Observability analysis and observer design of multicellular converters

This paper deals with the observability analysis and the observer design for the multicellular converter by taking into account its hybrid behavior. Firstly, we study the observability by using the recent results of the geometric approach, this study provides a simple necessary and sufficient condition of the observability of the converter for a given switching sequence. Secondly, we show the gathering information property of the converter, this property leads us to invent a new observer. This latter composed of two observers, the first one is a partial observer that estimate the observable states of the current mode and the other one is the gathering observer that gather the observable states of previous modes of the switching sequence. An application with simulations of the proposed observer to the three-cell converter by using a super twisting observer (as a partial observer) is given, the simulation results show the efficiency of our observer.