Bus Impedance Matrix-Z Bus

18
Power Systems I The Bus Impedance Matrix l Definition l Direct formation of the matrix u inversion of the bus admittance matrix is a n 3 effort u for small and medium size networks, direct building of the matrix is less effort u for large size networks, sparse matrix programming with gaussian elimination technique is preferred 1 - = bus bus Y Z

description

z bus

Transcript of Bus Impedance Matrix-Z Bus

  • Pow

    er Sy

    stem

    s I

    Th

    e B

    us

    Impe

    dan

    ce M

    atrix

    lD

    efin

    itio

    n

    lD

    irect

    fo

    rmat

    ion

    o

    f the

    m

    atrix

    uin

    vers

    ion

    of

    th

    e bu

    s ad

    mitt

    ance

    m

    atrix

    is

    a

    n3

    effo

    rtu

    for

    sma

    ll a

    nd

    med

    ium

    si

    ze n

    etw

    ork

    s, di

    rect

    bu

    ildin

    g of

    th

    e m

    atrix

    is le

    ss e

    ffort

    ufo

    r la

    rge

    size

    n

    etw

    ork

    s, sp

    ars

    e m

    atrix

    pr

    ogr

    amm

    ing

    with

    gau

    ssia

    n el

    imin

    atio

    n te

    chn

    iqu

    e is

    pr

    efe

    rre

    d

    1

    =bu

    sbu

    sY

    Z

  • Pow

    er Sy

    stem

    s I

    bus

    no

    de =

    gr

    aph

    ver

    tex

    line

    bran

    ch =

    ed

    ge

    Form

    ing

    the

    Bu

    s Im

    peda

    nce

    M

    atrix

    lG

    raph

    th

    eory

    te

    chn

    iqu

    es he

    lps

    expl

    ain

    th

    e bu

    ildin

    gpr

    oce

    ss

    0

    12

    3

    12

    3

    4

    5

    co-tr

    ee

    0

    12

    3

    12

    3

    4

    5

    sele

    cted

    tr

    ee

    j0.2

    j0.4

    j 0.4

    j0.4

    j0.8

    12

    3ex

    tendi

    ng

    tree

    br

    anch

    loop

    closin

    g br

    anch

  • Pow

    er Sy

    stem

    s I

    Part

    ial

    Net

    work

    m bus

    Z

    1 2 i j 0 Refe

    rence

    bus

    bus

    bus

    IZ

    V=

    Form

    ing

    the

    Bu

    s Im

    peda

    nce

    M

    atrix

    lB

    asic

    co

    nst

    ruct

    ion

    o

    f the

    n

    etw

    ork

    an

    d th

    e m

    atrix

  • Pow

    er Sy

    stem

    s I

    Part

    ial

    Net

    work

    m bus

    Z

    1 2 p m 0 Ref

    eren

    ce

    Part

    ial

    Net

    wo

    rkm bu

    sZ

    1 2 p m 0 Ref

    eren

    ce

    q

    q

    qqp

    pq

    Iz

    VV

    +=

    qq

    qI

    zV

    00+

    =

    Add

    ing

    a Li

    ne

  • Pow

    er Sy

    stem

    s I

    +=

    ==

    ==

    ====

    =

    qmp

    pqpp

    pmpp

    pp

    mp

    mm

    mp

    mm

    pppm

    ppp

    p

    pm

    p

    pm

    p

    qmp

    IIIII

    zZ

    ZZ

    ZZ

    ZZ

    ZZ

    Z

    ZZ

    ZZ

    Z

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    VVVVV

    MM

    LL

    LL

    MM

    OM

    OM

    M

    LL

    MM

    OM

    OM

    M

    LL

    LL

    MM

    21

    21

    21

    21

    22

    222

    21

    11

    121

    11

    21

    Add

    ing

    a Li

    ne

    to an

    Ex

    istin

    g Li

    ne

  • Pow

    er Sy

    stem

    s I

    ==

    ==

    =

    ====

    =

    qmp

    q

    mm

    mp

    mm

    pmpp

    pp

    mp

    mp

    qmp

    IIIII

    z

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    VVVVV

    MM

    LL

    LL

    MM

    OM

    OM

    M

    LL

    MM

    OM

    OM

    M

    LL

    LL

    MM

    21

    0

    21

    21

    22

    2221

    11

    2111

    21

    00

    00

    0000

    Add

    ing

    a Li

    ne

    from

    R

    efer

    ence

  • Pow

    er Sy

    stem

    s I

    Part

    ial

    Net

    wo

    rkm bu

    sZ

    1 p q m 0 Ref

    eren

    ce

    Part

    ial

    Net

    work

    m bus

    Z

    1 p i m 0 Ref

    eren

    ce

    0=

    +

    =

    pq

    lpq

    qp

    lpq

    VV

    Iz

    VV

    Iz

    00

    00

    =

    =

    pl

    p

    pl

    p

    VI

    z

    VI

    z

    Clo

    sin

    g a

    Loo

    p

  • Pow

    er Sy

    stem

