IEC standards for PV performance testing

• radiant source (natural sunlight or a solar simulator class BBA or better)
• a PV reference device in accordance with IEC 60904-2. If a class BBA simulator or better is used, the reference device shall be a reference module of the same size with the same technology to match spectral responsivity. Upon unavailability:
  • a class AAA simulator can be used, or
  • the spectral responsibility of the module according to IEC 60904-8 and the spectral distribution of the solar simulator need to be measured, and the module data corrected according to IEC 60904-7
• a suitable mount for supporting the test specimen and the ref device in a plane normal to the radiant beam
• apparatus for measuring I-V curve in accordance with IEC 60904-1

Procedure:

1. Connect the sorted o/p terminal of the module to the positive terminal of a DC insulation tester.
2. Connect the exposed metal part of the module to the -ve terminal of the test.
3. Increase the voltage applied by the tester at a rate not exceeding 500V/s to a max qual of (100v + 2* max system voltage). If the max system voltage does not exceed 50v, the applied voltage will be 500v. Maintain the voltage at this level for 1 min.
4. Reduce the applied voltage to 0v and short-circuit the terminals of the test equipment to discharge the voltage build-up in the module.
5. remove short-circuit
6. Increase the voltage at a rate not exceeding 500 V/s to 500 V or the maximum system voltage (whichever is greater). Maintain for 2 min at this level and determine insulation resistance.

**if the module area < 0.1 m2 , the insulation resistance should not less than 400 MΩ

**if the module area > 0.1 m2, the measured insulation resistance * module area should not be less than 40MΩ. m2.

• DC voltage source with current limitation, capable of applying 500 V or 1000V, plus twice the maximum system voltage of the module.
• instrument to measure insulation resistance

- Titl angle: (37±5)° -Total irradiance: 800 W/m² -Ambient temp: 20° C -Wind speed: 1m/s -Electric load: resistive load sized such that tehmodule will operate near its MPP at STC or an electronic MPPT

• radiant source (natural sunlight or a solar simulator class BBA or better)
• a PV reference device in accordance with IEC 60904-2. If a class BBA simulator or better is used, the reference device shall be a reference module of the same size with the same technology to match spectral responsivity. Upon unavailability:
  • a class AAA simulator can be used, or
  • the spectral responsibility of the module according to IEC 609-04-8 and the spectral distribution of the solar simulator need to be measured and the module data corrected according to IEC 60904-7
• a suitable mount for supporting the test specimen and the ref device in a plane normal to the radiant beam
• a means for monitoring the temp of the test specimen and the reference device to an accuracy of ±1°C and repeatability of ±0.5°C
• apparatus for measuring I-V curve in accordance with IEC 60904-1

• radiant source (natural sunlight or a solar simulator class BBA or better)
• equipment necessary to change the irradiance to 200W/m² without affecting the relative spectral irradiance distribution and the spatial uniformity.
• a PV reference device in accordance with IEC 60904-2. If a class BBA simulator or better is used, the reference device shall be a reference module of the same size with the same technology to match spectral responsivity. Upon unavailability:
  • a class AAA simulator can be used, or
  • the spectral responsibility of the module according to IEC 609-04-8 and the spectral distribution of the solar simulator need to be measured and the module data corrected according to IEC 60904-7
• a suitable mount for supporting the test specimen and the ref device in a plane normal to the radiant beam
• a means for monitoring the temp of the test specimen and the reference device to an accuracy of ±1°C and repeatability of ±0.5°C
• apparatus for measuring I-V curve in accordance with IEC 60904-1

• an open rack to support the test module and solar irradiation monitor in the specified manner. the rack should be designed to minimize heat conduction from the modules to interfere as little as possible with the free radiation of heat from their front and back surfaces.
• a solar irradiation monitor accurate to ±5%, mounted in the plane of the modules within 0.3 m of the test array
• means to mount the modules
• a resistive load sized such that the module will operate near its MPP or an electronic MPPT

Shunts in cells or at scribe lines Inadequate by-pass diode protection

• radiant source: natural light or a class BBB (or better) steady-state solar simulator with an irradiance of 800 W/m² to 1100 W/m²
• I-V curve tracer
• ameter
• opaque cover for test cells, shadowing according to the technology-specific parts of IEC 61215
• An IR camera to measure and record the module temp
• equipment to record irradiance levels, integrated irradiance and ambient temp.

