Cezary Worek

Integrated magnetic component in a 2kW resonant power supply

The paper presents a design of a 2kW Resonant Power Supply dedicated for telecom applications. The power supply is based on a series-parallel LCLC resonant converter, which has some interesting features, such as self protection from load short-circuit. The design comprises an integrated magnetic component intended to be used as the resonant tank inductors. The construction presented in the paper allows for reduction of the size of the inductors and improves the magnetic core utilization. The paper explains the principle of operation of the integrated magnetic component, followed by functional and magnetic field simulations. Measurement results are presented for final verification.

RFID reader design for identification of industrial metallic objects

An electronic circuit design of the RFID (Radio Frequency Identification) reader was the aim of our research. This device is designed for identification of transponders, which are present on the surface of metal elements or inside machine elements made of metal. In order to achieve that, we optimized the antenna reader circuit, that works in near field (magnetic coupling), by means of field flux lines analysis (using finite elements method) and experimental data collecting. Finally, one obtaines a specific shaped magnetic field around the reader.

Optoelectronic system of online measurements of unburned carbon in coal fly ash

Carbon-in-ash level is an important consideration for combustion efficiency as well as ash marketing. The optoelectronic analyzing system for on-line determination and monitoring of the u burned carbon content of ash samples is presented. The apparatus operates on the principle that carbon content is proportional to the reflectance of IR light. Ash samples are collected iso kinetically from the flue gas duct and placed in a sample tube with a flat glass bottom. The same is then exposed to a light. The reflectance intensity is used by the systems computer to determine residual carbon content from correlation curves. The sample is then air purged back to the duct or to the attached sample canister to enable laboratory check analysis. The total cycle time takes between 5 and 10 minutes. Real time result of carbon content with accuracy 0.3-0.7 percent are reported and can be used for boiler controlling.

LLC resonant converter with quality factor limiter

This paper presents the concept of a high-power DC/DC class of converters with a Q-factor limiter based on a serial LLC type resonant circuit. The Q-factor limiter allows highly accurate determination of the voltage/current limit values in the resonant circuits passive elements thus significantly increasing immunity to transient states. Properties of the proposed topology are confirmed by the results of simulations and measurements performed with a laboratory model.

Sequential cycle stealing — A novel control method dedicated for resonant converters

The most popular control method for resonant converters, the frequency modulation control, has low efficiency at loads lower than 40%. The proposed new method called Sequential Cycle Stealing (SCS), based on patented solution (PCT/EP2012/064379), improves efficiency by introducing selective stealing of converter switching cycles, while ensuring ZVS switching. The paper presents a preliminary implementation of the SCS controller with a brief description of its operation. The SCS controller operation is then verified in a LCLC resonant converter. Performance measurements, such as switching conditions, load step response, efficiency and conducted EMI are included in the paper. Finally, some improvements for the SCS controller are suggested in order to remedy some disadvantages of current implementation.

Software-defined digital radio basehand processor using Blackfin DSP

Software defined radio (SDR) is a common approach to wireless digital communication when flexibility, easy reconfiguration and fast prototyping time is required. In this article we present an application of a Blackfin DSP working as a baseband processor in a low-power software-defined digital radio link, under control of a uClinux operating system. Functional characteristics are shown along with the measured power consumption. Presented device can be used as a part of a testing framework, as a prototyping platform or as a baseband module in standalone digital transceiver.

Comparison of Wireless Technologies for Rotating Machinery Diagnostics

Recently, advances in low-power electronic technologies are being developed for applications in machinery condition monitoring. It is a very promising field of research, which will open vast possibilities. In many aspects machinery monitoring will become included in the Industry 4.0 and Internet of Things paradigm. Adoption of wireless data transmission and battery-powered solution will revolutionize condition monitoring and open it for new machinery. Big fields are, e.g., conveyors in mining and power generation businesses. Proper choice of the wireless data transmission technology is crucial for the success of the project. Many aspects need to be examined, the most important being power consumption, range, bandwidth, immunity to RF interference and last but not least—security. In the paper, we present the survey of several wireless technologies and we compare it towards application in the wireless condition monitoring system.

New Technologies for Wireless Energy-Efficient Machinery Diagnostic System

Numerous industries in the modern economy, e.g., power generation, environment protection, mining are prominent users of sensing technologies. Despite large increase in measurement technologies, many locations, especially remote, are still not being monitored, e.g., belt conveyors, large structures (boilers, cooling towers), moving structures (air heaters), remote machinery and other low-cost non-critical machinery. Some of the machines are covered by sensors using cable connection—this however yields high installation costs and maintenance problems. Using general purpose radio modems on the other hand makes it hard to achieve sufficient battery lifetime, range, and reliable connection. Fortunately, recent developments in low-power electronics and networking technologies open new possibilities in this field. The paper presents selected energy-efficient technologies and possibilities of their application for the condition monitoring of machinery, including long range, reliable and cost-effective radio modules, offering mesh networking capabilities, contactless battery system allowing convenient and safe in-field battery replacement in any environmental conditions and systematic approach to data processing including signal conditioning and validation.

Integrated Magnetic Component in a 2 kW Resonant Power Supply

Abstract The paper presents a design of a 2kW resonant power supply dedicated for telecom applications (i. e. battery charging applications). The power supply is based on a series-parallel LCLC resonant converter, which has some interesting features, such as self protection from load short-circuit. The design comprises an integrated magnetic component intended to be used as the resonant tank inductors. The construction presented in the paper allows for reduction of the size of the inductors and improves the magnetic core utilization. The paper explains the principle of operation of the integrated magnetic component, followed by functional and magnetic field simulations. Measurement results are presented for final verification.

Rapid temperature processing (RTP) system for selenization of photovoltaic materials

Rapid Temperature Processing (RTP) methodology is widely applied in thin-film photovoltaic materials technology due to high quality of fabricated cells and also perspectives for their mass manufacturing. This paper describes a RTP device structure which contains the graphite reactor for selenization of Cu/In or Cu/In/Se precursors. Strong nonlinearity of radiative energy transfer makes RTP controlling difficult so it still needs to be improved. Using mathematical model of the device, we are proposing the method of process controlling. Experimentally obtained temperature profiles of Rapid Temperature Processes are presented and compared with temperature profile of typical CIS selenization graphite reactor. Presented steering procedure, based on our model, gives improves by decreasing time needed for selenization and simultaneously reducing costs of the process.