Interactive Grid Interfacing System by Matrix Converter Based Solid State Transformer With Model Predictive Control
The back to back connection of two three to single phase matrix converters (MCs) through a high frequency transformer to create the so called MC based solid state transformer (SST) for interactive grid interfacing is proposed in this paper. The solution provides single stage bidirectional ac ac power conversion. There are advantages of no lifetime limited storage capacitors, light weight, and compact volume. The conventional modulation methods of this MC SST system require additional control design for power management. Besides, space vector modulation contains sophisticated voltage and current vectors computation and duty cycle composition, considering the two back to back connected three to single phase MCs. In this paper, a model predictive control (MPC) is proposed for this MC SST linking different ac grids. The proposed MPC predicts the state variables based on the discrete model of MC SST system and the present circuit variables, and then selects an optimal switching state that ensures the smallest value of a cost function, for the next sampling time. Simulation and experimental studies are carried out to demonstrate effectiveness and simplicity of the proposed MPC for such MC SST grid interfacing system.
IEEE Transactions on Industrial Informatics