摘要： The purpose of this paper is to study the response time of SMA Sunny Tripower 5.5 inverters. Material and method: The photovoltaic polycrystalline photovoltaic panels totaling 5000 W, which directly feeds an STP 500TL-20- 5.5kW Sunny Tripower grid inverter. Experimental research was conducted to test the possibility of using these inverters designed for solar systems coupled with wind turbines. As MPPT (maximum power point traking) inverters used for the above purpose, and delivering voltage to the national grid, they have an operating algorithm that allows them to adapt the impedance so that the group of photovoltaic panels delivers maximum power, indifferent to and the angle of incidence of the solar panels. The maximum voltage at which the panels work is 1000V, which allows the insertion of a large number of panels on the same string (virtually 1000/42 = 24 monocrystalline panels or 1000/37 = 27 polycrystalline panels). The algorithm mentioned above probes the power curve at various impedances, and then positions itself on the impedance at which the calculated power was the maximum. After a while, the process is resumed, since it is possible that the power received by the Sun panels has changed.The same algorithm is also respected by wind turbine inverters, with the observation that the sweep of the power curve and the positioning to the maximum value takes much less. This is necessary because the value of the wind speed is much faster than the sun. In addition, the safety of the turbine requires this, as it could lead to a wind turbulence. In conclusion, SMA Sunnny Tripower inverters are very slow in terms of loading and calculating the optimal operating point.