Measurement of noload voltage ratio error of ZN,yn11 grounding transformers
LI ahou1,LU Yucheng2
(1.Jiangmen Power Transmission and Substation Engineering Co., Jiangmen,Guangdong 529030,China;
2.Henan Installation Group Co.,Ltd.,Luoyang,Henan 471000,China)
Abstract:In view of the considerable difference between the measured noload voltage ratio error of the transformer in 220 kV Qunxing Substation of Jiangmen Power Supply Branch,GPG and the specification of the manufacturer,this paper presents a method to measure the ratio error of the grounding transformer with secondary windings.The principles and the procedures of the proposed method are described,and the accuracy of the results validated with a SC9-630/11.250/0.4 transformer.
Keywords:grounding transformer;ZN,yn11 connection;no-load voltage ratio;error