Frequency Converter: this is a device designed to convert alternating current (voltage) of one frequency into alternating current (voltage) of another frequency. The output frequency in modern converters can vary in a wide range and be both higher and lower than the frequency of the supply network. The circuit of any frequency Converter consists of power and control parts. The power part is usually made on thyristors or transistors that operate in the mode of electronic keys. The control part is performed on digital microprocessors and provides control of power electronic keys, as well as the solution of a large number of auxiliary tasks (control, diagnostics, protection).