SiC MOSFETs for future motor drive applications

Abstract

This paper investigates the switching performance of six-pack SiC MOSFET and Si IGBT modules for motor drive applications. Both the modules have same packaging and voltage rating (1.2 kV). The three bridge legs of the modules are paralleled forming a single half-bridge configuration for achieving higher output power. Turn-on and turn-off switching energy losses are measured using a standard double pulse methodology. The conduction losses from the datasheet and the switching energy losses obtained from the laboratory measurements are used as a look up table input when simulating the detailed inverter losses in a three-phase motor drive inverter. The total inverter loss is plotted for different switching frequencies in order to illustrate the performance improvement that SiC MOSFETs can bring over Si IGBTs for a motor drive inverter from the efficiency point of view. The overall analysis gives an insight into how SiC MOSFET outperforms Si IGBT over all switching frequency ranges with the advantages becoming more pronounced at higher frequencies and temperatures.

Comparative evaluation of a commercially available 1.2 kV SiC MOSFET module and a 1.2 kV Si IGBT module

“…The losses in the Si IGBT converter increases much more than in a SiC MOSFET converter because the tail current in the IGBT and Q rr in the anti-parallel diode exhibit strong dependency on temperature. In the SiC MOSFET, the turn-on losses decrease and turn-off losses increase, and in overall the total losses slightly increase with increasing temperature as shown in previous work [6].…”

“…However, one should not forget that the room temperature is not a real environment for a practical converter operation. The tail current in Si IGBT worsens with higher temperature, whereas the losses in SiC MOSFET increase a little or remain almost the same [5], [6].…”

“…For example, a six-pack SiC MOSFET module is compared with a six-pack Si IGBT module keeping similar gate resistance in [5] and under similar dv/dt conditions in [6]. Similarly, a half-bridge SiC MOSFET module is compared with a SiC IGBT module under same dv/dt conditions in [7].…”

Advanced aircraft power electronics systems — The impact of simulation, standards and wide band-gap devices

“…An interesting comparison is to observe the switching transients of IGBTs and their SiC MOSFET counterparts under the same switching conditions [53], and while the main over/undershoot tends to be lower for the SiC devices, there are clearly issues with ringing due to the increased transient switching speeds. This is also an indication of the sensitivity of the SiC devices to track inductance as a result of this shift in di/dt characteristic.…”

Soft switching loss measurements of a 1.2 kV SiC MOSFET module by both electrical and calorimetric methods for high frequency applications

“…There are several publications on the loss measurements with the hard switching of devices [5,6,7], but few on that with the soft switching [8,9,10]. Additionally, none of the publications have compared the losses between the electrical and calorimetric loss measurements where the main contribution of the paper lies.…”