Pole-restraining observer for single-phase 16.7-Hz traction line-side converter application

Linear design methods for state-quantity observers are used dominantly for power-electronic systems. The main reasons are the problems occurring with advanced approaches, namely complexity and high time effort of necessary stability proof and design process. In observer and control design, the special characteristics of power-electronic systems are often neglected. The robustness and the quality especially of the state estimation of the observer can be improved by the pole-restraining observer (PRO) approach. In this paper, the PRO approach is applied to a realistic 16.7-Hz two-level IGBT line-side-converter application. Simulation results outline the notably improved overall behaviour.