# LFM Code example SRCL 2nd-Mar-2020

# LFM Code naming conventions
# Just ISC and VOC are shown here

# PREFIXES
# m*** measured dimensioned (default if no prefix) W,A,V, Ohms ...
# r*** reference dimensioned W,A,V, Ohms ...
# n*** normalised dimensionless

# SUFFIXES
# ***_U uncorrected (default if no suffix)
# ***_T corrected for Tmodule 

# STC DEFINITIONS
G_STC      = 1         # kW/m2  irradiance
T_STC      = 25        # C      module temperature

# EXAMPLE REFERENCE AND TEMPERATURE CORRECTION VALUES
rIsc       =  1.177    # A 

rVoc       =  87.66    # V
rIsc_Alpha = +0.000388 # /K
rVoc_Beta  = -0.00231  # /K

# EXAMPLE MEASUREMENT VALUES FROM IV CURVES
mGi        = 0.5319    # kW/m^2 irradiance
mTmod      = 47.0      # C      module temperature

# measurements from IV curves
mIsc_U     = 0.5921    # A
mVoc_U     = 81.016    # V

# CALCULATE NORMALISED LFM VALUES
nIsc_U     = mIsc_U/rIsc/mGi
nVoc_U     = mVoc_U/rVoc

# CALCULATE LFM TEMPERATURE CORRECTIONS
nIsc_T = nIsc_U * (1-rIsc_Alpha * (mTmod - T_STC))
nVoc_T = nVoc_U * (1-rVoc_Beta  * (mTmod - T_STC))

# VALIDATE CALCULATIONS TO AT LEAST 4 FIGS

print ("          ref      calc   residual")
print ()
print ("nIsc_U=", 0.945777, "{0:6.6f}".format(nIsc_U),  "{0:6.6f}".format(nIsc_U - 0.945777))
print ("nVoc_U=", 0.924207, "{0:6.6f}".format(nVoc_U),  "{0:6.6f}".format(nVoc_U - 0.924207))
print ()
print ("nIsc_T=", 0.937704, "{0:6.6f}".format(nIsc_T),  "{0:6.6f}".format(nIsc_T - 0.937704))
print ("nVoc_T=", 0.971175, "{0:6.6f}".format(nVoc_T),  "{0:6.6f}".format(nVoc_T - 0.971175))