Roman Szewczyk

Low Current Transformer Utilizing Co-Based Amorphous Alloys

Metal oxide surge arresters have been widely used for protection of power system networks against overvoltages caused by atmospheric discharges or malfunction of devices connected to the network. During its operation, a surge arrester structure is degradated, which can be observed as an increase of a surge arrester leakage current. This paper presents an implementation of a new, high-permeability, Co64Fe4Ni1Si15B14 amorphous alloy as a current transformer for monitoring of a leakage current in low voltage surge arresters. The characteristics of the current transformer for different loads have been measured in the system using very sensitive current-voltage converter. Experimental results confirmed that low current transformer utilizing Co64Fe4Ni1Si15B14 amorphous alloy in annealed state gives a possibility to measure a leakage current about several μA with operating frequency 50 Hz. Moreover, the results indicate that the leakage current waveforms have a different shape than a pure sine wave voltage applied to the surge arrester enabling an evaluation of the device nonlinearity as a measure of its degradation by means of a resistive component of the leakage current.

E2LP: A Unified Embedded Engineering Learning Platform

The main idea behind this project is to provide a unified platform which will cover a complete process for embedded systems learning. A modular approach is considered for skills practice through supporting individualization in learning. This platform shall facilitate a novel development of universal approach in creative learning environment and knowledge management that encourage use of ICT. New learning model is challenging the education of engineers in embedded systems design through real-time experiments that stimulate curiosity with ultimate goal to support students to understand and construct their personal conceptual knowledge based on experiments. In addition to the technological approach, the use of cognitive theories on how people learn will help students to achieve a stronger and smarter adaptation of the subject. Applied methodology will be evaluated from the scientific point of view in parallel with the implementation in order to feedback results to the R&D.

Two-Axis, Miniature Fluxgate Sensors

Miniature fluxgate sensors are recently intensively developed and have become a valuable alternative to other magnetic sensors types. Presented two-axis miniature fluxgate sensors show new opportunities for further miniaturization of fluxgate magnetometers. Frame-shaped amorphous alloys cores for the sensors were etched from 25 μm-thick tape. Sensors were made in printed circuit board (PCB) multilayer technology. Sensors with Fe-based and Co-based cores were tested for different values of constant magnetic field in two directions. Experimental results confirmed their ability to accurately obtain two directional magnetic field measurements.

Reliability and Efficiency of Differential Evolution Based Method of Determination of Jiles-Atherton Model Parameters for X30CR13 Corrosion Resisting Martensitic Steel

Paper presents new possibilities of Jiles-Atherton model of magnetic hysteresis parameters determination. The main problem connected with this model is the fact that its parameters have to be determined during the optimization process. However, due to the local minima on the target function, the gradient optimization methods are not effective, whereas evolutionary strategies, such as (μ+λ) strategy, are very time consuming. Results of calculation presented in the paper indicate that differential strategies create possibility of reliable and fast determination of Jiles-Atherton model parameters. Paper also presents guidelines for practical determination of model’s parameters, which is very important from practical point of view.

Ferromagnetic Objects Magnetovision Detection System

This paper presents the application of a weak magnetic fields magnetovision scanning system for detection of dangerous ferromagnetic objects. A measurement system was developed and built to study the magnetic field vector distributions. The measurements of the Earth’s field distortions caused by various ferromagnetic objects were carried out. The ability for passive detection of hidden or buried dangerous objects and the determination of their location was demonstrated.

Effects of stress and its dependence on microstructure in Mn–Zn ferrite for power applications

Abstract The relationship between magnetoelastic properties and microstructure has been studied for a series with different bulk density of Mn 0.70 Zn 0.24 Fe 2.06 O 4 ferrite for switch mode power supplies applications. It is shown that in investigated ferrites, in spite of their small λ s value (equal 0.6×10 −6 ), the effect of stress is considerable. The course of magnetoelastic characteristics B ( σ ) H and H c ( σ ) H of investigated Mn–Zn ferrites depends significantly on its microstructure.

The Additional Error of Inertial Sensors Induced by Hypersonic Flight Conditions

The emergence of hypersonic technology pose a new challenge for inertial navigation sensors, widely used in aerospace industry. The main problems are: extremely high temperatures, vibration of the fuselage, penetrating acoustic radiation and shock N-waves. The nature of the additional errors of the gyroscopic inertial sensor with hydrostatic suspension components under operating conditions generated by forced precession of the movable part of the suspension due to diffraction phenomena in acoustic fields is explained. The cause of the disturbing moments in the form of the Coriolis inertia forces during the transition of the suspension surface into the category of impedance is revealed. The boundaries of occurrence of the features on the resonance wave match are described. The values of the “false” angular velocity as a result of the elastic-stress state of suspension in the acoustic fields are determined.

Magnetoelastic Villari effect in high-permeability Mn–Zn ferrites and modeling of this effect

Abstract The results of magnetoelastic investigation in Mn0.51Zn0.44Fe2.05O4 high-permeability ferrite are presented. The obtained results are compared with the energy-based Jiles–Atherton–Sablik model of the magnetization process. Dependence of models parameters on compressive stress up to 60xa0MPa is presented.

New method of characterization of magnetoelastic properties of amorphous ring cores

Abstract New method of characterization of magnetoelastic properties of amorphous ring cores is presented. The uniform compressive stresses are applied to the core perpendicular to the magnetic flux direction using special backings. The magnetoelastic properties of the amorphous Fe78 Si13 B9 ring core were investigated by the described method. The effect of stress up to 30xa0MPa is presented.

Measurement and Control System of the Plasmatron Plasma Reactor for Recovery of Metals from Printed Circuit Board Waste

The article presents the measurement and control system of plasmatron plasma reactor for utilization and recovery of metals from waste of printed circuit boards built in the Industrial Research Institute for Automation and Measurements in Poland. The plasma reactor is the key component of a test stand developed to conduct research on processing and recovery of metals from used electric and electronic equipment, especially from electronic printed circuit boards. The system allows, recording multiparametric measurements realized in real time and time-correlated, visualization of current values of measurements and states by means of SCADA software. Besides main functions of data acquisition and visualization, the system allows local and remote control of operation of reactor subsystems. Analysis of measurement chain is presented for the key parameter of reactor work, which is temperature measurement inside the reactor. Standard uncertainty of measurement of the temperature is evaluated and in this case equal to 5 °C.