pvlib.pvsystem.i_from_v¶
-
pvlib.pvsystem.i_from_v(resistance_shunt, resistance_series, nNsVth, voltage, saturation_current, photocurrent, method='lambertw')[source]¶ Device current at the given device voltage for the single diode model.
- Uses the single diode model (SDM) as described in, e.g.,
- Jain and Kapoor 2004 [1].
- The solution is per Eq 2 of [1] except when resistance_series=0,
- in which case the explict solution for current is used.
- Ideal device parameters are specified by resistance_shunt=np.inf and
- resistance_series=0.
- Inputs to this function can include scalars and pandas.Series, but it is
- the caller’s responsibility to ensure that the arguments are all float64 and within the proper ranges.
Parameters: - resistance_shunt : numeric
Shunt resistance in ohms under desired IV curve conditions. Often abbreviated
Rsh. 0 < resistance_shunt <= numpy.inf- resistance_series : numeric
Series resistance in ohms under desired IV curve conditions. Often abbreviated
Rs. 0 <= resistance_series < numpy.inf- nNsVth : numeric
The product of three components. 1) The usual diode ideal factor (n), 2) the number of cells in series (Ns), and 3) the cell thermal voltage under the desired IV curve conditions (Vth). The thermal voltage of the cell (in volts) may be calculated as
k*temp_cell/q, where k is Boltzmann’s constant (J/K), temp_cell is the temperature of the p-n junction in Kelvin, and q is the charge of an electron (coulombs). 0 < nNsVth- voltage : numeric
The voltage in Volts under desired IV curve conditions.
- saturation_current : numeric
Diode saturation current in amperes under desired IV curve conditions. Often abbreviated
I_0. 0 < saturation_current- photocurrent : numeric
Light-generated current (photocurrent) in amperes under desired IV curve conditions. Often abbreviated
I_L. 0 <= photocurrent- method : str
Method to use:
'lambertw','newton', or'brentq'. Note:'brentq'is limited to 1st quadrant only.
Returns: - current : np.ndarray or scalar
References
[1] A. Jain, A. Kapoor, “Exact analytical solutions of the parameters of real solar cells using Lambert W-function”, Solar Energy Materials and Solar Cells, 81 (2004) 269-277.