Trans.Adv.Packag., vol.29,no.3,pp.433–440,Aug.2006.

[37]J.Casazza and G.C.Loehr,The Evolution of Electric Power Transmis-

sion Under Deregulation:Selected Readings.Piscataway,NJ:IEEE Press,2000.

[38]T.J.Hammons,M.Willingham,K.N.Mak,M.D.Silva,M.Moro-

zowski,and B.K.Blyden,“Generation and transmission improvements in developing countries,”IEEE Trans.Energy Convers.,vol.14,no.3, pp.760–765,Sep.1999.

[39]T.J.Hammons,D.Woodford,J.Loughtan,M.Chamia,J.Donahoe,

D.Povh,B.Bisewski,and W.Long,“Role of HVDC transmission in

future energy development,”IEEE Power Eng.Rev.,vol.20,no.2, pp.10–25,Feb.2000.

[40] A.M.H.A.Karim,N.H.A.Maskati,and S.Sud,“Status of Gulf

co-operation council(GCC)electricity grid system interconnection,”in Proc.IEEE Power Eng.Soc.Gen.Meeting,2004,pp.1385–1388. [41]L.Weimers,“AC or DC:Which way should China go?”Modern Power

Syst.,vol.25,no.8,pp.11–17,2005.

[42] C.Ashmore,“Transmit the light fantastic[HVDC power transmission],”

IET Power Eng.,vol.20,no.2,pp.24–7,2006.

[43]L.Willis and N.Stig,“HVDC transmission:Yesterday and today,”IEEE

Power Energy Mag.,vol.5,no.2,pp.22–31,Mar./Apr.2007.

[44]G.Asplund,“Ultra high voltage transmission,”ABB Rev.,vol.2,pp.22–

27,2007.

[45]G.Asplund,K.Eriksson,and K.Svensson,“DC transmission based on

voltage source converters,”in Proc.CIGRE SC14Colloq.South Africa, 1997,pp.1–7.

[46]G.Asplund,K.Eriksson,and K.Svensson,“HVDC light—DC transmis-

sion based on voltage-sourced converters,”ABB Rev.,vol.1,pp.4–9, 1998.

[47]G.Asplund,K.Eriksson,and O.Tollerz,“HVDC light:A tool for electric

power transmission to distant load,”in Proc.VI Sepope Conf.,Salvador, Brazil,1998,pp.1–7.

[48] B.Andersen and C.Barker,“A new era in HVDC?”Inst.Electr.Eng.

Rev.,vol.46,no.2,pp.33–39,2000.

[49]G.Asplund,“Application of HVDC Light to power system enhance-

ment,”in Proc.IEEE Power Eng.Soc.Winter Meeting,2000,pp.2498–2503.

[50]U.Axelsson, A.Holm, C.Liljegren,M.Aberg,K.Eriksson,and

O.Tollerz,“The Gotland HVDC Light Project—Experiences from trial and commercial operation,”in CIRED Conf.,Amsterdam,The Nether-lands,2001,pp.1–5.

[51]K.Eriksson,“Operational experience of HVDC LIGHT,”in Proc.AC

DC Conf.Transmiss.,London,U.K.,2001,pp.205–210.

[52] A.Petersson and A.Edris,“Dynamic performance of the Eagle Pass

back-to-back HVDC Light tie,”in Proc.7th Int.Conf.AC-DC Power Transmiss.,London,U.K.,2001,pp.220–225,(Conf.Publ.No.485).

[53]T.F.Nestli,L.Stendius,M.J.Johansson,A.Abrahamsson,and P.

C.Kjaer,“Powering Troll with new technology,”ABB Rev.,vol.2,

pp.15–19,2003.

[54]S.G.Johansson,L.Carlsson,and G.Russberg,“Explore the power

of HVDC LIGHT—A Web based system interaction tutorial,”in Proc.

IEEE PES Power Syst.Conf.Expo.,New York,2004,pp.839–842. [55]L.Stendius and P.Jones,“The challenges of offshore power system

construction-bringing power successfully to Troll A,one of the worlds largest oil and gas platform,”in Proc.8th Inst.Electr.Eng.Int.Conf.AC DC Power Transmiss.(ACDC2006),pp.75–78.

[56] A.Persson and L.Carlsson,“New technologies in HVDC converter

design,”in Proc.AC DC Power Transmiss.,London,U.K.,1996,pp.387–392,(Inst.Electr.Eng.Conf.Publ.).

