宁东—山东±660 kV直流输电工程是世界上第1个采用±660 kV电压等级的直流工程，该工程采用单12脉动换流阀结构，单阀跨接电压最高，单阀串联晶闸管级数最多。以中国电力科学研究院与法国阿海珐(AREVA)公司联合推出的H400换流阀为基础，针对工程电压等级高的特点进行了设计优化，加装了阀组件均压电容，进行了全新的屏蔽罩设计并通过型式试验进行了验证。对该工程换流阀电气设计的成果进行了综述。

The Ningdong-Shandong ±660 kV HVDC transmission project is the first worldwide DC power transmission project in ±660 kV voltage grade, where the single 12-pulse converter bridge is used resulting in the highest single valve volage and the largest number of series-connected thyristors. Based on the H400 valve developed by China Electric Power Research Institute (CEPRI) together with AREVA company of France, the valves applied in the project are optimized by introducing valve section capacitor and equipping with new shielding case verified through type test. Furthermore, the electrical design achievements of the thyristor valve in the project is reviewed.