Energetica India Magazine: september 2020

SOLAR POWER Full Wireless Distributed and Redundant Control of Solar Trackers 36 energetica INDIA- September_2020 José Alfonso Teruel CTO Soltec Innovations During the last years PV plants tend to in- corporate full-wireless and other systems that secure the installations and contrib- ute to the customers’ trust. The objective of these systems is to anticipate adverse meteorological phenomena with greater precision and be prepared for the de- fense position or communicate a prob- lem in the plant with greater speed and precision. With operations and subsidiaries in the five continents, Soltec leads the solar PV market at the Latin American continent with more than 7 GW of solar trackers supplied. Soltec has recently released its latest generation of Trackers Control System. The new development is a comprehen- sive solution which integrates a new eco- system of devices. The main features of this new control system are: - Full Wireless Communications using Open Thread (released by Google) technology and MQTT protocol. - High availability with the self-healing mesh network, redundancy of all devices and no single point of failure. - Auto-Commissioning procedure for set- ting up and test Trackers automatically. - Super-fast installation of devices to structure. - Double life expectancy of batteries us- ing LiFePO 4 technology. Figure 1 - Thread Mesh Network with Trackers - Encrypted communications and indi- vidual identification, authentication and authorization of all users or devices with access to the network. - Full functional mobile APP for O&M pur- poses through NFC interface Open Thread released by Google is an open-source implementation of Thread ® . Thread is a low-power wireless mesh networking protocol designed for easy integration in the connected environ- ments. Being an IP-based open stan- dard, Thread allows smart devices to connect directly securely and reliably to the cloud. Open Thread solves the problem of communicating safely and securely tens of thousands of devices spread in large PV plants without the need of adding repeaters. The main components of the new com- munications and control system are the Tracker-Control-Box and the Gateway Control Units. Figure 2 - Tracker-Control-Box Tracker-Control-Box : A new enclosure which clamps to the tracker’s structure in record time and can be installed by only one person. The battery compart- ment is independent from the electron- ics circuits, allowing a secure and safe replacement. The main body is made of aluminum, having a direct thermal con - tact from the power electronics to the body. This new feature ensures the inter- nal temperature of the electronics devic- es, keeping them cooler than in previous designs, a feature that directly enhances the life expectancy of the internal com- ponents. Inside the Tracker-Control-Box the two main electronics boards are connected board to board in a “sandwich” fashion, this feature reduces the volume needed inside the box while improves the manu- facturing time. This “sandwich” of circuits can come out of the box as a package in case of replacement of inspection tasks. The two mentioned main boards are the Tracker-Controller-Unit (TCU) and the Serial Power Supply (SPS).