[57]L.Carlsson,“‘Classical’HVDC:Still continuing to evolve,”Modern

Power Syst.,vol.22,no.6,pp.19–21,2002.

[58]J.Varley,“HVDC:Fifty years on,”Modern Power Syst.,vol.24,no.10,

pp.18–20,2004.

[59] B.Dellby,G.Bergman,J.Karlstrand,and J.Kaumanns,“High-voltage

cable technology,”ABB Rev.,vol.4,pp.35–44,2000.

[60] A.Ericsson,M.Jeroense,J.Miller,L.Palmgvist,B.Railing,and P.Rif-

fon,“HVDC light cable systems—The latest projects,”in Proc.Nordic Insul.Symp.,2003,pp.107–116.

[61] B.Drugge,H.Fuhrmann,S.Laihonen,and J.Mood,“DryQ—Dry and

silent,”ABB Rev.,vol.1,pp.17–21,2005.

[62] A.M.S.Atmadji and J.G.J.Sloot,“Hybrid switching:A review of

current literature,”in Proc.IEEE Conf.Energy Manage.Power Del.

(EMPD),Singapore,1998,pp.683–688.[63]G.B.D.Lange and A.M.Chol,“Novel application of PWM switching

for DC traction circuit breakers,”in Proc.IEEE Int.Conf.Power Syst.

Technol.(PowerCon),2006,pp.1–6.

[]T.Genji,O.Nakamura,M.Isozaki,M.Yamada,T.Morita,and

M.Kaneda,“400V class high-speed current limiting circuit breaker for electric power system,”IEEE Trans.Power Del.,vol.9,no.3, pp.1428–1435,Jul.1994.

[65] C.Meyer and R.W.D.Doncker,“LCC analysis of different resonant

circuits and solid-state circuit breakers for medium-voltage grids,”IEEE Trans.Power Del.,vol.21,no.3,pp.1414–1420,Jul.2006.

[66] C.Meyer and R.W.D.Doncker,“Solid-state circuit breaker based on

active thyristor topologies,”IEEE Trans.Power Electron.,vol.21,no.2, pp.450–458,Mar.2006.

[67] C.Meyer,S.Schroder,and R.W.D.Doncker,“Solid-state circuit break-

ers and current limiters for medium-voltage systems having distributed power systems,”IEEE Trans.Power Electron.,vol.19,no.5,pp.1333–1340,Sep.2004.

[68]L.Tang and B.T.Ooi,“Protection of VSC-multi-terminal HVDC against

DC faults,”in Proc.IEEE Annu.Power Electron.Spec.Conf.(PESC), 2002,pp.719–724.

[69]W.Lu and B.T.Ooi,“DC overvoltage control during loss of con-

verter in multiterminal voltage-source converter-based HVDC(M-VSC-HVDC),”IEEE Trans.Power Del.,vol.18,no.3,pp.915–920,Jul.

2003.

[70] A.Nabae,I.Takahashi,and H.Akagi,“A new neutral-point-clamp PWM

inverter,”IEEE Trans.Ind.Appl.,vol.IA-17,no.5,pp.518–523,Sep.

1981.

[71]P.M.Bhagwat and V.R.Stefanovic,“Generalized structure of a multi-

level PWM inverter,”IEEE Trans.Ind.Appl.,vol.IA-19,no.6,pp.1057–1069,Nov.1983.

[72]T.A.Meynard and H.Foch,“Multi-level conversion:High voltage chop-

pers and voltage-source inverters,”in Proc.IEEE Power Electron.Spec.

Conf.,1992,pp.397–403.

[73]V.G.Agelidis,“A low-distortion multilevel pulse-width modulated in-

verter topology,”in Proc.IEEE Int.Symp.Ind.Electron.(ISIE),1995, pp.243–247.

[74]J.S.Lai and F.Z.Peng,“Multilevel converters—A new breed of power

converters,”IEEE Trans.Ind.Appl.,vol.32,no.3,pp.509–517, May/Jun.1996.

[75] F.Z.Peng,J.S.Lai,J.W.McKeever,and J.VanCoevering,“A mul-

tilevel voltage-source inverter with separate DC sources for static Var generation,”IEEE Trans.Ind.Appl.,vol.32,no.5,pp.1130–1138, Sep./Oct.1996.

