The paper presents an equivalent continuous-time state-space model in the synchronous dq reference frame for VSC-HVDC. Based on the model, a power controller is designed to follow command signals. A multi-input multi-output (MIMO) control scheme is developed in the paper. The scheme features feed forward compensation to eliminate the coupling between the d- and q-axis of the voltage source converter (VSC) model. Also, the response speed of the controller can be accelerated by introducing a derivative to the active power loop. With the simulation using PSCAD/EMTDC, the validity of the mathematic model and the feasibility of the power controller have been proved.

The developed MIMO control scheme effectively eliminates coupling between d- and q-axis in VSC-HVDC systems, accelerating response speed and proving the validity of the mathematical model.

Modeling of VSC-HVDC and its active power control scheme

Key Takeaway: The developed MIMO control scheme effectively eliminates coupling between d- and q-axis in VSC-HVDC systems, accelerating response speed and proving the validity of the mathematical model.