Control principles of AC electric drives

An algorithm for the synthesis of a control signal in the torque contour of AC electric drives is proposed. It is based upon the spectral analysis of harmonic current and conductancies along the air gap which is applicable to any electric machine with a magnetic non-symmetry of a rotor and combines the method of winding functions and the energy method of obtaining the electric drive's coordinates (MDS, induction, EMF, electromagnetic torque). In addition, it also allows one to search for the optimal shape of current according to the principle of the electric machine operation. Under this algorithm it is recommended to perform optimization calculations under the following assumptions: the converter is not saturated, steel magnetic conductivity is equal to infinity, and there are no scattering fluxes. An example of the best form of the phase currents of an electric drive with a synchronous independent-excitation reaction machine synthesis is shown.