[76]V.G.Agelidis and H.C.Goh,“Low-distortion variable-level PWM

technique,”Proc.Inst.Electr.Eng.Electr.Power Appl.,vol.145,no.2, pp.73–78,1998.

[77] F.Z.Peng,J.W.McKeever,and D.J.Adams,“Power line conditioner

using cascade multilevel inverters for distribution systems,”IEEE Trans.

Ind.Appl.,vol.34,no.6,pp.1293–1298,Nov./Dec.1998.

[78] B.Bijlenga,“HVDC device for converting between alternating voltages

and direct current voltages,”U.S.Patent80403,2002.

[79]Y.H.Liu,J.Arrillaga,and N.R.Watson,“Cascaded H-bridge voltage

reinjection—Part I:A new concept in multilevel voltage-source conver-sion,”IEEE Trans.Power Del.,vol.23,no.2,pp.1175–1182,Apr.

2008.

[80]Y.H.Liu,J.Arrillaga,and N.R.Watson,“Cascaded H-bridge voltage

reinjection—Part II:Application to HVDC transmission,”IEEE Trans.

Power Del.,vol.23,no.2,pp.1200–1206,Apr.2008.

[81] A.Lesnicar and R.Marquardt,“An innovative modular multilevel con-

verter topology suitable for a wide power range,”in Proc.IEEE Pow-erTech Conf.,Bologna,Italy,2003,pp.1–6.

[82]J.Dorn,H.Huang,and D.Retzmann,“Novel voltage-sourced converters

for HVDC and FACTS applications,”in Proc.CIGRE Meeting2007, Osaka,Japan,pp.314–321.

[83]S.Allebrod,R.Hamerski,and R.Marquardt,“New transformerless,scal-

able modular multilevel converters for HVDC-transmission,”in Proc.

IEEE Power Electron.Spec.Conf.,Rhodes,Greece,2008,pp.174–179.

[84] B.R.Andersen,L.Xu,P.J.Horton,and P.Cartwright,“Topologies for

VSC transmission,”Power Eng.J.,vol.16,no.3,pp.142–50,2002. [85]Y.H.Liu,J.Arrillaga,and N.R.Watson,“A new high-pulse voltage-

sourced converter for HVDC transmission,”IEEE Trans.Power Del., vol.18,no.4,pp.1388–1393,Oct.2003.

[86]L.B.Perera,N.R.Watson,Y.H.Liu,and J.Arrillaga,“Multilevel current

reinjection self-commutated HVDC converter,”Proc.Inst.Electr.Eng.

Gener.,Transmiss.Distrib.,vol.152,no.5,pp.607–15,2005.[87] B.T.Ooi and X.Wang,“Boost-type PWM HVDC transmission system,”

IEEE Trans.Power Del.,vol.6,no.4,pp.1557–1563,Oct.1991. [88]Z.Zhang,J.Kuang,X.Wang,and B.T.Ooi,“Force commutated HVDC

and SVC based on phase-shifted multi-converter modules,”IEEE Trans.

Power Del.,vol.8,no.2,pp.712–718,Apr.1993.

[]J.Kuang and B.T.Ooi,“Series connected voltage-source converter

modules for force-commutated SVC and DC-transmission,”IEEE Trans.

Power Del.,vol.9,no.2,pp.977–983,Apr.1994.

[90] A.Lindberg and T.Larsson,“PWM and control of three level voltage

source converters in an HVDC back-to-back station,”in Proc.AC DC Power Transmiss.,London,U.K.,1996,pp.297–302,(Inst.Electr.Eng.

Conf.Publ.).

[91]T.Nakajima,H.Suzuki,K.Sakamoto,M.Shigeta,H.Yamamoto,

Y.Miyazaki,S.Tanaka,and S.Saito,“Multiple space vector control for self-commutated power converters,”IEEE Trans.Power Del.,vol.13, no.4,pp.1418–1424,Oct.1998.

[92]V.G.Agelidis and L.Xu,“A novel HVDC system based onﬂying

capacitor multilevel PWM converters,”in Proc.CIGRE/IEEE PES Int.

Symp.Quality Security Electr.Power Del.Syst.(CIGRE2001),Wuhan, China,Sep.2001.

[93]L.Xu,V.G.Agelidis,and E.Acha,“Steady-state operation of HVDC

power transmission systems with voltage-source converters and simul-taneous Var compensation,”presented at the Eur.Power Electron.Conf.

(EPE2001),Graz,Austria.

