Slide 1 Harnessing Wind in China: Controlling Variability through Location and Regulation DIMACS Workshop: U.S.-China Collaborations in Computer Science.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Slide 1
Harnessing Wind in China: Controlling Variability through Location and Regulation
DIMACS Workshop:U.S.-China Collaborations in Computer Science and Sustainability
Algorithmic strategy» Hybrid lookahead with adaptive hour-ahead policy
• is determined at time t, to be implemented at time t’• is determined at time t’, to be implemented at time t’+1
» Important to recognize information content• At time t, is deterministic.• At time t, is stochastic.
, ' ' 1,...,24
', ' ' 1,...,24
24
, ' ', '' 1
( )
min ( , )t t t
t t t
t t t tx
ty
C x y
E
, 't tx
', 't ty
, 't tx
', 't ty
, 't tx
', 't ty
The stochastic unit commitment problem
Algorithmic strategy» Hybrid lookahead with adaptive hour-ahead policy
• is determined at time t, to be implemented at time t’• is determined at time t’ by the policy
» The policy is constrained by the solution which is influenced by two parameters:• p is the fraction of power allocated for spinning reserve• q is the fraction of the wind that we plan on using.
, 't tx
', 't ty
The stochastic unit commitment problem
, ' ' 1,...,24
24
, ' '' 1
min ( , ( ))t t t
t t tx
t
C x Y S
E
'( )tY S
'( )tY Stx
The unit commitment problem» Rolling forward with perfect forecast of actual wind, demand, …
hour 0-24 hour 25-48 hour 49-72
, 't tx
The stochastic unit commitment problem
When planning, we have to use a forecast of energy from wind, then live with what actually happens.
hour 0-24
The stochastic unit commitment problem
, 't tx
The unit commitment problem» Stepping forward observing actual wind, making small adjustments
hour 0-24
', 't ty
The stochastic unit commitment problem
The unit commitment problem» Stepping forward observing actual wind, making small adjustments
hour 0-24
The stochastic unit commitment problem
The unit commitment problem» Stepping forward observing actual wind, making small adjustments
hour 0-24
The stochastic unit commitment problem
The unit commitment problem» Stepping forward observing actual wind, making small adjustments
hour 0-24
The stochastic unit commitment problem
The unit commitment problem» Stepping forward observing actual wind, making small adjustments
hour 0-24
The stochastic unit commitment problem
The unit commitment problem» Stepping forward observing actual wind, making small adjustments
hour 0-24
The stochastic unit commitment problem
Analysis of wind
40 percent wind scenario
0 100 200 300 400 500 600 700 8000
20000
40000
60000
80000
100000
120000
140000
40% Deterministic Wind: Summary
Actual Wind
Actual Demand
Total Actual Power
Hour
Output (
MW)
Variability vs. uncertainty
40 percent wind scenario
0 100 200 300 400 500 600 700 8000
20000
40000
60000
80000
100000
120000
140000
160000
40% Stochastic Wind: Summary
Actual Wind
Predicted wind
Actual Demand
Total Actual Power
Hour
Output (
MW)
The effect of modeling uncertainty in wind
The stochastic unit commitment problem
5% wind 20% wind 40% wind 60% wind0
200000000
400000000
600000000
800000000
1000000000
1200000000
1400000000
Stochastic
Deterministic/Variable
Constant
Regulation using hydroelectric power
Deterministic wind: No hydro penalty Red line gives difference
between desired and actual output, showing almost perfect regulation.
Hydro penalty limits our ability to regulate the dam.
Deviations from desired output stay within 5 percent band.