Bhatti Paper

download Bhatti Paper

of 23

Transcript of Bhatti Paper

  • 7/30/2019 Bhatti Paper

    1/23

    This article was downloaded by: [Indian Institute of Technology - Delhi]On: 30 November 2012, At: 03:18Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House37-41 Mortimer Street, London W1T 3JH, UK

    Electric Power Components and SystemsPubl icat i on detai ls, including inst ruct ions for authors and subscr ipt ion inform ation:h t t p : / / w w w . t an df o nl i ne . co m / l oi / u em p 20

    React ive Power Cont rol of Autonomous Wind-DieselHybr id Power Systems Using Simul inkR. C. Bansal

    a& T. S. Bhatti

    b

    aElect rical and Elect ronics Engineering Division, School of Engineering and Physics, The

    Universi t y of t he South Paci f ic, Suva, Fi j ib

    Centre for Energy Studies, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi,

    IndiaVersion of r ecord f irst p ubli shed: 19 Sep 2007.

    To cite this art icle: R. C. Bansal & T. S. Bhat t i (2007): React ive Power Cont rol of Autonom ous Wind-Diesel Hybri d PowerSyst ems Using Sim ulink , Elect ric Power Component s and Syst ems, 35:12, 1345-1366

    To link to t his art icle: ht t p : / / dx.do i .o rg/ 10.1080/ 15325000701426096

    PLEASE SCROLL DOWN FOR ARTICLE

    Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions

    This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form toanyone is expressly forbidden.

    The publisher does not give any warranty express or implied or make any representation that the contentswill be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses shouldbe independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims,proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly inconnection with or arising out of the use of this material.

    http://dx.doi.org/10.1080/15325000701426096http://www.tandfonline.com/page/terms-and-conditionshttp://dx.doi.org/10.1080/15325000701426096http://www.tandfonline.com/loi/uemp20
  • 7/30/2019 Bhatti Paper

    2/23

    Electric Power Componen ts an d S ystems, 35:13451366, 2007

    Copyright Taylor & Francis Group, LLC

    ISSN: 1532-5008 print/1532-5016 online

    DOI: 10.1080/15325000701426096

    Reactive Power Control of AutonomousWind-Diesel Hybrid Power Systems Using Simulink

    R. C. BANSAL

    Electrical and Electronics Engineering Division

    School of Engineering and Physics

    The University of the South Pacific

    Suva, Fiji

    T. S. BHATTI

    Centre for Energy Studies

    Indian Institute of Technology, Delhi

    Hauz Khas, New Delhi, India

    Abstract This article presents reactive power control of autonomous wind-dieselhybrid power system for realistic load disturbance using Simulink. The simulationblock diagram of wind-diesel, multi-wind-diesel, and wind-multi-diesel hybrid systembased on Simulink is developed. Reactive power control performance is comparedusing three different types of static VAR compensator (SVC) models. Reactive power

    performance is also compared for wind-diesel, multi-wind-diesel, and wind-multi-diesel hybrid power systems.

    Keywords autonomous wind-diesel hybrid power system, diesel generator set, in-

    duction generator, multi-wind-diesel, reactive power compensation, Simulink, staticvar compensator, wind-multi-diesel

    1. Introduction

    In recent years there has been continuous growth of power generation from non-conven-

    tional energy sources. The main advantages of non-conventional sources of power gener-

    ation are no fuel consumption in most cases, sustainable, and eco-friendly. The major dis-

    advantage with these energy sources is that they are generally intermittent or fluctuating in

    nature.

    The non-conventional sources such as wind and micro/mini hydro, etc. are generally

    integrated with diesel system to increase the reliability of the system to supply power to

    the isolated loads. Such systems are called isolated/autonomous hybrid power systems.

    In hybrid power systems, there may be more than one type of electrical generators [1,2]. In such circumstances it is normal, though not essential, for generator(s), usually on

    Received 28 September 2006; accepted 13 March 2007.Address correspondence to Prof. R. Bansal, Electrical and Electronics Engineering Divi-

    sion, School of Engineering and Physics, Laucala Campus, Private Mail Bag, Suva, Fiji. E-mail:[email protected]

