METHOD AND INSTALLATION FOR EXPERIMENTAL DETERMINATION OF LEAKS BY EDDY CURRENTS

The invention relates to a method and an installation for experimental determination of leaks by eddy currents, which occur in the ferromagnetic cores of electrical machines and apparatuses which are in alternating magnetic field. According to the invention, the method consists, in a first stage, in successively magnetizing a ferromagnetic test piece embedded in an Epstein frame whose operating winding is supplied for the D.C. magnetization test from a D.C. source of variable voltage, while metering the electric D.C. power absorbed from the source while, in the second stage, for the A.C. magnetization test, the operating winding of the Epstein frame is supplied from an A.C. source of a given frequency, while metering the electric power absorbed from the A.C. source and, in the third stage, the difference between the values of the two types of energy is calculated and then it is divided by the duration of a test to obtain the leaks by eddy currents from the corresponding test piece, in the last stage the leaks being displayed on the display device of a personal computer. The installation, as claimed by the invention, consists of a module () comprising an Epstein frame having a ferromagnetic test piece to be subjected to the D.C. magnetization test after supplying the operating winding of the Epstein frame from a D.C. source (), by a contactor () being controlled by an electronic timer () which measures the duration of the magnetization test and ensures the same duration to the A.C. magnetization test of the embedded test piece, by connecting the operating winding of the Epstein frame to an A.C. source () by the contactor () controlled by a timer (); an electronic energy meter () recording the electric power absorbed from the D.C. source and the A.C. source during the magnetization tests, a data acquisition board () which takes over the information and sends it to a personal computer (). Invenţia se referă la o metodă şi la o instalaţie destinată determinării experimentale a pierderilor prin curenţii turbionari, produse în miezurile feromagnetice ale maşinilor şi aparatelor electrice aflate în câmp magnetic alternativ. Metoda conform invenţiei constă, într-o primă etapă, în magnetizarea succesivă a unei epruvete feromagnetice încorporată într-un cadru Epstein a cărui înfăşurare de excitaţie este alimentată pentru proba de magnetizare în c.c. de la o sursă de c.c. de tensiune variabilă, contorizându-se energia electrică de c.c. absorbită de la sursă; în a dou