[94] B.R.Andersen and L.Xu,“Hybrid HVDC system for power transmission

to island networks,”IEEE Trans.Power Del.,vol.19,no.4,pp.1884–10,Oct.2004.

[95]L.Xu and V.G.Agelidis,“A VSC transmission system usingﬂying

capacitor multilevel converters and selective harmonic elimination PWM control,”in Proc.7th Int.Power Eng.Conf.(IPEC2005),pp.1176–1181.

[96]L.Xu,B.R.Andersen,and P.Cartwright,“Multilevel-converter-based

VSC transmission operating under fault AC conditions,”Proc.Inst.

Electr.Eng.Gener.,Transmiss.Distrib.,vol.152,no.2,pp.185–93, 2005.

[97]L.Xu,B.R.Andersen,and P.Cartwright,“VSC transmission operating

under unbalanced AC conditions—Analysis and control design,”IEEE Trans.Power Del.,vol.20,no.1,pp.427–434,Jan.2005.

[98]J.H.Liu,J.Arrillaga,N.R.Watson,and A.R.Wood,“Multi-level volt-

age reinjection VSC HVDC transmission,”in Proc.8th Inst.Electr.

Eng.Int.Conf.AC DC Power Transmiss.(ACDC2006),pp.130–134.

[99]Y.H.Liu,L.B.Perera,A.Arrillaga,and N.R.Watson,“Application of

the multi-level current reinjection concept to HVDC transmission,”IET Gener.,Transmiss.Distrib.,vol.1,no.3,pp.399–404,2007.

[100]Y.H.Liu,L.B.Perera,J.Arrillaga,and N.R.Watson,“A back to back HVDC link with multilevel current reinjection converters,”IEEE Trans.

Power Del.,vol.22,no.3,pp.1904–1909,Jul.2007.

[101]M.Saeedifard,H.Nikkhajoei,R.Iravani,and A.Bakhshai,“A space vector modulation approach for a multimodule HVDC converter system,”

IEEE Trans.Power Del.,vol.22,no.3,pp.13–1654,Jul.2007. [102]L.Xu and V.G.Agelidis,“VSC transmission system usingﬂying capac-itor multilevel converters and hybrid PWM control,”IEEE Trans.Power Del.,vol.22,no.1,pp.693–702,Jan.2007.

[103]V.G.Agelidis,A.I.Balouktsis,and M.S.A.Dahidah,“Aﬁve-level symmetrically deﬁned selective harmonic elimination PWM strategy: Analysis and experimental validation,”IEEE Trans.Power Electron., vol.23,no.1,pp.19–26,Jan.2008.

[104]V.G.Agelidis,A.I.Balouktsis,and C.Cossar,“On attaining the multiple solutions of selective harmonic elimination PWM three-level waveforms through function minimisation,”IEEE Trans.Ind.Electron.,vol.55, no.3,pp.996–1004,Mar.2008.

[105]J.L.Thomas,S.Poullain,and A.Benchaib,“Analysis of a robust DC-bus voltage control system for a VSC transmission scheme,”in Proc.7th Int.Conf.AC-DC Power Transmiss.,London,U.K.,2001,pp.119–124, (Conf.Publ.No.485).

[106]Z.Huang,B.T.Ooi,L.A.Dessaint,and F.D.Galiana,“Exploiting volt-age support of voltage-source HVDC,”Proc.Inst.Electr.Eng.Gener., Transmiss.Distrib.,vol.150,no.2,pp.252–6,2003.

[107] F.A.R.Al Jowder and B.T.Ooi,“VSC-HVDC station with SSSC characteristics,”IEEE Trans.Power Electron.,vol.19,no.4,pp.1053–1059,Jul.2004.

[108] C.Du and M.H.J.Bollen,“Power-frequency control for VSC-HVDC during island operation,”in Proc.8th Inst.Electr.Eng.Int.Conf.AC DC Power Transmiss.(ACDC2006),pp.177–181.[109] A.Yazdani and R.Iravani,“Dynamic model and control of the NPC-based back-to-back HVDC system,”IEEE Trans.Power Del.,vol.21, no.1,pp.414–424,Jan.2006.

[110]Y.H.Liu,J.Arrillaga,and N.R.Watson,“Addition of four-quadrant power controllability to multi-level VSC HVDC transmission,”IET Gener.,Transmiss.Distrib.,vol.1,no.6,pp.872–878,2007.

