Six-Leg AC-AC Fault Tolerant Converter with Reduced Extra-Sensor Number

In order to prevent further damage and to provide the continuity of service of six-leg converter in case of open-switch fault, it is mandatory to perform fast fault detection and converter reconfiguration schemes. Extra sensors are needed to detect the faults rapidly. In this paper, a very fast FPGA-based fault detection scheme is presented that minimizes the number of additional voltage sensors. A six-leg fault tolerant converter topology without redundancy and with bidirectional power flow is studied. First simulations are carried out to evaluate the proposed fault detection principle and the fault tolerant converter topology. The fully digital control and the fault detection are implemented on a single FPGA. Experimental tests of the digital controller and the detection scheme are performed to verify the high performance of the proposed method. Copyright (C) 2011 Praise Worthy Prize S.r.l. - All rights reserved.