UL 61215-2012 pdf download
UL 61215-2012 pdf download.Crystalline Silicon Terrestrial Photovoltaic (PV)Modules – Design Qualification and Type Approval.
g) Adjust the temperature by means of a controller or alternately exposing and shading the test module as required to achieve and maintain the desired temperature. Alternately, the test module may be allowed to warm-up naturally with the data recording procedure of item d) performed periodically during the warm-up.
h) Ensure that the test module and reference device temperature are stabilized and remain constant within l 00 and that the irradiance as measured by the reference device remains constant within ±1 % during the recording period for each data set. All data must be taken at 1 000 Wm2 or be translated to that irradiance level.
i) Repeat steps d) through h). Module temperatures shall be such that the range of interest is at least 30
°C and that it is spanned in at least four approximately equal increments. A minimum of three measurements shall be made at each of the test conditions.
10.4.3.2 Procedure with a solar simulator
a) Determine the short-circuit current of the module at the desired irradiance at room temperature, in accordance with IEC 60904-1.
b) Mount the test module in the equipment used to change the temperature. Mount the PV reference device within the simulator beam. Connect to the instrumentation.
c) Set the irradiance so that the test module produces the short-circuit current determined in item a). Use the PV reference device to maintain this irradiance setting throughout the test.
d) Heat or cool the module to a temperature of interest. Once the module has reached the desired temperature, measure I, V0 and peak power. Change the module temperature in steps of approximately 5 00 over a range of interest of at least 30 00 and repeat the measurements of ‘sc’ V0 and peak power.
The second. called “the reference-plate method”. is faster but is applicable only to PV modules of the type which respond to changes of ambient temperature (within restricted ranges of wind speed and irradiance) in the same way as the reference plates used in the measurement. Crystalline silicon modules with a glass front and plastic back are in this category. The reference plates are calibrated using the same procedure as in the primary method.
10.5.3 Primary method
10.5.3.1 Principle
This method is based on gathering actual measured cell temperature data under a range of environmental conditions including the SRE. The data are presented in a way that allows accurate and repeatable interpolation of the NOCT.
The temperature of the solar cell junction (Ta) is primarily a function of the ambient temperature (Tamb), the average wind speed (V) and the total solar irradiance (G) incident on the active surface of the module. The temperature difference (T — Tanib) is largely independent of the ambient temperature and is essentially linearly proportional to the irradiance at levels above 400 Wm2. The procedure calls for plotting (T — Tamb) against G for a period when wind conditions are favorable. A preliminary NOCT value is then determined by adding 20 00 to the value of (T — Tamb) interpolated at the SRE irradiance of 800 Wm2. Finally, a correction factor, dependent on the average temperature and wind speed during the test period, is added to the preliminary NOCT to correct it to 20 °C and 1 ms1.
10.5.3.2 Apparatus
The following apparatus is required:
a) an open rack to support the test module(s) and pyranometer in the specified manner (see 10.5.3.3). The rack shall be designed to minimize heat conduction from the modules and to interfere as little as possible with the free radiation of heat from their front and back surfaces:
NOTE In the case of modules not designed for open-rack mounting. the test module(s) should be mounted as recommended by the manufacturer.
b) a pyranometer, mounted in the plane of the module(s) and within 0,3 m of the test array;
c) instruments to measure wind speed down to 0,25 ms1 and wind direction, installed approximately 0.7 m above the top of the module(s) and 1 .2 m to the east or west;
d) an ambient temperature sensor, with a time constant equal to or less than that of the module(s). installed in a shaded enclosure with good ventilation near the wind sensors;
e) cell temperature sensors. attached by solder or thermally conductive adhesive to the backs of two solar cells near the middle of each test module, or other equipment necessary for lEO-approved measurement of cell temperature:
f) a data acquisition system with temperature measurement accuracy of ±1 00 to record the following parameters within an interval of no more than 5 s.
