Threshold point calculation method using instantaneous phase current for switch fault diagnosis of AC-DC converters in hybrid grid systems

Abstract

This paper describes the threshold calculation method to improve switch fault diagnosis performance in the hybrid grid system. In order to achieve fast fault diagnosis, the threshold point calculation method is proposed by using instantaneous phase current instead of average phase current. Using the proposed method, the switch fault could be detected within 4 ms which is recommended value on the uninterruptible power supply (UPS). In order to verify the proposed method, theoretical analysis, operating principle and experimental results are presented. © 2019 IEEE.