Study on a hybrid fuzzy-PI controller applied to VSC-HVDC system

A hybrid fuzzy-PI controller for voltage source converter based HVDC (VSC-HVDC) transmission system is proposed in this paper. At first, the elementary model of VSC-HVDC is described. Then the fuzzy self-tuning control strategy is proposed, in which direct current control strategy and dual closed loop structure are designed in dq synchronous reference frame. Independent control of the active and reactive power is realized. Simulation results show that the designed control system obtains satisfying performance, and the adjustments of power flow could be achieved quicker than convention PI control.