Digital short-circuit diagnosis and reconfiguration of a fault tolerant VSI
Andre B. M. Oliveira, Robson Luiz Moreno, Ênio Roberto Ribeiro · 2017
Voltage source inverters (VSI) present, among other things, short-circuit faults in their switches. This article presents a short-circuit (SC) fault diagnosis (FD) method for a fault-tolerant inverter topology. Rough Sets Theory (RST) is used to develop the diagnostics (detection and location) for faults and determine a minimum set of diagnostic variables, i.e. control signals and inverter switch currents. The diagnostic rules, obtained using RST, are constructed with basic logic functions. Therefore, the SC fault diagnosis circuit is digital. The FD variables have a dual purpose: they are used in the diagnosis of SC fault and in the VSI reconfiguration procedure. The inverter topology is reconfigurable, since it has a redundant leg, fast fuses, and two auxiliary switches. The proposed diagnostic method and inverter reconfiguration procedure are supported by results obtained through simulation and experimentation.