The overhead transmission line protection scheme for the voltage-source converter-based HVDC grids

Abstract

The fast DC line protection technology is one of the main challenges to high-voltage direct current (HVDC) grids. Based on the Zhangbei HVDC grid project, this paper proposes a non-unit overhead transmission line protection scheme for bipolar voltage-source converter-based HVDC grids equipped with DC circuit breakers. The voltage gradient is used to detect faults rapidly and start the protection algorithm, and the voltage derivative criterion is adopted to discriminate the internal faults from the external ones. Two kinds of faulty pole identification methods are proposed based on the propagation characteristics between the line- and zero-mode voltages, ensuring the selectivity of the protection. The Zhangbei HVDC grid model is built in power systems computer-aided design/electromagnetic transients including DC and the performance of the proposed protection scheme is verified by simulation results of various fault conditions.

Keywords

• power transmission faults
• HVDC power convertors
• HVDC power transmission
• power overhead lines
• fault diagnosis
• power transmission protection
• power grids
• circuit breakers
• voltage-source convertors
• power system CAD
• EMTP
• high-voltage direct current grids
• Zhangbei HVDC grid project
• nonunit overhead transmission line protection scheme
• bipolar voltage-source-converter-based HVDC grids
• DC circuit breakers
• voltage gradient
• protection algorithm
• Zhangbei HVDC grid model
• fast DC line protection technology
• fault detection
• voltage derivative criterion
• faulty pole identification methods
• propagation characteristics
• zero-mode voltage
• line-mode voltage
• electromagnetic transients
• power systems computer-aided design