Krzysztof Górecki

• PhD, DSc
• Gdynia Maritime University

High frequency air transformers for switched-mode power supply (SMPS) are important components of wireless power transfer systems (WPT). This paper describes a compact thermal model of such transformers. This model takes into account self-heating in all components of such a transformer and mutual thermal couplings between these components. Methods...

Featured Application The presented results can be useful for engineers working on the reliability of the soldering process. Abstract In this paper, the issue of an aging process’s influence on power LEDs’ properties is considered. Some measured DC characteristics of these devices and their thermal and optical parameters obtained are presented afte...

This paper mainly aimed to construct a solar charger with power pack on camouflage fabric (280 × 305 × 3 mm) for military and civil use in mining and reconnaissance set. The solar charger includes a photovoltaic panel, supercapacitor module (composed of 8 supercapacitors XV series), converter (B10-1224-05) and connectors (SP1312/S2 and SP1312/S4)....

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The article considers the problem of an influence of partial shading on the characteristics of photovoltaic modules (PV modules). Different manners of connections of silicon solar cells contained in such modules are considered, e.g., classical PV modules (I and II generation of modules) and modules made using half-cut technology (III generation of...

The paper presents the results of measurements and calculations of the SEPIC converter characteristics, taking into account thermal phenomena in semiconductor devices and passive elements. Compact electrothermal models of the MOSFET transistor, diode, capacitor, and inductor are proposed. Parasitic phenomena are also included in these models. The f...

This article proposes a model of an air transformer taking into account the influence of the use of ferrite plates on properties of such a transformer. This model has the form of a subcircuit dedicated for the SPICE software. It takes into account the influence of such parameters as the number of turns of both windings, the distance between them, t...

This article proposes an electrothermal averaged model of a half-bridge DC–DC converter containing a power module. This kind of model enables the computation of characteristics of DC–DC converters using DC analysis. The form of the elaborated model is presented. Both the electrical and thermal properties of the analyzed DC–DC converter are included...

The paper describes the results of investigations illustrating the influence of the method of determining the excess of junction temperature and the selection of a function approximating the thermometric characteristic used in the procedure of measuring thermal resistance of a power MOS transistor on the measurement results. The investigations invo...

CPE-POWERENG is a flagship conference of the IEEE Industrial Electronics Society (IES) devoted to the dissemination of new ideas, research and work in progress within the fields of power electronics, renewable energy integration, power generation, transmission and distribution, power systems, electromechanical energy conversion, automation and EMC/...

In order to determine the junction temperature of semiconductor devices operating at different power supply and cooling conditions, their thermal parameters are needed. This article describes an original measurement set-up enabling the determination of thermal parameters of power semiconductor devices. In contrast to other set-ups described in the...

Printed circuit board assembly (PCBA) is a cost-effective hardware device used in mechanical, process, electrical, electronic, military, and medical equipment providing automated and digital functionalities for users. Keeping high quality standards in the PCBA production process is a major challenge for the electronics production industry. Defectiv...

The paper proposes a compact electrothermal model of the IGBT module in the form of a subcircuit for SPICE. This model simultaneously takes into account electrical phenomena occurring in the module components and thermal phenomena occurring in this module. In the description of electrical phenomena, the previously formulated models of the IGBT and...

The paper proposes a simple compact thermal model of a large LED module. This model takes into account self-heating in each of the LEDs contained in such a module and mutual thermal couplings between each pair of these LEDs. It also allows determining the waveforms of the junction temperature of each of the LEDs. In each moment of time, the tempera...

This article presents the results of the investigations concerning the influence of the printed circuit board (PCB) layout design on self and transfer transient thermal impedances characterizing thermal phenomena occurring in the network containing two power MOSFETs. The tested devices have the case D2PAK and are soldered to the PCB using the surfa...

This article analyzes the problem of modeling the properties of such magnetic elements as inductors, coupled inductors, and transformers using the SPICE software (version 17.2). Both the classical models of magnetic elements, built in this software, and the models implemented in the form of subcircuits are described. In particular, attention was pa...

