DEVICE FOR CALIBRATING INSTRUMENT CURRENT TRANSFORMERS Russian patent published in 2005 - IPC

FIELD: radio and electric measurement technology.

SUBSTANCE: device for calibrating instrument current transformers has shunts disposed in primary and secondary windings of instrument current transformer. Shunt disposed in the first winding of instrument current transformer is made in form of two imitators of resistors and one resistor with non-standardized error; all the resistors are connected in parallel. Current resistor imitators have to be current dividers which have primary windings connected in series with primary winding of instrument current transformer; secondary windings are connected with current terminals of resistors. Circuit for measurement of current and angular error of instrument current transformers is made in form of electromagnet current comparator. First shoulder of the comparator is connected with potential terminals of shunt through variable resistor in the second winding of instrument current transformer. The second shoulder is connected through resistor with potential terminals of shunt in the circuit of secondary winding of instrument current transformer. Winding intended for measuring angular error of instrument current transformer is connected with the secondary winding of auxiliary current transformer through phase-shifting capacitor. Indicator winding is connected with null indicator.

EFFECT: widened range of calibration.

2 dwg