Current transformer internal resistance measuring instrument

Abstract

The invention provides a current transformer internal resistance measuring instrument, which comprises a measuring instrument panel, wherein the measuring instrument panel is provided with an internalresistance measuring unit; the internal resistance measuring unit comprises a digital voltmeter head; a gear shifting piece is arranged above the digital voltmeter head; a reading switch button is arranged below the digital voltmeter head, an internal resistance measuring jack and a grounding wire jack are formed beside the reading switch button, the digital voltmeter head comprises a measuring chip and an LCD display screen, and the gear shifting piece, the reading switch button and the LCD display screen are all connected to the measuring chip. The current transformer internal resistance measuring instrument is integrated in the same device, and different phases of a plurality of windings can be measured at a time. When a test wire of a rear winding is inserted, the numerical value on the front surface is gradually stabilized, so that the waiting time is shortened. Whether the three-phase internal resistance of the same winding of a current transformer is balanced or not can be compared at a time, and comparison is more visual compared with a mode that one universal meter is used for measurement.

Description

technical field [0001] The invention relates to the field of electrical measurement, in particular to a current transformer internal resistance measuring instrument. Background technique [0002] In the work of relay protection, the periodic calibration of equipment includes a task of measuring the internal resistance of CT on the secondary side of the current transformer, which often requires the help of a multimeter. However, since there are many windings to be measured, and when using a digital multimeter to measure the internal resistance of each phase of each winding, it often takes a long time to obtain a stable value due to the characteristics of the object under test and the multimeter. It often takes a lot of time to measure the internal resistance of each phase of all windings with the test leads of a multimeter. Once under the condition of high outdoor temperature in summer, it is often difficult for maintenance personnel to withstand the outdoor high temperature...

AI Technical Summary

Problems solved by technology

However, since there are many windings to be measured, and when using a digital multimeter to measure the internal resistance of each phase of each winding, it often takes a long time to obtain a stable value due to the characteristics of the object under test and the multimeter. It often takes a lot of time to measure the internal resistance of each phase of all windings with the test leads of a multimeter

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