Observability and sliding mode observer design for Multi-cell Series Converter

The aim of this paper is to design a super twisting observer for a multi-cell series converter. First of all, the hybrid model of the multi-cell series converter is introduced. In order to check the observability of the floating capacitors voltages from the load current measurement, an observability analysis based on the hybrid approach of dynamic systems is given. Thereafter, super twisting observer are presented in order to observe the converter's floating capacitors. Simulations of three cells multi-cell converter highlight the efficiency of the proposed hybrid model and the performance of the observer in terms of floating voltages estimation.