SiC MOSFETs for Offshore Wind Applications

S Tiwari,T Undeland,O M Midtgård,R Nilsen

doi:10.1088/1742-6596/1104/1/012032

Abstract

Space and weight are critical factors for offshore wind applications during the construction, operation, and maintenance phases. Superior material properties of silicon carbide enable the development of power devices capable of switching fast as well as handling high power. Thus, this paper performs the quantitative evaluation of the total converter loss and efficiency at different switching frequencies in order to observe the potential performance gains that SiC MOSFETs can bring over Si IGBTs for such applications. When simulating the detailed converter losses in a three-phase, two-level topology; the turn-on and turn-off switching energy losses obtained from the laboratory measurement and the conduction losses acquired from the datasheet are used as a look-up table input. Additionally, the simulated results are compared with the analytical and the numerical solutions. In conclusion, this analysis gives an insight into how SiC MOSFET outperforms Si IGBT over all switching frequency ranges with the advantages becoming more visible at higher frequencies.

Highlights

The potential power produced from wind is directly proportional to the cube of wind speed [1]
Bandgap energy is about 3 times higher in silicon carbide (SiC) compared to Si which can be translated to switching devices with higher operating temperature; breakdown field intensity is about 10 times higher in SiC and this can lead to devices with higher breakdown voltage and still have the same conduction loss; higher thermal conductivity means faster heat dissipation which results in higher power density; and likewise, higher drift velocity enables faster transportation of carriers, and thereby faster switching of devices can be achieved
The results reveal that the total conduction loss (Pcon) is approximately equal to the total switching loss (Psw) at about 15 kHz and 25 kHz for the all-Si and all-SiC inverters, i.e., for the low frequency region, the conduction loss is a dominating part of the total inverter loss

Summary

Introduction

The potential power produced from wind is directly proportional to the cube of wind speed [1]. In [9], a performance comparison between SiC MOSFET with punch through (PT) type of Si IGBT (optimised for the switching loss) was investigated. It verifies the simulation results with the numerical and analytical calculations.

Laboratory testing of SiC MOSFET versus Si IGBT module

Findings

Conclusion