Three-phase adjustable polarity test meter

Abstract

The invention discloses a three-phase adjustable polarity test meter which comprises micro-ammeters and adjusting resistors. Three groups of micro-ammeters and adjusting resistors are arranged. Each group of micro-ammeter and adjusting resistor share the same size. The micro-ammeters and adjusting resistors are connected in parallel. One end of each micro-ammeter is connected to form a wiring terminal N, and the other end is respectively wiring terminals A, B and C. The micro-ammeters and resistors on the secondary side of a transformer are connected in series to form loops. According to the invention, the structure is simple and durable; three groups of micro-ammeters are arranged; previously, three times of pulse current are applied to determine the test phase, while pulse current is applied only once at the present; three-phase induction current is simultaneously observed to directly judge whether the test phase is correct; and the test accuracy and the test efficiency are improved.

Description

technical field [0001] The invention relates to the technical field of agricultural production equipment, in particular to a three-phase adjustable polarity tester. Background technique [0002] The current transformer is an important current conversion equipment in the substation. Its output signal is the only source of current data for protection, measurement and control, metering and other devices, which is of great significance to the safe operation of the substation and even the entire power grid. The current transformer polarity test is an important electrical test in the substation, which can ensure the correct connection of the secondary current loop and the correct winding of the current transformer coil from the source of the data. Current transformers generally use the DC method for polarity testing. The battery is connected to the primary side of the current transformer through a switch, and the secondary side of the current transformer is connected to a DC milli...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problems that the existing transformer polarity test equipment can only test one phase at a time, errors are easily generated, the instrument is easy to be damaged, and the test requirements cannot be met, the invention develops a three-phase adjustable polarity test meter, which can be up to Simultaneously measure the polarity of the three phase wires, and adjust the resistance of the measurement circuit according to the size of the secondary induced current, to ensure the safety of the instrument to the greatest extent on the premise of ensuring the measurement results, improve the accuracy of the test, and improve the test performance. Efficiency, improve the service life of the equipment

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