The bachelor thesis is focused on the principle of the static frequency converter. The thesis is divided into three parts: the principle of the converter function, the control elements of the converter and the analysis of the basic electrical quantities of the converter. The first part of the thesis deals with the basic parts of the static frequency converter, which can be rectifiers, inverters, etc. In the second part of the thesis you can find the correct way to install the converter, to enter the values via the input panel and also explanation of the connection of the inputs, outputs and other auxiliary contacts. The third part of the thesis describes transient phenomena when the converter is put into operation.