System identification based VSC-HVDC DC voltage controller design

The VSC-HVDC system is a preferred transmission and distribution technology due to its inherent advantages, such as more flexible control capabilities and no reactive power compensation requirements. It is suitable to integrate the renewable energies which always require controllable terminals. However, the controller parameters affects the system behaviors significantly, and improper parameters selection might lead the system to instability. Normal model representations are based on the system parameters which are known in advance. Most likely in a reverse direction, this paper develops a fast approach to derive the model representation of a VSC-HVDC system, particularly the DC-link model, based on the result of an active power step response, while the system parameters are not required. The parameters of DC-link voltage controller could be precisely determined afterwards, and the limits could be extracted as well. The parameters are applied back to the VSC-HVDC system and then verified the identified model and its controller.