Asymmetric modes in multiphase electric drives

The method of symmetrical components is used to study the influence of power supply asymmetry and / or electromagnetic asymmetry of the electric motor on energy losses and electromagnetic torque pulsations. It is shown that in multiphase motors, asymmetry results in additional losses due to the appearance of the symmetrical components of the fundamental harmonic with an alternating phase order. In this case, additional losses can reach a value that excludes the possibility of the electric motor operation in emergency mode of open or short circuit, despite the fact that formally such possibility exists. In addition, in multiphase motors under the conditions of asymmetric modes, there are pulsations of the electromagnetic torque with double frequencies of all harmonics of the spectrum of the power source.