An improved bootstrap method for the calibration of inductive voltage dividers

In this paper an improved bootstrap method used for the calibration of inductive voltage dividers(IVDs) is described which uses a special constructed reference transformer to decrease the system errors due to the screen current. The reference transformer is wound with a triaxial cable which was divided into two equal lengths by a break in the both of the outers. A initial measurement result shows that the error introduced by the changes of the reference voltage ratio is less than 1nV/V at 1592Hz by using this reference transformer.