Sliding mode and fault tolerant control for multicell converter four quadrants

In this paper, we present a multicell converter connected to a load R-L. We show its importance in the practical implementation of a sliding mode control algorithm. The validity of the controller is shown with simulation results. In the second part a topology with fault tolerant control of multicell converters is proposed. This topology is developed through analysis of different power device's failure modes. Our objective is to present a methodology for the diagnosis of the faults in cells by using an sliding mode observer. The generation of residue is used to know the indicators of the faults. Simulation results are presented in order to illustrate the performance of the proposed approach.

► The aim of the developed control to ensure the balancing of the voltage across the floating capacitors.
► The generation of the sliding surfaces is based on the measurement of the state variables.
► The state vector (SMC) contains the four floating voltages and the load current.
► The problem of the blocking of the switches could not to solve analytically.
► In FTC, we propose a hardware solution which consists in adding switches that call switches of inhibitions.