Operational Planning for Smart Distribution Grids

GREDOR Gestion des Réseaux Electriques de

Distribution Ouverts aux Renouvelables !

Task 3 - Operational Planning

General meeting Q. Gemine - ULg

January 27, 2014

!1

GREDOR - Gestion des Réseaux Electriques de Distribution Ouverts aux Renouvelables

Operational planning

!2

Goal ?

Anticipate and prevent, in the short term, insecure operation situations.



!2

When ?

Before real time operation.

Goal ?




!2

When ?

Before real time operation.

How ?

Using a set of actions provided to the Distribution System Operator.

Goal ?



Insecure operation situations

An electrical state is insecure if the operational limits of a network component are violated.

!3

Voltage limits at buses:

Bus i Vi ≤ Vi ≤ V̅i

e.g. : 0.95 p.u. ≤ Vi ≤ 1.05 p.u.!with 1 p.u. = 15 kV

Current limit within links:

Bus i Bus j

|Iij| ≤ I ̅ij


Decision framework

What does "before real time operation" means?

!4

Intraday

15 min 15 min 15 min … 15 min

Day-aheadDA

closure

……

Time

Potential decision stages


Decision frameworkTo prevent insecure situations, the future state of the grid needs to be anticipated. Because some phenomena are uncertain, more than one future might be credible.

!5

Time

?



!5

Time

?100%

50%

0%

Each realization of the uncertain phenomena corresponds to a scenario.

Scenario 1

Scenario 2

Scenario 3



!5

Time

?100%

50%

0%

Each realization of the uncertain phenomena corresponds to a scenario.

Scenario 1

Scenario 2

Scenario 3


Scenario trees

!6

At each decision stage, there is some uncertainty for the periods to come.

Time

Each path in the tree is a scenario.


Actions

!7

The actions considered for operational planning can be classified into two categories:

A. network reconfiguration (transparent to users)

‣ transformer ratios

‣ compensators

‣ topological changes

B. modulation of power injections (affect users)

‣ production curtailment

‣ load modulation (demand side management)


Illustrative Example

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Alternative?



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Optimization problem

!9

min expected cost of operation

s.t. no insure operation situation

among scenarios



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among scenarios

Objective



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among scenarios

Objective

｛ Constraints



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among scenarios

Objective

｛ Constraints



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among scenarios

Objective

｛ Constraints



!9



among scenarios

Objective

｛ Constraints



!10

Because of the power flow equations and of the time-coupling nature of the problem, it is very complex to solve and it cannot be addressed by out-of-the-box software solutions.



!10




!10




!10




!10


?



!11

Because of the complexity, we must use simplified versions of the original problem, called relaxations.



!11

Because of the complexity, we must use simplified versions of the original problem, called relaxations.

These last months, we focused on designing a relaxation that would feature both:

• a good approximation of the original problem

• an acceptable computationally complexity


Current state of the art GREDOR prototype

Approximation quality

Computational complexity

Current progress

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Current progress

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Current progress

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!13

Tim

e (s

)

1

100

10000

6 buses 9 buses 14 buses

1.207

11182254,7

40,738,7

Standard benchmark

GREDORbenchmark

Results for standard test networks with 8 periods and 9 decision stages.


Future work

!14

We are going focus on three main research axis:

•improve the design of the relaxation the solve the problem of operational planning both faster and more accurately

•simulate the operational planning tool on some test networks of RESA and ORES

•provide a quantification mean to evaluate the interaction mechanisms designed in task 1

Engineering

Operational Planning for Smart Distribution Grids