pvdeg.fatigue.solder_fatigue#

pvdeg.fatigue.solder_fatigue(weather_df, meta, time_range=None, temp_cell=None, reversal_temp=54.8, n=1.9, b=0.33, C1=405.6, Q=0.12, wind_factor=None)[source]#

Get the Thermomechanical Fatigue of flat plate photovoltaic module solder joints. Damage will be returned as the rate of solder fatigue for one year. Based on:

Bosco, N., Silverman, T. and Kurtz, S. (2020). Climate specific thermomechanical fatigue of flat plate photovoltaic module solder joints. [online] Available at: https://www.sciencedirect.com/science/article/pii/S0026271416300609 [Accessed 12 Feb. 2020].

This function uses the default values for 60-min input intervals from Table 4 of the above paper. For other use cases, please refer to the paper for recommended values of C1 and the reversal temperature.

Parameters:

weather_df (pd.dataframe) – Must contain dni, dhi, ghi, temp_air, windspeed, and datetime index
meta (dict) – site location meta-data
wind_factor (float, optional) – Wind speed correction exponent to account for different wind speed measurement heights between weather database (e.g. NSRDB) and the tempeature model (e.g. SAPM) The NSRDB provides calculations at 2 m (i.e module height) but SAPM uses a 10 m height. It is recommended that a power-law relationship between height and wind speed of 0.33 be used. This results in a wind speed that is 1.7 times higher. It is acknowledged that this can vary significantly.
time_range (timestamp series, optional) – Local time of specific site by the hour year-month-day hr:min:sec (Example) 2002-01-01 01:00:00 If a time range is not give, function will use dt index from weather_df
temp_cell (float series, optional) – Photovoltaic module cell temperature [C] for every hour of a year
reversal_temp (float, optional) – Temperature threshold to cross above and below [C] See the paper for other use cases
n (float) – fit parameter for daily max temperature amplitude
b (float) – fit parameter for reversal temperature
C1 (float) – scaling constant, see the paper for details on appropriate values
Q (float) – activation energy [eV]

Returns:

damage (float series) – Solder fatigue damage for a time interval depending on time_range [kPa]