| 摘要 |
electric measurement technology; verifying current transformers in wide range of currents and frequencies. SUBSTANCE: device has frequency- independent coaxial shunt in the form of three parallel-connected low- accuracy resistors inserted in current-transformer primary circuit for disconnecting these resistors from primary circuit and measuring conversion coefficient of frequency-independent shunt in current- transformer primary circuit. Circuit for measuring current and angular error of current transformer is made in the form of electromagnetic current comparator whose first arm is single-decade arrangement and second one is multiple-decade one. First arm is connected through variable resistor to potential terminals of third resistor of this shunt. Second arm is connected through resistor to potential terminals of frequency-independent coaxial shunt inserted in secondary circuit of current transformer. Its rated resistance equals that of third resistor of frequency-independent coaxial shunt inserted in transformer primary circuit. Transformer angular-error metering winding is connected through phase-shifting capacitor to secondary winding of auxiliary current transformer. Indicating winding is connected to null indicator. EFFECT: simplified design, enhanced measurement accuracy. 2 dwg |
