EEL 4213 Power Systems I Power System Design Project The single-line diagram shows a 31-bus interconnected power systems.
The following data are given:
Bus Data and Load Schedule The system base is 100 MVA
Bus Number Bus Type Nominal Voltage Load Real Power Power Factor
1
PQ
230 kV
43 MW
0.90
2
PQ
230 kV
28 MW
0.95
3
PV
115 kV
0 MW
1.0
4
PQ
115 kV
23 MW
0.92
5
PQ
230 kV
18.6 MW
0.91
6
PQ
230 kV
30 MW
0.96
7
PQ
230 kV
22 MW
0.87
8
PQ
115 kV
9.4 MW
0.94
9
PQ
69 kV
6.3 MW
0.86
10
PQ
69 kV
15.2 MW
0.87
11
PQ
115 kV
42 MW
0.91
12
PV
115 kV
0 MW
1.0
13
PQ
69 kV
12.7 MW
0.73
14
PQ
69 kV
16.8 MW
0.89
15
PQ
230 kV
34 MW
0.94
16
PQ
230 kV
37 MW
0.95
17
PV
230 kV
0 MW
18
PQ
69 kV
5.2 MW
0.63
19
PQ
115 kV
19.9 MW
0.97
1.0
Maximum Generator Power Output
300 MW / 0.9 pf
250 MW / 0.95 pf
350 MW / 0.9 pf
20
PQ
69 kV
0.8 MW
0.66
21
PQ
115 kV
40 MW
0.89
22
PQ
115 kV
26 MW
0.93
23
PQ
69 kV
2.5 MW
0.99
24
PQ
230 kV
46 MW
0.89
25
PQ
230 kV
33 MW
0.96
26
PQ
230 kV
44 MW
0.86
27
PQ
230 kV
81 MW
0.93
28
PQ
69 kV
2.3 MW
0.91
29
PQ
115 kV
15.3 MW
0.95
30
Slack
115 kV
0 MW
1.0
31
PQ
230 kV
74 MW
0.91
400 MW / 0.9 pf
Based on the data given:
Taking into consideration the load allocated above, select appropriate transmission line voltage ratings, MVA ratings, and distances necessary to supply these loads. Then determine the per unit transmission line impedances for the lines shown on the single-line diagram. Show your calculations. Select appropriate transformer voltage and MVA ratings, and determine the per unit transformer leakage impedances for the transformers shown on the single-line diagram. Develop a generation schedule for the 4 generator buses. Show on a copy of the single-line diagram in per unit the line impedances, transformer impedances, generator outputs, and loads that you have selecte d above. Using the power flow program, run a base-case power flow. In addition, to the printed input/output data files, show on a separate copy of the single-line diagram the per unit bus voltages as well as real and reactive line flows, generator outputs, and loads. Flag any high/low bus voltages for which 0.95 <= V <= 1.05 pu is violated, and any lines or transformer flows that exceed normal ratings. If the base case shows any high/low voltages or ratings exceeded, then correct the base case by making changes. Explain the changes you have made.
Repeat the power flow program step above. Rerun the power flow program and show your changes on a separate copy of the single-line diagram. Provide a typed report and summary of your results along with your calculations for the work above, the printed power flow input/output data, and copies of the single-line diagram. The report is to be in standard professional engineering format.
Graduate Students: After completing the above tasks, select one of the two following activities.
Select three buses on the system, and conduct a fault analysis for each of the buses. In the analysis, consider the four different types of faults that could happen. Determine the fault current contribution in each transmission line or transformer to the bus fault. Conduct an economic dispatch study on the system. Determine the loss coefficients. Does the dispatch violate any of the line or transformer limitations.
Branch Data Start Bus End Bus Circuit Type Line Distance 1
2
Line
50 km
1
5
Line
20 km
2
3
Transformer
3
4
Line
35 km
4
8
Line
25 km
5
6
Line
45 km
6
7
Line
40 km
7
9
Transformer
7
24
Line
8
9
Transformer
8
11
Line
60 km
8
19
Line
30 km
Transformer Tap Range
0.90 to 1.10 in steps of 2.5%
0.90 to 1.10 in steps of 2.5% 35 km 0.90 to 1.10 in steps of 2.5%
8
29
Line
55 km
9
10
Line
80 km
11
12
Line
65 km
11
13
Transformer
13
14
Line
14
15
Transformer
0.90 to 1.10 in steps of 2.5%
14
16
Transformer
0.90 to 1.10 in steps of 2.5%
15
17
Line
45 km
15
26
Line
65 km
16
17
Line
70 km
16
18
Transformer
0.90 to 1.10 in steps of 2.5%
19
20
Transformer
0.90 to 1.10 in steps of 2.5%
19
21
Line
50 km
21
22
Line
55 km
23
24
Transformer
24
25
Line
25 km
25
26
Line
60 km
26
27
Line
40 km
26
31
Line
55 km
27
28
Transformer
29
30
Line
0.90 to 1.10 in steps of 2.5% 70 km
0.90 to 1.10 in steps of 2.5%
0.90 to 1.10 in steps of 2.5% 65 km
30
31
Transformer
0.90 to 1.10 in steps of 2.5%
Standard Transformer Sizes Voltage Class
KVA Rating 10, 15, 25, 50 MVA
Standard Transformer Impedance Range Impedance Limit in Percent
High Voltage
Low Voltage
Winding (kV)
Winding (kV)
115
Approximate Efficiency
Min.
Max.
at 2 MVA
at 10 MVA
at 50 MVA
69
9.0
14.0
98.6 %
99.12 %
99.45 %
230
69
12.5
18.0
98.5 %
99.11 %
99.44 %
230
115
14.0
20.0
98.4 %
99.10 %
99.44 %
Electrical Characteristics of Bare Aluminum Conductors, Steel-Reinforced (ACSR)
Aluminum Strands
Outside
GMR,
Approximate
Area
(Al /
Diameter
Ds
Current Carrying
(kcmil)
Fe)
(inches)
(ft)
Capacity @ 75 C
AC Resistance @ 25 C (ohms/mile) small currents
AC Resistance @ 50 C (ohms/mile) 75% of current capacity
954
54/7
1.196
0.0403
1010
0.0982
0.1128
795
26/7
1.108
0.0375
900
0.117
0.1288
636
54/7
0.977
0.0329
770
0.148
0.1688
556
30/7
0.953
0.0328
730
0.168
0.1859
336
26/7
0.721
0.0244
530
0.278
0.306
266
6/7
0.633
0.00664
460
0.352
0.552
Available Tower Designs Click on image to enlarge
69 kV H-Frame
69 kV Single Circuit Steel Tower
69 kV Double Circuit Steel Tower
115 kV H-Frame
115 kV Single Circuit Steel
115 kV Double Circuit Steel
Tower
Tower
230 kV Double Circuit Steel Tower
