The article presents the most important causes of energy losses in magnetic circuits of electrical machines and describes a new design of a synchronized induction motor. The basic operational parameters of two structures: induction machine with squirrel cage (IM) and newly designed machine with a rotor with permanent magnets and a copper squirrel cage (induction machine synchronized with self-starting (LSPMSM) have been identified and compared. Performance characteristics were determined for work in steady states. In both cases the stator, type Sg 100L-4B of 3 kW induction motor was used. It has been shown that the PSPMSM supplied from the public mains grid shows the efficiency approx. 5% higher than the conventional motor. The influence of the change in the supply voltage frequency on the work of both structures was tested, i.e. on the measured efficiency, power factor and the electricity from electrical grid. Studies have shown that the LSPMSM can be a replacement for an induction motor. It has been shown that the torque pulsations occurring in the new structure (cogging torque) do not increase the environmental risks.