A mathematical model of the admittance between tapped windings and their shield for ratio instruments

A mathematical model is developed for the equivalent admittance dependent on the measurable admittance distributed between the shield and individual sections of a tapped winding. The model makes possible the calculation of ratio instrument errors, correcting admittances, and the input admittance caused by the admittance to the shield. These parameters strongly depend on both the type of supply and the location of the shield with respect to the winding connection. Experimental results are presented that demonstrate the usefulness of the model for an enhancement of ratio instrument accuracy.<
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