    1345

  • 7/30/2019 Bhatti Paper

    3/23

    1346 R. Bansal and T. Bhatti

    Nomenclature

    A, B , C system, control, and disturbance matrix, respectively

    , thyristor firing angle and small deviation in thyristor firing angle,

    respectively

    power angle between terminal voltage and armature internal emf

    BSVC, BSVC reactive susceptance of the SVC and small change in its value,

    respectively

    EM, EM electromagnetic energy stored in induction generator (IG) and

    small deviation in energy stored, respectively

    Efd 1, Eq1, E0

    q1,

    Efd 2 , Eq2, E0

    q2

    small change in voltages of exciter, internal armature emf under

    steady state and transient conditions of synchronous generator

    (SG) 1 and 2 respectively

    KA, KE , KF, KR,

    K , KV

    amplifier, exciter, stabilizer, VAR regulator, thyristor firing, and

    hybrid power system gain constants, respectively

    KP, KI proportional and integral controller gain constants of the VAR

    regulator, respectively

    IG

    efficiency of the IG

    PI W, PIG , PS G real power input to the IG, real power generated by IG and SG,

    respectively

    PL, QL real and reactive power load demand, respectively

    QI G, QI G 1, QI G 2 reactive power required by IG, IG 1, and IG 2, respectively

    QS G, QS G 1, QS G 2 reactive power generated by SG, SG 1, and SG 2, respectively

    QSVC reactive power generated by SVC

    Qc rating of the SVC

    QR system reactive power rating

    r1, x1, r0

    2, x0

    2 stator resistance, stator reactance, rotor resistance and rotor re-

    actance referred to primary side of IG, respectively

    Req , Xeq , Xm equivalent resistance, equivalent reactance and magnetizing re-

    actance of the IG, respectively

    s slip of the IG

    Td SVC average dead time of zero crossing in a three phase systemT thyristor firing delay time

    T1, T2, T3, T4 time constants of the SVC regulator of lead-lag type

    TE , TF, TR, TV exciter, stabilizer, regulator, and hybrid power system time con-

    stants, respectively

    T0do

    direct axis open circuit transient time constant

    V system terminal voltage

    V, Vref small change in terminal and reference voltage, respectively

    Va1, Va2,

    Vf 1, Vf 2

    small change in the amplifier output of amplified 1 and 2, and

    exciter feedback voltages of exciter 1 and 2, respectively

    xd, x0

    ddirect axis reactance of SG under steady state and transient state

    conditions, respectively

    x, u, p state, control, and disturbance vector, respectively

    the diesel, to be synchronous, and wind turbine generator(s) to be asynchronous (induc-

    tion) [2]. An IG offers many advantages over a conventional SG, like reduced unit cost,

    ruggedness, brushless (in squirrel cage construction), absence of separate DC source, ease

    of maintenance, self-protection against severe overloads and short circuits, etc. [36]. A

    major disadvantage of an IG is that it requires reactive power support for its operation.

  • 7/30/2019 Bhatti Paper

    4/23

    Reactive Power Control of Hybrid Power Systems 1347

    In addition, most of the loads are also inductive in nature. The mismatch in generation

    and consumption of reactive power can cause a serious problem of large voltage fluctu-

    ations at generator terminals. A number of FACTS (flexible AC transmission systems)

    devices have been developed to provide the reactive power to the system. SVC is one of

    the FACTS device that has been used in conventional power systems, and can also beemployed in isolated power systems.

    In recent times, there has been large number of application of Matlab/Simulink

    developed by the Math Works Inc., for solving various power system problems [710].

    With the addition of several toolboxes and Simulink, Matlab provides an interactive

    environment with hundreds of reliable and accurate built in functions. Simulink is a

    window-based package built in the Matlab software and consists of a library of basic

    building blocks, which can be combined to form a dynamic model.

    This article presents reactive power control of autonomous wind-diesel hybrid power

    system for realistic (step plus stochastic) load disturbance using Simulink. In the con-

    sidered wind-diesel hybrid system (transfer function block diagram shown in Figure 1),

    SG along with an IEEE type-I excitation system is considered to be connected to diesel

    generator (DG) set and IG on wind system. The DG set acts as a local grid for the

    wind energy conversion system. The system has a SVC to provide the required reactive

    power in addition to the reactive power generated by the SG. Simulink block diagrams

    for autonomous wind-diesel, multi-wind-diesel (2 wind-1 diesel), and wind-multi-diesel

    (1 wind-2 diesel) hybrid power systems have been developed as shown in Figures 2, 3,

    and 4, respectively, to compare their reactive power requirement performance. Figures 3

    and 4 can be developed by incorporating the components of multiplicity of wind and

    diesel system, respectively.

