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A five-level power factor correction topology with fault-diagnosis and fault-tolerant capabilities is proposed and analyzed. This structure is derived from the well-known three-level one-pole double-boost including double-stacked redundant and low-storage-energy flying capacitor cells. Two fault-diagnosis strategies are presented. The first one directly operates the monitoring of the voltages across the flying capacitors, detecting and localizing the faulty switch by means of two sensors. The second one is based on indirect voltage vector detection through only one sensor. Both of these strategies are analyzed and simulated with the efficient phase disposition pulsewidth modulation technique. The design and the most important features are highlighted owing to a digital control frame and a single-phase mock-up rated at 115 V/400 V, - 4 kW, and 2 \times 31 kHz. The presented results also offer a dedicated strategy permitting an optimized real-time reconfiguration in postfault operation. [ABSTRACT FROM PUBLISHER]

Power-factor-corrector (PFC) converters are now commonly used in low-power supply systems connected to ac net- works. In addition to their basic PFC properties, they constitute the best technical solution to directly obtain the compatibility with a large range of ac voltages provided by different distribution networks around the world (typically, from 85 to 265 V rms). It is the main application of these converters. This function is achieved with an additional cost and volume, and this extra price to pay needs to be minimized. In this context, we first recall the main approaches of the de- sign of conventional PFCs based on the boostconverter topology. We emphasize the different critical points of the sizing that mainly concern the input choke and the silicon devices, in regard with the choice of the switching frequency. Few ways of improvement are then presented for these conventional PFCs. In a second part, always in the context of a large input voltage range, we consider the possibility to introduce the multi-level concept to reduce the input choke and filters. A solution using a multi-level flying Capacitor Two-Cell converter is presented. It is shown that it can lead to a significant increase of the performances, with several options of sizing which can be suited to different requirements of the applications. [ABSTRACT FROM AUTHOR]

Presents a study which examined the application of soft-switching in imbricated-cell multi-level converters. General properties of a hard-switched multicell converter; Analysis of the auxiliary resonant commutated pole multicell converter.