Nonlinear Control Structure of Grid Connected Modular Multilevel Converters   A. Hajizadeh, L.E.Norum, A.Ahadpour Shal   2017/04/25

Abstract

This paper implements nonlinear control structure based on Adaptive Fuzzy Sliding Mode (AFSM) Current Control and Unscented Kalman Filter (UKF) to estimate the capacitor voltages from the measurement of arm currents of Modular Multilevel Converter (MMC). UKF use nonlinear unscented transforms in the prediction step in order to preserve the stochastic characteristics of a nonlinear system. In order to design adaptive robust control strategy and nonlinear observer, mathematical model of MMC using rotating d-q theory has been used. Digital time-domain simulation studies are carried out in the Matlab/Simulink environment to verify the performance of the overall proposed control structure during different case studies.

Authors and affiliations

A. Hajizadeh(1), L.E.Norum(2), A.Ahadpour Shal(3)
1. Department of Energy Technology, Aalborg University. Campus of Esbjerg – (Denmark)
2. Department of Electric Power Engineering, Norwegian University of Science and Technology, Trondheim, Norway
3. Faculty of Electrical Engineering and Information Technology, RWTH-Aachen University, Germany

Key word

Nonlinear Control, Kalman Filter, Nonlinear observer, Modular Multilevel Converter

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