The production of a solar photovoltaic plant is intrinsically linked to the ability of the solar trackers to accurately follow the sun's path and maximize solar energy collection. The solar trackers, which are responsible for orienting the PV panels to the perpendicular of the sun throughout the day, require effective communication between them to ensure coordinated operation and thus maximum energy production.
In this article, we will explore in detail the key components of solar trackers and how communication between them is established to optimize plant performance.
The main controller
The main controller plays a crucial role in the efficient operation of the plant. It is in charge of managing the solar algorithm, generates and sends the position setpoints for solar tracking and the appropriate operating mode to all the plant's tracker controllers.
This system can be monitored and controlled through the PV plant's SCADA system, allowing remote control of each tracker. In addition, the overall plant controller collects information such as communication status, the position recorded at each tracker controller and its alarms, facilitating effective plant management.
The gateway
Gateways installed in the field are used to facilitate communication. These devices are connected to each other and to the general controller via Ethernet or fiber optics. Communication between the gateways and the tracker controllers is done wirelessly using the LoRa (Long Range) protocol. The LoRa connection is a long range wireless communication technology designed for the communication of low power consumption devices in Internet of Things (IoT) applications.
The Gateway, configured as a LoRa message forwarder, plays an important role in amplifying the wireless signal, allowing the main controller to cover all tracker controllers in the plant.
Meteorological tower
The meteorological tower is responsible for real-time wind monitoring. Using a LoRa wireless communication card, this unit provides up-to-date information on wind speed and direction, allowing the general controller to issue alarms in case of adverse weather conditions, and place the solar trackers in defense position.
The meteorological towers are equipped with an anemometer, which measures wind speed and direction, and an autonomous power supply system, consisting of a battery and a PV panel.
Tracker controllers
These controllers are installed on each of the solar structures, connected to the motor responsible for moving the tracker, to an inclinometer capable of measuring real-time position, and communicate via LoRa with the main controller. Like the meteorological towers, they are powered by an autonomous system composed of a PV panel and a battery.
These controllers have the following purposes:
- Receive information from the main controller.
- Adjusting angular positioning according to the time of day:
- Solar tracking during the day.
- Backtracking.
- Defense positioning
- Manage weather alarms detected by meteorological towers:
- Wind alarm.
- Snow alarm.
- Hail alarm.
- Control the direct current (DC) motor of the tracker.
- Execute control algorithms to read the inclinometer information.
- Send tracker information to the main controller.
When the tracker controller operates in automatic mode, the main controller can manage the solar tracking remotely. In case of a wind or snow alarm, the main controller will stop sending the solar angle setpoint and transmit the fender position.
If the battery level is insufficient to continue solar tracking, the tracker controller will command the motor to automatically move to the defense position. Once the battery recovers, the tracker will return to its previous state.
In summary, the communication system among solar trackers plays a fundamental role in optimizing the performance of a photovoltaic solar plant. From the main controller, acting as the operation's brain, to the gateways and field devices, each component works together to always ensure maximum solar energy capture and efficient operation.
Vector Renewables, with its extensive international experience, has a team of professionals offering a complete technical consultancy service. In this way, Vector Renewables provides services to facilitate communication between solar trackers during the construction phase of the plant, as well as throughout its lifetime, through all our specialised departments globally.