Regulated motor drives are powered via AC-AC converters. In the beginning of this master thesis a theoretical background of synchronous motors is described and thus the need for powering them via converters. Main part of the thesis consists of design and implementation of power (supply) part of the converter for powering a circulating pump with a synchronous motor with permanent magnets. The first stage of the power module is implemented with a single-phase PFC rectifier circuit, known as a boost PFC converter, which converts mains AC voltage to DC voltage. Furthermore, it ensures appropriate mains current shape, which improves power factor and lowers harmonic currents. That greatly increases the efficiency of powered motor and meets the directives of EN 61000-3-2. Second stage of the power module consists of a three-phase transistor bridge circuit that provides the motor with a supply voltage of a variable amplitude and frequency. The selection of components is justified by calculations. Finally, the operation of the power module is confirmed by measurements.