Automation of Permeance Nonuniformity Measurements the Teeth Zone in Electrical Micromachines

A technique for measuring the permeance nonuniformity in rotating transformers based on analyzing the harmonic composition of their permeance is presented. For estimating the permeance nonuniformity, it is proposed to use its influence on the spatial change of the magnetic flux vector position. The suggested technique can be used for diagnosing the operation of not only rotating transformers and selsyns, but also other AC electrical machines. The use of the proposed permeance nonuniforrmity measurement method allows the measurement to be made within a shorter period of time and yields a real permeance variation law. Two schematic designs of experimental benches for implementing the developed technique are proposed, and the bench equipment structure and bench operation principle are described. By using the experimental bench equipment it is possible to obtain extensive data characterizing spectral nonuniformity of the permeance of prototypes and to estimate the accuracy characteristics of rotating transformers and selsyns. A technological bench made according to a simpler design makes it possible to carry out prompt checks of permeance nonuniformity during manufacture of rotating transformers and selsyns, and in periodically performing their calibration checks. The experimentally obtained oscillograms are presented. The external appearance of the obtained graph allows a judgment to be made about the level of rotational pulsations caused by the rotating transformer magnetic circuit anisotropy and the level of pulsations determined by the tooth zone permeance nonuniformity. The use of the proposed technique makes it possible to simplify the permeance nonuniformity measurement process, to visualize it, and to automate technological monitoring of the electrical machinery manufacturing process.