Summary: ABB Suite of Power Transmission Test Cases

1
SummaryABB Suite of Power Transmission Test
Cases
Mats Larsson Corporate Research ABB Switzerland
Ltd. Jan 19, 2004
2
Collapse Scenario

• Line tripping (L3) after 100 s
• Inherent Load Recovery
• Tap Changer Tries to Restore Voltage
• Generator field limit activated at 286 s
• Collapse

3
Control Objectives

• Stabilize all voltages within 0.9 - 1.1 p.u.
• Use minimal amount of load shedding
• Control voltage at bus 4 as close as possible to
  1 p.u.
• Capacitor and tap changer control can be used
  freely

4
Medium Scale ABB Test Case

• Three copies of small case
• Similar control objectives
• Recovery dynamics in
• load (continuous)
• Transformers (discrete)
• Inputs
• Line impedances (disturbance)
• 3 Capacitors
• 3 Voltage Refs. Transformer (optional)
• 3 Load shedding
• Outputs
• 3 Load voltages
• 2 Generator field voltages

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Case 1 Tripping of Lines
Vload2
Vload3
1
0.9
0
100
200
300
400
GEfd2
GEfd3
1.8
1.7
1.6
0
100
200
300
400
pos2
pos3
15
10
5
0
0
100
200
300
400

• Collapse in 400 secs

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Case 2 Cap Switch in Area 2
Vload2
Vload3
1.05
1
0.95
0.9
0
100
200
300
400
GEfd2
GEfd3
1.8
1.7
1.6
0
100
200
300
400
pos2
pos3
6
4
2
0
100
200
300
400
System.C2.step
1
0

• Cap switch at 100 secs stabilizes

0
100
200
300
400
7
Case 3 Tap Reference Change (-5)
Vload2
Vload3
1
0.98
0.96
0.94
0
100
200
300
400
GEfd1
GEfd2
1.8
1.7
1.6
0
100
200
300
400
pos2
pos3
6
4
2
0
0
100
200
300
400

• Tap reference at 100 secs stabilizes

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Case 4 Second line trip
Vload2
Vload3
1
0.8
0.6
0.4
0
100
200
300
400
GEfd1
GEfd2
1.8
1.75
1.7
1.65
1.6
0
100
200
300
400
pos2
pos3
12
8
4
0
100
200
300
400

• No longer stable ...

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Case 5 Added load shedding at bus 3
Vload2
Vload3
1
0.96
0.92
0
100
200
300
400
GEfd1
GEfd2
1.8
1.7
1.6
1.5
0
100
200
300
400
pos2
pos3
4
2
0
0
100
200
300
400

• Additional load shedding stabilizes

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Model Complexity

• 6 disturbance inputs - (0,1,2)
• Control inputs
• 3 capacitors - (0,1)
• 3 load shedding (0,1,2,3)
• 3 tap voltage refs (0.81.2)
• Continuous dynamics
• 3 loads (2 dynamic states each)
• Discrete dynamics
• 3 transformers (3 states each)
• 2 generator limiters (2 states each)

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Possible work on new model

• Scaling of Model-predictive approaches (ETH,
  Grenoble?)
• Testing of decentralized schemes (Lund, Grenoble)
• Requests for customized versions welcome ...

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Large scale case CIGRE Nordic 32

• 52 Discrete control inputs
• Load shedding
• Generator voltage setpoints
• Tap changers
• 10 Controlled outputs
• Load voltages
• 67 Constrained outputs
• All voltages, generator currents
• State-space 1041 nodes

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Generator Trip No Emergency Control

• At 10 s Gen 4062 Trips
• Lost generation compensated by hydro units in the
  north
• Increased losses in transmission corridor, lower
  voltage in southern region
• Generators in the south increase reactive power
  production

4012

• At 30 s Gen 1043 and 4042 at limit
• Voltage support lost in middle and southern parts

4042

• At 50 s Tap changers restore load
• Further voltage decrease
• Collapse at 180 s

1043
4062
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Generator Trip Model Predictive Control
Generator trip
1
0.95
Voltage (p.u.)
0.9
0.85
V1043
V4012
V4042
0.8
0
100
200
300
400
500
Time (sec)
15
Constraint Management
1.1
1.05
1
Armature Currents
0.95
0.9
0.85
200
400
600
800
1000