pvlib.pvsystem.calcparams_cec¶
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pvlib.pvsystem.
calcparams_cec
(effective_irradiance, temp_cell, alpha_sc, a_ref, I_L_ref, I_o_ref, R_sh_ref, R_s, Adjust, EgRef=1.121, dEgdT=-0.0002677, irrad_ref=1000, temp_ref=25)[source]¶ Calculates five parameter values for the single diode equation at effective irradiance and cell temperature using the CEC model described in [1]. The CEC model differs from the De soto et al. model [3] by the parameter Adjust. The five values returned by calcparams_cec can be used by singlediode to calculate an IV curve.
Parameters: - effective_irradiance : numeric
The irradiance (W/m2) that is converted to photocurrent.
- temp_cell : numeric
The average cell temperature of cells within a module in C.
- alpha_sc : float
The short-circuit current temperature coefficient of the module in units of A/C.
- a_ref : float
The product of the usual diode ideality factor (n, unitless), number of cells in series (Ns), and cell thermal voltage at reference conditions, in units of V.
- I_L_ref : float
The light-generated current (or photocurrent) at reference conditions, in amperes.
- I_o_ref : float
The dark or diode reverse saturation current at reference conditions, in amperes.
- R_sh_ref : float
The shunt resistance at reference conditions, in ohms.
- R_s : float
The series resistance at reference conditions, in ohms.
- Adjust : float
The adjustment to the temperature coefficient for short circuit current, in percent
- EgRef : float
The energy bandgap at reference temperature in units of eV. 1.121 eV for crystalline silicon. EgRef must be >0. For parameters from the SAM CEC module database, EgRef=1.121 is implicit for all cell types in the parameter estimation algorithm used by NREL.
- dEgdT : float
The temperature dependence of the energy bandgap at reference conditions in units of 1/K. May be either a scalar value (e.g. -0.0002677 as in [3]) or a DataFrame (this may be useful if dEgdT is a modeled as a function of temperature). For parameters from the SAM CEC module database, dEgdT=-0.0002677 is implicit for all cell types in the parameter estimation algorithm used by NREL.
- irrad_ref : float (optional, default=1000)
Reference irradiance in W/m^2.
- temp_ref : float (optional, default=25)
Reference cell temperature in C.
Returns: - Tuple of the following results:
- photocurrent : numeric
Light-generated current in amperes
- saturation_current : numeric
Diode saturation curent in amperes
- resistance_series : float
Series resistance in ohms
- resistance_shunt : numeric
Shunt resistance in ohms
- nNsVth : numeric
The product of the usual diode ideality factor (n, unitless), number of cells in series (Ns), and cell thermal voltage at specified effective irradiance and cell temperature.
See also
References
[1] A. Dobos, “An Improved Coefficient Calculator for the California Energy Commission 6 Parameter Photovoltaic Module Model”, Journal of Solar Energy Engineering, vol 134, 2012.
[2] System Advisor Model web page. https://sam.nrel.gov.
[3] W. De Soto et al., “Improvement and validation of a model for photovoltaic array performance”, Solar Energy, vol 80, pp. 78-88, 2006.