The voltage coefficient determination of high voltage capacitive divider by serial summation of voltage transformers

Abstract

The paper presents an absolute measurement method of determining the voltage coefficient(VC) of high voltage capacitive dividers(CVD) by serial summation of voltage transformers. Under a series of double-voltages, by successively comparing a CVD with a full-insulated transformer, a semiinsulated transformer and their series, the VC of the CVD were gotten. The method was verified by using two voltage transformers rated with ( ) ( ) 110 3 kV 100 3 V in series. Index Terms -Current comparator, gas compressed capacitor, voltage coefficient，voltage ratio, voltage transformer.

Development of ultrahigh‐voltage standard voltage transformer based on series voltage transformer structure

“…Therefore, the error Ė of K would be Ė ≃ 0.5 1 + α + γ˙+ β˙ (6) Therefore, for an SVT that consists of two VTs with K 2 = K 1 K 3 and M = 0.5, the ratio error of SVT is Ė ≃ 0.5 1 + α + γ˙+ β˙.…”

“…Further, the calibration is carried out from 20 to 120% of the rated voltage, C N and C X are the input terminals of reference and under test capacitors. Method B: According to (6), the errors in the SVT could be determined by the errors in T 1 , T 2 , and T 3 ; therefore, by only calibrating T 1 , T 2 , and T 3 at 500 kV/ √3 and obtaining their errors, the errors in the SVT could be calculated. Fig.…”

“…10b, T 2 is calibrated alone, the error is β˙. Finally, the total error Ė of SVT would be calculated by formula (6). In Fig.…”

“…The errors of standard are <0.01% and 0.4 min. Meanwhile, this method has also been referred to carry on precise measurement of voltage ratio standard [6] benefited to the two independent structure design, this type SVT has been used to carry on the VT calibration onsite [7].…”