New configuration of high-power inverter drives

New configurations for high-power and high performance drives suitable for steel rolling mill drives are presented. Three-level inverters using 6 inch, 6 kV, 6 kA GTOs, can deliver 10000 kVA output. But in case of drives rated more than several thousands of kW, this capacity is still insufficient. Usually, two three-level inverters are then combined using bulky, expensive inter-phase reactors. To meet these problems, a new configuration using the wound rotor induction motor and two inverters is proposed. In this configuration, the outputs of the two inverters are combined electromechanically in the machine; then novel features suitable for high-power drives can be obtained.