Ihsan Jabbar Hasan, Chin Kim Gan, Meysam Shamshiri, Mohd Ruddin Ab Ghani and Rosli Bin Omar
Indian Journal of Science and Technology
1685
Vol 7 10 | October 2014 | www.indjst.org
substations has been selected among the 275 candidate substations. Meanwhile, this igure indicates the num-
bers of consumers which assigned to their particular substation.
2.2 Optimum Feeder Routing using MST
As explained in introduction the prim’s algorithm has been utilizes in this paper to ind the optimum feeder routing
of LV and MV networks. But the only prim’s algorithm cannot carry out our desire optimal routing. he modiied
prim algorithm needs to be performed because of some technical requirement such as, open loop feeders and
not allowed branches pass through each other. Figure 6 shows the proposed modiication algorithm using prim’s
algorithm in MST in order to ind the optimum feeder routing in distribution network.
Figure 7 shows the obtained results ater LV and MV feeder routing using modiied MST algorithm. It depicts
the LV feeder path with purple line color and MV con- ductors by black line color. he LV feeders are connected
adequately without passing each other as shown in igure. It demonstrated the modiied algorithm has succeeded to
solve the feeder routing problem by considering the prob- lem constraints.
3. Problem Formulation
In distribution system planning, the geographical dis- tribution of loads density and allocation of feasible
candidate substations are the important information in the study year. Based on optimization point of view,
Figure 3. he optimum substation placement lowchart
using PSO.
START Initialization
Create random solution, considering the maximum
number of substation Evaluate the solutions by
substituting in objective function Determining the personal
and global bests Update position and velocity
Population number?
Check the stop condition
END
Population and iteration numbers. Consumer coordinates and etc.
Distance calculation between consumers and candidate substations.
Iteration= Iteration+1
Yes
Yes No
No
Figure 4. Consumers and candidate substation.
200 400
600 800
1000 200
400 600
800 1000
X [m] Y [m]
Consumers Candidate Substation
Figure 5. Selected MVLV substations ater optimization.
200 400
600 800
1000 100
200 300
400 500
600 700
800 900
X [m] Y [m]
Indian Journal of Science and Technology Vol 7 10 | October 2014 | www.indjst.org
1686
Figure 6. he lowchart of modiied MST algorithm in
order to solve the optimum feeder routing in distribution network.
START Initialization of
MST algorithm Distance calculation between all
graph points and create the graph Calculate the weight of
each branch Prim Algorithm
Is there any branch cross
the other branches?
Extract the obtained tree to the OpenDSS file as
the Line data connections END
Repeat the algorithm to find the non-cross
minimum branch Consumers and Substations
Coordinates X,Y
Does the graph nodes
finished? Yes
Yes No
No
Figure 7. Obtained network ater optimum feeder routing
for LV and MV in 164 consumers distribution network.
200 400
600 800
1000 100
200 300
400 500
600 700
800 900
1 7
8 10
13 14
16 23
34 42
45 79
121 164
175 187
200 205
228 233
242 245
265 297
307 309
340 349
358 433
437 4
11 18
25 84
101 103
109 127
134 153
163 168
183 212
260 273
337 344
367 438
463 476
20 29
32 48
57 70
78 82
90 107
115 120
124 126
131 135
149 151
165 167
184 195
230 250
254 257
274 302
339 370
392 448
35 37
40 44
47 49
50 52
54 62
81 94
112 128
137 143
150 152
166 179
185 189
281 298
321 330
347 355 363
364 371
390 417
420 428
430 434
440 444
447 451
460 496
41 58
63 72
73 75
86 88
96 100
111 118
139 144
148 171
182 227
261 272
299 325
328 368
377 389
393 409
412 423
431 435
458 462
466 482
498 67
74 92
97 105
106 130
132 138
142 146
154 178
197 253
262 263
276 285
310 312
315 343
365 383
385 400
401 402
427 454
468 470
479 481
486 499
157 160
161 162
174 188
191 196
217 218
220 223
229 234
236 238
241 246
247 258
264 266
268 277
279 286
289 317
327 351
360 382
384 388
418 421
436 446
456 457
464 485
488 492
2 9
22 30
55 56
60 61
71 80
117 169
172 190
201 222
248 271
284 305
332 334
359 362
375 381
478 490
15 24 26
33 87
102 110
113 199
214 225
235 239
293 294
426 432
461
194 231
232 249
251 252
255 275
288 300
319 352
369 373
387 391
410 441
471 474 483
3 5 6
38 43
46 51
77 85
89 91
98 108
141 155
180 209
210 211
215 221
240 244
259 267
270 283
303 314
326 331
333 336
398 453
459 469
487 497
17 27
28 31
36 39
59 64
65 76
83 93
95 99
104 119
123 133
145 186
193 203
204 256
287 290
296 311
329 348
350 366
376 379
394 405
413 414
424 425
455 493
12 19
21 53
66 68
116 122
158159 176
198 207
208 216
224 226
243 291
301 304
313 318
338 341
345 354
372 386
395 399
403 404
406 415
422 429
439 445
452 465
472 477
480 278
308 322
342 353
357 380
419 489
495
114 125
136 156
170 173
181 202
213 219
237 269
280 282
295 306
316 324
346 356
361 374
396 407
408 411
416 442
443 449
473 475
491 494
500 69
129 140
147 177
192 206
292 320
323 335
378 397
450 467
484
X [m] Y [m]
bus, c Maximum load capacity of all substation, and d cost minimization of new substation construction.
