In the run-up to EU standards that will
soon require individual circuit breakers for each PV module, Liten researchers
have been busy working on new self-test solutions. They came up with a circuit
board that can isolate each module and generate its I–V characteristic (the
current–voltage curve, represented as a graph) in less than a thousandth of a
second. The I–V characteristic is then analyzed by software developed to detect
the electrical signatures characteristic of different types of faults.
The system not only detects faults, but it
can also identify exactly what type of fault has occurred and where. In the
event of an incident, the defective module can be shut off without affecting
the rest of the system and without stopping energy production. The system also
eliminates the need to send a technician on site to individually test each
module with a portable I–V tester.
Finally, the electronics
can be integrated into new PV module designs or retrofitted on existing modules
by adding an external unit measuring just a few centimeters. The patented system
has been tested at several PV plants. Several manufacturers have already shown
interest.