    Simulation block diagrams of three different types of SVC models have been used to

    compare their performances. The basic difference in the transfer function block diagrams

    is the type of VAR regulator used. In SVC type-I [11, 12] the VAR regulator is an

    amplifier with a gain and time constant. The regulator in SVC type-II [13, 14] is a twin

    lead-lag type for providing compensation for the time delays in the firing circuit and due

    to phase sequence dead time delay of zero crossing. The VAR regulator is proportionalplus integral in SVC type-III [15, 16]. The Simulink block diagrams of IEEE type-I

    excitation system and SVC type-I, -II, and -III have been shown in Figure 5(a), 5(b),

    5(c), and 5(d), respectively. The advantage of simulation block diagram is that a block

    diagram containing many elements can be replaced by a single block having input and

    output terminals, e.g., SVC and excitation system in Figures 24 have been shown by

    single block.

    2. Mathematical Modeling of Wind-Diesel Hybrid System

    Detailed mathematical modeling of autonomous wind-diesel hybrid power system based

    on power equations has been presented in [1719]. System data considered are given

    in Appendix 1. Small changes in real power are mainly dependent upon the frequency,

    whereas small change in reactive power is mainly dependent on voltage [20]. The ex-citation time constant is much smaller than the prime mover time constant, its transient

    decay much faster, and does not affect the load frequency control (LFC) dynamic. Thus,

    cross coupling between LFC and AVR loop is negligible. The reactive power balance

    equation of the system under steady state condition is

    QS G C QSVC D QL C QI G (1)

  • 7/30/2019 Bhatti Paper

    5/23

    1348 R. Bansal and T. Bhatti

    Figure 1. Transfer-function block diagram for reactive power control of wind-diesel autonomoushybrid power system.

  • 7/30/2019 Bhatti Paper

    6/23

    Reactive Power Control of Hybrid Power Systems 1349

    Figure 2. Simulation block diagram of wind-diesel autonomous hybrid power system for step plus

    stochastic disturbance.

  • 7/30/2019 Bhatti Paper

    7/23

    1350 R. Bansal and T. Bhatti

    Figure 3. Simulation block diagram of multi-wind-diesel autonomous hybrid power system for

    step plus stochastic disturbance.

  • 7/30/2019 Bhatti Paper

    8/23

    Reactive Power Control of Hybrid Power Systems 1351

    Figure 4. Simulation block diagram of wind-multi-diesel autonomous hybrid power system for

    step plus stochastic disturbance.

  • 7/30/2019 Bhatti Paper

    9/23

    1352 R. Bansal and T. Bhatti

    Figure 5. Simulation block diagram of (a) IEEE type-I exciter, (b) SVC type-I, (c) SVC type-II,

    and (d) SVC type-III.

  • 7/30/2019 Bhatti Paper

    10/23

    Reactive Power Control of Hybrid Power Systems 1353

    For the small incremental reactive power balance analysis of the hybrid system, (1) in

    Laplace form can be written as

    V.s/ D fKV=.1 C sTV/gfQS G .s/ C QSVC.s/ QL.s/ QI G .s/g (2)

    KV D1

    DV(3)

    TV D2HR

    DVV0(4)

    where V0 is the nominal value of system voltage, HR is a constant of the system and its

    unit is s and its value depends upon the constant Kr (considering that system reactive

    power rating is Kr times the rated magnetizing reactive power of the IG), DV is the small

    increase in reactive power loads with small increase voltage, i.e., DV D @QL=@V p.u.

    kVAR/p.u. kV. The parameter DV can be found empirically. KV =.1 C sTV/ is transfer

    function of hybrid power system. The values of KV and TV can be computed using

    (3) and (4), respectively, with the data given in Appendix 1, and their values have been

    shown in Figures 2, 3, and 4. The values of KV and TV remain the same with SVC

    type-I, type-II, and type-III for wind-diesel hybrid power system. The following section

    presents the mathematical modeling of various components of hybrid systems.

    2.1. The Flux Linkage Equations

    The flux linkage equation of the round rotor synchronous machine for small perturbation

    is [21]

    d

    dtE0q D

    Efd Eq

    T0do

    (5)

    In (5), Eq is given by

    Eq Dxd

    x0d

    E0q .xd x

    0

    d/

    x0d

    cos V (6)

    For small changes (5), using (6) in Laplace transform form can be written as

    .1 C sTG/E0

    q .s/ D K1Efd .s/ C K2V.s/ (7)

    where

    TG Dx0

    dT0

    do

    xd(8)

    K1 D x0d=xd (9)

    K2 D f.xd x0d/ cos g=xd (10)

    The values of K1 (K11 and K12 in case of wind-multi-diesel system) and K2 (K21

    and K22 in case of wind-multi-diesel system) can be computed using (9) and (10),

    respectively, with the data given in Appendix 1, and their values have been shown in

    Figures 2, 3, and 4. The values of K1 and K2 remain the same with SVC type-I, type-II,

    and type-III for wind-diesel hybrid power system.