This article presents the results of computer analysis of selected switching networks. In these analyses, the influence of selected parasitic components of electronic switches on the total and active power losses in these switches is considered. Analyses are performed using the SPICE software for two models of semiconductor switches: an ideal switc...

This paper presents the results of investigations of thermal parameters characterizing self-heating and mutual thermal couplings in selected LED lighting sources. Three types of such sources are considered. They are characterized by different dimensions and different mounting manners. The tested devices are described and the applied measurement met...

This article presents the method of implementation and the results of experimental investigations illustrating an influence of parameters of the signal controlling the current flowing through power LEDs on their junction temperature and on parameters characterizing the light emitted by them. The measurement system used and the tested power LEDs are...

The paper presents modern technologies of electrochemical energy storage. The classification of these technologies and detailed solutions for batteries, fuel cells, and supercapacitors are presented. For each of the considered electrochemical energy storage technologies, the structure and principle of operation are described, and the basic construc...

Light Emitting Diodes (LEDs) are the most commonly used light sources. Temperature strongly affects their operation. Considering that multiple devices are often placed in a single housing, thermal couplings between devices become important. This problem is illustrated here based on the example of a light source containing four LEDs in a single pack...

This article presents a new model of a dedicated air transformer for computer analyses of wireless power transfer systems. This model includes a form of subcircuit for SPICE. It takes into account the electric, magnetic and thermal properties of the modeled device. The form of the elaborated model is presented and the results of its experimental ve...

Featured Application The presented results can be applied in the analysis of properties of the assembly process of RF networks. Abstract The paper discusses selected statistical methods enabling the effective assessment of the influence of selected factors on the efficiency of the assembly process of RF systems. The considerations were carried out...

This paper presents the results of investigations into modeling the DC and dynamic characteristics of an alkaline electrolyzer. A model of the device under consideration is proposed in the form of analytical relationships in which the coefficients depend on the concentration of the potassium hydroxide solution contained in the electrolyzer under co...

This paper presents the current state of knowledge in the field of wireless power transfer. The concept of such a transfer and the basic methods of its implementation are described, together with block diagrams of the necessary devices. The technologies of electrical power transfer over short and long distances are characterized. The most popular e...

Featured Application The presented results can be applied in computer analyses of switched networks and in the proper estimation of the junction temperature of transistors in such networks. Abstract This paper presents a method of fast computations of waveforms of the junction temperature of power SiC-MOSFETs (silicon carbide metal–oxide–semicondu...

The paper analyzes the influence of the material from which the ferromagnetic core of a transformer is made on the characteristics of a full-bridge converter. Experimental investigations were carried out for three bridge converters containing transformers with ring cores made of various materials: iron powder, ferrite, and nanocrystalline material....

In this paper, a detailed review of contemporary cooling systems of semiconductor devices is presented. The construction and the principles of operation of selected components of passive and active cooling systems, as well as selected computer tools supporting the design of such systems, are described. The dependences of thermal parameters calculat...

Featured Application The presented results can be applied in the assembly process of RF networks. Abstract The paper presents the results of investigations illustrating the influence of imperfections in the soldering process on thermal properties of transistors operating in RF (Radio Frequency) systems. The methods of measurements used to determin...

In the current paper, an analysis of the influence of cooling system selection on the thermal parameters of two thermally coupled power MOSFETs is presented. The required measurements of the thermal parameters were performed using the indirect electrical method at different values of power dissipated in the investigated transistors and various supp...

In the paper, an embedded system dedicated to control lighting of the workplace is proposed. The construction of the considered lighting system with a power LED (Light Emitting Diode) and the idea of its control are presented. Some results of investigations of the constructed lighting system, particularly those of the measurements of its optical an...

Purpose This paper aims to present the results of investigations that show the influence of ZnO composite soldering paste on the optical and thermal parameters of power light-emitting diodes (LEDs). Design/methodology/approach ZnO nanocomposite solder alloys were produced via the ball milling process from the solder paste Sn99Ag0.3Cu0.7 (SACX0307)...

