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Title: The Development of a DC Breakdown Voltage Test for Photovoltaic Insulating Materials

Conference ·
OSTI ID:1581519
 [1];  [2];  [3];  [4];  [5];  [6];  [7];  [1];  [2];  [7];  [1];  [1]
  1. National Renewable Energy Laboratory (NREL), Golden, CO (United States)
  2. Borealis AB
  3. DuPont Photovoltaic and Advanced Materials
  4. Isovoltaic AG
  5. The 3M Company
  6. Agfa-Gevaert NV
  7. DuPont Photovoltaic Solutions

The ability of electrical insulating materials within a module to act as insulators is a key safety requirement for PV technology. Direct current breakdown voltage is therefore now specified for relied-upon insulator materials in the IEC 61730-1 safety standard. To fulfill that requirement, a new test method has been developed within the IEC TS 62788-2 backsheet standard for the measurement of breakdown voltage. The development of the test will be described, including the verification of the most critical parameters relative to factors such as defect population(s), dielectric medium, electrode size, electrode surface roughness, maximum current limit, moisture conditioning, number of replicate specimens, rate of voltage rise, specimen thickness, test polarity, and test temperature. Many of these parameters were specifically explored in discovery experiments as the test method was developed. An interlaboratory round-robin (R-R) experiment was conducted to further validate the test method by quantifying its repeatability and reproducibility. The materials examined in the R-R include the backsheet materials: polyethylene terephthalate (PET, two thicknesses), polyvinyl fluoride (PVF), and laminated PVF/PET/PVF ('TPT') as well as the encapsulants poly(ethylene-co-vinyl acetate) (EVA), and polyvinyl butyral (PVB). The precision of the test method as well as key factors contributing to the measurement will be described.

Research Organization:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
DOE Contract Number:
AC36-08GO28308
OSTI ID:
1581519
Report Number(s):
NREL/PO-5K00-68703
Resource Relation:
Conference: Presented at the 2017 IEEE 44th Photovoltaic Specialist Conference (PVSC), 25-30 June 2017, Washington, D.C.
Country of Publication:
United States
Language:
English