A comparative study of control schemes for VSCHVDC transmission system

Firstly, in this paper we briefly review the control schemes for the VSC-HVDC system. Then, present conventional PI decoupling control, hysteresis current control and deadbeat current control schemes for the VSC-HVDC transmission system connecting two AC grids. Furthermore, compare their advantages and disadvantages in the VSC-HVDC control systems. Finally, Case of two-terminal VSC-HVDC system is developed in MATLAB/SimPowerSystems and the dynamic performance of the system is evaluated during system start up, grid voltage sags and power reversal changes. Simulation results show that these three control schemes for VSC-HVDC system can offer good dynamic performance when system start up, voltage sags in the grid and power reversal in the system. Different control schemes have different responses performance in the system. Thus, we can choose different control schemes according to the system control requirements and applications.