Interruption Phenomenon Analysis and Optimization Research on the Conventional HVDC Converter Valve in Asynchronous Interconnected Power System

This paper provides an in-depth analysis of the issue of direct current interruption in the conventional HVDC converter valve in asynchronous interconnected power system. Through trigger channel verification and optical intensity testing, it was found that the interruption on-site was caused by a weak intensity of the received light, which prevented normal triggering and was tripped by the action of the break over diode (BOD) after the voltage rise. After extensive experimental analysis, a solution was proposed to reasonably increase the input light intensity margin of the thyristor and reduce the current limiting resistance of the valve control system. The proposed solution was successfully implemented on-site, effectively resolving the problem of converter valve interruption and ensuring the safe and reliable operation of the asynchronous section between the Yunnan Power Grid and the Southern Power Grid's main network.