Details

Autor(en) / Beteiligte

• Ma, Jing
• Geng, Ruonan
• Liu, Chen
• Ma, Ruichen
• Xu, Yitong
• Wang, Zengping

Titel

A pilot protection method for direct-drive wind farm transmission lines based on the variance of high-frequency impedance

Ist Teil von

• International journal of electrical power & energy systems, 2024-01, Vol.155, p.109534, Article 109534

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2024

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• •Pilot protection for wind farm outlet line based on variance of high-frequency impedance.•Can accurately identify internal faults and unaffected by control strategy of wind farm.•Only requires transmission of logic information and has low requirements on communication.•Establishing high-frequency fault supplementary networks of sending-end system.•Deriving matching relationship between high-frequency 1-mode impedances on two line ends. Concerning the difficulty in identifying faults on the transmission line of direct-drive wind farm connected to DC transmission system, a pilot protection method for the wind farm transmission line based on the variance of high-frequency impedance is put forward. First, the topologies of the transmission line farm-side converter and DC-side converter in different conducting states are analyzed, and combining the high-frequency characteristics of different system components, the equivalent high-frequency 1-mode models of the farm-side system and the DC-side system are built. Then, the high-frequency 1-mode fault models of the transmission line under internal faults and external faults are established, and the high-frequency 1-mode impedances on ends of two lines are derived. Finally, a protection criterion is constructed according to the matching relationhip between the high-frequency 1-mode impedances and different fault scenes. Experimental tests are conducted on the RT-LAB platform and verify that the method can accurately identify internal faults from external faults, unaffected by the control strategy of the wind farm.