阀组状态转换自动顺序控制是直流控制系统的一项基本功能，阀组状态转换能否自动完成也是检验直流控制系统工作稳定性的重要指标。介绍了云广直流工程阀组状态转换的实现过程，分析了当前回路设计存在的不合理因素及其安全隐患，并提出了解决方法。该解决方法已成功应用到云广直流工程和糯扎渡直流工程中，对保证特高压直流系统的现场稳定运行具有积极作用。

The automatic sequence control function of valve group state transition is one of the most basic control functions for DC system. The successful auto-completion of valve group state transition is also the important inspection index of working stability for DC control system. This paper introduced the implementation process of valve group state transition in Yunnan-Guangdong DC transmission project, analyzed the irrationality of current circuits design and its hidden danger. The solution method proposed has been successfully applied in Yunnan-Guangdong and Nuozhadu DC transmission projects, which has certain practical significance to the steady operation of UHVDC systems.