Circuit for checking on-site accuracy of current transformer under condition of underload operations

Abstract

The invention relates to a circuit for checking on-site accuracy of a current transformer under the condition of underload operations, comprising a test power supply, a voltage regulator, a power current transformer, a current transformer to be tested, a standard current transformer, a comparison type current transformer checking meter, a current comparator, a load box and a null indicator. In the circuit for checking the on-site accuracy of the current transformer under the condition of the underload operations, the on-site accuracy of the current transformer under the condition of the underload operations is checked by utilizing a magnetic potential balance method, therefore, a measurement error of the current transformer which works below 1% of rated current can be accurately measured, and the defect of the traditional method is effectively compensated. The circuit provided by the invention has the advantages of simple structure and convenience for use, and the measurement error of the current transformer can be directly read through the comparison type current transformer checking meter.

Description

【Technical field】 [0001] The invention relates to the technical field of electrical parameter testing, in particular to an on-site accuracy checking circuit for a current transformer under low-load operating conditions. 【Background technique】 [0002] The transmission (exchange) power of the power transmission and transformation project is relatively low in the initial stage of operation, so the electric energy metering device generally operates under low load or even very low load conditions, although the current transformer used for metering is generally It is made of permalloy or microcrystalline material as iron core, and its magnetic permeability is high, but it may also exceed the scope of its error performance index assessment. Therefore, it is necessary to test its comprehensive error under low-load operating conditions. and determine its eligibility. 【Content of invention】 [0003] The object of the present invention is to provide an on-site accuracy verification...

AI Technical Summary

Problems solved by technology

[0002] The transmission (exchange) power of the power transmission and transformation project is relatively low in the initial stage of operation, so the electric energy metering device generally operates under low load or even very low load conditions, although the current transformer used for metering is generally It is made of permalloy or microcrystalline material as iron core, and its magnetic permeability is high, but it may also exceed the scope of its error performance index assessment. Therefore, it is necessary to test its comprehensive error under low-load operating conditions. and determine its eligibility

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