Chng I :

Hng dn s dng Power World Simulator

HNG DN S DNGCHNG TRNH POWERWORLD SIMULATORGii thiu

PowerWorld Simulator l mt trong nhng phn mm m phng h thng in ca hng PTI. Phn mm cung cp cc cng c m phng hiu qu v quan trng cho php kho st cc i tng, h thng hay qu trnh k thut - vt l gip ngi k s in c kh nng rt ngn thi gian v gim c chi ph nghin cu. iu quan trng nht ca phn mm ny l kh nng tnh ton bi ton gi thnh in nng v hin th trc tip gi thnh ny ti cc thanh ci cng nh trn cc ng dy ti in. y l mt cng c rt hu ch trong vic tnh ton thit k v nh ch vn hnh cho h thng in v hn na l hng ti mc tiu th trng in Vit Nam.2.1 S lc cc i tng trn s n tuyn( Thanh ci (Bus): Bus l ni m cc thit b nh ng dy/my bin p,my pht, ti ni vo.C 3 loi Bus:

( Slack bus(swing): bus cn bng

( Load bus:hu ht trong h thng l load bus

( Voltage controlled bus: in p bus c iu chnh trong phm vi cho trc

( ng dy/my bin p(Transmission line/transformer): thit b truyn ti cng sut gia cc bus.

( Ngun( Generator): ngun pht cng sut

( Ti(load): Thit b tiu th cng sut( Thit b b:

( Swiched shunt: B ngang

( Series capacitor: B dc

( My ct (Circuit Breakers ): thit b ng/ct cc thit b khc nh: DZ/MBA, ngun,ti

( Biu hnh trn: thit b th hin mc mang ti ca DZ/MBA( V mt s thit b khc: mt phn cch, hnh nn

2.2.To mt Case mi

khi ng chng trnh nhp i chut vo biu tng PowerWorld Simulator. to mt Case mi, t menu chnh chn File>New Case hoc click ln nt Open simulator Case trn thanh cng c. Mn hnh s chuyn sang mu trng, y l mu mc nh ca mt s mt si mi ca Powerworld, cc s mt si ny c dng trong vic phn tch ti hin li h thng in 3 pha v dng 1 dy th hin mi thit b 3 pha. xem mt file c sn chn File >Open Case t menu chnh hoc chn nt Open Case trn thanh cng c.2.2.1. Chn thit b phn phi( Bus ) Bus l thnh phn quan trng nht ca m hnh h thng in, n c dng th hin cc im kt ni ni m cc thit b c kt ni vi nhau trong h thng in. Trong vic xy dng m hnh h thng in dng PowerWorld Simulator bn c th v cc Bus trn s mt si gn vi cc thit b nh my pht v ti vi Bus. Vic chn cc Bus trn s mt si ni chung l n gin gm cc bc sau:- chn Insert>Bus t menu chnh hoc chn nt Bus trn thanh cng c.

- Click chut ln nn s ni m bn mun t Bus mi. Khi s xut hin mt hp thoi Bus Options.

Hnh2.1- Hp thoi Bus options T hp thoi ny chng ta nhp y thng tin cn thit nh t tn, kch c, nh hng vng, in p nh mc ca Bus cng nh Ti v cc thnh phn r nhnh ni vo n.- Click OK ng hp thoi, Bus mi s xut hin, n c hnh dng l mt ng thng nm ngang hoc thng ng trn s .2. Chn mt my pht Tip theo chng ta gn My pht vi Bus, cc My pht cng c chn theo tng bc tng t nh chn Bus, trnh t nh sau:- Chn Insert>Generator t menu chnh hoc chn nt Generator trn thanh cng c.

- Click chut tri ln Bus trn s v tr m bn mun gn vo, lc hp thoi Generator Options s xut hin.

Hnh 2.2 - Hp thoi Generator Options T hp thoi ny chng ta nhp y thng tin cn thit, nh la chn n v ca My pht, kch thc hin th, chiu, cng sut tc dng gii hn, cng sut phn khng gii hn, im t in p v bng gi. - Click OK, ng hp thoi kt thc vic to lp My pht. S s trng ging nh s di y.

