A novel N+k fault-tolerant hot-swap DC/AC inverter design

In this paper, a new fault tolerant inverter design is presented, with N+k redundancy and hot-swapping capability. The proposed method uses N+k parallel H- bridges capable of fault detection and isolation. An open collector "fault" signal can be set or control each bridge. A flexible control unit accepts, activates or deactivates the "fault" signals of all the H-bridges. A prototype inverter with four H-bridges and multilevel modulation was constructed and tested in the laboratory to verify the practical problems of the method. The proposed method is mainly intended for non-cascaded inverters.