Analysis and Discussion on the Field Testing of AC Filters in UHVDC Convert Station

In order to improve the testing measurement accuracy of electrical equipment of ultra high voltage direct current(UHVDC) transmission project,we analyzed the ultra high-voltage AC filter design principles,methods and performance requirements,introduced the AC filter field testing principles and methods,and tested AC filter in various mode of connections,which depended on Xiangjiaba-Shanghai ± 800 kV UHVDC transmission project.The test results show that the connection mode has a great impact on the measurement results.Non-standard connection mode of testing winding would generate unexpected inductance and stray capacitance,which will cause remarkable errors in measuring value.Accordingly,the rationalization proposals of measurement method are presented,for example,the testing line should be put right under the equipment so that the influence of winding inductance and stray capacitance can be reduced.The conclusion can provide a certain amount of technical support to filter equipment design,testing and standardization.