A thermal network will be presented to model a multi-layer structure consisting of a semiconductor structure, integrated Peltier heat pump and a cooling fin. A criterion will be set up to determine the optimal Peltier current to minimise the chip temperature using the power dissipation as the control parameter. Compared with classical methods, the...

Purpose This paper presents the results of the investigations of LED modules soldered with the use of different soldering pastes. Design/methodology/approach The tested power LED modules are soldered using different solder pastes and soldering processes. Thermal parameters of the performed modules are tested using indirect electrical methods. The...

The paper proposes a new electrothermal model of a coupled inductor containing a nanocrystalline core dedicated to the analysis of electrical energy conversion systems. The formulated model has a form of a subcircuit for SPICE. The model takes into account the influence of direct current, frequency, skin effect, temperature, self-heating, and mutua...

In the paper, selected problems that are related to the measurements of thermal parameters of power MOSFETs that are placed on a common heat sink are analysed. The application of the indirect electrical method, the contact method, and the optical method in measuring self and mutual transient thermal impedances of these transistors is presented. The...

The paper analyses the influence of the size, the shape and the ferromagnetic material which is used to make a ferromagnetic core on thermal parameters of an inductor. The investigations were carried out for: inductors containing toroidal cores made of the ferrite F867 materials with the different outer diameter, for toroidal cores made of differen...

The paper discusses the methods of fast analysis of DC–DC converters dedicated to computer programmes. Literature methods of such an analysis are presented, which enable determination of the characteristics of the considered converters in the steady state and in the transient states. The simplifications adopted at the stage of developing these meth...

Purpose The purpose of this study is to investigate the validation of the usefulness of cooling systems containing Peltier modules for cooling power devices based on measurements of the influence of selected factors on the value of thermal resistance of such a cooling system. Design/methodology/approach A cooling system containing a heat-sink, a P...

This article proposes a model of an actual photovoltaic installation situated in the Gdynia Maritime University, Poland. This model is formulated in the form of a SPICE network. In the presented model, the influence of selected weather parameters and thermal phenomena on the properties of the components of this installation are taken into account....

Featured Application The presented results can be applied in designing impulse transformers and switch-mode power supplies. Abstract This article proposes a new form of compact electrothermal model of impulse transformers. The proposed model is dedicated for use with SPICE and it is formulated in the network form. It simultaneously takes into acco...

The paper presents the results of investigations illustrating the influence of the method of assembling the die of the IGBT to the base of the TO-220 lead frame on its thermal parameters. The properties of the tested semiconductor die and the methods of assembling it in the case are presented. The measurement method used here, belonging to the indi...

This paper presents the results of investigations on the influence of thermal phenomena—self-heating in semiconductor devices and mutual thermal couplings between them—on the characteristics of selected electronics networks containing bipolar transistors (BJTs) or insulated gate bipolar transistors (IGBTs). Using the authors’ compact electrothermal...

This paper proposes a model of a coupled inductor which takes into account the influence of frequency, temperature, and a constant component, IDC, of currents in the windings on the parameters of the considered element. A description of the model and methods of measuring parameters of the inductor using an impedance analyzer and a chamber for therm...

The properties of Sn99Ag0.3Cu0.7 (SACX0307) solder alloy reinforced with ZnO nanoparticles were investigated. The primary ZnO particle sizes were 50, 100, and 200 nm. They were added to a solder paste at a ratio of 1.0 wt %. The wettability, the void formation, the mechanical strength, and the thermoelectric parameters of the composite solder alloy...

This article compares properties of two measurement set-ups dedicated to determining thermal parameters of power LEDs. The standard T3Ster set-up and the custom set-up developed in Gdynia Maritime University are considered. Both set-ups are described and the used measurement procedure is presented. The manner of measurement of optical power of the...

The article concerns the investigations of solar cells irradiated by waste light. The measurement method and instruments used are presented. Using this method, the spectra of the light emitted by different light sources are presented and the results of measurements of sensitivity characteristics of the selected solar cell are shown. On the basis of...

