pvconstants¶
This module contains configuration constants for PVMismatch, such as number of
points in IV curve to calculate, flag to use parallel processing and parallel
processing parameters. This module also contains some utility functions like
npinterpx() and
get_series_cells() are defined
here too.
PVconstants¶
-
class
pvmismatch.pvmismatch_lib.pvconstants.PVconstants(npts=101)¶ Class for configuration constants
Parameters: npts (int) – number of points in IV curve -
E0= 1000.0¶ [W/m^2] irradiance of 1 sun
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Imod_negpts= None¶ array of points with decreasing spacing from 1 to just less than but not including zero
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Imod_pts= None¶ array of points with increasing spacing from 0 to 1
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T0= 298.15¶ [K] reference temperature
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calcParallel(I, V, Vmax, Vmin)¶ Calculate IV curve for cells and substrings in parallel.
Parameters: - I – currents [A]
- V – voltages [V]
- Vmax – max voltage limit, should be max Voc [V]
- Vmin – min voltage limit, could be zero or Vrbd [V]
Type: I: list,
numpy.ndarrayType: V: list,
numpy.ndarray
-
calcSeries(I, V, meanIsc, Imax)¶ Calculate IV curve for cells and substrings in series given current and voltage in increasing order by voltage, the average short circuit current and the max current at the breakdown voltage.
Parameters: - I – cell or substring currents [A]
- V – cell or substring voltages [V]
- meanIsc – average short circuit current [A]
- Imax – maximum current [A]
Returns: current [A] and voltage [V] of series
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k= 1.38064852e-23¶ [kJ/mole/K] Boltzmann constant
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negpts= None¶ array of points with increasing spacing from 1 to just less than but not including zero
-
npts¶ number of points in IV curves
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pts= None¶ array of points with decreasing spacing from 0 to 1
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q= 1.6021766208e-19¶ [Coloumbs] elementary charge
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NumPy Extrapolating Interpolant¶
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pvmismatch.pvmismatch_lib.pvconstants.npinterpx(x, xp, fp)¶ Numpy interpolation function with linear extrapolation.
Parameters: - x (array_like) – The x-coordinates of the interpolated values.
- xp (1-D sequence of floats) – The x-coordinates of the data points, must be increasing.
- fp (1-D sequence of floats) – The y-coordinates of the data points, same length as xp.
Returns: y – The interpolated values, same shape as x.
Return type: {float, ndarray}
Raises: ValueError– If xp and fp have different length
Get Series Cells¶
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pvmismatch.pvmismatch_lib.pvconstants.get_series_cells(cell_pos_column, prev_col=None)¶ Get the sequence of series cells between parallel crossties.
Parameters: - cell_pos_column – column in cell position pattern
- prev_col – previous column in cell position pattern
Returns: indices of series cells
Formulas¶
Vdiode¶
-
pvmismatch.pvmismatch_lib.pvconstants.Vdiode(Icell, Vcell, Rs)¶ Calculate Vdiode from current, voltage and series resistance.
Parameters: - Icell – cell current [A]
- Vcell – cell voltage [V]
- Rs – cell series resistance [\(\Omega\)]
Returns: diode voltage [V]
Idiode¶
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pvmismatch.pvmismatch_lib.pvconstants.Idiode(Isat, Vdiode, Vt, n)¶ Calculate diode current using Shockley diode model.
Parameters: - Isat – diode saturation current [A]
- Vdiode – diode voltage [V]
- Vt – thermal voltage [V]
- n – diode ideality factor
Returns: diode current
Note
Thermal voltage is defined as …
\[V_t = \frac {k_B * T} {q_e}\]
