Design and optimization of an axially-slitted high-speed solid rotor induction motor

Shielded axially slitted solid rotor design for high‐speed solid rotor induction motors

“…Research done in [9,[12][13][14][15] shows that the optimum slit depth for a simply slitted rotor geometry is about half of the radius of the rotor in a regular AS-SRIM. The axially slitting of the rotor increases the reluctance of tangential flux, thus flux intends to prefer a radial way and it diffuses deeper.…”

“…With their solid-rotor structure, solid rotor induction motors (SRIMs) have the advantage of the simplicity of construction, which in turn decreases the production cost and with its single piece of the ferromagnetic material body, possesses robustness against thermal and mechanical stress that the machine experiences when in operation [1][2][3][4][5][6][7][8][9].…”

“…[5]. A method of increasing the motors electromagnetic performance is to slit the rotor axially [6][7][8][9]. By slitting the structure axially, the rotors low-frequency impedance is decreased while current and flux are forced to use created teeth paths which in turn increases the torque output and decreases the eddy-current losses [12].…”

“…Since CRIM and smooth SRIM were shown to be the worst for high-speed operations [18], only performance results of AS-SRIM, CC-SRIM and SAS-SRIM with end-rings are compared. lower efficiency is its higher rotor impedance, higher reluctance of solid steel than that of a laminated steel, higher eddy currents and greater adverse effects of harmonics [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”

High‐speed solid rotor induction motor design with improved efficiency and decreased harmonic effect

“…Several methods are applied to refine the drawbacks of SRIM which are installing end rings on both ends of rotor, opening axial slits on rotor surface, or coating the rotor surface with a highly conductive material [2,[5][6][7][10][11][12][13][14][15][16][17][18].…”