  • 7/30/2019 Bhatti Paper

    11/23

    1354 R. Bansal and T. Bhatti

    2.2. The Synchronous Generator Equations

    Under transient condition QSG is given by [20]

    QS G D E0

    qV cos V2

    x0d

    (11)

    For small perturbation (11) can be written as

    QS G DV cos

    x0d

    E0q CE 0q cos 2V

    x0d

    V (12)

    In Laplace transform (12) can be written as

    QS G .s/ D K3E0

    q.s/ C K4V.s/ (13)

    where

    K3 D .V cos /=X0d (14)

    and

    K4 D .E0q cos 2V /=x0

    d (15)

    The values of K3 (K31 and K32 in wind-multi-diesel system) and K4 (K41 and

    K42 in wind-multi-diesel system) can be computed using (14) and (15), respectively,

    with the data given in Appendix 1, and their values have been shown in Figures 2, 3,

    and 4. The values of K3 and K4 remain the same with SVC type-I, type-II, and type-III

    for wind-diesel hybrid power system.

    2.3. IEEE Type-1 Excitation System Equations

    IEEE type-1 excitation system [22], as shown in Figure 5(a), is considered for the syn-

    chronous generator of the hybrid system. From the block diagram, the transfer function

    equations neglecting saturation function (SF) can be written as

    Efd.s/ D1

    KE C sTEVa.s/ (16)

    Va.s/ DKA

    1 C sTA V.s/

    KF

    TFEfd .s/ C Vref.s/

    (17)

    Vf .s/ DKF=TF

    1 C sTFEfd.s/ (18)

    The values of transfer functions of amplifier, exciter, and stabilizing circuit, as shown

    in Figure 5(a), are obtained using the data of Appendix 1. This excitation system has

    been represented by a single block in Figures 24.

  • 7/30/2019 Bhatti Paper

    12/23

    Reactive Power Control of Hybrid Power Systems 1355

    2.4. The Induction Generator Equations

    The small deviation in reactive power absorbed by the IG by neglecting the effect of

    variation in reactive power with the variation of slip/speed (constant slip/speed model)

    and by considering the effect of variation in reactive power with variation in slip/speed(variable slip/speed model) can be written as [1719]

    QIG .s/ D K5V.s/ (19)

    where

    K5 D2V Xeq

    R2Y C X2eq

    (20)

    QIG .s/ D K6PI W.s/ C K7V.s/ (21)

    where

    K6 C

    Xeq

    RP .R2Y C X2eq /=2RY (22)

    K7 D2V

    R2Y

    C X2eq

    "Xeq

    RPXeq

    fRP .R2Y

    C X2eq/=2RYg

    #(23)

    where

    RP Dr 02s

    .1 s/ (24)

    RY D RP Req (25)

    Req D r1 C r0

    2 (26)

    Xeq D x1 C x0

    2 (27)

    This article considers the variable slip model of IG. The values of K6 (K61 and K62

    in multi-wind-diesel system) and K7 (K71 and K72 in multi-wind-diesel system) can

    be computed using (22) and (23), respectively, with the data given in Appendix 1, and

    their values have been shown in Figures 2, 3, and 4. The values of K6 and K7 remainthe same with SVC type-I, type-II, and type-III for wind-diesel hybrid power system.

    2.5. SVC Equations

    The reactive power supplied by the SVC is given by [23]

    QSVC D V2BSVC (28)

    For small perturbation, (28) can be written in Laplace transform form as

    QSVC.s/ D K8V.s/ C K9BSVC.s/ (29)

    where

    K8 D 2VBSVC (30)

  • 7/30/2019 Bhatti Paper

    13/23

    1356 R. Bansal and T. Bhatti

    and

    K9 D V2 (31)

    The state equations of a SVC type-I in Laplace transform can be written as

    BSVC.s/ D1

    1 C sTdB0SVC.s/ (32)

    B0SVC.s/ DK

    1 C sT.s/ (33)

    .s/ DKR

    1 C sTR.Vref.s/ V.s// (34)

    The state equations of a SVC type-II in Laplace transform can be written as

    01.s/ D1 T2=T4

    1 C sT4

    0.s/ (35)

    02.s/ DKR.1 T1=T3/

    1 C sT3.Vref.s/ V.s// (36)

    where

    0.s/ D 02.s/ C KRT1

    T3.Vref.s/ V.s// (37)

    .s/ D 01.s/ CT2

    T4.0.s// (38)

    The state equations of a SVC type-III in Laplace transform can be written as

    0.s/ D KIs

    fVref.s/ V.s/g (39)

    where

    .s/ D 0.s/ C KPfVref.s/ V.s/g (40)

    Equations (32) and (33) remain the same in SVC type-II and type-III.

