Simple Fuzzy Self-tuning PI Controller for Multi-terminal HVDC Transmission Systems

Abstract This paper describes fuzzy logic-based self-tuning controller parameters for the rectifier side current regulators and inverter side gamma regulators in a multi-terminal high-voltage direct current (MTDC) transmission system. A four-terminal MTDC system is considered, with the detailed modeling of converters, transformers, source impedances, transmission lines, and filters. Simulations are conducted using MATLAB/SIMULINK® to generate transient responses. The simulation results using a fuzzy self-tuning proportional-integral (PI) controller and a fixed-parameter PI controller are compared. The transient simulation studies presented reveal the superior performance of the fuzzy self-tuning PI controller over the fixed-parameter PI controller in the MTDC transmission systems.