.TransiEnt.Producer.Electrical.Conventional.Components.VDI3508Plant_PrimaryBalancing

Information

1. Purpose of model

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This model is based on the simplified representation of a power station unit found in the norm VDI/VDE 3508.

The model takes the set value of the electric power output (P_Target) and translates it to a change into a target thermal input. Meanwhile, the turbine valve aperture remains completely opened. Thus, the model is in natural sliding-pressure operation mode.

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

The model is based on typical time responses of the power plant components. No phyisical modeling has been conducted.

3. Limits of validity

(Purely technical component without physical modeling.)

4. Interfaces

P_Target: receives the target value of the electric power in W

epp: Mainly delivers the real output of the power plant.

5. Nomenclature

(no elements)

6. Governing Equations

(no equations)

7. Remarks for Usage

The values of Tu, Tg, Ts can be found in the norm. The following table summarizes these values:

*** Recirculation steam generator (drum)

Oil and gas Tu = 5 to 10 s Tg ≈ 60 s TS = 130 to 250 s

Hard coal * with liquid slag removal

Hard coal * with dry slag removal

Tu ≈ 120 s Tg ≈ 200 s TS = 130 to 250 s

Tu = 20 to 60 s Tg ≈ 150 s TS = 130 to 250 s

Brown coal* Tu = 30 to 60 s Tg ≈ 250 s TS = 130 to 250 s

*** Once-through steam generator

Tu = 5 to 10 s Tg = 60 to 150 s TS = 40 to 120 s

Tu = 50 to 200 s Tg = 200 s TS = 60 to 100 s

Tu = 20 to 60 s Tg = 150 to 250 s TS = 60 to 140 s

Tu = 30 to 60 s Tg ≈ 250 s TS = 60 to 140 s

8. Validation

According to [1] Chapter 7, "in the operating mode "steam generator in control"... the actual output follows the setpoint after the unit delay, which results from the delay within the controlled power station (Fig. 22a).

9. References

[1] VDI/VDE3508

Pitscheider, 2007

10. Version History

Model created by Ricardo Peniche

Model generalized for different electrical power ports by Jan-Peter Heckel (jan.heckel@tuhh.de) in July 2018

Model modified by Robert Flesch (flesch@xrg-simulation.de) in Feb 2021: introduced current power feed back to control (due to interface adaption)