    s I

    Elim

    inat

    ing

    a n

    ode

    fro

    m th

    e sy

    stem

    bus

    ll

    Told bus

    nbu

    sll

    nT

    n

    nbu

    sold

    nn

    bus

    nbu

    s

    nbu

    sllnT

    ll

    lln

    bus

    nT

    ln

    nbu

    sold

    nn

    bus

    nbu

    s

    l

    nbu

    s

    lln

    Tn

    old

    nn

    bus

    nbu

    s

    IZ

    ZZ

    ZI

    ZZ

    ZI

    ZV

    IZZ

    II

    ZI

    Z

    IZ

    IZ

    V

    II

    ZZ

    ZZ

    V

    =

    =

    =

    +

    =

    +

    =

    =

    ]1[

    ]1[

    ]1[

    ]1[

    ][

    ]1[

    ]1[

    ]1[

    ]11[

    ]1[

    ]1[

    ]1[

    ]1[

    ][

    ]1[

    ]1[

    ]11[

    ]1[

    ]1[

    ][

    ]1[ 00

    Kro

    n R

    edu

    ctio

    n

  • Pow

    er Sy

    stem

    s I

    pqqq

    pppq

    ll

    lmqp

    llpm

    qmpq

    qqpp

    qpp

    q

    mp

    mq

    mm

    mq

    mp

    m

    qpqq

    qmqq

    qpq

    pppq

    pmpq

    ppp

    pq

    mq

    p

    mqp

    ZZ

    Zz

    Z

    IIIII

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    Z

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    VVVV

    20

    1

    11

    111

    11

    11

    111

    1

    +

    +=

    =

    MM

    LL

    LL

    MM

    OM

    MO

    M

    LL

    OL

    MM

    LM

    MO

    M

    LL

    MM

    Then

    ex

    ecute

    K

    ron re

    duct

    ion on

    Z l

    l

    Add

    ing

    a Li

    ne

    betw

    een

    tw

    o Li

    nes

  • Pow

    er Sy

    stem

    s I

    ppp

    ll

    lmqp

    llpm

    pipp

    p

    mp

    mm

    mi

    mp

    m

    ipim

    iiip

    i

    pppm

    pipp

    p

    pm

    ip

    mip

    Zz

    Z

    IIIII

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    Z

    VVVV

    +=

    =

    0

    1

    1111

    11

    11

    111 0

    MM

    LL

    LL

    MM

    OM

    MO

    M

    LL

    OL

    MM

    LM

    MO

    M

    LL

    MM The

    n ex

    ecute

    K

    ron

    re

    duct

    ion on

    Z l

    l

    Add

    ing

    a Li

    ne

    from

    a

    Lin

    e to

    R

    efer

    ence

  • Pow

    er Sy

    stem

    s I

    K

    ron

    R

    edu

    ctio

    n

    lK

    ron

    re

    duct

    ion

    re

    mo

    ves

    an

    ax

    is (ro

    w &

    colu

    mn

    ) fro

    m a

    mat

    rix w

    hile

    re

    tain

    ing

    the

    axis

    s

    nu

    mer

    ical

    in

    fluen

    ce

    ll

    lkjl

    old jk

    new jk

    lmqp

    lllm

    lilp

    l

    ml

    mm

    mi

    mp

    m

    ilim

    iiip

    i

    plpm

    pipp

    p

    lm

    ip

    mip

    ZZZZ

    Z

    IIIII

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    ZZ

    Z

    VVVV

    =

    =

    MM

    LL

    LL

    MM

    OM

    MO

    M

    LL

    OL

    MM

    LM

    MO

    M

    LL

    MM

    1

    1111

    11

    11

    111 0

  • Pow

    er Sy

    stem

    s I

    Z-

    Bu

    s B

    uild

    ing

    Ru

    les

    lR

    ule

    1:

    A

    dditi

    on

    o

    f a br

    anc

    h to

    th

    e re

    fere

    nce

    ust

    art

    with

    e

    xist

    ing

    net

    wo

    rk m

    atrix

    [m

    m

    ]u

    crea

    te a

    n

    ew n

    etw

    ork

    m

    atrix

    [(m

    +1)

    (m

    +1)]

    w

    ithn

    the ne

    w off-

    diago

    na

    l row

    an

    d co

    lum

    n fill

    ed

    with

    (0)

    nth

    e di

    ago

    nal e

    lem

    ent (m

    +1),

    (m+

    1) fill

    ed

    with

    th

    e ele

    ment i

    mpe

    dan

    cez q

    0

  • Pow

    er Sy

    stem

    s I

    Z-

    Bu

    s B

    uild

    ing

    Ru

    les

    lR

    ule

    2:

    A

    dditi

    on

    o

    f a br

    anc

    h to

    an

    ex

    istin

    g bu

    su

    con

    ne

    ctin

    g to

    e

    xist

    ing

    bus

    pu

    sta

    rt w

    ith e

    xist

    ing

    net

    wo

    rk m

    atrix

    [m

    m

    ]u

    crea

    te a

    n

    ew n

    etw

    ork

    m

    atrix

    [(m

    +1)

