5-level double-boost PFC with fault-tolerant capability

A new 5-level non-differential PFC topology with fault tolerant capability is presented and compared to known structures. It is derived from a 3-level double-boost PFC. The series-connection of the two low-voltage switching-cells decoupled by a single flying capacitor provides a fault-tolerant capability and a post failure operation increasing the availability of converter. The most important features are highlighted. Moreover, a AC115V - DC400V - 4 kW - 2 times 48 kHz mock-up was built to validated studies. A preliminary analysis is also presented on the physical / electrical failure mode of a 600V/60A CoolMostrade taking into account the post-failure stability from a series redundancy standpoint.