[111]P.Hao,W.Zanji,and C.Jianye,“Study on the control of shunt active DCﬁlter for HVDC systems,”IEEE Trans.Power Del.,vol.23,no.1, pp.396–401,Jan.2008.

[112]W.Lu and B.T.Ooi,“Premium quality power park based on multi-terminal HVDC,”IEEE Trans.Power Del.,vol.20,no.2,pp.978–983, Apr.2005.

[113]H.Jiang and A.Ekstrom,“Multiterminal HVDC systems in urban areas of large cities,”IEEE Trans.Power Del.,vol.13,no.4,pp.1278–1284, Oct.1998.

[114]V.G.Agelidis and C.Mademlis,“Technology of offshore wind turbines and farms and novel multilevel converter-based HVDC systems for their grid connections,”Wind Eng.,vol.26,no.6,pp.383–395,2002. [115]N.M.Kirby,L.Xu,M.Luckett,and W.Siepmann,“HVDC transmission for large offshore wind farms,”Power Eng.J.,vol.16,no.3,pp.135–141, 2002.

[116] A.B.Morton,S.Cowdroy,J.R.A.Hill,M.Halliday,and G.D.Nichol-son,“AC or DC?Economics of grid connection design for offshore wind farms,”in Proc.8th Inst.Electr.Eng.Int.Conf.AC DC Power Transmiss.

(ACDC2006),London,U.K.,pp.236–240.

[117]P.Bresesti,W.L.Kling,R.L.Hendriks,and R.Vailati,“HVDC connec-tion of offshore wind farms to the transmission system,”IEEE Trans.

Energy Convers.,vol.22,no.1,pp.37–43,Mar.2007.

[118]W.Lu and B.T.Ooi,“Multiterminal LVDC system for optimal acqui-sition of power in wind-farm using induction generators,”IEEE Trans.

Power Electron.,vol.17,no.4,pp.558–563,Jul.2002.

[119]W.Lu and B.T.Ooi,“Optimal acquisition and aggregation of offshore wind power by multiterminal voltage-source HVDC,”IEEE Trans.

Power Del.,vol.18,no.1,pp.201–206,Jan.2003.

[120]L.Xu,L.Yao,and C.Sasse,“Grid integration of large DFIG-based wind farms using VSC transmission,”IEEE Trans.Power Syst.,vol.22,no.3, pp.976–984,Aug.2007.

[121]L.Ran,D.Xiang,L.Hu,and K.Abbott,“V oltage stability of an HVDC system for a large offshore wind farm with DFIGs,”in Proc.

8th Inst.Electr.Eng.Int.Conf.AC DC Power Transmiss.,2006,pp.150–154.

[122] D.Xiang,L.Ran,J.R.Bumby,P.J.Tavner,and S.Yang,“Coordinated control of an HVDC link and doubly fed induction generators in a large offshore wind farm,”IEEE Trans.Power Del.,vol.21,no.1,pp.463–471,Jan.2006.

[123]L.Xu and P.Cartwright,“Direct active and reactive power control of DFIG for wind energy generation,”IEEE Trans.Energy Convers., vol.21,no.3,pp.750–758,Sep.2006.

[124]S.Bozhko,R.V.Blasco-Gimenez,R.Li,J.Clare,and G.Asher,“Control of offshore DFIG-based wind farm grid with line-commutated HVDC connection,”IEEE Trans.Energy Convers.,vol.22,no.1,pp.71–78, Mar.2007.

[125]L.Xu and Y.Wang,“Dynamic modeling and control of DFIG-based wind turbines under unbalanced network conditions,”IEEE Trans.Power Syst.,vol.22,no.1,pp.314–323,Feb.2007.

[126] D.Zhi and L.Xu,“Direct power control of DFIG with constant switching frequency and improved transient performance,”IEEE Trans.Energy Convers.,vol.22,no.1,pp.110–118,Mar.2007.

[127]S.Bozhko,G.Asher,R.Li,J.Clare,and L.Yao,“Large offshore DFIG-based wind farm with line-commutated HVDC connection to the main grid:Engineering studies,”IEEE Trans.Energy Convers.,vol.23,no.1, pp.119–127,Mar.2008.

[128] A.Prasai,J.S.Yim,D.Divan,A.Bendre,and S.K.Sul,“A new architecture for offshore wind farms,”IEEE Trans.Power Electron., vol.23,no.3,pp.1198–1204,May2008.

