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Effects of hygrothermal environment on PID acceleration
for crystalline Si photovoltaic modules
SAYURI-PV 2016
○Yasushi Tachibana, Takeshi Toyoda, Toshiharu Minamikawa (IRII)
Yukiko Hara, and Atsushi Masuda (AIST)
2016/10/5
Venue:Auditorium in AIST Tsukuba Central Campus
1
Supported by NEDO
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2
・Combined test = PID test after DH test → Experiment on p-type
multicrystalline silicon cell → PID was accelerated by DH test
・Accelerated test of PID → Elucidation of the PID mechanism →
Establishment of high acceleration test method
Purpose
Today’s Topics
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3
p-type multicrystalline silicon cell 2 models (cell A, B)
cell A : Strong DH resistance cell B : Weak DH resistance
EVA film
Glass
Back sheet
Lamination
One cell module
PV Samples
Cell EVA
Glass
Back sheet
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Room temperature
w/o voltage
application 85℃,
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Procedure of Combined Test
5
DH
PID test
-1000V
85℃ less than 2%rh
4h X 5 (20h)
One cell modules
DH test
DH test 3000h
DH test 4000h
1000h
2000h
DH test : 85℃,85%rh
4 modules
4 modules
4 modules
4 modules
4 modules
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PID 0h PID 5h PID 10h PID 15h PID 20h
DH 0h
DH 1000h
DH 2000h
DH 3000h
DH 4000h
EL Images (cell A)
6
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Pmax (cell A)
・After DH test for 4000 h Pmax reduced by about 5%.
・Pmax of all modules decreased by PID tests. ・Reduction in Pmax
after PID test was larger for modules subjected to longer DH test
prior to PID test.
0
0.2
0.4
0.6
0.8
1
1.2
0 5 10 15 20
Normalized Pmax
Time of PID test(h)
DH0
DH1000
DH2000
DH3000
DH4000
1.000
1.000
0.986
0.984
0.949
0
0.2
0.4
0.6
0.8
1
1.2
0 1000 2000 3000 4000
Normalized Pmax
Time of DH test (h)
7
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EL images (cell B) PID 0h PID 5h PID 10h PID 15h PID 20h
DH 0h
DH 1000h
DH 2000h
DH 3000h
DH 4000h
8
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1.000
1.002
0.989
0.434
0.238 0
0.2
0.4
0.6
0.8
1
1.2
0 1000 2000 3000 4000
Normalized Pmax
Time of DH test (h)
Pmax (cell B)
・Reduction in Pmax was about 1% after DH test for 2000 h. ・Pmax
was less than half, after DH test longer than 3000 h.
・For modules subjected to DH test shorter than 2000 h, Pmax
decreased by PID test. ・Surprisingly, Pmax increased by PID test
for modules subjected to DH test longer than 3000 h prior to PID
test.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 5 10 15 20Normalized Pmax
Time of PID test(h)
DH0
DH1000
DH2000
DH3000
DH4000
9
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Rsh (cell B) Internal shunt resistance (Rsh) of modules were
estimated from the
slope around the origin of the dark I-V curve.
Rsh of all modules decreased with an increase in PID test
time.
→ PID progressed.
Degradation by DH test was recovered.
→ Recovery was larger than degradation ( DH test longer than
3000 h )
10
1.0E+00
1.0E+01
1.0E+02
1.0E+03
1.0E+04
1.0E+05
1.0E+06
0 5 10 15 20
Rsh(Ω)
Time of PID test(h)
DH0
DH1000
DH3000
DH4000
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I-V (cell B)
0
2
4
6
8
10
0 0.2 0.4 0.6 0.8
Current (A)
Voltage (V)
DH4000h→PID DH0
DH2000
DH4000
DH4000-
PID20
0
2
4
6
8
10
0 0.2 0.4 0.6 0.8
Current (A)
Voltage (V)
DH3000h→PID DH0
DH2000
DH3000
DH3000-
PID20
・Fill factor and series resistance were recovered by PID
test.
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・For the two models of p-type multicrystalline silicon cell
Combined test = PID test after DH test
【Cell A and B】 → PID progressed by PID test after DH test 【Cell
B】 → Two types of degradation was confirmed → New phenomena that
Pmax increased by PID test were found
・PID may be easy to occur in the area of hygrothermal
environment, such as tropical zone. → It is important to estimate
anti-PID modules in the hygrothermal environment.
Conclusions