Hnh 2.3 S mt si gm 1 Bus v 1 My pht3. Thm Bus th hai cng vi Ti Tng t, thm Bus th hai chn Insert>Bus t menu chnh hoc click vo nt Bus trn thanh cng c.- Click chut ln nn s ni no pha bn phi ca Bus th nht. Khi s xut hin mt hp thoi Bus Options. in y cc thng s cn thit,v click OK kt thc vic chn Bus th hai.- v Ti ta chn Insert>Load t menu chnh hoc click vo nt Load trn thanh cng c. Click chut tri ln im cui ca Bus th hai ny, ngay lc hp thoi Load Options s xut hin.

Hnh2. 4 Hp thoi Load Options- in y cc thng s cn thit nh Ti l cng sut tc dng(MW), cng sut phn khng(Mvar), hng ca biu tng, ..- Click OK ng hp thoi v kt thc vic chn Ti. S lc ny c dng nh hnh v.

Hnh 2.5 S mt si c 2 Bus, My pht v Ti

4. Chn ng dy xoay chiu ni hai Bus vi nhau, chng ta s chn ng dy AC bng cch:- Chn Insert>Tranmission Line t menu chnh hoc click vo nt Tranmission Line trn thanh cng c. Click chut tri vo im bt u ng dy v ko chut n im cui ng dy. Trong qu trnh ko chut bn c th v tng on ng dy theo mnh bng cch click chut tri mt ln cho mt on, v kt thc on cui cng hnh thnh ng dy th nhp i chut ti im cui ng dy. Hp thoi Tranmission Line / Transformer Options s xut hin.

Hnh 2.6 Hp thoi Tranmission Line / TransformerNhp y cc thng s cn thit nh cc thng s ng dy nh in tr, in khng, dung dn

- Click OK kt thc vic chn ng dy.

Hnh 2.7 S mt si gm : 2Bus , My pht, Ti , ng dy 5. Chn flow pie chart trn ng dy Khi ng dy c v xong n s t ng c 1 flow pie chart, bn c th chn thm vo line flow pie chart bng cch click vo nt line flow pie chart sau click gn ng dy, hp thoi s xut hin, in ng v c th thay i kch c .

Hnh 2.8 Hp thoi Line/ Tranformer flow pie chart - Click OK ng hp thoi.

6. Chn my ct

- Chn Insert> Circuit breaker t menu chnh hoc chn nt Circuit breaker trn thanh cng c v click ln ng dy gn Bus 1. Hp thoi Circuit breaker Options s xut hin.

Hnh 2. 9- Hp thoi Circuit breaker- Click OK kt thc, v tng t ta chn my ct gn Bus 2.7. Chn my bin p chn 1 my bin p trc ht chng ta cn chn 1 Bus th 3 khc cp in p.- Chn Insert> Tranformer t menu chnh hoc chn nt Tranfomer trn thanh cng c, sau click ln Bus 3 v v 1 ng dy ti Bus 2 khi bn v xong ng dy th hp thoi Tranmission Line /Transformer Option s xut hin. Nhp cc thng s cn thit nh in tr, in khng,dung dn, kch c

Hnh 2.10 Hp thoi Tranmission Line /Transformer Option- Click OK kt thc,v lp li tng t v thm 1 my bin p gia Bus 1 v Bus 3 khi hon thnh ta c s di y:

Hnh 2.11 S 3Bus , My pht, My bin p, ng dy, Ti 8. Chn t b ngang (Swichted Shunt ) Swichted Shunt l gm cc t in ghp li cung cp nng lng phn khng (MVAR) hoc tiu th cng sut phn khng.- Chn Insert>Swichted Shunt t menu chnh hoc chn nt Swichted shunt trn thanh cng c. Click ln Bus m bn mun t khi hp thoi Swichted Shunt Option s xut hin.

Hnh 2.12 Hp thoi Swichted Shunt Options Xc nh s Bus v nhp gi tr nh mc vo Nominal Mvar .

- Click OK ng hp thoi , gi s ta t t b Bus 3 , s nh sau:

Hnh 2.13 S mt si c Swichted Shunt8. Ghi tiu , hin th cc thng s cho Bus v ng dyChng ta xy dng gn nh xong mt Case mi, tuy nhin trc khi kt thc chng ta s nhp mt s thng tin trc tip ln s gip ta quan st hot ng ca s c tt hn.- Chn Insert>text t menu chnh a hp thoi text object ra nhp tn m ban mun t v click OK. nh dng nhanh chn Fromat>Font chn font, mu, c ch t hp thoi Format Multiple Objects- thm cc thng s hin th nh in p, dng cng sut, tn tht cng sut ta thc hin nh sau: ( Nhp chut phi ln Bus hoc ng dy gi menu con.( Chn Add new fields Around Bus t menu con. N s m hp thoi Bus fields.

