Operation, Control and Protection of DRU-MMC Hybrid HVDC System for Offshore Wind Integration

Hybrid HVDC technology, integrating diode rectifier units (DRUs) and modular multilevel converters (MMCs) in parallel, has emerged as a promising and cost-effective solution for large-scale wind integration in recent years. This thesis investigates a parallel-connected diode rectifier-based high-voltage direct current (DRU-HVDC) link and a modular multilevel converter-based high-voltage direct current (MMC-HVDC) link in a Hybrid-HVDC system designed to transmit offshore wind power to onshore grids. A comprehensive start-up process for the hybrid DRU-MMC HVDC system is outlined, with a focus on comparing the start-up transient performance of two different power transmission sequences to minimize start-up current. An optimized start-up scheme for the DR-HVDC link is proposed and validated to reduce inrush current during the conducting process. Furthermore, an enhanced passive filter, parallel to the DR-HVDC system, is proposed to facilitate continued power transmission and prevent overcurrent following pole-to-ground (PTG) fault incidents.

Author

• Wang, Haoyu

Language

• English

Date created

• 2024

Type of Work

• Master's Thesis

License

• All rights reserved

Rights statement

• In Copyright

GW Unit

• Electrical Engineering

Degree

• M.S.

Advisor

• Ahmadi, Shahrokh Ahmadi

Committee Member(s)

• Huang, Pengxiang
• Dehghanian, Payman

Persistent URL

•  https://scholarspace.library.gwu.edu/etd/ms35t9473