At ScanPro, our testing service utilises a specially designed in-field photovoltaic IV curve tracer that is linked via software it is possible to simulate the operating performance of a photovoltaic solar module by plotting its current versus voltage characteristics in the form of a line on a graph.
IV curve tracing is a method of establishing a measurement of performance of an individual PV module, or a whole string of PV modules. The measurement is displayed using a plotted graph along with the electrical measurements captured. Using a specially designed in-field photovoltaic IV curve tracer that is linked via software it is possible to simulate the operating performance of a photovoltaic solar module by plotting its current versus voltage characteristics in the form of a line on a graph.
When free of flaws the measurement produced is a neatly curved representation and should closely match that of the manufacturers laboratory measured IV curve. Using this test method you can compare data samples captured to identify if a defect is present.
Each brand and model of PV module will have a different maximum performance output, so this graph will vary and look different depending on output. When conducting IV curve trace tests to capture accurate data it is important that all the test parameters are understood. With the right conditions and the use of some important test accessories, and mathematics it is possible to produce an in-field acquired IV curve test.
These parameters combined will simulate standard test conditions (STC) so that the final calculations produced by the hand-held tracer is as accurate as possible. This includes, inclination angle of the PV module, cell temperature, the solar irradiance levels measured at plane-of-array (POA), the modules performance specs saved into the test sequence, location information, orientation and the number of PV modules tested in series or parallel.
Once all of this information is know it is possible to generate accurate IV curve tests without the need for the PV module to be connected to the grid.
One of the biggest benefits of performing IV curve tracing is the need to not require a load or final connection to the inverter. This is greatly beneficial during commissioning before systems are fully energised as faults or flaws in the modules or DC wiring system are able to be identified immediately. As the installation progresses tests can be conducted, not at the end when finally connected. By completing these quality control checks before the string is brought online you can make corrective repairs which will save lots of time latter on.
The findings extracted from IV curve tracing is normally delivered to our clients in the form of a pdf report. We can also integrate test results into excel spreadsheets and supply the IV curve tracer files so that they can be used by the client on compatible software.
Using IV Curve tracing you have the potential to locate:
- Broken or damaged silicone cells
- Sub-circuit failure
- String wiring connection issues
- Shading issues
- Module mismatching
- Shorted Bypass diodes
- Excessive series resistance
- Low shunt resistance
Value our IV Curve Tracing delivers to our clients:
- Locate wiring flaws before energising circuits – this can greatly reduce wasted time spent conducting fault finding
- Provide a form of professional testing documentation that addresses both quality control and performance modelling
- Manage and monitor PV module health by tracking performance over time – benchmark degradation to match expected lifespan losses
- Maintain compliance to contractural O&M obligations
- Address commissioning requirements
- Identify issues with shading and the losses associated with it
- Measure if silicone cell failure is present
- Identify if mismatched modules are connected
- Make repairs to the array string wiring before final electrical terminations are made
Deliver confidence, build credibility and support investment.