Double-pulse inverter feeds 6-phase asynchronous motor for harmonic loss reduction

Especially for battery-fed drives e.g., in electric vehicles, a DC link capacitor is needed to reduce harmonic losses caused by the DC link current. For this a new drive, a double-pulse inverter and a double-fed asynchronous motor is presented. With this, the DC link current harmonics can nearly be halved and the harmonic torque can be reduced as well. The double-pulse inverter consists of two inverters taking the same DC link voltage. So, the double-pulse inverter is redundant, e.g., in case of a defect in one inverter it is possible to drive with reduced power. The asynchronous motor has two 3-phase windings and can easily be developed out of a standard machine. With this, each inverter feeds 3 phases of the motor. A theoretical 6-phase model of the motor can be reduced to a 2-phase model. For simulation, the motor can be described with space vectors. Simulation results and the experiences made show the advantages mentioned