IMPACT"O'F 1MBEDDED GENERATION 
ON 33 KV DISTRIBUTION SYSTEM 
VOLTAGE 
 
 
By 
P. S. S. CHANDRARATNE 
 
 
This thesis was submitted to the department of Electrical 
Engineering in partial fulfillment of the requirements for the Degree 
of Master of Engineering 
 
 
Supervised By: Dr. H. Y. R. PERERA 
 
 
Department of Electrical Engineering 
University of Moratuwa 
Sri Lanka 
 
2004 
 
82461 
 
 
 
 
  
Abstract 
 
Recently introduced schemes of Embedded Generation on the radial distribution 
lines have several remarkable advantages though· they produce some of the technical 
problems on the network. One of the major problems encountered is the variation of 
steady state voltage during the switching on/off operation of the Embedded 
Generators. The consumers connected on the line are subjected to larger variations 
during such operations. This research focuses on the study of the steady state voltage 
variation patterns and proposes solutions to mitigate the problem. 
 
The utilities impose several standards and require meeting specifications in 
connecting generators on the distribution network. Focusing on the effects on the 
locally connected COnStHl1erSto the network, both domestic and industrial, they are 
subjected to most of the prevailing technical problems arisen out of connecting 
Generators on the lines. 
 
Mainly, the problem of steady state voltage variations experienced by the consumer 
and finding ways of mitigating the same is discussed in this research paper. Data 
collection, application of load flow theories, modelling in SynerGEE software, 
analysis, application of mitigate measures on the model and the conclusion of the 
outcome of the research work are presented. 
 
