Energetica India Magazine: september 2020

SOLAR POWER 37 energetica INDIA- September_2020 Figure 3 - Tracker-Controller-Unit subfield of trackers is controlled by a single GCU which integrates a powerful embedded computer, three independent Open Thread interfaces, RS485 inter - face for sensors, GNSS connection for position and time synchronization, GPRS communications and USB ports and SD card slot for mass storage. The new mesh communications are in- terfaced with the OpenThread modules and the new GCU incorporates three of them. The #1 OpenThread interface labeled as “Ant 1” is the main interface for communicating with all the trackers assigned inside the subfield, the other two interfaces “Ant 2” and “Ant 3” are available for redundant features. In case one GCU becomes unavailable, the closest ones will assume the control over the trackers, maintaining all the trackers available with double GCU redundancy. The GCU software runs over Linux O.S. and offers a comprehensive HMI allow- ing configuration and monitorization of all the parameters related to the GCU and all the TCUs assigned. Tracker-Controller-Unit (TCU) : A new controller designed from scratch which breaks with the previous generations as it uses the latest technologies on the market. The main microcontroller has been replaced increasing the per- formance and memory and allowing new smart features like self-diagnos- tic with full reports, self-calibration and auto-commissioning to name some of them. This new controller integrates our patented Over-Angle-Detector (OAD) for redundant security and a high accuracy current sensor for preventive mainte- nance analysis. Serial Power Supply (SPS) : The next generation of our patented serial power supply which charges the battery pack from the current that flows through the existing strings over the tracker. This new generation improves the power conversion efficiency and is compatible with a broad range of battery technol- ogies, including LiFePO 4 cells. One of the most important features is the auto- matic string/panel mode which ensures the battery pack will be kept in a good state of charge independently of the string status. This feature switches from string to panel mode in case the string is not working for some reason like in- verter maintenance, problems with the transformers or grid connection, fuses, or connections problems. The new SPS integrates a new digital control allowing the monitorization of all the internal parameters and being able to be updated over-the-air. Gateway-Control-Unit (GCU) : Each Figure 4 - Serial-Power-Supply Figure 5 - Gateway Control Unit Figure 6 - GCUs Redundancy At the “cold-commissioning” stage of the plant installation, the new GCU is able to set up the whole subfield with indepen - dence of the status of the rest of the plant (plant network, energization, inverters, etc). The time is synchronized through its GPS interface and the meteorological measurements are performed directly at the GCU with the corresponding sensors connected (wind, snow, flood, tempera - ture, etc). The standard interfaces between the trackers network to third party SCADAs are MQTT and OPC-UA, having an OPC- UA server at each GCU.