POWER ENGINEERING AND ELECTRICAL ENGINEERING VOLUME: 10 | NUMBER: 1 | 2012 |MARCH
© 2012ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 1
EVALUATION OF COOPERATION WPP AND PVCONNECTED
THROUGH THE SHARED TRANSFORMER TO THE NETWORK
22 KV
Tomas SUMBERA1, F an isek STRIDA1, Zdenek HRADILEK1, S anisla RUSEK1
1Depa men o Elec ical Enginee ing, Facul y o Elec ical Enginee ing and Compu e Science, VSB–Technical Uni e si y o
Os a a, 17. lis opadu 15, 708 33 Os a a Po uba, Czech Republic
omas.sumbe a@ sb.cz, an isek.s ida@ sb.cz, zdenek.h adilek@ sb.cz, s anisla . usek@ sb.cz
Abs ac . The a icle deals wi h e alua ion he
coope a ion possibili y o wind and sola powe plan s
connec ed h ough he common ans o me o he 22 kV
ne wo k. Coope a ion e alua ion is, based on measu ed
da a, o wind powe plan abou ins alled capaci y 2 MW
and o sola powe plan abou ins alled capaci y
1,1 MWp. In he nex pa o his a icle he e is he
analysis o sui able locali ies o cons uc ion o „hyb id
sys em (WPP+PV)“ in he Czech Republic. The las pa
o he a icle deals wi h analysis o ac i e powe
luc ua ion o indi iduals elec ic sou ces compa ed wi h
sys em WPP + PV and wi h e alua ion he e ec s a e
sys em connec ion WPP + PV o he 22 kV ne wo k.
Keywo ds
Wind powe plan , sola powe plan , a ailabili y
a io, ac i e powe .
1. In oduc ion
Wind and sola powe plan s ha e a g ea ad an age
compa ed o common sou ces o elec ic powe ha hey
don’ equi e nei he any uel du ing he elec ic powe
p oduc ion no p oduce any haza dous was e and was e
p oduc s, especially CO2. Con e sion e iciency o wind
powe and sola adia ion in o elec ical ene gy is e y
small. Wind powe plan e iciency anges a e age abou
50 % and sola powe plan om 15 % o 22 %,
depending on he ype o PV panel. A main disad an age
o wind and sola powe plan s is uns able and s ochas ic
elec ical ene gy supply, which is in luenced by a la ge
numbe o ac o s, such as seasons, day ime, wind speed,
sola adia ion in ensi y, e c.
In he Czech Republic he e is he lack o sui able
locali ies cons uc ion o bo h wind powe plan s and
sola powe plan s. F om e iciency equi emen o
p ima y ene gy con en , which is se ou in Dec ee
475/2005 Coll. in ended o he law implemen a ion
abou enewable sou ces, i is assumed ha a e age
annual a e in he place o wind powe plan cons uc ion
up on high o he wind u bine o o axis will be 6 m·s-1
and mo e. The e doesn´ exis any no ice ha would
egula e wha should be minimal sum o sola adia ion in
he place o sola powe plan cons uc ion, and mos o
la ge sola powe plan s a e buil in he place wi h low
sola adia ion in ensi y.
In his a icle we e alua e wind and sola powe
plan s coope a ion, connec ed h ough he common
ans o me o he 22 kV ne wo k. E alua ion is ealized
o July and Oc obe . The da a a e ob ained om
measu emen s om wind powe plan wi h ins alled
capaci y 2 MW and om sola powe plan wi h ins alled
capaci y 1,1 MWp, loca ed in Mo a ian-Silesian egion.
2. Coope a ion E alua ion WPP +
PV
Elec ici y supplies om wind powe plan a en’
dependen on day ime, as is he case o sola powe
plan , bu only on wind speed. Wind powe plan could
co e elec ici y supply a nigh du ing coope a ion WPP
+ PV.
Fig. 1 shows he ins an aneous powe wa e o ms
a hou ly in e als o July. Wind powe plan a ailabili y
a io was an a e age abou 14 % in July and sola powe
plan a ailabili y a io was an a e age 18 %.
Fig. 2 shows he ins an aneous powe wa e o ms
in he selec ed days. F om he g aph we can see ha 8. 7.
a 19:00 sola powe plan s opped o supply elec ici y o
he ne wo k and his supply was co e ed by wind powe
plan only. On 10. 7. we can see ha be ween 13:00 and
14:00 supplied load inc eased signi ican ly om alue
1215 kW o 2050 kW.