    (m

    +1)]

    w

    ithn

    the ne

    w off-

    diago

    na

    l row

    an

    d co

    lum

    n fill

    ed

    with

    a co

    py o

    f row

    p

    and

    colu

    mn p

    nth

    e di

    ago

    nal e

    lem

    ent (m

    +1),

    (m+

    1) fill

    ed

    with

    th

    e ele

    ment i

    mpe

    dan

    cez p

    q pl

    us

    the di

    ago

    nal i

    mpe

    dance

    Z p

    p

  • Pow

    er Sy

    stem

    s I

    Z-

    Bu

    s B

    uild

    ing

    Ru

    les

    lR

    ule

    3:

    A

    dditi

    on

    o

    f a lin

    kin

    g br

    anch

    uco

    nne

    ctin

    g to

    e

    xist

    ing

    buse

    s p

    an

    d q

    ust

    art

    with

    e

    xist

    ing

    net

    wo

    rk m

    atrix

    [m

    m

    ]u

    crea

    te a

    n

    ew n

    etw

    ork

    m

    atrix

    [(m

    +1)

    (m

    +1)]

    w

    ithn

    the ne

    w off-

    diago

    na

    l row

    an

    d co

    lum

    n fill

    ed

    with

    a co

    py o

    f row

    q

    min

    us

    row

    p

    an

    d co

    lum

    n q

    min

    us

    colu

    mn

    p

    nth

    e di

    ago

    nal e

    lem

    ent (m

    +1),

    (m+

    1) fill

    ed

    with

    z pq

    + Z p

    p +

    Z q

    q - 2

    Z pq

    upe

    rform

    Kr

    on

    re

    duct

    ion

    o

    n th

    e m

    +1

    row

    a

    nd

    colu

    mn

  • Pow

    er Sy

    stem

    s I

    Z-

    Bu

    s B

    uild

    ing

    Ru

    les

    lR

    ule

    4:

    A

    dditi

    on

    o

    f a lin

    kin

    g br

    anch

    uco

    nne

    ctin

    g to

    e

    xist

    ing

    bus

    p a

    nd

    refe

    ren

    ce

    ust

    art

    with

    e

    xist

    ing

    net

    wo

    rk m

    atrix

    [m

    m

    ]u

    crea

    te a

    n

    ew n

    etw

    ork

    m

    atrix

    [(m

    +1)

    (m

    +1)]

    w

    ithn

    the ne

    w off-

    diago

    na

    l row

    an

    d co

    lum

    n fill

    ed

    with

    a co

    py o

    f the

    ne

    gativ

    e o

    f row

    p

    and

    the ne

    gativ

    e o

    f colu

    mn p

    nth

    e di

    ago

    nal e

    lem

    ent (m

    +1),

    (m+

    1) fill

    ed

    with

    z p0

    + Z p

    pu

    perfo

    rm Kr

    on

    re

    duct

    ion

    o

    n th

    e m

    +1

    row

    a

    nd

    colu

    mn

  • Pow

    er Sy

    stem

    s I

    j0.2

    j0.4

    j 0.4

    j0.4

    j0.8

    12

    3

    0

    12

    3

    12

    35

    4

    Net

    wo

    rkG

    raph

    Lin

    e ad

    din

    g ord

    er:

    1-

    0, 2-

    0, 1-

    3, 1-

    2, th

    en 2-

    3

    Exam

    ple

  • Pow

    er Sy

    stem

    s I

    Ex

    ampl

    e

    [] []

    6.0

    02

    .00

    4.0

    02.0

    02

    .0.3

    4.0

    00

    2.0

    .2

    2.0

    .1.0

    jj

    jj

    jj

    jj

    ()(

    )

    =

    =

    571

    .005

    7.0

    171

    .005

    7.0

    285

    .005

    7.0

    171

    .005

    7.0

    171

    .0

    17.0

    4.1

    2.0

    2.0

    2.0

    4.1

    2.0

    4.0

    2.0

    2.0

    6.0

    02

    .04.0

    04.0

    02.0

    2.0

    02

    .0

    .4

    11

    jj

    jj

    jj

    jj

    jj

    jj

    jZ

    jj

    jj

    jj

    jj

    jj

    jj

  • Pow

    er Sy

    stem

    s I

    Ex

    ampl

    e

    34.0

    16.0

    12.0

    16.0

    24.0

    08.0

    12.0

    08.0

    16.0

    14.1

    514

    .022

    8.0

    114

    .051

    4.0

    571

    .005

    7.0

    171

    .022

    8.0

    057

    .028

    5.0

    057

    .011

    4.0

    171

    .005

    7.0

    171

    .0

    .5

    jj

    jj

    jj

    jj

    jj

    jj

    jj

    jj

    jj

    jj

    jj

    jj

    j