500 kV变频串联谐振系统空心电抗器的外部涡流损耗分析

Analysis of External Eddy Current Loss of 500 kV Frequency Conversion Series Resonant Reactor

变频串联谐振系统品质因数(Q值)是决定现场耐压试验中试品电压能否达到额定值的关键,电抗器作为串谐系统的关键部件,其漏磁损耗会严重影响整体系统的Q值。为提高系统Q值,利用有限元方法,针对500kV海缆耐压试验设计的变频串联谐振系统空心电抗器,仿真分析了不同绝缘高度对电抗器涡流损耗的影响,发现将电抗器垫高其外径的1/2以内,可有效降低地网中的损耗功率。进而通过试验测量了不同底座高度下该变频串联谐振系统空心电抗器的Q值和地网发热情况。结果表明,地网中涡流主要集中在电抗器绕组外边缘下方,与仿真结果基本一致。

The quality factor(Qvalue)of frequency conversion series resonant system is the key to determine whether the voltage of the test sample can reach the rated value in the field breaking-down test.The reactor is the key component of the series resonant system,and the magnetic-leakage loss of which will seriously affect the Q value of the whole system.In order to improve the Q value of the system,the influence of different insulation heights on the eddy current loss of the hollow reactor of the variable frequency series resonant system designed for 500 kV cable withstand test was analyzed based on the finite element method.The simulation results show that blocking up the reactor half of its outer diameter by insulator,the loss power in the grounding network can be effectively reduced.Furthermore,the Qvalue of the hollow reactor and the heating condition of the grounding grid are measured under different base heights.The results show that the eddy current in the grounding grid is mainly concentrated below the outer edge of the reactor winding,which is basically consistent with the simulation results.