POWER ENGINEERING AND ELECTRICAL ENGINEERING VOLUME: 10 | NUMBER: 1 | 2012 |MARCH
© 2012ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 2
Fig. 1: The cou se o ins an aneous powe WPP, PV and WPP + PV – July.
Fig. 2: The cou se o ins an aneous powe WPP, PV and WPP + PV – om 8. 7. o 10. 7.
A ailabili y a io o WPP + PV sys em would
mo e abou 15 % in July. The sys em would supply
355 MWh, om ha 209 MWh wind powe plan and
145 MWh sola powe plan .
Fig. 3 shows he ins an aneous powe wa e o ms
in Oc obe . The sola powe plan a ailabili y a io was
an a e age 9 % in his mon h and wind powe plan
a ailabili y a io was signi ican ly highe han in July and
i s a e age alue was 25 %. F om he p ocess we can see
ha elec ici y supply was mainly om wind powe plan .
Fig. 3: The cou se o ins an aneous powe WPP, PV and WPP + PV – Oc obe .
Fig. 4 shows he ins an aneous powe wa e o ms
in he selec ed days. F om he p ocess we can see ha load supply om sola powe plan was sho e abou
4 hou s han in July.
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© 2012ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 3
Fig. 4: The cou se o ins an aneous powe WPP, PV and WPP + PV – om 8. 10. o 15. 10.
A ailabili y a io alue o WPP + PV would mo e
abou 19 % in Oc obe . The sys em would supply
440 MWh, om ha 366 MWh wind powe plan and
73 MWh sola powe plan .
3. Sui able Locali ies Analysis o
Hyb id Sys em (WPP + PV)
Cons uc ion
3.1. Wind Powe Plan s
Wind powe plan is conside ed as one o he mos
g owing powe sou ces all o e he wo ld. By 2020 he
sha e o elec ical ene gy deli e ed om wind powe
plan s should inc ease o 12 % om he o al global
consump ion.
F om e iciency equi emen o p ima y ene gy
con en , which is se ou in Dec ee 475/2005 Coll.
in ended o he law implemen a ion abou enewable
sou ces, i is assumed ha a e age annual a e in he
place o wind powe plan cons uc ion up on high o he
wind u bine o o axis will be 6 m·s-1 and mo e.
Fig. 5: A e age wind speed ield a a heigh o 100 m abo e he
su ace.
The Ins i u e o A mosphe ic Physics o he
Sciences Academy in he CR p epa ed he map o
a e age wind speed in he CR a he heigh 100 m abo e
he su ace, see Fig. 5 which is he ypical o o heigh a
cu en wind powe plan s. Th ee combined models VAS,
WAsP and PIAP we e used o calcula e he a e age wind
speed.
3.2. Sola Powe Plan s
Sola ene gy is a ailable a ound he wo ld. Howe e , i is
an uns able ene gy sou ce which is depended on day ime,
wea he , season and cloud amoun in a gi en loca ion.
This me hod o elec ical ene gy p oduc ion is
qui e capi al in ensi e. In compa ison o all o he ways o
elec ici y de elopmen , especially RES is 5 imes mo e
in ensi e. C ys alline silicon echnology is used in his
case. Sola cells can be ei he monoc ys alline o
polyc ys alline and hei e iciency is in he ange om
15 o 22 %, speci ied li e ime is up o 25 yea s. Howe e ,
p oducing pho o ol aic cells i sel is e y ene gy
in ensi e as he ene gy olume o p oducing one cell is
deli e ed by one pho o ol aic cell in ou condi ions o e
app ox. 6 yea s.
The sola adia ion incidence on he a ea o he
CR does no ha e he same in ensi y a all places. The
a e age annual sum o global adia ion is in Fig. 6.
Fig. 6: A e age annual sum o global adia ion.
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© 2012ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 4
3.3. Locali ies Analysis
Sui able locali y o hyb id sys em cons uc ion is loca ed
mainly in he Vysocina (Highlands). A e age annual sum
o global adia ion is 1054 kWh·m-2 and a e age wind
speed a he heigh 100 m abo e he su ace is highe han
5,5 m·s-1, as we can see in Fig. 7. O he sui able locali y
is he sou he n pa o Sou he n Mo a ian egion, whe e
is a e age annual sum o global adia ion, bu a e age
wind speed doesn’ exceed 7 m·s-1.
Fig. 7: Sui able locali ies o hyb id sys em WPP + PV cons uc ion.
