特高压直流换流阀试验能力提升技术

为满足洲际能源互联应用要求，需要开发±1 100 kV、6 250 A的特高压超大容量直流换流阀技术。针对特高压超大容量直流换流阀研发需求，以国家电网公司重点实验室（电力系统电力电子实验室）现有试验能力为依托，完成了试验能力提升系列技术研究工作。通过搭建直流及冲击试验装置电磁分析模型，研究了装置表面电场分布特点及场强变化规律，提出了场强抑制措施，通过优化实验室屏蔽系统和改善屏蔽罩曲率半径等方法，完成了绝缘试验能力提升。针对换流阀的运行试验能力，通过优化整流变配置，提升水冷系统参数，设计新型故障电流拓扑等工作，使得运行试验直流电流试验能力提升至7 500 A，故障电流试验能力提升至60 kA，完成了运行试验能力提升。通过试验证明了±1 100 kV、6 250 A等级换流阀试验能力提升的正确性和有效性。

Upgrading Technology of UHVDC Converter Valve Test Capability

To meet the requirements of the intercontinental energy interconnection application, it is needed to develop the ±1 100 kV and 6 250 A ultra-large capacity UHVDC converter valve technology. Based on the existing test capability of China State Grid Corp Key Laboratory (Power System Power Electronics Laboratory), this paper studied the upgrading technologies of test capability, according to the research and development needs of the ultra-large capacity UHVDC converter valve. Through constructing the electromagnetic analysis models of DC and impacting equipment, this paper studied the electric field distribution characteristics and field intensity variation law on the equipment surface； proposed suppression measures for field strength； and completed the promotion of insulation test capability through the methods of optimizing laboratory shielding system, improving the curvature radius of shielding case, etc. According to the running test capability of converter valve, through the works of optimizing rectifier transformer, upgrading water-cooling systems parameters and the topology design of new fault current, the DC current test capability of operation test reached 7500 A, and the fault current test capability reached 60 kA, which completed the promotion of operation test capability. Finally, the test proved the correctness and effectiveness of ±1 100 kV and 6 250 A converter valve test capability.