modelSimplifiedUnitCommitment

Very simple unit commitment model

Extends from TransiEnt.Basics.Icons.DiscreteBlock, Modelica.Blocks.Interfaces.DiscreteBlock (Base class of discrete control blocks).

Information

1. Purpose of model

Simple heuristic model for a unit commitment of generators. Based on the load prediction (or actual load if no prediction is available) and the minimum and maximum power boundaries of the available generators the algorithm in this model commits or decommits the generators. Commitment means the generator is operating.

Since no maximum gradients are taken into account a safety factor is introduced which allows to commit more generators to be on the safe side (simple gain on the load prediction).

Furthermore, generators can be marked as must-run, if they are absolutely needed e.g. for control power or coupled heat generation.

2. Level of detail, physical effects considered, and physical insight

See 1.)

3. Limits of validity

There is no check at all that the produced unit commitment is able to cover the actual demand

4. Interfaces

Input: Load (prediction)

Output: Boolean for each generator (true = generator should be in operating mode)

5. Nomenclature

(No remarks)

6. Governing Equations

(No remarks)

7. Remarks for Usage

See 1.) and tester

8. Validation

(No remarks)

9. References

(No references)

10. Version History

Model created by Pascal Dubucq (dubucq@tuhh.de) on 06.04.2017

Parameters

TypeNameDefaultDescription
SI.TimesamplePeriod (from DiscreteBlock)Sample period of component
SI.TimestartTime (from DiscreteBlock)0First sample time instant
IntegernoutsimCenter.generationPark.nMODPlantsNumber of plants
Real[nout]C_varsimCenter.generationPark.C_var_MOD
Modelica.Units.SI.Power[nout]P_minsimCenter.generationPark.P_min_MOD
Modelica.Units.SI.Power[nout]P_maxsimCenter.generationPark.P_max_MOD
Modelica.Units.SI.Power[nout]P_initP_min
Booleanunit_mustrunfill(false, nout)Can be used to prevent plants to shut down (e.g. chp plants)

Connectors

TypeNameDefaultDescription
TransiEnt.Basics.Interfaces.Electrical.ElectricPowerInP_loadpredLoad prediction
Modelica.Blocks.Interfaces.BooleanOutput[nout]zBoolean operating state of individual units (unit commitment)
TransiEnt.Basics.Interfaces.Electrical.ElectricPowerIn[nout]P_R_posUpwards reserve constraint, reduces maximum production (values are supposed to be positive)
TransiEnt.Basics.Interfaces.Electrical.ElectricPowerIn[nout]P_R_negDownwards reserve constraint, increases minimum production (values are supposed to be positive)

Components

TypeNameDefaultDescription
SimCentersimCenter
Integermerit_orderPreferred order of generator dispatch
SI.PowerP_missingNot yet covered electric load
SI.PowerP_thisUnitPower assigned to this unit
RealC_varsorted
Modelica.Units.SI.Power[nout]P_max_effP_max - P_R_posEffective maximum load considering upwards control reserve
Modelica.Units.SI.Power[nout]P_min_effP_min + P_R_posEffective minimum load considering downwards control reserve