    The values of K8 and K9 can be computed using (30) and (31), respectively, with

    the data given in Appendix 1, and their values have been shown in Figures 24. The

    values of K8 and K9 remain the same with SVC type-I, type-II, and type-III for wind-

    diesel hybrid power system. VAR gain KR in SVC type-I and type-II; and KP and KIin SVC type-III have been optimized and their values have been shown in Figures 5(b),

    5(c), and 5(d), respectively. Dynamic responses of hybrid system have been shown in

    Figures 610 using optimum settings of the gain parameters of the SVC.Based on the above mathematical equations, Simulink block diagram of wind-diesel,

    2 wind-1 diesel, 1 wind-2 diesel isolated hybrid power system have been developed as

    shown in Figures 2, 3, and 4, respectively. The state space equations can be written in a

    standard form for load voltage control system as

    Px D Ax C Bu C Cp (41)

  • 7/30/2019 Bhatti Paper

    14/23

    Reactive Power Control of Hybrid Power Systems 1357

    Figure 6. Dynamic responses of the wind-diesel autonomous hybrid power system with SVC

    type-I for 1% realistic increase in reactive power load plus 1% step increase in input wind power.

  • 7/30/2019 Bhatti Paper

    15/23

    1358 R. Bansal and T. Bhatti

    Figure 7. Dynamic responses of the wind-diesel autonomous hybrid power system with SVC

    type-II for 1% realistic increase in reactive power load plus 1% step increase in input wind power.

  • 7/30/2019 Bhatti Paper

    16/23

  • 7/30/2019 Bhatti Paper

    17/23

    1360 R. Bansal and T. Bhatti

    Figure 9. Dynamic responses of the multi-wind-diesel autonomous hybrid power system with SVC

    type-II for 1% realistic increase in reactive power load plus 1% step increase in input wind power

    of both wind machines.

  • 7/30/2019 Bhatti Paper

    18/23

    Reactive Power Control of Hybrid Power Systems 1361

    Figure 10. Dynamic responses of the wind-multi-diesel autonomous hybrid power system with

    SVC type-II for 1% realistic increase in reactive power load plus 1% step increase in input wind

    power.

  • 7/30/2019 Bhatti Paper

    19/23

    1362 R. Bansal and T. Bhatti

    For the autonomous wind-diesel system with SVC type-I, II, and III, 2 wind-1 diesel

    with SVC type-II, and 1 wind-2 diesel with SVC type-II hybrid power system state space

    equations can be written as

    2.6. Wind-diesel System

    State space equations with SVC type-I

    Px D Efd Va Vf E0

    q BSVC B0

    SVC V T

    u D Vref

    p D QL PI WT (42)

    State space equations with SVC type-II

    Px D Efd Va Vf E0

    q BSVC B0

    SVC 0

    1 0

    2 V T

    u D Vref

    p D QL PI WT (43)

    State space equations with SVC type-III

    Px D Efd Va Vf E0

    q BSVC B0

    SVC 0 V T

    u D Vref

    p D QL PI WT (44)

    2 Wind-1 diesel system with SVC type-II

    Px D Efd Va Vf E0

    q BSVC B0

    SVC 0

    1 0

    2 V T

    u D Vref

    p D QL PI W 1 PI W 2T (45)

    1 Wind-2 diesel system with SVC type-II

    Px D Efd 1 Va1 Vf 1 E0

    q1 Efd 2 Va2 Vf 2 E0

    q2

    BSVC B0

    SVC 0

    1 0

    2 V T

    u D Vref

    p D QL PI W T (46)

    Elements of matrices A, B, and C can be obtained from above mathematical model-

    ing/simulation block diagrams of Figures 15.

  • 7/30/2019 Bhatti Paper

    20/23

    Reactive Power Control of Hybrid Power Systems 1363

    3. Simulation Results and Discussions

    In this section, dynamic responses of wind-diesel hybrid power systems are presented.

