Calculul de Regim Permanent al Unui SSE

Sa se calculeze regimul permanent de functionare ale unui SSE avand schema monofilara data in figura de mai jos in care se cunosc puterile nodale consumate si generate la noduri.

Date commune:

Linia 3-4=70km;

8-9=48km;

Lungimi (km)

2-3 5-6 6-8

190 60 80

Puteri (MW)

P5 P6 P8

114 90 82

Etapa I:

Calculul parametrilor schemelor echivalente ale liniilor si transformatoarelor.

Date de catalog pentru linii

Tipul Un

(kv) S

(mm) Z 0 Y0

r0 (Ω/km) x0

(Ω/km) G0(s/km) B0(s/km)

LEA 220 s.c 1*450 0.068 0.418 0 2.77*10-6

LEA 220 d.c 1*450 0.068 0.414 0 2.79*- 6

LEA 400 s.c 2*450 0.0337 0.324 0 3.55*10- 6

LEA 400 d.c 2*450 0.0337 0.322 0 3.58*10- 6

Relatiile pe care le folosim la calculul parametrilor liniilor sunt:

Z=r0/ng*l+j(x0/ng*l)

Y=j*bo*l*nc

Date de catalog pentru transformatoare

TR 1 TR 2 ATR

Sn(MVA) 400 125 400

UnIT 400 242 400

UnJT 24 10.5 231

usc(%) 15.2 11 11.5

∆Psc(kW) 920 380 1020

i0(%) 0.4 0.5 0.5

∆Pfe(kW) 350 135 290

Reglaj +-5%IT +-5%IT +-12*1.25%JT

Calculul parametrilor liniilor

LINIA 2-3: Un=400kV; nc=2; L=190km

z=(r0/nc)*L+j*(x0/nc)*L=(0.0337/2)*190+j*(0.322/2)*190=3.2015+j*30.59[Ώ]

y=j*b0*L*nc=j*3.58*190*2*10-6=j*1360.4*10-6[S]

LINIA 3-4: Un=400kV; nc=1; L=70km

z=(r0/nc)*L+j*(x0/nc)*L=(0.0337*70+j*(0.324*70)=2.35+j*22.68[Ώ]

y=j*b0*L*nc=3.55*10-6*70=0.0002485[S]

LINIA 5-6: Un=220kV; nc=2; L=60km

z=(r0/nc)*L+j*(x0/nc)*L=(0.068/2)*60+j*(0.414/2)*60=2.04+j*12.42[Ώ]

y=j*b0*L*nc=(2.79*10-6)*2*60=0.0003348[S]

LINIA 6-8: Un=220kV; nc=2; L=80km

z=(r0/nc)*L+j*(x0/nc)*L=(0.068/2)*80+j*(0.414/2)*80=2.72+j*16.56[Ώ]

y=j*b0*L*nc=2.79*10-6*2*80=0.0004464[S]

LINIA 8-9: Un=220kV; nc=1; L=48km

z=(r0/nc)*L+j*(x0/nc)*L=(0.068*48)+j*(0.418*48)=3.264+j*20.064[Ώ]

y=j*b0*L*nc=2.77*10-6*48=0.00013296[S]

Tab. nr.2 Calculul parametrilor liniilor

Linia i-k Un

(kv) nc L

(km) Parametrii rezultanti Ilim.termic

Ka(30o)

R[Ω] X[Ω] B[S]

2-3 400d.c. 2 190 3.2015 30.59 0.0013604 1.602

3-4 400s.c. 1 70 2.359 22.68 0.0002485 0.802

5-6 220 d.c. 2 60 2.04 12.42 0.0003348 1.604

6-8 220 d.c. 2 80 2.72 16.56 0.0004464 1.604

8-9 220 s.c. 1 48 3.264 20.064 0.00013296 0.802

Calculul parametrilor transformatoarelor:

TR1:

Zn=Un2/Sn=1.44[Ώ];

ur(%)=(∆Psc*10-3/Sn)*100=920*10-3*100/400=0.23[%];

ux(%)=usc(%)=15.2[%];

r= ur *Zn/100=0.23*1.44/100=0.003312[Ώ];

x= ux *Zn/100=15.2*1.44/100=0.2188[Ώ];

∆Qm=i0*Sn/100=0.4*400/100=1.6 [Mvar];

g=∆Pfe*10-3/Un2=350*10-3/24*24=0.6076*10-3 [S];

b=∆Qm/Un2=1.6/24*24=0.002777[S].