modelVDI3508Plant
Extends from TransiEnt.Producer.Electrical.Base.PartialDispatchablePowerPlant (Abstract model of an electric power plant with a power setpoint input connector).
Information
1. Purpose of model
//rp
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
Can not be used to model plants with control power provision, use VDI3508PBPlant instead
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:
|
Once-through steam generator |
|
Oil and gas |
Tu=5...10s Tg=60s Ts=130...250s |
Tu=5...10s Tg=60...150s Ts=40...120s |
Hard coal with liquid slag removal |
Tu=120s Tg=200s Ts=130...250s |
Tu=50...200s Tg=200s Ts=60...100s |
Hard coal with dry slag removal |
Tu=20...60s Tg=150s Ts=130...250s |
Tu=20...60s Tg=150...250s Ts=60...140s |
Brown coal |
Tu=30...60s Tg=250s Ts=130...250s |
Tu=30...60s Tg=250s Ts=60...140s |
*** 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)
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | nSubgrids (from PartialElectricPowerPlant) | simCenter.iDetailedGrid | For calculation of statistics in subgrids (=1 local grid, e.g. hamburg, =2 surrounding grid, e.g. UCTE grid |
| Physical Constraints | |||
| Modelica.Units.SI.Power | P_el_n (from PartialElectricPowerPlant) | 300e6 | Nominal power of plant |
| Real | P_min_star | 0.4 | |
| SI.Frequency | P_grad_max_star | 0.12/60 | Fraction of nominal power per second (12% per minute) |
| SI.Time | t_startup | 3600 | Block startup time |
| Statistics | |||
| Modelica.Units.SI.Efficiency | eta_total (from PartialElectricPowerPlant) | 0.6 | Total efficiency of plant for emission calculation |
| EnergyResource | typeOfResource (from PartialElectricPowerPlant) | EnergyResource.Conventional | Type of energy resource for global model statistics |
| PrimaryEnergyCarrier | typeOfPrimaryEnergyCarrier (from PartialElectricPowerPlant) | PrimaryEnergyCarrier.BlackCoal | Type of primary energy carrier for co2 emissions global statistics |
| Boolean | integrateElPower (from PartialElectricPowerPlant) | simCenter.integrateElPower | true if electric powers shall be integrated |
| Boolean | integrateCDE (from PartialElectricPowerPlant) | simCenter.integrateCDE | true if CDE shall be integrated |
| Boolean | calculateCost (from PartialElectricPowerPlant) | simCenter.calculateCost | true if costs shall be calculated |
| Integer | nSubgrid | 1 | Index of subgrid for moment of inertia statistics |
| Expert Settings › Plant characteristics | |||
| SI.Time | T_u | 60 | Dead time of steam generation (5...200s) |
| SI.Time | T_g | 250 | Balancing time of steam generation (60...250s) |
| SI.Time | T_S | 130 | Storage time of steam generator (60...250s) |
| Real | x_T_hp | 0.2 | Fraction of power provided by high pressure turbine stage (fast response) |
| SI.Time | T_lp | 20 | Time constant of low pressure turbine (10...25s) |
| SI.Time | T_gen | 10 | Generator run-up time constant (5...15s) |
| SI.Inertia | J | T_gen*P_el_n/(2*simCenter.f_n*pi)^2 | Lumped moment of inertia of whole power plant |
| Initialization | |||
| SI.ActivePower | P_el_star_init | 1 | |
| Expert Settings › Block control | |||
| TransiEnt.Basics.Types.ClaRaPlantControlStrategy | steamGeneratorControl | ClaRaPlantControlStrategy.NSP | Control strategy for power plant |
| Real | m_T_set_slp_start | 0.3 | Relative mass flow at which modified pressure operation begins |
| Real | m_T_set_slp_end | 0.9 | Relative mass flow at which modified pressure operation ends |
| Real | y_T_slp | 0.9 | Constant turbine valve apparture in modified pressure operation |
| Expert Settings | |||
| SI.Time | t_eps | 10 | Set point power has to be above the minimum power for t_eps time before plant leaves halt state |
| SI.Frequency | y_grad_inf | 1 | Very high power gradient used for plant shut-down |
| Boolean | fixedStartValue_w | false | Whether or not the start value of the angular velocity of the plants mechanical components is fixed |
| SI.Time | Td | simCenter.Td | Time constant of integrator |
| Boolean | useThresh | simCenter.useThresh | Use threshould for suppression of numerical noise |
| Real | thres | simCenter.thres | If abs(u-y)< thres, y becomes a simple pass through of u. Increasing thres can improve simulation speed. However to large values can make the simulation unstable. A good starting point is the choice thres = tolerance/1000. |
| Real | thres_hyst | 1e-10 | Threshold for hysteresis for switch from halt to startup (chattering might occur, hysteresis might help avoiding this) |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.Basics.Interfaces.Electrical.ActivePowerPort | epp (from PartialElectricPowerPlant) | ||
| TransiEnt.Basics.Interfaces.Electrical.ElectricPowerIn | P_el_set (from PartialDispatchablePowerPlant) | Electric power setpoint |