Study on overvoltage of hybrid LCC-VSC-HVDC transmission

Abstract

Hybrid line commutation converter-voltage-source converter high-voltage direct current transmission (LCC-VSC-HVDC) power transmission has unique technical advantages, but its overvoltage study is not sufficient at present. In this study, the typical overvoltage phenomenon of hybrid LCC-VSC-HVDC power transmission is analysed and verified by power systems computer-aided design/electro-magnetic transient design and control simulation. On the one hand, overvoltage mechanism of modular multilevel converter module caused by single-phase grounding fault at the valve side of VSC transformer is analysed, and arresters are configured for the protection of the valve. On the other hand, the stress of the arresters at the LCC side is analysed. Installing current reversing protection on the VSC side is proposed. The research of this study provides the recommended arresters configuration in the converter station of hybrid LCC-VSC-HVDC power transmission system.

Keywords

• HVDC power transmission
• HVDC power convertors
• earthing
• power transmission protection
• voltage-source convertors
• overvoltage protection
• power transmission faults
• arresters
• valves
• power transformers
• LCC-VSC-HVDC power transmission system overvoltage
• modular multilevel converter module
• single-phase grounding fault
• valve side
• VSC transformer
• valve protection
• current reversing protection
• arresters configuration
• converter station
• power systems computer-aided design/electromagnetic transient design and control simulation
• line commutation converter-voltage-source converter high-voltage direct current
• PSCAD/EMTDC
• hybrid LCC-VSC-HVDC power transmission