The characteristics of the diode for a single module is defined by the equation:

Where:

I_d is the current of the diode (A), V_d is the voltage of the diode (V), I₀ is the saturation current of the diode (A), nI is the ideality factor which is generally close to 1.0, k is the Boltzmann constant(1.3806 e-23 J / K) q is the electron charge (1.6022 e-19 C) T is the temperature of the cell (K) and Ncell is the number of cells connected in series in a module PV.

The figure below shows the characteristic I-V curves, and the dependence of the solar irradiance S and the module temperature T.

Feature I-V dependence on the Solar Irradiance and the Temperature

Mask and Parameters

The PV model has two tabs:

Model: Configuration choices (array) and the 5 PV model parameters
Database: Allows the user to select a module PV from over 21,000 modules from leading manufacturers from the California Energy Commission.

Model Tab

Parameter name	Description	Unit	Variable
Description	PV Module name selected in the tab Database.		Description
Number of modules connected in parallel	Number of modules connected in parallel.	#	Npar
Number of modules connected in series	Number of modules connected in series.	#	Nser
Maximum power Pmax	Power obtained at the point of maximum power (Vmp,Imp). P max = Vmp x Imp.	W	Pmax
Number of cells per unit	Number of cells per module.	#	Ncell
Open circuit voltage	Voltage obtained when the terminals of the assembly (array) are left open.	V	Voc
Short circuit current	Current obtained when the terminals of the assembly (array) are shorted.	A	Isc
Voltage at maximum power point	Voltage at maximum power point.	V	Vmp
Current at maximum power point	Current at maximum power point.	A	Imp
Temperature coefficient of Voc	Sets the change in Voc depending on the temperature.	% / ° C	Beta_Voc_pc
Temperature coefficient of Isc	Sets the change in Isc depending on the temperature.	% / ° C	Alpha_Isc_pc
Light-generated current	Current for a module under standard test conditions (STC) coming out of the controllable current source which models the current generated by the light.	A	IL_ref
Diode saturation current	The diode saturation current for a module under standard test conditions (STC).	A	I0_ref
Diode ideality factor	PV Module ideality factor.	#	nI_ref
shunt resistance	shunt resistor for under standard test conditions module (STC).	Ohm	Rsh_ref
Series resistance	series resistance for a module under standard test conditions (STC).	Ohm	Rs_ref

Database Tab

This tab lets you choose a PV from the database of the CEC. The user can enter the module name or just a letter and then click on Inquiry and all the modules that contain that letter or name appear in the table. Once the selected module, the user must click Load parameters to load the model with the respective parameter values.

The user can also right click on the desired module and then choose the option “Load parameters in component” for the model parameters to be updated.

Ports, Inputs, Outputs and Signals Available for Monitoring

Ports

Name	Description
Plus	Network connector on the DC side; The + indicates this is the positive terminal (supports only 1-phase connections).
Minus	Network connector on the DC side; The - indicates this is the negative terminal (supports only 1-phase connections).

Inputs

Name	Description	Units
T	Temperature of the PV cell	Celsius
S	Sun irradiance over the PV	W/m²

Outputs

Name	Description	Units
V	DC output voltage	V
I	DC output current	A

Sensors

Name	Description	Unit
S	Signal representing the irradiance to which the array is exposed	W/m²
T	Signal representing the temperature to which the array is exposed	Celsius
V	DC output voltage measurement	V
I	DC output current measurement	A

Additional Information

PV Panel Equivalent Circuit Diagram

The terminology followed in the PV modeling is given below:

Cell: single unit of the photovoltaic semiconductor that converts the solar irradiance into electricity.
Module: group of cells connected in series and parallel to achieve a desired voltage and current.

PV Modeling

In the PV model developed, the diode is replaced by a non-linear resistor which can accurately model the PV at different temperatures as an input. Note that the temperature can be changed during the simulation in offline as well as in real time. On the other hand, the shunt resistor has been replaced by a variable resistor according to the irradiance S. The figure below shows the internal circuit of the PV model.

The model PV model contains many types of modules PV predefined from the database Photovoltaic (PV) modules to the Energy Commission's Solar Equipment Lists of the California Energy Commission (CEC) (November 2018). More than 21,000 modules from leading manufacturers are listed in this database includes the manufacturer's specifications measured for standard test conditions (STC) (Irradiance of 1000 W/m2 and 25 ° C).

Limitations

When the user creates their own PV module, they must also update the 5 parameters from an optimization function external to HYPERSIM.
At the time of this writing (DEC2019), this model does not participate in the load flow solution.

References

L. G. Monteiro Oliveira et al., "Computational implementation of photovoltaic modules mathematical models for software application to estimate PV systems energy production," 2015 International Conference on Solar Energy and Building (ICSoEB), Sousse, 2015, pp. 1-6

W. De Soto, S. A. Klein and W. Beckman. « Improvement and validation of a model for photovoltaic array performance ». Solar energy, vol. 80, no. 1, pp. 78-88, 2007

MathWorks, PV Array Mathworks.com. https://www.mathworks.com/help/physmod/sps/powersys/ref/pvarray.html

Photovoltaic (PV) Modules to the Energy Commission’s Solar Equipment Lists, California Energy Commission, Nov. 2018. [Online]. Available: https://www.gosolarcalifornia.ca.gov/equipment/pv_modules.php

Description

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