AC generator stator bar strand current testing system and method for measuring strand current

Abstract

The invention discloses an AC generator stator bar strand current testing system and a method for measuring strand current. The system comprises a power supply platform, a stator bar testing platformand a stator bar strand current testing platform. The power supply platform comprises two power supply devices. Each power supply device comprises an AC adjustable power supply and a single-phase voltage step-down transformer. The stator bar testing platform comprises a steel core with a trough and two stator bars. The steel core is composed of a plurality of equidistantly arranged steel core segments. The trough is internally provided with two stator bars which are vertically arranged. The stator bar strand current testing platform comprises a magnetic field acquisition device and a signal converting module. The magnetic field acquisition device performs communication with an upper computer through the signal converting module. The magnetic field acquisition device comprises a plurality of PCBs for measurement. All PCBs for measurement are equidistantly fixed through connectors and are mounted at two ends of each stator bar. The AC generator stator bar strand current testing system and the method for measuring the strand current realize stator bar strand current measurement based on no stator bar end structure damage.

Description

technical field [0001] The invention relates to the field of generator stator bar detection, in particular to a test system for the strand current of an alternator stator bar and a method for measuring the strand current. Background technique [0002] The stator bar of a large alternator is wound by many flat copper strands in parallel, and the nose end is connected by a parallel headgear. In addition, in order to increase the firmness of the stator bar of a large alternator, the stator bar is extruded and glued. The individual strands of the rod are tightly connected together so that there are no gaps between the strands. [0003] Due to the different positions of the flat copper strands of the stator bar at the end and the slot, the interlinked leakage magnetic flux is different, so that the magnetic leakage induced electromotive force generated by each flat copper strand is different, and the strands Circulating current and circulation loss are generated between the wire...

AI Technical Summary

Problems solved by technology

[0004] In order to measure the inhibition effect of the transposition method on the circulating current, it is important to measure the transposition strand current of the stator winding of the alternator. The current electromagnetic current transformer, Hall current transformer, Rogowski coil current transformer and other sensors Neither can be buried between the stator bar strands

[0005] At present, in order to facilitate the measurement of the current of the stator bar strands, the strands at the end of the stator bar are opened to form a certain gap between each strand, and then a current transformer is buried to measure the current of each strand of the stator bar. Although this method can realize the measurement of the strand current, it destroys the stator bar structure of the large alternator, so that the leakage magnetic flux interlinked by each strand of the stator bar is different from that of the actual stator bar strands. The cross-link leakage flux is not the same, resulting in inaccurate measurement of the stator bar strand current. On the other hand, this method will cause permanent damage to the stator bar structure, which is not conducive to large-scale alternator stator bar strands Current Detection

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