Implementation of Fault-Tolerant Control for Five-Level Double-Boost Power Factor Corrector Converter

The modular multilevel topology is the double-boost type. This topology can be implemented either in single-phase or three-phase implementation, as well as in interleaved connection. As all converters of its type, this converter provides high power quality in terms of power factor and total harmonic distortion. In addition, the topology provides redundant states that are used to balance the flying capacitors during normal operation and to implement a post-fault reconfiguration strategy to provide continues operation when the permanent-short circuit failures occurs. Two control strategies using phase-shifted carrier PWM and phase disposition PWM are presented. The characteristics of the converter topology and the control strategies are demonstrated through mathematical analysis and simulation. A mock-up of the converter was constructed to verify the feasibility of both control strategies and the post-fault reconfiguration strategy.