Hnh 2.14- Hp thoi Bus fields( Chn v tr m bn mun thm mi v click OK . Hp thoi Bus fields m ra.

Hnh 2.15 Hp thoi Bus Field Options ( Chnh sa v la chn kiu hin th ri click OK. Ln lt lm tng t cho ng dy, My pht, Ti ta c cc thng s trn s m ta mun hin th. Ta c s n gin sau:

Hnh 2.16 S Case c hin th cc thng s n gin 9. Chy m phng mt Case chy m phng 1 Case trc ht chng ta click vo nt Run Mode trn thanh cng c.

Sau chn Simulator>Play hoc click vo nt single solution trn thanh cng c. S hot ng nh hnh 17, v bn hon thnh mt Case mi.

Hnh 2.17 S Case ang hot ng 2.3.Cch gii quyt vn ti u cng sut (OPF)

PowerWorld Simulator l mt phn mm ng dng c thit k m phng hot ng ca h thng in cao p. Trong ch chun Simulator gii bi ton tnh tro lu cng sut bng thut ton Newton Raphson. Vi s tng cng cng sut ti u (OPF), Simulator OPF cng c th gii nhng phng trnh s dng OPF. c bit Simulator OPF gii bi ton OPF s dng thut ton LP.Mc ch ca OPF xc nh cc tiu hm mc tiu (hm chi ph) bng cch thay i s iu khin h thng khc nhau m c ch n cc rng buc cn bng cng nh cc rng buc khng cn bng, n dng m t rng buc cn bng cng sut v cc gii hn hot ng khc.Trong Simulator OPF, chc nng LP OPF tm li gii ti u bng cch th dn gia li gii chun v tip n gii thut ton tuyn tnh thay i cc iu chnh h thng loi b bt k vi phm gii hn no.1. Gii mt OPF, v d cho h thng 3 Bus:

y chng ta s bt u vi Case 3 Bus (B3LP) c trong PowerWorld / Simulator/ Sample Cases. Bus 1 l Slack bus.Tt c cc Bus c kt ni vi nhau qua ng dy c khng 0,1pu v c gii hn l 100MVA, c mt ti 180MW Bus3.

Chi ph ca cc my pht l:- Bus 1: 10 $/ MWh, phm vi 0 400 MW

- Bus 2: 12 $/ MWh, phm vi 0 400 MW

- Bus 1: 20 $/ MWh, phm vi 0 400 MW

Ta tin hnh cc bc sau:

- M Case B3LP.- Kim tra cc thng s trn ng dy bng cch click phi ln mi ng dy, Bus, my pht v chn cc hp thoi Line/Bus/Generator information t menu s xung.

- Chn Run Mode.

Hnh 2.18 S 3 Bus m phng s dng LP OPF > Primal LP - tnh OPF, yu cu trng trng thi AGC ca tt c cc min (Areas) phi c chn l OPF. t AGC ca min thnh OPF: Chn LP OPF>OPF Areas. Hp thoi OPF Areas Records s t ng m ra. Kim tra trng trng thi AGC c chn l OPF cha. Nu cha, th nhp i chut ln trng thay i gi tr, sau ng hp thoi OPF Areas Records.

- Chn LP OPF > Primal LP m phng Case. Ch l gii hn trn ng dy khng c t trc p buc.Bn c th thy hnh ging nh di y:

Ch : ng dy ni Bus 1 v Bus 3 b qu ti v ton b cc Bus c cng chi ph .2. OPF Line Limit Enforcement (Rng buc gii hn ng dy)- Chn LP/OPF >OPF Areas. Ct Branch MVA xc nh liu gii hn MVA trn ng dy v my bin p (m c t nht mt u ni vo min ny) c c p buc hay khng. i vi ng dy truyn ti hay my bin p c rng buc OPF th chc nng Line/ Transformer Constraints phi khng b v hiu ha trn hp thoi OPF Option. V ring tng ng dy/my bin p phi thc hin rng buc trn mn hnh hin th OPF line/ Tranformer MVA Constraints.- Nhp i chut ln trng Branch MVA thay i gi tr thnh Yes, sau ng hp thoi OPF Areas.- Chn LP/ OPF > Options.

- Hp thoi LP OPF t ng m ra, chn mc Constraint Option v click Disable line/ Tranformer MVA Limit Enforcement loi b du chn.- Click Solve LP OPF sau click OK.

