Wide area control strategy for multiple VSC-based DC links interconnecting dispersed wind farms

The paper focuses on a power management scheme in a multi-terminal DC transmission systems for integration of large-scale wind farms spread over a wide area. The proposed power management scheme addresses the reliability concerns in a multi-terminal DC transmission system in case of the most severe fault conditions, such as permanent fault in DC link and open circuit fault at the terminal of the grid-side converter. The primary objective of the proposed scheme is to avoid lost of wind farms power in case permanent faults by providing an alternative path for the power flow through a redundant path. In case of DC faults resistive fault current limiters were used to suppress the current to a reasonable level to enable disconnection of the faulty line. To validate the proposed scheme, a computer model has been built in Matlab-Simulink. Transient and permanent DC link faults are considered in order to demonstrate the effectiveness of the proposed power management scheme.