Model Predictive Control Strategy of Multi-Port Interline DC Power Flow Controller

Abstract

There are issues with flexible DC transmission system such as a lack of control freedom over power flow. In order to tackle these issues, a DC power flow controller (DCPFC) is incorporated into a multi-terminal, flexible DC power grid. In recent years, a multi-port DC power flow controller based on a modular multi-level converter has become a focal point of research due to its simple structure and robust scalability. This work proposes a model predictive control (MPC) strategy for multi-port interline DC power flow controllers in order to improve their steady-state dynamic performance. Initially, the mathematical model of a multi-terminal DC power grid with a multi-port interline DC power flow controller is developed, and the relationship between each regulated variable and control variable is determined; The power flow controller is then discretized, and the cost function and weight factor are built with numerous control objectives. Sub module sorting method and nearest level approximation modulation regulate the power flow controller; Lastly, the MATLAB/Simulink simulation platform is used to verify the correctness of the established mathematical model and the control performance of the suggested MPC strategy. Finally, it is demonstrated that the control strategy possesses the benefits of robust dynamic performance, multi-objective control, and a simple structure.