Silniki elektryczne z magnesami trwałymi umieszczonymi na wirniku

Electric motors with permanent magnets placed along rotor's circumference may operate as: -synchronous motors with permanent magnets (PM SM) -sinusoidally controlled brushless dc motors with permanent magnets (PMDC BMSC) -trapezoidally controlled brushless dc motors with permanent magnets (PMDC BMTC). In each case the electromechanical properties of the drive are different, this is influenced by the control method and electromagnetic field distribution in the armature slot. The induction distribution should induce sinusoidal rotation voltage in the armature winding of PMSM and PMDCBMSC and trapezoidal rotation voltage in PMDCBMTC, respectively. Synchronous motors are supplied with voltage of set (forced) frequency. The rotational speed is controlled by changing the supply voltage frequency. The mathematical model of synchronous motors in steady and quasi-steady states is given in Equations (2-10). The electronic commutator in brushless pm motor is built into the motor, same as mechanical commutator in dc motors. The electronic commutator is supplied with dc voltage. The windings' current is of variable character, but its frequency depends on the rotational speed of the motor. This speed is controlled and set by changing the electronic commutator supply voltage. If the current waveforms generated by electronic commutator in A, B, C phases windings are trapezoidal, then the motor is denoted as trapezoidally controlled. The mathematical model of this motor is given in Equations (11-14). If the current waveforms generated by electronic commutator in A, B, C phases windings are sinusoidal, then the motor is denoted as sinusoidally controlled. The mathematical model of the motor is given in Equations (15-20).