Encapsulant loss of adhesion & elasticity Encapsulant & backsheet discoloration Ground fault due to backsheet degradation Degradation of Optics

• A temp-controlled test chamber with a window or fixture for a UV light source and the module under test. it should be capable of maintaining the module's temperature at (60±5)°C
• A means for monitoring module's temp to an accuracy of ±2°C and repeatability of ±0.5°C. the temp sensor should be attached to the front and back surfaces of the module near the middle without obstructing anuy of the UV light incident
• instruments to measure the irradiance of UV light produced by the UV light source from 280 nm to 400nm.
• A UV light source capable of producing UV radiation with an irradiance uniformity of ±15%.
• for light sources with a negligible spectral content in the visible range the module should be short circuited. alternatively the module can be connected to a load sized such that the module will operate near the MPP. the latter is recommended for light sources emitting a significant portion of light in the visible spectrum where the module exhibits a power equal to or larger than 20% of its STC measures power.

Broken interconnect Broken cells Electrical bond failure Junction box adhesion Module open circuit – potential for arcing

• a climatic chamber with automative temperature control with means for circulating the air inside and means to minimize condensation on the module during the test, capable of subjecting one or more modules to the thermal cycle.
• Means for mounting the modules in the chamber, so as to follow free circulation of the surrounding air. the thermal conduction of the mount or support should be low, so that, for partial purposes, the modules are thermally isolated

Junction box adhesion Inadequate edge deletion*

to determine the ability of the module to withstand the effects of high temp and humidity followed by sub-zero temp.

• a climatic chamber with automatic temp and humidity control, capable of subjecting one or more modules to the humidity-freeze cycle.
• Means for mounting the modules in the chamber, so as to follow free circulation of the surrounding air. the thermal conduction of the mount or support should be low, so that, for partial purposes, the modules are thermally isolated
• measurement instrumention having an accuracy of ±2°C and repeatability of ±0.5°C for measuring and recording the temp of the module
• means for monitoring, throughout the test, the continuity of the internal circuit of each module.

Delamination Encapsulant loss of adhesion & elasticity Junction box adhesion Electrochemical corrosion of TCO* Inadequate edge deletion*

relative humidity: (85±5)% test duration: 1000 h

the pull force should be applied at the center point of the box.

• A shallow trough tank must be of sufficient size to accommodate the module with its frame, allowing it to be placed flat and in a horizontal position within the solution. It should contain enough water or wetting solution to adequately wet the surface of the module while meeting the following requirements:
  • resistivity: 3500ohm/cm or less
  • Solution temperature: (22±2)°C
• Spray equipment
• Dc voltage source with current limitation
• Intrument to measure insulation resistance

Broken glass Broken interconnect ribbons Broken Cells Electrical bond failures

To determine the ability of module to withstand a minimum static load

• A sturdy test base is required, allowing the modules to be mounted either with the front side facing up or down. This test base should enable the module to deflect freely during load application, following the manufacturer's recommended mounting method. An electrical continuity measurement device is also necessary. Additionally, appropriate weights or pressure mechanisms must be provided to ensure that the load can be applied gradually and evenly.

Broken cells Broken Optics

• moulds of suitable material for casting spherical ice balls (min diameter of 25mm)
• A freezer controlled at (-10±5)°C
• a storage container for sorting the ice balls at (-4±2)°C
• A launcher capable of propelling an ice ball.
• mounting support according to manufactures instruction
• A balance to measure the mass of ice ball to an accuracy of (±2)%
• An instrument to measure the velocity of ice ball to an accuracy of (±2)%

Overheating of diode causing degradation of encapsulant, backsheet or junction box

• Instrument for heating the module to a temp of (90±5)°C
• Temp sensor
• voltage measurement instrument for measure junction voltage
• current source for applying a current equal to 1.25 times the STC short-circuit current
• I-V curve tracer

- An instrument to measure irradiation.

- A mounting structure that is co-planar with the reference device.

- Use the reference device to set the irradiance between 800 W/m² and 1000 W/m².

- A temperature sensor.

- A resistive load.

Broken interconnect ribbons Broken Cells Electrical bond failures