    In practical situation variation in reactive power load is not in step, but the variation

    is realistic (step plus stochastic) in nature. There are number of realistic disturbancesavailable in Matlab/Simulink toolbox to simulate the realistic situation. In the present

    case, step plus stochastic load disturbances, i.e., step plus normally (Gaussian) distributed

    random signal, has been considered for the simulation of different configurations of

    autonomous hybrid power systems and stochastic disturbance is properly adjusted by

    multiplying suitable value of constant K10, as shown in Figures 24. The dynamic

    responses of some of the system variables are shown for the optimum gain settings for

    the autonomous hybrid power systems and are compared in terms of first swing amplitude

    and settling time, etc.

    The dynamic responses for 1% realistic increase in reactive power load plus 1%

    step increase in input wind power with SVC type-I, type-II, and type-III are shown

    in Figures 6, 7, and 8, respectively. Figures 9 and 10 show the dynamic responses

    for 1% realistic increase in reactive power load plus 1% step increase in input wind

    power with SVC type-II for multi-wind-diesel and wind-multi-diesel hybrid power systemrespectively. Figures 68 show the small deviations in terminal voltage ( V), reactive

    power supplied by SVC (QSVC), reactive power supplied by synchronous generator

    (QSG ), and reactive power absorbed by induction generator (QI G), in parts (a), (b),

    (c), and (d), respectively. Figure 9 shows the small deviations in V, QSVC, QS G , and

    power absorbed by induction generators (QI G 1 and QIG 2); and Figure 10 shows

    the small deviations in V, QSVC, small deviations in power supplied by synchronous

    generators (QSG 1, QS G 2) and QI G in parts (a), (b), (c), (d), and (e), respectively.

    To get the dynamic responses with SVC type-II and type-III, SVC type-I in the simulation

    block diagram can be replaced by SVC type-II and type-III of Figures 5(c) and 5(d),

    respectively, in Figures 24. The maximum peak deviations of different parameters of

    hybrid power systems have been presented in Table 1.

    From Figures 610, it is observed that initially the synchronous generator provides

    the reactive power required by the load, but substantially it is met by the SVC alone, andtherefore the steady state values of V and QS G become zero. It is also found from

    Table 1 that the respective peak deviations are less with SVC type-II and SVC type-

    III as compared with SVC type-I. The settling time is about 0.015 sec. for the system

    responses with SVC type-II, and SVC type-III, but with SVC type-I it is about 0.15 sec.

    Table 1

    The peak deviations of different parameters of wind-diesel hybrid system

    System and

    SVC type V QSVC QSG QIG

    Wind-diesel, I 0.00187 0.02592 0.01374 0.00321

    Wind-diesel, II 0.00184 0.02089 0.01356 0.00320

    Wind-diesel, III 0.00184 0.02102 0.01356 0.00320

    2 Wind-1 diesel, II 0.00203 0.02183 0.01438 0.00322 (IG 1)0.00071 (IG 2)

    1 Wind-2 diesel, II 0.00087 0.01947 0.00618 (SG 1) 0.00308

    0.00724 (SG 2)

  • 7/30/2019 Bhatti Paper

    21/23

    1364 R. Bansal and T. Bhatti

    Performance of SVC type-II and type-III is better than SVC type-I in terms of first peak

    deviations and settling time.

    It is also observed from Figures 9 and 10 that the settling time remains almost same

    as in previous cases. It is also seen that multiplicity in the wind power generation reduces

    the reactive power performance of the system whereas multiplicity in the diesel generatorsystem improves the same. It is further observed from Figures 9 and 10 that performance

    of SVC type-II and type-III is better than SVC type-I.

    4. Conclusions

    This article has presented the effectiveness of the application of Simulink tool for reactive

    power control of autonomous wind-diesel hybrid power systems. Simulink is very effec-

    tive and easy for studying and comparing the performance of the systems with different

    types components, e.g., various types of SVCs and different types of disturbances, etc.

    A reactive power control study of sample wind-diesel isolated hybrid power system with

    three types of SVCs and multi-wind-diesel, wind-multi-diesel hybrid systems with SVC

    type-II have been presented in this article. It is seen that performance of SVC type-II and

    type-III is better than SVC type-I in terms of first peak deviations and settling time. It is

    also observed that multiplicity in the wind power generation reduces the reactive power

    performance of the system whereas multiplicity in the diesel generator system improves

    the same.

