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Electro ii motores trifasicos

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  • ESCUELA SUPERIOR POLITECNICA DE CHIMBORAZO

    ELECTROTECNIA II

    POR:MILTON JAYA

    COD:1035

  • CIRCUITO CON 4 MOTORES

    DATOS:

    5%v10% M1: Pmec=1oHP ; =o.4 ; fp=0.6; L=50m M2: Pmec=12HP ; =0.5 ; fp=0.7; L=70m M3: Pmec=15HP ; =0.6 ; fp=0.7; L=80m M4: Pmec=9HP ; =0.7 ; fp=0.8 ; L=85m

  • MOTOR 1

    Pmec=7460w

    Pele=7460/0.4=18650w

    I=P/3.v.cos=18A

    Conductor de calibre #14 AWG; Seccin 2.08 mm

    Rl=.l/s =0.42

    v=3.Rl.Il.cos=7.8v

    BREKER=18x1.25=22.5A

    BREKER DE 25A

    POTENCIAS:

    P=3.I.V.cos=18706.1w

    Q=3.I.V.sen=24629.7VAR

    S=(P+Q)=30894.1VA

  • MOTOR 2

    Pmec=8952w

    Pele=8952/0.5=17904w

    I=P/3.v.cos=15A

    Conductor de calibre #14 AWG; Seccin 2.08 mm

    Rl=.l/s =0.5

    v=3.Rl.Il.cos=9.1v

    BREKER=15x1.25=18.7A

    BREKER DE 20A

    POTENCIAS:

    P=3.I.V.cos=18186.5w

    Q=3.I.V.sen=18446.3VAR

    S=(P+Q)=25903.9VA

  • MOTOR 3

    Pmec=11190w

    Pele=11190/0.6=18650w

    I=P/3.v.cos=15A

    Conductor de calibre #14 AWG; Seccin 2.08 mm

    Rl=.l/s =0.6

    v=3.Rl.Il.cos=10v

    BREKER=15x1.25=18.7A

    BREKER DE 20A

    POTENCIAS:

    P=3.I.V.cos=18186.5w

    Q=3.I.V.sen=18688.9VAR

    S=(P+Q)=26077.2VA

  • MOTOR 4

    Pmec=6714w

    Pele=6714/0.7=9591.4w

    I=P/3.v.cos=7A

    Conductor de calibre #16 AWG; Seccin 1.31mm

    Rl=.l/s =1.1

    v=3.Rl.Il.cos=10v

    BREKER=7x1.25=8.75A

    BREKER DE 10A

    POTENCIAS:

    P=3.I.V.cos=9695.4w

    Q=3.I.V.sen=7296.67VAR

    S=(P+Q)=12134.2VA

  • INTENSIDAD TOTAL

    IT=I1+I2+I3+I4

    IT=18+15+15+7=55

    BREKER PRINCIPAL

    55X1.25=68.7A BREKER DE 70A

  • POTENCIAS TOTALES:

    PT=P1+P2+P3+P4=18706.1+18186.5+18186.5+9695.4 PT=64774.5WW

    QT=Q1+Q2+Q3+Q4=24629.7+18446.3+18688.9+7296.6

    QT=69061.5VAR

    ST=SUMATORIA DE S EN FORMA VECTORIAL

    S1=30894.1^J53= (18592.5+J24673.1)

    S2=25903.9^J46= (17994.3+J18633.7)

    S3=26077.2^J46= (18114.7+J18758.3)

    S4=12134.2^J37= (9690.8+J7302.5)

    ST=94647.9^J47= (64392.3+J69367.6)

    PT=64774.5W

    QT=69061.5VAR

    ST=94647.9 ^J47VAR

  • GRAFICA

    Tg23=Q1/P

    Q1=PTg23=27495.1VAR

    QT=Q1+Q2

    Q2=QT-Q1=69061.5-27495.1

    Q2=41566.4VAR

    Q2/3=13855.4VAR

    XC=V/Q2 XC=72.2

    C=1/2.f.xc

    C=36.7f

  • ESQUEMA MULTIFILAR

  • MOTOR TRIFASICO

    DATOS:

    Pmec=3000w

    Cos=0.79 f=50Hz

    =0.76

  • SOLUCION:

    Potencia elctrica:

    Pele=Pmec/

    Pele=3947.4w

    Intensidad:

    I= P/3.v.cos

    I=13.8A

    Calibre de conductor:

    #14 AWG; seccin 2.08mm

    Rl=xl/s=o.29

  • Cada de tensin:

    v=I x Rl

    v=4v

    220-100%

    4-x=10.35v no cumple

    Bajo la seccin

    Rl= x l/s=0.75

    v=I x Rl

    v=10.35v

    220-100%

    10.35-x=4.7% si cumple

  • Mejoramiento de fp:

    S=3xvxI

    S=5258.5VA

    Q=S x sen

    Q=34428.1VAR

    Qf =Ptg =1675.6VAR

    QC=Q-QF=(34428.1-1675.6)

    QC=1767.2VAR

    C=QC/2.f.v

    C=116.22F

  • CIRCUITO DESEQUILIBRADO CON RL

    DATOS:

