A new simplified adaptive control scheme for multi-terminal HVDC transmission systems
This paper proposes a new control scheme for multi-terminal HVDC (MTDC) systems to improve the performance during the system transients such as AC line faults. The new method is called parallel multi-proportional-integral (MPI) control scheme. This new control scheme provides wide range of controller parameters and has the ability to response quickly. To evaluate the performance of the proposed control scheme, a four-terminal HVDC system is considered with the detailed modeling of converters, commutation transformers, source impedances, line parameters, and filters. Simulation results from various transient conditions are compared between the proposed controller, the fuzzy logic-based auto-tuning PI controller, and the conventional fixed-parameter PI controller. The SimPowerSystems and the fuzzy logic toolboxes in the MATLAB/SIMULINK software package are used to conduct the simulations. Simulation results show that the MPI controller has better performance than the conventional fixed-parameter PI controller and has very similar responses compared to the fuzzy logic-based auto-tuning PI controller without any added complexity in controller design procedure for a MTDC system.
multi-terminal hvdc system parallel multi-pi fuzzy tuning weak ac system