    References

    1. Hunter, R., and Elliot, G., Wind-Diesel Systems, A Guide to the Technology and its Implemen-

    tation, New York: Cambridge University Press, 2004.

    2. Nacfaire, H., Wind-Diesel and Wind Autonomous Energy Systems, London, UK: Elsevier Ap-

    plied Science, 1989.

    3. Bansal, R. C., Bhatti, T. S., and Kothari, D. P., A bibliographical survey on induction gen-

    erators for application of non-conventional energy systems, IEEE Trans. Energy Convers.,

    Vol. 18, No. 3, pp. 433439, 2003.

    4. Sandhu Khan, P. K., and Chatterjee, J. K., Three-phase induction generators: A discussion

    on performance, Elect. Mach. Power Syst., Vol. 27, pp. 813832, 1998.

    5. Bansal, R. C., Three-phase self-excited induction generators (SEIG): An overview, IEEE

    Trans. Energy Conver., Vol. 20, No. 2, pp. 292299, June 2005.

    6. Tandon, A. K., Murthy, S. S., and Berg, G. J., Steady state analysis of capacitors excited

    induction generators, IEEE Trans. Power Apparatus Syst., Vol. PAS-103, No. 3, pp. 612618,

    1984.

    7. Schoder, K., Hasanovic, A., Feliachi, A., and Hasanovic, A., PAT: A power analysis toolbox

    for MATLAB/Simulink, IEEE Trans. Power Syst., Vol. 18, No. 1, pp. 4247, 2003.

    8. Allen, E., LaWhite, N., Yoon, Y., Chapman, J., and Ilic, M., Interactive object-oriented simula-

    tion of interconnected power systems using Simulink, IEEE Trans. Educat., Vol. 44, pp. 8795,

    February 2001.

    9. Ordys, A. W., Pike, A. W., Johnson, M. A., Katebi, R. M., and Grimble, M. J., Modelling and

    Simulation of Power Generation Plants, London: Springer-Verlag Ltd., 1994.

    10. Saadat, H., Power System Analysis, Singapore: WCB/McGraw-Hill, 1999.

    11. Balasubramanyam, P. V., Murthy, A. S. R., and Parameswaran, P., Design of variable s tructure

    controller for static VAR compensator, Elect. Mach. Power Syst., Vol. 26, pp. 431450, 1998.

    12. IEEE Special Stability Working Group (Taylor, C. W., Scott, G., Hammad, A., Wong, W.,

    Osborn, D., Ramos, A. J. P., Johnson, B., McNabb, D., Arabi, S., Martin, D., Thanawala,

    H. L., Luini, J., Gonzalez, R., and Concordia, C.), Static VAR compensator models for power

  • 7/30/2019 Bhatti Paper

    22/23

    Reactive Power Control of Hybrid Power Systems 1365

    flow and dynamic performance simulation, IEEE Trans. Power Syst., Vol. 9, No. 1, pp. 229

    240, February 1994.

    13. Mathur, R. M., Stabilisatation techniques in power systems static VAR compensation, In-

    ternational Federation of Automatic Control (IFAC) Symposium, Bangalore, India, December

    1986.14. Padiyar, K. R., and Verma, R. K., Damping torque analysis of static VAR system controllers,

    IEEE Trans. Power Syst., Vol. 6, No. 2, pp. 458465, 1991.

    15. Hammad, A. E., Analysis of power system stability enhancement by static VAR compen-

    sators, IEEE Trans. Power Syst., Vol. PWRS-1, No. 4, pp. 222227, November. 1986.

    16. Hammad, A. E., and El-Sadek, M., Application of thyristor controlled VAR compensator for

    damping sub-synchronous oscillations in power systems, IEEE Trans. Power Apparatus Syst.,

    Vol. PAS-103, pp. 198212, 1984.

    17. Bansal, R. C., Automatic Reactive Power Control of Autonomous Hybrid Power Systems, Ph.D.

    Thesis, Centre for Energy Studies, Indian Institute of Technology, Delhi, India, April 2003.

    18. Bansal, R. C., Bhatti, T. S., and Kothari, D. P., A novel mathematical modelling of induction

    generator for reactive power control of isolated hybrid power systems, Int. J. Modelling

    Simulat., Vol. 24, No. 1, pp. 17, 2004.

    19. Bansal, R. C., Bhatti, T. S., and Kothari, D. P., Automatic reactive power control of isolated

    wind-diesel hybrid power systems for variable wind speed/slip, Int. J. Elect. Power Compon.Syst., Vol. 32, No. 9, pp. 901912, September 2004.