A statistical way of approach is used to obtain the percentage of consumers affected 
in the case studies undertaken during the study. Recommendations are made that lead 
to mitigation of the problem concerned. 
,\cknowled~ements 
Declaration 
\b.., tract 
CONTENTS 
iii 
1\' 
\' 
I ,i..,t of ,\bbre\·iations and.:;, mbols us;:d \ ' 1 
J.ist of figures 
Chapter l 
Ll 
1.2 
1.3 
1.-l 
Chapter 2 
2.1 
2.2 
23 
2.-l 
2.5 
2.h 
Ch.1pter .1 
3.1 
3.2 
33 
3.-f 
1.5 
3.6 
3.7 
3.8 
3.9 
:uo 
'tl I 
3.12 
1.n 
:t 1-l 
\Ill 
Introduction 
t\th .Jnlcl~t>:- of Emlwddcd Ct·awration 2 
Concerns 1t1r l:mlx•ddcd Ccncr,1tion 2 
·r \pes of Lmlwddt•d (;l'twrators / 
'I he voltage pat h'rn of l{,ld i,1l I )istribution Systt'm J 
I'<HV('I' )•)ow (_ell\ ul.ltions 7 
Trarbfcr of power lwl wt•t•n l wo nodes 7 
Bus Cl,lssificntion R 
Tlw Nl'lworl.. h.lllcllitllls 10 
ltcr.lli\'t' methods II 
Comp.uison of 11\'l'clliH• methods 12 
I lw compt•ns..llaon hciS\'d Load I low method 1-l 
~y ... tt•m Modl'lling 17 
Tt•(hnKiliC (l( .,\..,kill llltH.Idling in~\ ncrCEE IS 
Some suggl'<.,lt•d clpproclC:ht•s to kMd allocation clpplil•d in 20 
Svner(,J·F 
Ovt>rvit'W o~ ..,, awr( .I E nwthodology 22 
1\dv.mt.lgt•..,of lo.ld flow nwthod in ',ynerCFr. 2.1 
Dis,lth cllllclgt•s of loc~d II ow ml'lhod in SynerCEE 2-l 
B.llanted load flow .m.1 lvsis 2-l 
Convergt'l1t't' proress 25 
Volt,lgt• drop tclk ul.1tions in b.l i.IIKt'd .md by-phase an.lly'->i.., 2(, 
Rad i.1 I lo.1d tlnw algorithms 
~ample fcl'dl'r modd tN•d in '-,vawrCU ·: 
Load 1:1ow outw,lrd prop,lg,ltion 
Load llow in\\'.ll'd prop.lg.llinn 
I. i 11l'cl ri Sc.l I ion 
lht• 1\llcllmodl•lling pron·ss 
---
26 
27 
.., ... 
_, 
2S 
::!t) 
29 
<. 'h.1ptcr 4 
4.1 
-1.2 
.. u 
-l..t 
-1.5 
-1.6 
4.7 
4.S 
Ch.lpkr ') 
<. h.1 pll'r 6 
6.1 
6.2 
Rdcn:nrcs 
~\pp!:'ndic!:'" 
2 
3 
4 
5 
6 
7 
8 
9 
10 
II 
Regulator Modelling 
Autotransfornwr .,.., Volt.1gc Rq!,ui.Jtor 
The Rq~ul,1tor Modd 
Mathematical n.·prl'"l'nt,llion of Rq~ul.1tor 
Re~ulator 1-. V \ rating 
The loMI tap ch.1ngN ,1nd nllltrollcr modl'l 
'I he Capacitor Bank .1s \'oltagt' l{t'gulator 
Selt·\.·tion of k\' rating ot <.'.lp.Kitors 
I )!:'tails of<.. .lpt~ritor <.. omp<•n.;.ltJon 
C.i..,!:' '-ltud\ 
Cnmnwnts and Rt>nlmnwnd,lttons 
Comnwnts 
H.ecommendations 
/ 
31 
31 
31 
35 
37 
3S 
3S 
39 
,19 
42 
50 
51 
52 
53 
Sample feeder t.1h.en for .1na l\'si.., Cl haldena 33 kV feeder from ')') 
B.idulld CSS) 
St'l!:'ct!:'d s(;'( tions of tlw s.unph• l<'t>dt>r t.lkt>n for plotting voltag!:' ."ii 
\ ariations in Lase d.1t<1 
Sample output dat.1 from c.,, nl·r<..l·E ck'L·tric \ ' l·rsion 3.3 (Case 1) '19 
~amplt' output data from~~ twr<...l·l ~ l :lt'<.' tri( \ l'rsion 3.3 (Ca~ 2) o2 
... 
Sample output dat.1 from S\'rwr( .1 : 1 ~ l :lectric \ ersion 3..1 (lase 3) 65 
Sa mplt' output d,1t,1 from S\ rwr( ,1•1 ~ I :l(;'(· tril' \ t;>ro.;ion .1.1 (( ast' 4) 6..'-' 
Sample output data from s, rwr<-:I·E Ek•rtrit' \'ero.;ion 1.3 (Case 5) 70 
Sample output d,1t<1 from S\nt•rCI·E Ek·dril Yl•rsion 3.3 (Case 6) 7-l 
Dat.1 tal-.en for tlw st,1tisli<'<11,m.1 lyo.;is lor .111 cas<•s (T<~bll' 7) 78 
St<~tistical an.1lvsis results. 79 
Statistic<tl il nalysio., r<'"ldts HO 
~ 
II 
ACKNOWLEDGEMENTS 
I ""ish to thank for the <~cademic ~taff of the Dcpartntcnt of Elcctricill Engineering, 
lJnin•rsity of Moratmva for the support <1nd guidance provided throughout the 
period of the course PC Diploma / v1Fng in Fk>ctrical Engineering. 
Specially, I wish to C\.tL•nd nw cordial th.111ks hl Prof. J. R. Lucas, Dr. I l. 'I. R. 
Perera, Dr. f\. Wickramaar<~chchi, and Dr. I I. J. C. Pciris for their e>-.tended 
support in carrying out il MICC<.'sslulrL's<.'Mch project. 
..1 
lhc authors of the booko... when• n•ft•rt•nCL' is made with in connection to the 
successful completion of this project wi ll <1lo...o be appreciated and acknowledged. 
My appreciation is also extended to Mr. P. 1 . C. K<Hiyawasam, Project Milnager, 
Mr. G. J. i\luthgc, Chief Engineer (Svstl'l11 Coni rol) of CEB for the supervision of 
tlw research praclical worb done b) me. 
C\h special appreciations will be delivered to the officers of Distribution Planning 
Branch and ~1r. K. P. P. PL'rL'ra, lilcctrical Engineer (Distribution Planning 
Branch) of CEB for his fullest corponltion <.'xll'ndcd towards the acti\·ities of 
