Post on 19-Jul-2020
PID: an invisible danger for solar systems and how to prevent it
PV Magazine Quality RoundtableIntersolar, 21st June 2018
Andrea Viaro, Head of Technical Service & Product Mgmt. Europe
2
Total Quality Management
1. Comprehensive QC/QAacross entire value chain
2. CertifiedQC/QA process, methodology, acc.criteria, devices and staff
3.
Advancedinspection equipment & data mgmt. system
4. AccurateQC protocols
5. Consistentcontrol results
6. Globally‐distributedcontrol
3
IEC Test Sequence
Long-Term Performance: Accelerated Aging
4Reference : DNV-GL
Thermal Cycle 8004x MORE SEVERE THAN STANDARD
El. Connections Stress TestResults: -0.85% (average)
Damp Heat 30003x MORE SEVERE THAN STANDARD
Laminate Stress TestResults: -2.01% (average)
MinimumIEC requirement
Jinko Solar
5
PID Main Factors
PID’S MAIN
FACTORS
Climate weather cond.
System
Module
Cells
-Topology -Module position-System voltage
Encapsulant and module design (frame, isolation…)
Temperature, humidity
Anti-Reflecting Coating
6
PID Phenomenon
Power degradation due to a potential of the module relative to ground
Leakage current through the encapsulant and glass
Accumulation of positive charge on cell surface
FF, Vmpp and Impp ↓↓
Frame Glass
Eva Cell
+ + + + + + + + + + + + + + + + +
7
PID Environment Conditions
8
PID System Topology
SYSTEM LEVELInverter with transformer
• Negative pole functional grounding for p-doped cells
• Positive pole functional grounding for n-doped cells
Transformer less inverter
•“Soft grounding” required• Overnight recovery possible
‐1000
‐800
‐600
‐400
‐200
0
200
400
600
800
1000
0 2 4 6 8 10 12 14 16 18 20 22
Potential to grou
nd (V
)
Module position in the string
(‐) Grounded
Floating
(+) Grounded
9
PID Effect
Thermal Picture with “L/U‐shaped” Pattern Effects on IV‐Curve (Rsh, FF, Vmpp, Impp, Voc)
EL before and after PID phenomenon Inverter wake‐up & drop‐off (Voc)
(Floating System and PV modules installed in the most negative part of the string)
‐0.2
0
0.2
0.4
0.6
0.8
1
6 11 16
10
PID case study
• Installation peak power: 100kW
• Date of installation: 2012
• Location: Coastal environment
• Panel type: JKM-240P60 (not anti-PID certified)
• Solution implemented: - PID recovery system operating overnight- String polarity swap to speed up the recovery time
• Result: PV system PR recovered up to initial value after about 6 months
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PID case study
106I-V@STC 106I-V Nominal 106Pwr@STC 106Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260
12
PID case study
104I-V@STC 104I-V Nominal 104Pwr@STC 104Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260
13
PID case study
102I-V@STC 102I-V Nominal 102Pwr@STC 102Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260
14
PID case study
98I-V@STC 98I-V Nominal 98Pwr@STC 98Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260
15
PID case study
94I-V@STC 94I-V Nominal 94Pwr@STC 94Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260
16
PID case study
91I-V@STC 91I-V Nominal 91Pwr@STC 91Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260
17
PID case study
89I-V@STC 89I-V Nominal 89Pwr@STC 89Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260Reduced FF
-11% Pmax
18
PID case study
85I-V@STC 85I-V Nominal 85Pwr@STC 85Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260Reduced FF
-16% Pmax
19
PID case study
84I-V@STC 84I-V Nominal 84Pwr@STC 84Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260Reduced FF
-22% Pmax
20
PID case study
79I-V@STC 79I-V Nominal 79Pwr@STC 79Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260Reduced FF
-17% Pmax
21
PID case study
78I-V@STC 78I-V Nominal 78Pwr@STC 78Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260Reduced FF
-14% Pmax
22
PID case study
73I-V@STC 73I-V Nominal 73Pwr@STC 73Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260Reduced FF
Lower Voc
-28% Pmax
23
PID case study
71I-V@STC 71I-V Nominal 71Pwr@STC 71Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260
Lower Rsh
Lower Voc
Reduced FF
-49% Pmax
24
PID case study
69I-V@STC 69I-V Nominal 69Pwr@STC 69Pwr Nominal
Voltage [V]0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Cur
rent
[A]
0
1
2
3
4
5
6
7
8
9
Power [W
]
0
20
40
60
80
100
120
140
160
180
200
220
240
260
Lower RshReduced FF
Lower Voc
-37% Pmax
25
PID case study
PV plant PR decreasing trend during PID development phase
26
PID case study
PV plant PR increasing trend after recovery solution implementation
27
PID-Resistance: The “Eagle” Series
℃
First PID-resistant Module(IEC62804 Standard)
85℃/85% RH, 192 hrs.
No Corrective or Preventive Actions for PID
Typical Installation Topology and Flexibility
Maximized Production
28
Andrea ViaroHead of Tech. Service & Product Mgmt. Europe
Email: andrea.viaro@jinkosolar.com
Mob. +41.795598898
Web: www.jinkosolar.eu