The Modeling and Control Study of VSC-MTDC System

Abstract

VSC-Multi-Terminal Direct Current(VSC-MTDC) system is much more controllable and economic. In this paper, the mathematical model for the VSC-MTDC system is set up. Base on this model, the multi-terminal constant DC voltage control scheme with an offset component was developed for MTDC system in the distribute network. Decoupling linear PI controllers are applied for the independent control of active and reactive power. Constant DC and AC voltage controller is implemented respectively for source side and loads side for the high quality power supply. Simulation results show that the control scheme is very effective. With the proposed control strategies, dynamic process of the system can be controlled effectively. What is more, the control law is not complex and it is in the local mode. All of these merits make the control strategy very practical.