Hnh 2.19 Gii v d 3PLP vi p buc gii hn trn ng dy. LP OPF phn b li loi b vi phm gii hn. Chi ph cc Bus c thay i so vi v d trc. Chi ph mi Bus 3 l 14 $/MWh. kim tra iu ny ta thc hin tip:

- Tng 1MW Bus 3, click chut phi ln ti v nhp 181.0 ln trng Constant Power /MW Value trong hp thoi Load option v click OK.

- Chn LP OPF > Primal LP.Ton b chi ph tng ln 1935 $/hr so vi gi tr trc l 1921 $/hr, ta thy chnh lch 14$/hr khi Bus 3 tng ln 1MW.3. Gii thch vn Bus 3 LMP = 14$/MWh .

Ton b ng dy c cng tng tr, cng sut chy trn cc mch c phn b t l nghch vi tng tr

- i vi Bus 1 cp 1MW cho Bus 3, khi 2/3MW chy trc tip theo ng t 1 n 3, trong khi 1/3MW s theo ng 1 n 2 n 3.- Tng t, i vi Bus 2 cung cp 1MW cho Bus 3, th 2/3 MW s theo ng 2 n 3 v 1/3MW s theo ng 2 n 1 n 3.

- cung cp thm 1MW cho Bus 3, ta cn thay i cng sut pht ca my pht 1 (Pg1) cng vi cng sut thay i my pht 2 (Pg2) bng 1MW.

Pg1 + Pg2 = 1MW- Vi ng dy t 1 n 3 b gii hn nn khng th cho php tng cng sut truyn trn .

(2/3)Pg1 + (1/3)Pg2 = 0 - Gii h phng trnh trn ta c:

Pg1 = - 1MW v Pg2 = 2MW

Cost = (Pg*LMP) = [(-1MW)*(10.00$/MWh) + (2MW)*(12.00$/MWh)]

= 14.00$/hr.

4. Chi ph ca OPF khi c rng buc .

Tng t nh chi ph ca Bus, bn cng c th tnh chi ph ca vic thc hin rng buc trn ng dy. i vi ng dy truyn ti gi tr ny th hin phn chi ph h thng tit kim c khi gii hn cng sut tng ln 1.0MVA .Chn LP OPF>OPF Line and Transformer, hp thoi OPF constraints m ra. Ch : ct MVA Marginal Cost hin th 6.0 cho ng dy t Bus 1 n Bus 3. Gi tr ny c xc nh nh sau: - Nu khng c s thay i h thng ti

Pg1 + Pg2 = 0

- Nu ta thm 1 MVA cho dng trn nhnh t Bus 1 n Bus 3

(2/3)Pg1 + (1/3) Pg2 = 1

- Gii h phng trnh trn ta c:

Pg1 = 3MW v Pg2 = - 3MW

Cost = (Pg*LMP) = [(3MW)*(10.00$/MWh) + (-3MW)*(12.00$/MWh)]

= - 6.00$/hr.

Nh vy li tit kim c 6.00$/hr.

5. OPF khng th p buc c rng buc.Tip theo ta s quan st Case vi cc rng buc khng p buc c. Ta tin hnh tng ti Bus 3 ln 250 MW v chy li LP OPF.- Click chut phi ln Bus 3 v nhp 250 vo trng Constant Power/ MW Value.

- Chn LP OPF > Primal LP.

Ch rng ng dy ni gia Bus 3 vi cc Bus khc t gii hn MVA v my pht Bus 3 ang cung cp cho ti. Khi ti vt qu cc gii hn trn ng dy truyn ti.

Hnh 2.20 Gii v d B3LP vi my phat Bus 3 ang mang ti.Tip theo ta s m my pht Bus 3 v nh vy rng buc khng p buc c na:

- Click ln biu tng my ct mu ni gia my pht v Bus 3 m my ct - Chn LP OPF > Primal LP

Hnh 2.21-Gii v d B3LP vi rng buc khng p buc c.Tt c hai rng buc khng th p buc, nu 1 rng buc c th p buc do khng iu khin Slack gn vi s p buc m rng buc khng th loi b t LP c bn. Ch l gi tr LMP Bus 3 t n 1000$/MWh. Chi ph ph thuc chi ph ty ca bin Slack, gi tr ny c xc nh trng Marginal Violation Cost ca hp thoi LP OPF > Options.

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