Accordingly, the objective functions of substation place- ment and sizing can be formulated as follows:
CL C P
L Loss
i i
nlb
=
=
Â
. .8760
1
2 where, CL is the total losses cost for a study year,
C
L
[kWh] is the cost of real power losses which is provided in
12
C
L
=168 kWyear], P
Loss i
[kW] is the real power losses at consumer i and nlb is the number of consumers.
he investment cost of substation should be annui- tized to able to accumulate with other network costs
13
. hus, to annuitize the investment cost of distribution net-
work, the following economical consideration should be performed.
VC C
j d
j i
S j
ns lb
i nlb
= Ê
Ë Á
ˆ ¯
˜
= =
 Â
var
. ,
1 1
3
FC C
j
S fix
j ns
=
=
Â
1
4
C VC
FC
S S
S
= +
5 where VC
s
is the total substation variable cost, C
var
j is
the cost of substation j per MVA, d
lb
j,i is the consumer
demand i which connected to substation j. FC
s
repre- sents the total ixed cost of substations and C
ix
j is the ixed cost of substation j. he variable cost of substation
included the cost of operation and maintenance, and the ixed cost consists of installation and other related ix cost
of substation such as land and equipment prices and etc.
IC C
C
S j
l j
ns
=
=
Â
1
6
CC IC
d d
d
T T
= +
+ -
1 1
1 7
where IC stand for Investment Cost [], C
S
is the total substation installation and operation costs [], C
l
is the total cost of the lines [], CC is the annuitized capital cost
[year], d is the discount rate and T is the number of operation years.
the following constraints must be satisied in order to optimal distribution substation allocation and feeder
routing, which are: a supplying all the consumers of the networks, b acceptable voltage drops at the receiving
Ihsan Jabbar Hasan, Chin Kim Gan, Meysam Shamshiri, Mohd Ruddin Ab Ghani and Rosli Bin Omar
Indian Journal of Science and Technology
1687
Vol 7 10 | October 2014 | www.indjst.org
hus, the main objective function that needs to be minimized can be written as follows:
Min Z
CL CC PF =
+ +
8 where Z is the total cost function and PF is the penalty
factor which is calculated by the optimization constraints. For instance, if the voltage is out of the deined range,
therefore the violation amount of voltage will multiply to the constant ine rate Beta which can be written as
follows:
PF Violation
i i
nv
= ¥
=
Â
b
1
9 where, nv is number of violations and β is the ine rate.
he irst constraint of distribution network planning is acceptable voltage drop at receiving bus V
i
which volt- age should be within the speciied range.
0 95 1 05
. .
£ £ V
i
10 he next constraint of distribution network planning
is the longest distance of each consumer from the distri- bution substation which introduced by substation radius
based on standard. To consider this constraint the follow- ing condition must be considered:
D R
j i
j
£
max
11 where
D
j i
is stand for distance between substation j to consumer i and
R
j max
is the maximum acceptable radius of substation j that can supply the consumers. Based on
the standard, in LV feeder the maximum length of feeder can be up to 0.5–1 km. In urban networks, the length of
11 kV feeders in generally up to 3 km and for rural networks is up to 20 km.
4. Result and Discussion