    20. Elgerd, O. I., Electric Energy System Theory An Introduction, New Delhi India: Tata McGraw

    Hill, 1982.

    21. Bhatti, T. S., Interactive Excitation and Speed Governor Control of Power Systems, Ph.D.

    Thesis, Electrical Engineering Department, Indian Institute of Technology, Delhi, India, May

    1984.

    22. IEEE Special Working Group on Modelling of Excitation Systems (Crenshaw, M. L., Bollinger,

    K. E., Byerly, R. T., Cresap, R. L., Eilts, L. E., Eyre, D. E., Keay, F. W., Kundur, P., Larsen,

    E. V., Lee, D. C., Luini, J. F., Pillote, R. G., and Dandeno, P. L.), Excitation system models for

    power system stability studies, IEEE Trans. Power Syst., Vol. PAS-100, No. 2, pp. 494509,

    February 1981.

    23. Padiyar, K. R., Power Systems Dynamics, Stability and Control, Bangalore, India: Interline

    Publishing, 1996.

    Appendix 1

    The data of the wind-diesel, multi-wind-diesel, wind-multi-diesel hybrid power system,

    system capacity/load, reactive power, synchronous generator, induction generator, exci-

    tation system, and the SVCs under consideration are as follows in Table 2.

    Table 2

    Parameters of hybrid systems

    Multi-wind-diesel

    system

    Wind-multi-diesel

    system

    System parameter

    Wind-diesel

    system IG 1 IG 2 SG 1 SG 2

    System capacity/load

    Wind capacity (kW) 150 150 50 150

    Diesel capacity (kW) 150 150 150 75

    Load (kW) 250 300 300

    Base power (kVA) 250 300 300

    (continued)

  • 7/30/2019 Bhatti Paper

    23/23

    1366 R. Bansal and T. Bhatti

    Table 2

    (Continued)

    Multi-wind-diesel

    system

    Wind-multi-diesel

    system

    System parameter

    Wind-diesel

    system IG 1 IG 2 SG 1 SG 2

    Synchronous generator

    PS G (p.u. kW) 0.4 0.333 0.333 0.1667

    QSG (p.u. kVAR) 0.2 0.162 0.162 0.081

    Eq (p.u.) 1.1136 1.1242 1.1242 1.1083 () 21.05 17.2483 17.2483 6.91

    E 0q (p.u.) 0.9603 0.9804 0.9804 1.01

    V (p.u.) 1.0 1.0 1.0 1.0

    xd (p.u.) 1.0 1.0 1.0 0.8

    x0d

    (p.u.) 0.15 0.15 0.15 0.12

    T0do

    (s) 5.0 5.0 5.0 5.0

    Induction generator

    PI G (p.u. kW) 0.6 0.5 0.1667 0.5

    QIG (p.u. kVAR) 0.189 0.1343 0.0426 0.1343

    PI W (p.u. kW) 0.75 0.63 0.21 0.63

    IG (%) 80 80 80 80

    r1 D r0

    2 (p.u.) 0.19 0.19 0.55 0.19

    x1 D x0

    2 (p.u.) 0.56 0.56 1.6 0.56

    s (%) 4.1 3.49 3.37 3.49

    Load

    PL (p.u. kW) 1.0 1.0 1.0

    QL (p.u. kVAR) 0.75 0.75 0.75

    pf (lag) 0.8 0.8 0.8

    Reactive power data

    QSVC (p.u. kVAR) 0.498 0.7649 0.6413

    Qc (p.u. kVAR) 0.5727 0.87961 0.7375

    (rad.) 2.4440 2.4452 2.45568IEEE type-I excitation system

    KA 40 40 40

    TA (s) 0.05 0.05 0.05

    KF 0.5 0.5 0.5

    TF (s) 0.715 0.715 0.715KE 1.0 1.0 1.0

    SF (s) 0.0 0.0 0.0

    TE (s) 0.55 0.55 0.55

    SVC data

    SVC type-I

    T (s) 0.005 0.005 0.005Td (s) 0.00167 0.00167 0.00167

    TR (s) 0.715 0.715 0.715

    SVC type-IIT (s) 0.005 0.005 0.005

    Td (s) 0.00167 0.00167 0.00167

    T1 D T2 D T3 D T4 (s) 0.715 0.715 0.715

    SVC type-III

    T (s) 0.005 0.005 0.005

    Td (s) 0.00167 0.00167 0.00167