Abstract：This paper studies DC line protection strategy of Xing-an HVDC project based on siemens technical route, and points out that under metallic return line, the existing protection strategy is not rigorous. In the case of non-operating pole line fault, longitudinal differential protection of non-operating pole starts which should not be exported, while the operating pole protection is not equipped with quick protection strategy for Non-operating pole line fault. The non-operating pole line fault cannot be removed quickly. This paper analyzes a Xing-an DC non-operating pole line fault event under metallic return line and further verifies the hidden danger of DC line protection strategy, and proposes the relative logic optimization suggestions of the sampling circuit of non operating pole DC differential protection blocking and operating pole protection.
2020, Vol. 21 
