PID: an invisible danger for solar systems and how to prevent it

Transcription

1 PID: an invisible danger for solar systems and how to prevent it PV Magazine Quality Roundtable Intersolar, st June Andrea Viaro, Head of Technical Service & Product Mgmt. Europe

2 Total Quality Management. Comprehensive QC/QA across entire value chain. Certified QC/QA process, methodology, acc.criteria, devices and staff. Advanced inspection equipment & data mgmt. system. Accurate QC protocols. Consistent control results. Globally distributed control

3 IEC Test Sequence

4 Long-Term Performance: Accelerated Aging Minimum IEC requirement Jinko Solar Thermal Cycle x MORE SEVERE THAN STANDARD El. Connections Stress Test Results: -.% (average) Damp Heat x MORE SEVERE THAN STANDARD Laminate Stress Test Results: -.% (average) Reference : DNV-GL

5 PID Main Factors Temperature, humidity Climate weather cond. Anti-Reflecting Coating Cells PID S MAIN FACTORS System -Topology -Module position -System voltage Module Encapsulant and module design (frame, isolation )

6 PID Phenomenon Power degradation due to a potential of the module relative to ground Frame Glass Leakage current through the encapsulant and glass Accumulation of positive charge on cell surface Eva Cell FF, Vmpp and Impp

7 PID Environment Conditions

8 PID System Topology SYSTEM LEVEL Inverter with transformer Potential to ground (V) ( ) Grounded Floating (+) Grounded Negative pole functional grounding for p-doped cells Positive pole functional grounding for n-doped cells Transformer less inverter Module position in the string Soft grounding required Overnight recovery possible

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)

10 Installation peak power: kw Date of installation: Location: Coastal environment Panel type: JKM-P (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 months

11 Current [A] Power [W] Voltage [V] I-V Nominal Pwr Nominal

12 Current [A] Power [W] Voltage [V] I-V Nominal Pwr Nominal

13 Current [A] Power [W] Voltage [V] I-V Nominal Pwr Nominal

14 Current [A] Power [W] Voltage [V] I-V Nominal Pwr Nominal

15 Current [A] Power [W] Voltage [V] I-V Nominal Pwr Nominal

16 Current [A] Power [W] Voltage [V] I-V Nominal Pwr Nominal

17 Reduced FF Current [A] -% Pmax Power [W] Voltage [V] I-V Nominal Pwr Nominal

18 Reduced FF Current [A] -% Pmax Power [W] Voltage [V] I-V Nominal Pwr Nominal

19 Reduced FF Current [A] -% Pmax Power [W] Voltage [V] I-V Nominal Pwr Nominal

20 Reduced FF Current [A] -% Pmax Power [W] Voltage [V] I-V Nominal Pwr Nominal

21 Reduced FF Current [A] -% Pmax Power [W] Voltage [V] I-V Nominal Pwr Nominal

22 Reduced FF Current [A] -% Pmax Lower Voc Power [W] Voltage [V] I-V Nominal Pwr Nominal

23 Lower Rsh Reduced FF Current [A] -% Pmax Power [W] Lower Voc Voltage [V] I-V Nominal Pwr Nominal

24 Lower Rsh Reduced FF Current [A] -% Pmax Power [W] Lower Voc Voltage [V] I-V Nominal Pwr Nominal

25 PV plant PR decreasing trend during PID development phase

26 PV plant PR increasing trend after recovery solution implementation

27 PID-Resistance: The Eagle Series No Corrective or Preventive Actions for PID Typical Installation Topology and Flexibility Maximized Production First PID-resistant Module (IEC Standard) /% RH, hrs.

28 Andrea Viaro Head of Tech. Service & Product Mgmt. Europe Mob. +. Web: