Controllable-Fulx PMSM With Novel Design of Magnetic Circuit in Rotor — Memory Motors

This paper presents a novel magnetic circuite structure of internal composite-rotor controllable-fulx permanent-magnet synchronous machines (PMSMs), or named Memory Motors. According to the given pole pair number, the special placement and dimension of NbFeB and AlNiCo permanent magnets (PMs) brings a ture wide range speed operation to the motors. The magnetization statu of PMs can be changed with d-axis stator current vector pules regulated by the closed loop control system. Further more, once the indensity of magnetization has been changed, the motors will memorize the flux density level. Following the description of the motors' principle, the internal magnetic field has been analyzed by finite element method, and the proposed assumption has been proved feasible. Studies point out that the result of flux weakening can be better, and the influence of armature reaction on air-gap PM-flux is diminished when the larger q-axis magnetic resistance is designed.