Reducing the dv/dt of Motor Inverters by a Two Leg Resonant Switching Cell

Conference: PCIM Europe 2018 - International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management
06/05/2018 - 06/07/2018 at Nürnberg, Deutschland

Proceedings: PCIM Europe 2018

Pages: 8Language: englishTyp: PDF

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Fuchslueger, Thomas; Ertl, Hans (TU Wien, Institute of Energy Systems and Electrical Drives, Power Electronics Section, Gusshausstrasse 27-29, A-1040 Wien, Vienna, Austria)
Vogelsberger, Markus (Bombardier Transportation Austria GmbH, Product and R&D_Management RoQ_M_DRIVES, Hermann Gebauer Straße 5, 1220 Vienna, Austria)

The switching speed of modern inverter semiconductor devices (esp. wide-bandgap devices) increasingly rise resulting in low switching losses but high output voltage dv/dt rates causing stress on the insulation system of the load (i.e. traction motor). This paper presents and analyzes a novel concept for reducing the output voltage dv/dt of motor inverters avoiding any reduction of the semiconductor’s basic switching speed (which would be an alternative for dv/dt reduction in principle, however, paid by increased switching losses). The proposed concept is achieved by splitting up the half-bridge of a single phase into two legs which are gated slightly delayed against each other and combining their output voltages by a small interphase transformer. The transformer’s stray inductance in connection with an additional capacitor forms a resonant circuit which shows a cosine edge shaped output (motor) voltage at low dv/dt rates for a properly tuned design.