Dr. Fernandes at IITB, has invented a improved an electric powered motor in-wheel drive system with an inverted switched reluctance motor drive system adapted to provide improved efficiency, compactness and maintenance free operation in the vehicle system.
The motor drive system has a stator and a rotor. The stator comprises a stack of plate laminations made of ferromagnetic material. The laminations are stacked face-to-face and suitably adhered to one another. The stator includes a few outwardly extending stator poles facing concavely to the stator pole faces. The Rotor circumscribing the stator comprises of rotor poles which faces outwards concavely to the rotor pole faces. Windings are wound about the stator poles in such a way that for every stator pole of one polarity there is a corresponding pole of an opposite polarity.
The drive system comprises of an inverted motor with selected windings connected to a converter controller system. It is operable to selectively generate pulses of electrical current through windings. The timing of current pulses generated by current pulse generating circuit in the controller is determined by a position sensor. At zero degree rotor position the controller provides an excitation in the phase windings to generate a torque on rotor causing rotor to rotate counterclockwise and to align wide rotor pole with the excited phase. At 22.5 degrees rotor position, wide rotor poles and adjacent energized phase A, stator poles are in a minimum reluctance position with respect to each other as a result of a constant gap being formed there between.
Stator is disposed within central bore defined by rotor pole faces. The rotor is advanced through 15 mechanical degrees by the energization of phase B and de-energization of phase A. However, the movement of rotor may extend beyond 15 mechanical degrees by similar energization of phase C. The increasing or decreasing inductance of a phase winding corresponds to the respective decreasing or increasing reluctance in the magnetic flux path associated with the phase winding. The windings are energized in response, rotor experiences a torque in a counterclockwise direction that results in minimum reluctance in the rotor, maximum inductance position with respect to stator. It is by this method the engine works in a very efficient manner.
Indian patent application no. 365/MUM/2007 Patent grant no. 241923
Inventors: B G Fernandes, D P Mahajan