modelling of the case study lll'twork in SvnL•rCEE o...oftwMe package and assisting 
nw in succe~sful completion of this r<.'SL'Mch pclper. 
Fin.1lly, this research paper is respectably forw.:~rdcd to my beloved parents 
encouraging towMds sucn•ss in <.'v<.•ry clC tion I involved in my life, wife Priyani 
.lnd two sons Sandes and ViJun who hav<.• bt•en ell ways with my success. 
---
P. S. S. CHANDRARATNE 
PFJEFJ I7/00 
Ill 
Q~CJ,A RATIQN 
In accordance with the requirements of tlw M,lsler of Engineering (Electrical) of the 
University of Moratuwa, Sri Lanka, l produCl' the following thesis titled "Impad of 
Emb~.:ddcd Generation on J3 k \ Dt~tnbutwn ~)'~tcm Voltage". 
This '' ork was performed under the Mtpervision of Prof. J. R. Lucas and Dr H. ) . R. 
Perer<1 of the Department of Electrical Engml'cring, Uni\crsit} of Moratuwa. l 
declare that the work '>ubrnitted in this rl'Sl'Mch p.1pl·r i-.. my own to the be..,t e>..cept 
as acknowledged in the text and footnotl'" etc., ,md have not )cen previou-..ly 
submitted for a degree at the Univcr-..it) of Mort1tuwa or <any other instihttion. 
~ 
P. S. S. CHAN DRA RATNE 
PI!/ EE/ 17 /00 
0..1.. December 200-l 
~ ~ Or. II. Y. R. PCRERA .. 
Supervisor 
0 1. December 200-l 
.... 
I\ 
Abbreviations and Symbols used 
Abbreviation/ Descript ion 
Symbol 
CEB · Ceylon Electricity Bo.1rd 
GSS Grid Sub~tation 
EG 1 Embedded Generation 
kV I kilo Volt... 
k V 1\. I kilo volt ampt•res 
kW 
kva r 
PT 
CT 
LIX 
LTC 
Ps 
Q. 
PR 
QR 
r< 
Pt~n 
P Lo..•J 
p, o, ...... 
Qc. 
Q\.en 
Qlo.lll 
Ql.t'~"-..... 
R 
kilo Watt 
Kilo volt Mnpt•rc re,Klive Power 
Potential Tran~former 
Currcn t 'T ransfornwr 
Line Drop Com pens,, tor 
Load l'ap Ch,1nger 
Sending End /\.clive Power (kW) 
Sending End Reactive Power (kvar) 
Receiving bnd /\.clive Power (kW) 
Receiving bnd Re,Klive Power (kv.u) 
Gcncmtor /\.clive Power (kW) 
1\.ctivc Power of the (,ener,1lor connected 
1\.cti\·c Pmvcr <..on ... umcd b; the lo,1d 
/\.clive Power lo-.ltn the -.y-.tl'm 
Generator Rl',1ctivl' Power (k\M) 
Reactive Power of the Ct•m·rator connected 
Reactive Powt>r consunwd by the loc1d 
Reactive Power l o~l in llw ~ystcm 
Resistance of the lint• 
t) I Vol tagc 1\.ngle 
X 1/\.vcrage value of,, ~el of dat,, 
>... I Reactance of the line 
V" I Sending end Volt,,gt• 
;f 
.__ 
II 
II\ 
i' 
l'll'P JO l•1" l' JO llO!ll'!Jl'j\ JO lll;)!:>ypo:) ',) 
l')t'p JO ),)s l' JO UOI)l'I.'I.~)U pJepUElS .U 
,)~h.!l[Oj\ pu;) ~LI!,\!;):J;)~ ~I J\ 
Figure 
No. 
hg. 1.1 
Fig. 1.2 
Fig. 2.1 
Fig. 3.1 
Fig. 3.2 
Fig. 4.1 
rig. 4.2 
Fig. --1.3 
h~. 4.-l 
Fig. 4.5 
Hg. 4.o 
l·ig. 4.7 
Fig. --l.S 
fig. 4.9 
Fig. 4.10 
T,1ble 5.1 
1-ig. 5.1 
Pig. 5.2 
1-ig. 5.3 
T:ig. SA 
fig. 5.5 
hg. 5.6 
l'ig. 6.1 
f-ig. 6.2 
List of Figures & Tables 
Description 
Variation of\ oltagl' ,1long .1 d istriblltion lint> (Without Generation) 
\ ariation of volt,lgt' along a distribution line (With added Generation) 
Powt>r tlow in d radial nt'lworl.; 
Sample radi.ll k•l'dl•r in Svm•r( ;EF 
Lood flm, techniqul' ust•d inS} 1Wr( ,I I 
The Ideal lrJnsfornwr n•pn·~enlalmn 
Autotran:>iormcr t~s l3ud, lOillll'llion 
Autotransformer ,1s I3oo:>l conncdion 
The voltage regulator model 
Model for m.1thC'm.llil'tll rl'presenlat ion 
Connection ot PT's, CT's ,1 nd I I )( Model 
Feeder wilhoutl.1pacitor rompensation 
Vector dio!-,'Tdm of fl'l'lkr withou t ct~pt~citor 
ft>eder with ,1 C.1p,1l itor fl'gu1.1tor nH111l'dc·d 
\'ector diagram of Ieeder wilh c.lp.Kilor cotUllXlcd 
0ddils of l.l!>t' ~tudics nwddk'd in ~vnt•rt.l I 
... 
/ 
\ ·oltage distribution ,1t st'll'cll•d nodes of the sample teeder- (ase I 
\'oltagt> distribution at sc•ll•dt•d nodt•s of the s.1mple feeder - Case 2 
\ oltagt> distribution ,11 Sl'll•dt>d nodt>s of tht> s<unplt' feeder- Case 3 
Voltagt> distribution at Sl'll'dl•d nodt>" of tlw SClmple feeder- Ca!-.e -I 
Voltage dbtribution tlt sl•lcck•d nodl•s of the sample feeder- Case 5 
Volta~e distribution at sl'il'Cll·d nodl'S ollhe s.unpk feeder- Case 6 
VJriill ion of sl(•,ldv ..,ltlll' voll,1gt• in ,,II C<1S<.:'S- Cilsl's 1-6 
Stat isti<.:,ll Comp,Hison of Node· Voltc1gl' VMit~ tion fo r C.Jscs 1-6 
--
Page I 
No. 
\Ill 
-I 
5 
7 
27 
1ll 
1 1 
12 
33 
3--l 
35 
18 
ll) 
-Ill 
-Ill 
-I I 
-!2 
-tl 
45 
46 
47 
-IS 
49 
50 
51