Electricity: measuring and testing – Measuring – testing – or sensing electricity – per se – With coupling means
Reexamination Certificate
2006-04-18
2006-04-18
Nguyen, Vinh (Department: 2829)
Electricity: measuring and testing
Measuring, testing, or sensing electricity, per se
With coupling means
C324S547000
Reexamination Certificate
active
07030602
ABSTRACT:
A method for evaluating the accuracy of a current transformer is presented. The current transformer has a primary winding and a secondary winding. A current is not circulated through the primary winding. A load is disconnected from the current transformer. A load impedance is measured of an internal instrumentation associated with the current transformer. The resistance in the secondary winding of the current transformer is determined. The load impedance is compared to a standard burden. A standard burden value is selected. The secondary voltage for a rated current is determined. The injection voltage is adjusted to the value of the secondary voltage. The exciting current and power are measured. The ratio error or the phase angle are then calculated by using the exciting current and power.
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Khalin Vladimir M.
Powers Nicholas S.
Chan Emily Y
Harness & Dickey & Pierce P.L.C.
Kuhlman Electric Corporation
Nguyen Vinh
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