Anisotropy-based self-sensing design and control of induction machines

Abstract The operation of an induction machine (IM) without a mechanical position sensor saves cost and reduces its volume. At zero and low speeds, anisotropy-based self-sensing control (SSC) methods can be used, but IMs do not inherently exhibit the necessary rotor-fixed anisotropy for these methods. By means of modified rotor designs with an additional asymmetrical winding or modulated slot openings, a rotor-fixed anisotropy can be introduced. Nevertheless, an operation with SSC at low speed has still only been demonstrated with reduced flux or torque. Now, with a modified rotor and a novel compensation for the saturation-dependent anisotropy, a successful operation with SSC at rated torque and zero to low speed is presented.