Smart Hybrid Inverter: A Practical Guide

This work presents practical implementation details of a smart hybrid inverter for both on-grid and off-grid system operation with battery energy storage (BES) and photovoltaic (PV) energy generation. The inverter provides a seamless integration between the utility grid and the BES, granting uninterruptible load supply and the possibility of grid ancillary services. Both hardware and firmware are characterized in this paper. The hardware structure of the smart inverter is detailed showing how main functions are integrated. Practical considerations focusing on real implementation aspects are discussed in order to overcome common mistakes and problems found in the test bench scenario. Vital functions such as sampling, filtering and controller implementation are also discussed. The firmware structure is presented, which guarantees a smooth performance of both real time and communication processors. Experimental results are shown to validate the proposed solution.