Decision Tree Based Power System
Dynamic Security Assessment
Group 8
Ishita Ray, Yajun Wang
3.23.2016
Constraints from previous groups
Group
Base Case
Constraints
1
40GW
PG4<501.46
PG65_2>994.13
2
42.5GW
PG6>753.61
3
45GW
PG6<764.39
4
47.5GW
PG4<418.49
PG9<1743.54
5
50GW
PG4<336
6
52.5GW
PG4<329.62
PG9<1728.05
7
55GW
PG4<317.83
PG11<1981.40
Case Scenarios
Case
Load (GW)
Percentage
Change (%)
Generation (GW)
Percentage
Change (%)
1
56
-2.61
57.012
-2.65
2(Base)
57.5
0
58.566
0
3
59
2.61
60.059
2.55
4
60
4.35
61.081
4.29
TSAT Security Assessment
Case
No. of secure
contingencies
No. of insecure
contingencies
1
312
44
2
304
52
3
308
48
4
316
40
Power Angle and Voltage Response
Secure case
Insecure case
Generator Rotor Angle (Degrees)
Generator Rotor Angle (Degrees)
1000
80
800
40
600
400
0
200
-40
0
-80
0
4
8
12
16
20 Sec
0
Bus Voltage (pu)
4
8
12
16
20 Sec
4
8
12
16
20 Sec
Bus Voltage (pu)
1.2
1.2
1.1
1.1
1
1
0.9
0.9
0.8
0.8
0.7
0.7
0.6
0.6
0
Contingency No. 270
4
8
280: 3P @ 80# - 31
12
16
20 Sec
0
Contingency No. 356
372: 3P @ 61# - 60
Decision tree – unpruned
Test option – Cross-validation with 20 folds.
Decision tree – pruned
Test option – Cross-validation with 20 folds.
Decision tree – unpruned
PG77<=3518.83
PG6>=760
PG13>=1727.04
Decision tree –pruned
PG77<=3518.83
PG6>=760
Constraints Summary
Group
Base Case
Constraints
1
40GW
PG4<501.46
PG65_2>994.13
2
42.5GW
PG6>753.61
3
45GW
PG6<764.39
4
47.5GW
PG4<418.49
PG9<1743.54
5
50GW
PG4<336
6
52.5GW
PG4<329.62
PG9<1728.05
7
55GW
PG4<317.83
PG11<1981.40
57.5GW
PG77<3518.83
PG6>760
PG13>1727.04
8
Discussion
Convergence Issue – Scaling generation did not help
5-11
Discussion
Convergence Issue - Solved
Discussion
Test option – Cross-validation with 20 folds.
•
•
•
•
•
Include the results from group 1,2,5,6,7,8.
4 row data for power flow in each case.
24 row data for power flow in this case.
More time and space complexities.
Higher accuracy and TP rate.
Discussion
Verify all the important machine and give different constraints.
Find machine 4,6,9,11,13,77.
Give new information about machine 18,70,65-1.
Thank you!
Special thanks to
Qingxin!