Analysis and Verification of Operating Characteristics of Hybrid Inverter with External Power Meter

This paper deals with the non-standard behavior of a hybrid inverter equipped with external measurement, which was observed during one of the many tests performed in the ResLab laboratory at Brno University of Technology. It focuses on the inverter control processes which intend to maintain a power flow balance within the hybrid system consisting of photovoltaic source, battery storage and load. The paper contains a theoretical background, a description of the hybrid system configuration together with the laboratory equipment used for the test purposes, a simulated scenario, measurements results and its evaluation. The results show that the inverter does not fulfill its function in certain situations and its operation may even have a negative impact on the distribution grid at the point of common coupling.