T. Fuchslueger, M. Vogelsberger, H. Ertl:
"Reducing dv/dt of Motor Inverters by Staggered-Edge Switching of Multiple Parallel SiC Half-Bridge Cells T";
Talk: PCIM, Nürnberg, Germany; 06-16-2017 - 06-18-2017; in: "PCIM Europe 2017", VDE, (2017), ISBN: 978-3-8007-4424-4; 7 - 673.

A novel concept for reducing the output voltage dv/dt of PWM inverters (especially for traction motor applications) is proposed which however keeps high semiconductor switching speed resulting in low switching losses. Each phase of the intended converter is formed by a parallel arrangement of half-bridge legs which are PWM operated such that a small time-delay is given between the legs (time staggered switching). The output voltages of the legs subsequently are combined by an interphase transformer/inductor network/device to a total output voltage of staircase-type switching edge behavior which finally leads to a much lower dv/dt at the motor terminals despite high-speed semiconductor switching. The paper describes the basic principle and application variants, the dimensioning and the required current balancing. Finally, measurements taken from a laboratory testing setup are presented.

http://publik.tuwien.ac.at/files/publik_265876.pdf