modelPVPlant

Information

1. Purpose of model

The purpose of this model is to calculate the power of a photovoltaic (PV) module or several modules with inverter.

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

Model is based on empiric equations and PV manufacturers data. Optical losses are being consideres due to loss factors for soiling and refraction and reflexion (contained in the incidence angle modification). Degradation of the modules and inverter consumption is not included in the model.

3. Limits of validity

The model has been validated with System Advisor Model simulation results [1] for fixed PV arrays without shading influences. The results are best with Tilt angle of ~30°.

The model has not been entirely validated for sun tracking. Disabling Incidence Angle Modifications seems to improve results with tracking enabled.

4. Interfaces

Input:

GHI_in for global horizontal irradiation

T_in for ambient temperature

WindSpeed_in for wind speed

Output:

epp for connection to a grid containing frequency and power

5. Nomenclature

See parameter and variable descriptions in the code.

6. Governing Equations

6.1. Plane of Array (POA) Irradiation

The POA irradiation is being calculated in IrradianceOnATiltedSurface model.

6.2. Module Temperature

The module temperature T_module is estimated following [2]:

T_module = 273.15 + T_in + POA_Irradiation * (exp(-3.47 - 0.0594 * WindSpeed_in))

6.3. Direct Current Power output P_dc

P_dc is calculated by:

P_dc = PowerCurve_PV_Irradiation.y[1] * PowerCurve_PV_Temp.y[1] / Pmpp * (100 - LossesDC) / 100 * P_inst / Pmpp

PowerCurve_PV_Irradiation.y[1] is the Maximum Power Point (MPP) power at the current Irradiation at reference temperature of the simulated module. PowerCurve_PV_Temp.y[1] is the MPP power at the current temperature at reference irradiation of the simulated module. Pmpp is the MPP power at reference conditions of the simulated module. LossesDC are the losses in % through Connections, Wiring, Tracking Error and Mismatches. P_inst is the cumulated installed power.

6.4. Power Output P_out

P_out is calculated by:

if P_dc*EfficiencyCurve_Inverter.y[1]*(100-LossesAC)/100 < P_inverter then
  P_out=P_dc*EfficiencyCurve_Inverter.y[1]*(100-LossesAC)/100;
else
  P_out=P_inverter;
end if;

EfficiencyCurve_Inverter.y[1] is the efficiency of the simulated inverter depending on the inverter load. If P_dc exceeds the inverter power P_inverter the output is cut off to P_inverter as its maximum, where P_inverter is defined as the installed PV DC power divided by DCtoACratio which is the ratio between installed DC and AC power. LossesAC are losses on the AC side not included in inverter efficiency.

7. Remarks for Usage

For the calculation of the output power, manufacturer datasheets are to be digitalized, e.g. with http://arohatgi.info/WebPlotDigitizer/. This is an example for a Sanyo HIT 200BA module [2]. Digitalize the following figures:

[2]

[2]

After digitalization, calculate the MPP power of each curve and write those to a record as shown in TransiEnt.Producer.Electrical.Photovoltaics.Advanced_PV.Characteristics. For the above shown curves the record is:

record PVModule_Characteristics_Sanyo_HIT_200_BA3

extends Generic_Characteristics_PVModule(

  MPP_dependency_on_Temp_fixedIrradiation=[
 0,214.3545548;
 25,200.8472531;
 50,187.3094253;
 75,173.1095017],
  MPP_dependency_on_irradiation_fixedTemperature=[
  0,0;
200,37.69290789;
400,77.36493756;
600,117.7097234;
800,159.0501238;
1000,201.294124]);

annotation (Icon(coordinateSystem(preserveAspectRatio=false)), Diagram(coordinateSystem(preserveAspectRatio=false)));

end PVModule_Characteristics_Sanyo_HIT_200_BA3;

Hereby the firste table (MPP_dependency_on_Temp_fixedIrradiation) gives the MPP power (second column) for fixed irradiation and different temperatures (first column) and the second table (MPP_dependency_on_irradiation_fixedTemperature) gives the MPP power (second column) for fixed temperature and different irradiation (first column).

8. Validation

The model has been validated with System Advisor Model simulation results [1] for bigger fixed PV arrays without shading influences.

IWEC or TMY data was used in Hamburg, Munich and Miami.

9. References

[1] https://sam.nrel.gov/
[2] http://store.affordable-solar.com/site/doc/Doc_sanyo_specs_20061106173925.pdf

10. Version History

Advanced_PV by Oliver Schülting and Ricardo Peniche, Technische Universität Hamburg, Institut für Energietechnik, 2015
Revision by Tobias Becke, Technische Universität Hamburg, Institut für Energietechnik, 2016

Parameters

Connectors

Components

Contents

Name	Description
ProducerCosts
Skymodel