Research on overvoltage characteristics and arrester operation under typical failure of Ultra High Voltage DC project

Abstract

Accurately predicting the overvoltage level under typical faults and operating condition in the UHVDC (Ultra High Voltage DC) transmission project is not only beneficial to the insulation coordination design of the system, improving the security and reliability of the system, but also helping to reduce the project cost. Based on the circuit transient simulation platform, this paper builds a UHVDC transmission system simulation model, analyzes the typical overvoltage sources, compares the overvoltage characteristics of the system under 3 types and 12 typical operating faults including the inverter side, rectifier side, and DC line side, and analyzes the operation of the arrester under fault conditions. Results show that when the midpoint of the line is ground faulty, an overvoltage of 1791kV will appear at the midpoint of the non-faulty DC line, which is the most serious overvoltage of the DC line, and when a ground fault occurs at the outlet of the DC line on the rectifier side or the inverter side, the overvoltage amplitude of the DC valve top on the corresponding side is the highest, which respectively are 1324kV and 1190kV. The research results provide a reference for the insulation coordination of the UHVDC transmission project.

Keywords

• UHVDC transmission
• Insulation coordination
• Overvoltage
• Circuit transient simulation
• Operation failure