| Abstract |
Conventional traction vehicles for AC-mains contain a line-transformer in the propulsion chain. This
transformer, especially for 15 kV/16.7 Hz main lines, is bulky, expensive and has high losses. This
paper proposes a completely new transformerless configuration which reduces weight and dimensions
of the drive power chain and improves the efficiency. On the line side, series connected voltage source
inverters are directly connected via a line choke to the overhead line. This leads to DC-links on different
voltage potentials, which ask for a new motor concept. The proposed 3-star induction motor with three
independent 3-phase windings is fed by three 3-phase inverters on different voltage potentials. A new
control structure for this 3-star induction motor becomes necessary and is proposed. |
