MULTIVARIABLE FUZZY ADAPTIVE SLIDING MODE CONTROL OF VSC-HVDC FOR POWER FLOW REFERENCE TRACKING

摘要

This paper presents a Multivariate Fuzzy Adaptive Sliding Mode Control (MFASMC) as an effective control method for systems with uncertain dynamics and unpredictable disturbances. The MAFSMC method is applied in the case of power flow reference tracking of a Voltage Source Converter High Voltage Direct Current (VSC-HVDC) transmission system. Based on Kirchhoff's equations and synchronous (d-q) transformation, a state space dynamic model of VSC-HVDC interconnecting two asynchronous electrical grids is developed. The control algorithm uses a Fuzzy Adaptive Disturbance Estimator (FADE) method with to estimate terms referring to uncertain dynamics and disturbances in the system. Through the stability analysis, stable design gains are found to insure robustness and better performance while keeping the control at an appropriate level. For the VSC-HVDC system, the FADE method with the switching term is shown to provide a very satisfactory performance.