4. Powe Fluc ua ion E alua ion
Ac i e powe descending a wind powe plan s is caused
by change o wind speed. Wind powe plan wo ks in
wind speed ange om 3 m·s-1 o 25 m·s-1. Wind speed is
dependen on landscape segmen a ion (meadows, o es s,
ci ies). Ac i e powe descending a sola powe plan is
caused by change o sola adia ion in ensi y. Sola
adia ion in ensi y changes i sel du ing he day and
du ing he season. An impo an ac o in luencing he
sola powe plan s is he sola panels o a ion, clouds
in luence, panels pollu ion by dus and snow.
Di e ence equency o ac i e powe among
pa icula hou s is shown in Fig. 8 and Fig. 9. The
luc ua ion size o ac i e powe is he mos equen ly
below alue 480 kW du ing July and below alue
320 kW in Oc obe .
The g aphs show ha powe descending is lowe
in compa ison wi h he indi idual sou ces. I is impo an
o pe cei e ha he ins alled capaci y o sys em was
3,1 MW, om ha 2 MW a WPP and 1,1 MWp a PV.
Fig. 8: His og am DP – July.
Fig. 9: His og am DP – Oc obe .
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© 2012ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 5
5. Connec ion In luence o he 22 kV
Ne wo k
Resou ces connec ion was e alua ed on a eal ne wo k in
Mo a ian-Silesian egion. The e we e modeled eeding
subs a ion a ea 110/22 kV mainly wi h 22 kV ou side
conduc ion. WPP and PV a e connec ed o his ne wo k.
Fu he mo e he e was c ea ed supply ne wo k
model 110 kV om 400/110 kV supply subs a ion o
110/22 kV supply subs a ion. The a ea load 110 kV was
modeled acco ding o eal da a om win e measu emen
2009.
The e a en’ a ailable any loading da a o
pa icula dis ibu ion ans o me s 22/0,4 kV (DTS) o
modeling powe aking-o in 22 kV ne wo k. The DTS
load was modeled by pe cen ual loading o ins alled
powe DTS. T ans o me in subs a ion 110/22 kV is
abou 25 MVA powe .
Maximum ol age peaks we e selec ed o
in luence e alua ion on he ne wo k and on he condi ions
in he subs a ion. The Tab. 1 shows pe cen ual ol age
change a e connec ion PV, WPP o WPP + PV sys em.
The wind powe plan was calcula ed wi h cos j = 0,98
induc i e and he sola powe plan was calcula ed wi h
cos j = 1.
Tab. 1: The ol age di e ence a he connec ion poin .
dU [%] – 10 h o July dU [%] – 4 h o Oc obe
PV WPP WPP+
PV WPP PV WPP
+ PV
Connec ion
poin 0,50 1,78 2,25 0,57 1,12 1,67
Bus ba
110 kV 0,09 0,46 0,54 0,10 0,30 0,38
Bus ba
22 kV 0,04 0,17 0,21 0,05 0,11 0,16
In July, he alue o su e able ol age change
DU= ±2 % was exceeded a he connec ion poin , which
is inconsis en wi h he ules o he dis ibu ion sys em.
In his case is necessa y o con ol powe low om he
sou ce, bu his legisla ion does no allow ye .
Fig. 10: Scheme 22 kV ne wo k.
Fig. 11: Scheme 110 kV ne wo k.
6. Conclusion
WPP + PV sys em, Hyb id sys em, should ha e been kep
in connec ion wi h sui able accumula ion. In his sys em
he e isn’ so equen and signi ican change o powe
descending due o ins alled powe han in sepa a ely
wo king sou ces. Big sys em ad an age is possibili y o
elec ici y supplies a nigh , when he sola powe plan is
ou o o de .
WPP + PV sys em con a enes ules o
dis ibu ion sys em du ing wo king due o ol age
inc easing a he connec ion poin , whe e is allowed
ol age change DU= ±2 %. Pa o he ene gy could be
used o echa ge he ba e y and he o he pa would
co e powe supplies o he ne wo k, in he case o
accumula ion connec ion o he sys em.
Acknowledgemen s
This con ibu ion was p epa ed in he amewo k o
esea ch p ojec CZ.1.05/2.1.00/03.0069 and SP2012/53.
Re e ences
[1] HRADILEK, Zdenek and Tomas SUMBERA. Reliabili y o
elec ical powe supplies om enewable sou ces. In: 11 h
Con e ence Elec ic Powe Enginee ing 2010. Czech Republic,
B no, 2010, p. 401-406. ISBN 978-80-214-4094-4.
