Non-linear control and stabilisation of VSC-HVDC transmission system based on Type-2 fuzzy sliding mode control

Abstract: This paper presents a robust non-linear hybrid controller based on Type-2 fuzzy and sliding mode control strategy for VSC-HVDC transmission link, which inherits the benefits of these two methods. The interval Type-2 fuzzy (IT2FSMC) is used to handle the uncertainties to enhance the real time performance. The sliding mode control combines with the fuzzy system to compensate the influence of un-modelled dynamics and chattering phenomena on the system response, and also to improve the robustness of the reaching phase of the sliding mode control (SMC). The effectiveness of the proposed controller is demonstrated through digital simulation studies using MATLAB/SIMULINK software package. The simulation results show that the proposed controller contribute significantly towards improving the damping behaviour of the VSC-HVDC system with regard to parameter variations and external load disturbances compared to conventional PI controller under a wide range of operating conditions.