Design of Bypass Network for Fast Switching Inverters using an Innovative Hybrid DC-Link

The development of low-inductance components suitable for fast-switching wide bandgap inverters has been a major focus of the last years. To realise fast and clean switching without ringing, most power modules are equipped with integrated high-frequency capacitors. In order to damp the oscillation, it is quite common to integrate additional resistances. This paper introduces a DC-link inverter concept that requires no internal high-frequency capacitor due to a small stray inductance in the current commutation loop. The prototype is composed of a hybrid DC-link with optimised DC-link capacitor technologies, which can be used for a cost-efficient and compact inverter concept. We discuss the effects of the parasitic elements of the different DC-link capacitor technology and investigate into a low ESL capacitor interconnection with two different capacitors in order to realise a current commutation loop (CCL) inductance below 6 nH.