Scientific paper ID 2039 : 2020/3

On a global scale, the development of the energy sector in the field of renewable energy sources (RES), and of photovoltaic systems in particular, moves on parallel tracks for both high-power and for the low-power photovoltaic systems (PVS), which are applicable to family lodgings and households. At present, Bulgaria’s share of energy generation by low-power PVS is negligible as compared to that of the high-power PVS, which can be attributed to the technical features of the former, as well as to their affordability and the consumers’ capacity to use them.

The developments of technology in the field of low-power invertors of electric energy over the recent years is driven by both their parameters and by market demand. Their easy integration and intuitive use are the key factors for user preference. The other quality indicators, which determine their electromagnetic capability, are the THD and the sinusoidalisation of PVS output current and voltage, which is d for the normal operation of electric meters, machinery and equipment. Developmental trends focus primarily on this and optimal circuit solutions are sought to match such applications.

Thereby, a hybrid electric energy invertor, which shares all the advantages of modern-day invertors, was experimentally tested on an operational PVS and its input/output characteristics were outlined.

A circuit solution is offered for the high-power section of the invertor undergoing the testing, and explanation is provided as to its advantages and drawbacks.

The report contains the main results of the experimental testing under various loads in real exploitation conditions.