ABSTRACT:

This paper presents a robust nonlinear controller for VSC-HVDC transmission link using input-output linearization and sliding mode-control strategy. The feedback linearization is used to cancel nonlinearities and the sliding mode control offers invariant stability to modeling uncertainties due to converter parameter changes, changes in system frequency, and exogenous inputs. Comprehensive computer simulations are carried out to verify the proposed control scheme under several system disturbances, such as changes in short-circuit ratio, converter parametric changes, and faults on the converter and inverter buses. Based upon the time-domain simulations in the MATLAB/SIMULINK environment, the proposed controller is tested.