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The paper focuses on studying the external-rotor synchronous reluctance motor. The analysis is performed to estimate the influence of the number of stator slots and non-magnetic areas in the rotor (i.e., flux barriers) on the electromagnetic torque and torque ripple of the studied motor. It is concluded that the increase in the number of stator slots Z = 6 to Z = 18 causes an approximately twofold decrease in the ripple factor, but torque increases by 5 %. Electromagnetic torque will be increased approximately by 24 %, if non-magnetic flux barriers are created in the rotor of the studied synchronous reluctance motor.

This paper focuses on studying the synchronous reluctance motors as an alternative to low-power commutator motors. Analysis is done for the improved design of synchronous reluctance motor with a segmental external rotor. Relevant equations and a suitable method are proposed for calculating characteristics of the synchronous reluctance motors operating in a specific mode with electronic commutation as switched reluctance motors. It is concluded that synchronous reluctance motors in this mode can provide a wide range of characteristics and are quite competitive with commutator motors used in low-power devices.

The paper presents an overview of brushless electric motors used in hand electric tools and household appliances. Analysis of the motor types has shown that synchronous reluctance motors are the most reliable for lowpower drives of such tools and appliances due to their simple design, long service life and low cost of production. Solutions are proposed for significant decrease in the quadrature-axis magnetic flux of the synchronous reluctance motor. The motors are shown to develop the specific electromagnetic torque up to 0.35÷0.4 Nm/kg.

In the paper, the possibilities to apply synchronous brushless motors in the electric hand tools are considered. The potential of such motors is estimated in a wide range of characteristics. In particular, estimation is made for the electric hand plane with a synchronous motor having outer rotor and excitation from permanent magnets.