    VA=93ej0v

    VB=93ej120v

    VC=93e-j120v

    Rl=0.93

    Z1=1.84ej46.1 Z2=1.54e-j46.1 Z3=2.05ej61.5

  • Impedancias ZA=Z1+Rl=(1.27+j1.32)+0.93=2.55ej31.25 ZB=Z2+Rl=(1.06-j1.4)+0.93=2.27e-j29.25 ZC=Z3+Rl=(0.98+j1.80)+0.93=2.61ej43.57 Admitancias YA=1/ZA=0.39e-j31.05 YB=1/ZB=0.49ej29.25 YC=1/ZC=0.38e-j43.57

    Cada de tensin

    UNN=(EA.YA+EB.YB+EC.YC)/(YA+YB+YC+YN)

    UNN=

    [(35.9e-j31.05)+(40.6ej149.25)+(35.03e-j163.57)]/[(0.33-

    j0.20)+(0.38+j0.21)+(0.26-j0.27)+1]

    UNN=38.5e-j168.47/1.98e-j7.52

    UNN=19.44e-j160.98(V)

  • Intensidades

    IA=(EA-UNN)YA

    =93-(-18.37-j6.34)x0.39e-j31.05

    =110.75ej3.2xo.39e-j31.05=43.19e-j27.85(A)

    IB=(EB-UNN)YB

    =[(-46.1+j79.8)-(-18.37-j6.34)]x0.44ej29.25

    =90.43ej107.84x0.44ej29.25=39.79ej137.09(A)

    IC=(EC-UNN)YC

    =[(-46.1-j79.8)-(-18.37-j6,34)]0.38e-j48.57

    =78.52e-j110.68x0.38e-j43.57=29.84e-j154.25(A)

    Cadas de tensin

    VA=IA.ZA=115.23ej3.4(V)

    VB=IB.ZB=90.32ej107.84(V)

    VC=IC.ZC=77.88e-j110.68(V)

  • Potencias

    PA=IA VF cos=4254.7(w)

    PB=IB VF cos=3135.6(w)

    PC=IC VF cos=1683.7(w)

    PT=9073.3(W)

    QA=IA VF sen=2582.5(VAR)

    QB=IB VF sen=1756.1(VAR)

    QC=IC VF sen=1601.7(VAR)

    QT=5940.3(VAR)

    ST=(PT+QT)

    ST=10844.9(VA)

  • ENCONTRAR RL DEL SISTEMA Y RESOLVER

    DATOS:

    Z1=10ej40

    Z2=8ej45

    Z3=12ej50

    Vl=208v

    VF=120v

  • INTENSIDAD

    I1=Vl/Z1

    I1=208ej0/10ej40

    I1=20.8e-j40(A)

    I2=vl/Z2

    I2=208e-j120/8ej45

    I2=26e-j165(A)

    I3=vl/Z3

    I3=208ej120/12ej50

    I3=17.3(A)

    Calculo calibre conductor

    #12AWG; seccin 3.31mm

    Rl=0.0175x50/3.31

    Rl=0.26

    208100%

    x3.5%=7.28v

  • Sumamos la Rl con impedancias Za=Z1+Rl=(7.66+j6.42)+0.26 Za=10.2ej39 Zb=Z2+Rl=(5.65+j5.65)+0.26 Zb=8.2ej43 Zc=Z3+Rl=(7.71+j9.19)+0.26 Zc=12.2ej49 Admitancias Ya=1/Za=0.09e-j39 Yb=1/Zb=0.12e-j43 Yc=1/Zc=0.08e-j49 Yn=1/0.26=3.84 Diferencia de potencial UNN=(EA.YA+EB.YB+EC.YC)/(YA+YB+YC+YN) UNN= (10.8e-j39+14.4e-j163+9.6ej71)/[(0.06-j6.79)+(0.08-j0.08)+(0.05-j0.06)+3.84] UNN=25.4e-j3.9/4.1e-j2.6 UNN=6.2e-j1.3(v)

  • Intensidades

    IA=[(EA-UNN)YA]

    =[120-(6.19-j0.14)]0.09e-j39

    =113.8ej0.07x0.09e-j39=10.2e-j38.9(A)

    IB=[(EB-UNN)YB]

    =[(-60-j103.9)-(6.19-j0.14)]0.12e-j43

    =123.07e-j122x0.12e-j43=14.7e-j165(A)

    IC=[(EC-UNN)YC]

    =[(-60+j103.9)-(6.19-j0.14)]0.08e-j49

    =123.3ej122x0.08e-j49=9.8ej73(A)

    Cadas de tensin

    UA=(EA-UNN)=113.8ej0.07(v)

    UB=(EB-UNN)=123.6e-j122(V)

    UC=(EC-UNN)=123.3ej122(V)

  • Potencias

    PA=IA VF cos=889.1w

    PB=IB VF cos=1279.2w

    PC=IC VF cos=776.7w

    PT=2945w

    QA=IA VF sen=746.1VAR

    QB=IB VF sen=1279.2VAR

    QC=IC VF sen=956.6VAR

    QT=2950.9VAR

    S=(P+Q)=4169.1VA.