The monitoring system places a PLC-based slave unit in a connection box. Current and solar voltage data measured on individual strings*1 are sent to the monitor unit via an existing power line. Consequently, no additional wiring is needed for communication purposes. Moreover, since power required to operate slave units is supplied from the solar power line, no mains cord is required.
The monitoring system is compatible with clamped current sensors as well as with the penetrating type. Sensors, slave units, and the master unit can be added to an existing system without the need to modify the existing mega-solar equipment.
Drawing on our years of experience in PLC technology, the monitoring system exhibits high communication performance against power supply noise and is fully protected from lightning surges.
Slave units 160 mm x 130 mm x 50 mm in size and 500 g in weight are small enough to be installed in a connection box, requiring no extra outdoor enclosure. The master unit can be further downsized, although depending on the installation location and method. It is possible to reduce installation costs since the monitoring system can be installed easily whether with an existing or newly-installed mega-solar system.
A row of series-connected photovoltaic panels
Overvoltage and overcurrent generated by lightning strikes