A Modified 2-Dimensional Decentralized Interleaving Algorithm for Multilevel Multileg Converters

Abstract

This paper proposes a modified algorithm to interleave the carrier signals in decentralized controller for multi-level multi-leg converter. Structure of these converters includes a number of semiconductor modules which are arranged in series and parallel to compose a matrix. The serial modules allow increasing the voltage levels of converter, while, the parallel modules allow increasing the working power of converter, therefore, the multi-level multi-leg converter can be applied in high-voltage high-power systems. The size of matrix can be changed by adding or removing the rows or columns at required positions while the system is working. The multi-level multi-leg converter can be controlled by a traditional algorithm which includes a central micro-controller using for all modules. However, this algorithm has a disadvantage when the system has a large amount of modules, at that time, the controller does not have enough resource to operate the algorithm. A decentralized algorithm has proposed to solve this problem, in this method, each module has its own controller to communicate and exchange the information with the horizontal and vertical neighboring modules over the communication channel. From the collected information, the controller of each module will calculate the phase angle of that module so that all carrier signals are interleaved successfully. This proposed algorithm also has a disadvantage, it cannot work correctly with matrices where number of rows and columns have non-one common divisor, they are called special matrices. This research focus on adjusting the algorithm so that it can work with all type of matrices including the special matrices. The ability of dynamical restructuring of system as well as the convergence speed of the algorithm are also considered and evaluated when some modules are added or removed. The research demonstrated the efficiency and the feasible by simulation results and experiment results. The proposed algorithm is simulated by the MATLAB/SIMULINK program and is experimented on micro-controller TMS320F28069.