System controls grid-connected solar PV plants

The Smart String Box bundles Carlo Gavazzi surge arrestors, power supply and EOS array master module, string controller and environmental module, as well as a third-party isolator device, all packaged in an IP66-rated enclosure.

It is suitable for installations ranging from 10-120kW and manages up to 250A of total string current.

Smart String Box systems can be fused on both the negative and positive side.

Carlo Gavazzi DSF surge arrestors embody a special internal backup to ensure they remain safe at the end of varistor life, thus ensuring safe transient overvoltage protection.

The Eos-Array controller is designed to be flexible, easily scalable and composed of a series of modular elements to provide efficient local and remote control of a solar plant, targeting small to medium or high-power installations.

With no auxiliary bus wiring, the system is simple to install and straightforward to expand.

String efficiency and inverter performance are monitored, enabling operators to isolate faults, failures and inefficiencies as soon as they occur.

Built-in independent monitoring provides basic or comprehensive plant control and monitoring on DC and AC sides.

The expandable system gathers accurate and dependable data to help maintain an efficient revenue stream from PV installations.

Controllers promptly advise users of events such as blown fuses, PV module disconnection or inverter failure, to enable rapid maintenance measures to be carried out, significantly reducing service time and missed production costs.

There is no monthly charge for the data, which is stored locally to give users full control.

Monitoring systems also provide users with information including calculations of DC/AC conversion efficiencies and Balance of System.

In addition, solar irradiation, wind speed and PV temperature are recorded and available for analysis.

Data are displayed in graphical and analytical format and in real time.

Alarms can be set for reduced efficiency and interrupted production, with notifications sent via email or SMS according to the type of alarm.

Anti-theft monitoring can also be added to the Smart String Box, notifying users as soon as a panel is removed.

Components and modules of the Smart String Box are fully compliant with UK and international photovoltaic electrical regulations.