[2] PROKOP, Lukas, Zdenek HRADILEK and Tomas
SUMBERA. Applica ion o WPP Powe Flows Measu emen
Me hodology. In: Con e ence P ognozawanie w
Elek oene ge yce PE 2010. Poland, Wisla, 2010, p. 121-122.
ISBN 978-83-61118-82-4.
[3] HRADILEK, Zdenek and Tomas SUMBERA. Simula o o
powe o ecas ing gained om wind powe plan s. P zeglad
elek o echniczny. 2010, ol. 86, iss. 8, p. 196-199. ISSN 0033-
2097.
[4] SUMBERA, Tomas. Reliabili y o elec ici y supply om
enewable sou ces and possibili ies p edic ing powe . In: 8 h
Con e ence WOFEX 2010. Czech Republic, Os a a, 2010, p.

POWER ENGINEERING AND ELECTRICAL ENGINEERING VOLUME: 10 | NUMBER: 1 | 2012 |MARCH
© 2012ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 6
33-38. ISBN 978-80-248-2276-1.
[5] RUSEK, S anisla , F an isek STRIDA and Tomas SUMBERA.
The Issue o Vol age Changes in Elec ici y Ne wo k in
Rela ion o Ope a ion o Wind Powe Plan s. In: Con e ence
ELNET. Czech Republic, Os a a, 2010, p. 27-34. ISBN 978-
80-248-2349-2.
[6] HRADILEK, Zdenek and Tomas SUMBERA. Reliabili y and
P edic ions o Powe Supplied by Wind Powe Plan s. In:
In e na ional Con e ence on Renewable Ene gies and Powe
Quali y 2011. Las Palmas de G an Cana ia, Spain, 2011, p.
254-259. ISBN 978-84-614-7527-8.
[7] HRADILEK, Zdenek and Tomas SUMBERA. Simula o o
P edic ion o Ene gy Ob ained om Wind Powe Plan s. In:
12 h Elec ic Powe Enginee ing 2011. Czech Republic, Kou y
nad Desnou, 2011. ISBN 978-80-248-2393-5.
Abou Au ho s
Tomas SUMBERA was bo n in Mo a ska T ebo a. In
2008 he g adua ed VSB-Technical Uni e si y o Os a a,
Facul y o Elec ical Enginee ing and Compu e Science,
powe enginee ing ield. Today he is Ph.D. s uden in he
Depa men o Elec ical Powe Enginee ing, Technical
Uni e si y o Os a a and he applies himsel o he issue
o he wind and sola powe plan s in luences o he
dis ibu ion sys em.
F an isek STRIDA was bo n in P os ejo . In 2007 he
g adua ed VSB-Technical Uni e si y o Os a a, Facul y
o Elec ical Enginee ing and Compu e Science, powe
enginee ing ield. Today he is Ph.D. s uden in he
Depa men o Elec ical Powe Enginee ing, Technical
Uni e si y o Os a a and he applies himsel o he issue
o ne wo ks op imaliza ion wi h enewable ene gy
sou ces.
S anisla RUSEK was bo n in Ha i o -Sucha. In 1981
he g adua ed VSB-Technical Uni e si y o Os a a,
Facul y o Mechanical Enginee ing and Elec ical
Enginee ing, powe enginee ing ield. He g adua ed
scien i ic pos g adua e a Facul y o Elec ical
Enginee ing and Compu e Science B no, elec ical
machines and de ices, in 1989. Pos -g adua e educa ion
a Facul y o Science Palacky Uni e si y Olomouc in
uni e si y educa ion g adua ed in 1991. He was
habili a ed a he FEECS VSB Os a a in 1991. He is
p o esso om 2001.
Zdenek HRADILEK was bo n in B no. A e g adua ion
o college educa ion a Facul y o Elec ical Enginee ing
and Compu e Science B no Uni e si y o Technology in
1962 he wo ked as a echnician in company Sou he n
Mo a ian powe plan s in B no, han he wo ked as a
majo powe -supply di ec o in Hea -supply Os a a and
om 1966 un il now he is a he VSB-Technical
Uni e si y Os a a. His scien i ic p epa a ion g adua ed
by his candida e disse a ion de ending a he B no
Uni e si y o Technology, powe supply ield, in 1972.
He de ended his doc o al hesis a he Czech Technical
Uni e si y in P ague in 1988. His pedagogical and
scien i ic wo k is ocused in powe enginee ing ield. He
was appoin ed associa e p o esso in 1977 and a he ime
o elec ici y depa men incep ion in 1978 he became i s
leade . He unde ook his unc ion, wi hou pause, un il
2009. He was appoin ed p o esso in 1988.