EMI Prediction of Future Device GaN with Reverse Conduction Characteristic in HVDC System

Gallium nitride (GaN) HEMT have become popular in high voltage direct current (HVDC) transmission systems due to its fast switching speed and the ability to operate at high frequencies. However, it is generally known that high-speed switching actions will increase the electromagnetic interference (EMI) of power electronic devices and affect the stability of the HVDC system. Hence, this paper proposes an analytical method to predict EMI generated by GaN HEMT during switching process, and quantifies the impact of reverse conduction characteristics on EMI. The results show that the reverse conduction characteristics of GaN HEMTs mainly affect EMI in the high frequency range, and as the reverse conduction voltage increase, EMI becomes more severe. Experimental tests are also performed to verify the analysis results.