RFI P2P Link Kit forms Inverter-Meter Connectivity at Brisbane Campus.

About

RFI worked with partner Pulse Electrical to establish inverter-meter connectivity in order to complete solar system commissioning for a renewable project at a large Brisbane campus. With multiple challenges in its terrain, traditional hardline cabling methods could not be used and a fully wireless solution was required.

Challenge

 An 80kw solar system was recently installed at a large Brisbane campus as part of a local government renewable project. To be fully operational, the solar system had to complete the commissioning process and establish comms between the energy meter and solar inverter. The campus faced multiple challenges in its terrain which meant conventional hardline cabling methods could not be used. Due to space constraints, the solar inverter was located in a concrete comms room, over 140 meters from the energy meter. To add more complexity, there were several classrooms and campus structures in between both locations.

Solution

Compatible with most inverters with an RS485 connection, RFI’s P2P Link Kit can be installed to create a wireless link between meters and inverters rather than a hardline cable. In this situation, the P2P Link Kit was the ideal solution as it could still be installed even with buildings and concrete in the way. Consisting of two pre-configured Digi Xbee modems, GPO power packs, cables and ISM antennas, the kit is designed to be a quick and easy, plug and play solution for establishing RS485 wireless links. Operating in the ISM 900MHz band, the signal can go long distances without additional operation charges.

While the P2P Link Kit is normally sufficient for bridging between the inverter and the meter, on this site, there were additional complications to setting up a wireless link. As there was proximity to a cell tower, and the campus was extremely built-up additional range extension was required.

RFI’s CSM500 antennas and specialised brackets were used to ensure that the antennas were situated as high as possible to avoid obstacles and sit outside of the double-lined switchboards. While this did improve the signal, to ensure coverage could span the full distance of the campus a third modem was used as a range extender to ‘hop’ the signal from one end to the other.

Results 

By combining the P2P Link Kit with additional CSM500 antennas and a third modem, communications between the inverter and meter were successfully set up, allowing an otherwise difficult site to be fully commissioned.