Flood mode is a special weather mode used in situations where the water level under the tracker rises enough to enter in contact with PV modules. In these situations, the water can damage PV modules due to the excessive force of the waterflow over them or by causing short-circuits on cables or any other potential material damages.
The risk can be mitigated by installing a sensor to measure the water level. This sensor must be placed at the tracker, located on the deepest part of the site for an early detection.
The measurements of this sensor are read by the NCU periodically. Both water level and water increase level will be monitored to decide when to trigger or untriggered the flood mode.
If the flood mode is triggered by NCU or SCADA, the protect commands will be sent to all trackers within the flood area to position the PV modules horizontally for maximum safety.
AUTOMATIC: When SBOX detects a water level above the threshold it will trigger a Water Level Alarm to the NCU. The NCU and will send the information to the SCADA which will enable the Flood Mode to all trackers in the “Flood Risk Controlled Area” automatically.
MANUAL: A local operator can force the Flood Mode to all the trackers in an area.
When flood mode is active, the TCU algorithm will move tracker to horizontal position to make sure the bottom part of the module is always above the detected water level.
Each NCU measures the water level and monitors the relative increment (or decrement) tendency. A flood alarm and consequent trigger of flooding mode will occur at any time the following condition occurs:
Arctech’s SCADA can always force a flood stow mode. However, if an automatic response is desired the site must be provided with a flood sensor. Arctech can provide a radar water-level sensor which can be read by NCU. The flood data will be collected to SCADA systems.
Arctech provides a radar level sensor to detect the depth of water underneath. This sensor could be placed on the tracker.
In order to protect your plant efficiently a flood study must be taken previously. Usually, these studies mark the site with areas of potential flood risk. It is a responsibility of the client to decide what would be the best position to install the flood sensors.
Arctech understands the danger of flooding and has a prevention system based on the creation of “Flooding Risk Controlled NCU Areas”. These areas divide the plant into several areas controlled by one single NCU. Only those NCU with flood sensors can enter to flood mode. Only the trackers under NCU control will activate flood mode.
Each NCU will collect the data periodically from its attached sensor for an update on the water level value and trigger an alarm information. SCADA will get the latest water level value and flood alarms from NCUs.
If a flood alarm is raised, the SCADA will get the alarm information from NCU. NCU will send command to trackers to the correspondent area to go flooding mode by broadcast the signal.
A geotechnical and historic data study of the site must be provided to decide which area has more risk to floodings and which tracker is the best measuring location.
The sensor then will be placed at the motor level of a tracker and pointed to the ground. A service box called SBOX (Sensor Box) is also installed to provide power and communication interface with NCU.
Please proceed to the appropriate installation manual to know more about how to install and calibrate.
