MEASURING THE COMPONENTS OF THE COMPLEX RESISTANCE OF MUTUAL INDUCTION BY THE PHASE METHOD

Abstract

A microcontroller device for digital measurement of the components of the complex resistance of mutual induction of magnetically coupled coils is described for the case when the coils contain a ferromagnetic core. In this case, an active component appears in the complex mutual induction resistance due to magnetic losses in the core, and both components of this resistance are in a nonlinear relationship with magnetic induction in the core. The measurement object and methods for measuring its parameters on alternating current are briefly presented. For the invariant measurement of the components of the complex resistance of mutual induction, a phase method is proposed in combination with the time division of the measurement channel. The measuring circuit is powered by a sinusoidal alternating current. An informative parameter of the measuring circuit output signal is the phase shift angle between the two voltages. These voltages are supplied to the analog inputs of the programmable microcontroller. During the measurement process, the microcontroller controls the switching of the measurement channel, measures the angle of the phase shift between the output voltages of the measuring circuit and calculates the components of the complex resistance of mutual induction according to the specified algorithms. The theory of the method is described, mathematical models for determining the measured parameters are obtained. The setup used for the experimental study of the method is described. The measurements were carried out under two modes of core magnetization: as close as possible to the mode of a given induction or a given magnetic field strength. Experimental curves of the dependence of the measured parameters on the magnetic induction in the core are obtained. The results of the study show that the developed device can be used to measure the components of the complex resistance of mutual induction of coils with a ferromagnetic core in both laboratory and industrial conditions.