June-Seok Lee and Kyo-Beum Lee, “An Open-Switch Fault Detection Method and Tolerance Controls Based on SVM in a Grid-Connected T-Type Rectifier With Unity Power Factor,” IEEE Transactions on Industrial Electronics, vol. 61, no. 12, pp. 7092–7104, Dec. 201 > Paper

Multilevel converter topologies are widely used in applications of wide-power range. The T-type topology, which is one of many

three-level topologies, has an advantage in terms of efficiency compared to the neutral-point-clamped (NPC) type. In applications

using the T-type topology, interest in reliability has been increased recently. Therefore, the open-switch fault detection method and

tolerance control for T-type rectifiers, which are different from those of T-type inverters, are necessary to improve the reliability of

applications. When the open-switch fault of switches connected to a neutral point occurs, an NPC-type rectifier cannot restore

distorted input currents; however, a T-type rectifier is able to eliminate input current distortion completely. In this paper, an open-

switch fault detection method is proposed and can find a position of the open-switch fault. Moreover, two tolerance controls based

on space vector modulation are proposed and their characteristics are analyzed. The effectiveness and performance of the proposed

open-switch fault detection method and two tolerance controls are verified by simulations and experiments.