特高压变压器差动保护动态模拟试验研究

Dynamic Simulation on Differential Protection of Ultra-high Voltage Transformer

特高压输电对我国来说是一个崭新的课题,必须大力进行细致严谨的研究工作,解决面临的、可能出现的各种技术问题,确保其安全可靠的运行。针对我国建设中的特高压输电系统采用的1000kV特高压变压器,介绍了特高压变压器的内部结构特点和设计参数、差动保护配置方案、动态模拟试验模型,并通过动态模拟试验对特高压变压器发生各种内部故障时和空载合闸时各种差动保护的灵敏性和可靠性进行了研究,得到如下结论:大差差动保护能灵敏反映主绕组内部的各种故障,而对于调压绕组和补偿绕组的内部故障则灵敏度明显不足,说明了配置调压绕组差动保护和补偿绕组差动保护的充分性和必要性;变压器空载合闸时二次谐波制动原理对调压绕组差动保护和补偿绕组差动保护也有一定的涌流制动作用。

Ultra-high voltage （ UHV） transmission possesses enormous economic benefits and technical superiorities, which is a new subject for China and must be studied emphatically. The paper analyzes the actual structure, parameter and differential protection scheme of UHV transformer which will be used in UHV transmission project under construction in China, and its dynamic simulation experiment system is introduced. Through dynamic simulation experiment results, the sensitivity and reliability of differential protections are studied when kinds of internal faults happen and UHV transformer is no-loaded switched on. The following conclusions are obtained： The main winding ＇s differential protections is sensitive to main winding＇s internal faults, but can＇t operate sensibly when the voltage regulating winding or the voltage compensating winding inter-turn faults happen, and the differential protection of the voltage regulating winding and the voltage compensating winding are needed respectively, on the other hand, which can be restrained effectively by second harmonic restraint method when UHV transformer is energized.