孤岛运行作为云广特高压直流输电工程的设计运行方式之一,能够有效地提高南方电网的稳定水平,但必须以解决过电压问题为前提.研究了云广特高压直流系统的闭锁方式及快速移相速度对孤岛运行方式下过电压水平的影响,结果表明:大组滤波器切除后延时切除换流变是限制孤岛方式下过电压水平的重要措施；先降电流定值后快速移相的保护闭锁逻辑与直接快速移相的保护闭锁逻辑相比,能大幅度减小双极Block时避雷器的吸收能量；减小快速移相速度对限制双极ESOF时的过电压水平和降低避雷器吸收能量是有利的.%The mode of islanded operation is one of the normal operation modes designed for Yunnan - Guangdong UHVDC project as the stability level of China Southern Power Grid (CSG) can be effectively enhanced with the project operating in the mode under a premise of its overvoltage to be controled. The influence of block process and force retard speed of Yunnan - Guangdong UHVDC on the overvoltage level in islanded mode is studied, and the results are as following: It is an important measure for suppressing overvoltage level to switch off converter transformer after ac filters switched off; the arrester's absorption energy in the case of bipolar block can be greatly reduced with the protection logic of decreasing current order and then doing force retard in comparison with the logic of doing force retard directly; and it is favorable for the reduction of both overvoltage and arrester's absorption energy to lower the force retard speed in the case of bipolar ESOF.
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