CALIBRATION OF AC INDUCTION MAGNETOMETER

The aim of this paper is to describe a procedure and experimental setup for calibration of AC induction magnetometer. The paper presents an overview of the previous research and results of measurement of magnetic flux density inside large-diameter multilayer solenoid. This solenoid is magnetising coil of the magnetometer. The paper also describes a system of five smaller coils of the magnetometer which are placed inside the large solenoid. Three small coils are pickup coils, accompanied with two compensation coils, of which one is an empty coil for magnetic field measurement. The experimental results of calibration of this coil system have been presented. A proper discussion of all the results presented has been also given in the paper

ANALYSIS OF MEASUREMENT ERROR IN DIRECT AND TRANSFORMER-OPERATED MEASUREMENT SYSTEMS FOR ELECTRIC ENERGY AND MAXIMUM POWER MEASUREMENT

Analysis of error in measuring electric energy and maximum power within direct and half-indirect measurement system at the voltage of 0.4kV is presented in the paper. The analysis involved all the elements of the measurement system, i.e. calibration and testing of the transformer-operated and direct digital energy meters and measuring current transformers. This equipment was also used for measurements in the transformer substation aiming at error analysis at measurements made under the real conditions

HARMONIC ANALYSIS AND MODELLING OF MAGNETISATION PROCESS IN SOFT FERROMAGNETIC MATERIAL

The aim of this paper is to present a research of magnetic hysteresis loops of a toroidal ferromagnetic core made of electrical steel. The experimental results of induced voltage, magnetic induction and hysteresis loop obtained at different frequencies of the sinusoidal excitation magnetic field have been presented. The harmonic content of the induced voltage and magnetic induction have been calculated using Fast Fourier Transformation. Observed variation of higher harmonics with frequency has been correlated to the mechanism of magnetic domain walls damping. A variation of harmonics of the magnetic induction with the amplitude of the excitation magnetic field has been analysed and a proper mathematical model has been proposed. Furthermore, the influence of the triangularly shaped excitation magnetic field and the distorted shape excitation that produces sinusoidal induction on the shape of hysteresis loop and harmonic content of the induced voltage and the magnetic induction has been analysed and discussed