UL-62108:2012 pdf free download – STANDARD FOR SAFETY Concentrator Photovoltaic (CPV) Modules and Assemblies – Design Qualification and Type Approval.
10.1.2 Major visual defects
For the purpose of design qualification and type approval, the following are considered to be major visual defects:
a) broken, cracked, bent, misaligned, or torn external surfaces, including lens, mirror, receiver body, frame, and junction box;
b) broken or cracked cells;
c) bubbles or delamination forming a continuous path between any part of the electrical circuit and the edge of the receiver;
d) visible corrosion of any of the active circuitry of the sample;
e) adhesive or sealant failures;
f) loss of mechanical integrity, to the extent that the installation and/or operation of the modules or assemblies would be impaired.
10.1.3 Requirements
No major visual defects.
10.2 Electrical performance measurement
10.2.1 Purpose
The purpose of the electrical performance test is to identity electrical pertormance degradation of test samples caused by required tests. The focus of this test is on the power degradation, not on the absolute power output, which will be covered by a separate power and energy-rating standard.
Repeatability of the measurement is the most important factor for this test.
10.2.2 Outdoor side-by-side I-V measurement
The side-by-side (SBS) I-V measurement identifies power degradation of a test sample by comparing its post-stress test relative power to its pre-stress test relative power. The relative power is defined as the maximum power output of the sample under test divided by the maximum power output of the control sample, measured under similar test conditions. This method is based on the assumption that the changes of the control sample’s electrical performance are negligible during the whole qualification test period. By using this method, test condition variables are self-correcting, and the complex translation procedures are eliminated.
The side-by-side I-V measurement is required for each test sample upon the starting and final I-V measurements. It is optional for all intermediate I-V measurements.
When applying this method to receivers, the control receiver and the receiver under test should be installed with a proper optical and mechanical system so that during the test, the concentrated light and thermal conditions of these two receivers are similar to the real operating conditions.
10.2.2.1 Procedure
Measure the relative power of a test sample according to the following procedures:
a) Conduct the test on a favorable day and during a period of time that meets the following conditions:
— sky is clear, DNI is greater than 700 W/m2, and its variation is less than 2 % in any 5 mm
interval;
— for systems with acceptance halt-angle larger than 2,5°, no visible clouds or hazy conditions
in 45° view angle around the sun;
— wind speed is less than 6 m/s, and no gust of greater than 10 rn/s in 10 mm before any
measurement.
NOTE Pay attention to the tracking system’s rigidity and make sure it is stable under the windy condition.
b) Mount the test sample and the control sample side-by-side on a two-axis tracker. The alignment of the samples to sunlight could be done by either of following two sequences.