This thesis analyzes the problem of enhancing the efficiency of energy conversion in wind energy conversion subsystems integrated in combined wind and photovoltaic conversion system. The first part of the thesis is dedicated towards describing combined energy conversion systems in which each of the subsystems is described separately and then connected into an integrated unit. After presenting general difficulties, which may occur during realization, in the second part of the thesis, the focus shifts to the concrete problem of energy conversion in the wind energy conversion part of the system, in which as relevant data is used total harmonic distortion and power factor. The main goal is to find on of the rectifier topologies, which by working, produces the best parameters possible. At first, the topology of the three-phase unregulated bridge rectifier is sampled after which is described his operation principle completed by simulations of the rectifier's connection with different types of load. Inferior results of the total harmonic distortion of source, as well as the power factor, encourage the representation of a different type of rectifier, the Vienna rectifier. In final part, the thesis describes in detail the topology and working principle of the Vienna rectifier and gradually describes the parameters of essential importance for a successful implementation of the controlling algorithm. The final realization of the controlling circuit with three regulation loops: voltage loop, current loop and the regulation of exiting voltage symmetry lead to successful results. The results of the total harmonic distortion amount to ≈3%, and power factor ≈99% gained with the help of the Vienna rectifier demonstrate the great progress in comparison with the three-phase unregulated bridge rectifier, whose total harmonic distortion amounted to ≈141% and power factor ≈57% for the same type of load (RC), significantly inferior valuations. A confirmation of satisfying parameters is also given by the data that the final valuations satisfy the first class of quality under the IEC-61000-2-4 norm.