[129]W.Tang and R.H.Lasseter,“LVDC industrial power distribution system without central control unit,”in Proc.IEEE Annu.Power Electron.Spec.

Conf.(PESC),2000,pp.979–984.

[130]M.Brenna,G.C.Lazaroiu,and E.Tironi,“High power quality and DG integrated low voltage DC distribution system,”in Proc.IEEE Power Eng.Soc.Gen.Meeting(PES),Montreal,QC,Canada,2006,pp.1–6.

[131]K.Fleischer and R.S.Munnings,“Power systems analysis for direct current(DC)distribution systems,”IEEE Trans.Ind.Appl.,vol.32, no.5,pp.982–9,Sep./Oct.1996.[132] D.Nilsson and A.Sannino,“Efﬁciency analysis of low-and medium-voltage dc distribution systems,”in Proc.IEEE Power Eng.Soc.Gen.

Meeting,Denver,CO,2004,pp.2315–2321.

[133]M.Furuse,S.Fuchino,N.Higuchi,and I.Ishii,“Feasibility study of low-voltage DC superconducting distribution system,”IEEE Trans.Appl.

Supercond.,vol.15,no.2,pp.1759–1762,Jun.2005.

[134] A.Sannino,G.Postiglione,and M.H.J.Bollen,“Feasibility of a DC network for commercial facilities,”IEEE Trans.Ind.Appl.,vol.39,

no.5,pp.1499–1507,Sep./Oct.

2003.

Nikolas Flourentzou(S’07)received the B.Eng.de-gree(with honors)in electronics and communica-tions engineering from the University of Birming-ham,Birmingham,U.K.,in2002,and the joint M.Sc. degree in power electronics and drives from the Uni-versity of Birmingham and the University of Not-tingham,Nottingham,U.K.,in2003.He is currently working toward the Ph.D.degree in power systems at the University of Sydney,Sydney,N.S.W.,Australia.

His current research interests include power elec-

tronic converters for power system

applications.

Vassilios G.Agelidis(S’–M’91–SM’00)was born

in Serres,Greece.He received the B.S.degree in elec-

trical engineering from the Democritus University of

Thrace,Thrace,Greece,in1988,the M.S.degree

in applied science from Concordia University,Mon-

treal,QC,Canada,in1992,and the Ph.D.degree in

electrical engineering from the Curtin University of

Technology,Perth,W.A.,Australia,in1997.

From1993to1999,he was with the School of

Electrical and Computer Engineering,Curtin Uni-

versity of Technology.In2000,he joined the Center for Economic Renewable Power Delivery,University of Glasgow,Glasgow, U.K.,as a Research Manager.He has authored or coauthored several journal and conference papers as well as Power Electronic Control in Electrical Systems (Newnes,2002).From January2005to December2007,he was the Inaugural Chair in Power Engineering in the School of Electrical,Energy,and Process Engineering,Murdoch University,Perth.Since January2007,he has been the Energy Australia Chair of Power Engineering at the University of Sydney,Syd-ney,N.S.W.,Australia.

Dr.Agelidis received the Advanced Research Fellowship from the U.K.’s Engineering and Physical Sciences Research Council(EPSRC-UK)in2004. He was the Vice President Operations of the IEEE Power Electronics Society for2006–2007.He was an Associate Editor of the IEEE P OWER E LECTRONICS L ETTERS from2003to2005.He was the Power Electronics Society(PELS) Chapter Development Committee Chair from2003to2005.He is currently an AdCom member of the IEEE PELS for2007–2009.He has been the Technical Chair of the39th IEEE PESC’08,Rhodes,

Greece.

Georgios D.Demetriades(M’06)was born in Fama-

gusta,Cyprus,in August1967.He received the M.Sc.

degree in electrical engineering at the Democritus

University of Thrace,Thrace,Greece,the Techni-

cal Licentiate and Ph.D.degrees in power electron-

ics from the Royal Institute of Technology(KTH),

Stockholm,Sweden.

He was in Cyprus for two years period.In1995,

he joined ALSTOM Power Environmental Systems,

Sweden.In2000,he joined ABB Corporate Research,

V¨a ster˚a s,Sweden,where he is currently a Research and Development Engineer.His current research interests include power elec-tronics,high-frequency dc–dc power resonant converters,high-power convert-ers,and high-frequency electromagnetic modeling.下载本文

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