Design of a Prototype for Inverter Monitoring with SunSpec Modbus Protocol

Abstract: In a context of growth of the company in which the project was conducted, and to provide a simple and cost efficient solution to PV system monitoring, the development of prototype using Modbus Sunspec is studied in this thesis. The project is developed using an engineering approach, which defines a clear scope, a schedule and detailed objectives for the prototype. After analysing the available options and assessing the needs for an own product, a complete design of a solution is developed. Divided in two blocks, it uses several technologies. On the hardware side, a Raspberry Pi is coded in python and is using an Ethernet cable to communicate with the inverters with the protocol Modbus TCP/IP. The hardware is interfaced with Emoncms, the software and an open source website specifically designed to monitor energy uses. On site tests could not happen partly due to a slowness of the PV market in Myanmar, however other tests with artificial data show good operations and stability of the prototype. Designed to be capable of interfacing with several brands of inverters and gather the monitoring in one only website, the prototype meets most of the objectives. To use it, it will need further improvements and validation of reliability, another approach could be to enhance the automation and control capabilities for smart grid designs.