This paper proposes a new compact electrothermal model of the Insulated Gate Bipolar Transistors (IGBT) dedicated for SPICE (Simulation Program with Integrated Circuit Emphasis). This model makes it possible to compute the non-isothermal DC characteristics of the considered transistor and the waveforms of terminal voltages and currents of the inves...

The problem of an influence of cooling conditions of power semiconductor devices on properties of selected DC–DC converters is considered. The new version of electrothermal average model of a diode-transistor switch for SPICE (Simulation Program with Integrated Circuit Emphasis) is used in the investigations. This model makes it possible to take in...

In the paper, the electrical and optical parameters of wirelessly controlled LED lamps of the Hue type are analysed. Features of this class of wirelessly controlled LED lamps given by the producer are described and a measuring setup for the electrical and optical parameters of the considered LED lamps is proposed. The results of measurements of the...

This paper concerns the problem of modelling electrical, thermal and optical properties of multi-colour power light-emitting diodes (LEDs) situated on a common PCB (Printed Circuit Board). A new form of electro-thermo-optical model of such power LEDs is proposed in the form of a subcircuit for SPICE (Simulation Program with Integrated Circuits Emph...

The paper presents some investigation results on the properties of forced cooling systems dedicated to electronic devices. Different structures of such systems, including Peltier modules, heat sinks, fans, and thermal interfaces, are considered. Compact thermal models of such systems are formulated. These models take into account a multipath heat t...

This article proposes effective methods of measurements and computations of internal temperature of the dies of the Insulted Gate Bipolar Transistor (IGBT) and the diode mounted in the common case. The nonlinear compact thermal model of the considered device is proposed. This model takes into account both self-heating phenomena in both dies and mut...

The task of mathematical model building for the dynamics of the generated power by a photovoltaic installation is considered. Models of such installations are actual both for the industrial electricity generation and for the creation of special intelligent modules with autonomous power supply. To build this mathematical model, it is proposed to use...

In the design of modern power electronics converters, especially DC-DC converters, circuit-level computer simulations play an important role. This article analyses the accuracy of computations of the boost converter characteristics in the steady state using an electrothermal averaged model of a diode–transistor switch containing an Insulated Gate B...

The paper considers the problem of measuring power losses in the ferrite core contained in the inductor. The new method of measuring these losses is proposed. This method consists in using thermal properties of the ferrite core. The concept of the developed measuring method and the measurement set-up that enables implementation of this method are d...

This paper presents the results of experimental investigations illustrating the influence of the spectra of the light emitted by power LEDs on their thermal, photometric and radiometric parameters. The investigations were performed for six diodes emitting white or monochromatic light of different spectra. Each of these diodes was produced by the sa...

Abstract— A task of building of a mathematical model of dynamics of generated electric power by photovoltaic installation is considered in the paper. Built interval discrete model of a real photovoltaic installation takes into account a seasonality factor. To build the model, application of a structural identification method of interval discrete mo...

Purpose This paper aims to present the results of investigations that show the influence of soldering process parameters on the optical and thermal parameters of power LEDs. Design/methodology/approach The power LEDs were soldered onto metal core printed circuit board (MCPCB) substrates in different soldering ovens: batch and tunnel types, charact...

In this paper, a new thermal model of the inductor is proposed. This model takes into account self-heating in the core and in the winding, and mutual thermal couplings between the mentioned components of the inductor. The form of the elaborated thermal model is presented. In this model, the influence of power dissipated in the core and in the windi...

This paper is devoted to the analysis of the influence of thermal pads on electric, optical, and thermal parameters of power LEDs. Measurements of parameters, such as thermal resistance, optical efficiency, and optical power, were performed for selected types of power LEDs operating with a thermal pad and without it at different values of the diode...

This paper proposes a compact electrothermal model of an impulse transformer dedicated for SPICE. The proposed model takes into account magnetic, thermal and electrical properties of the considered device. The network representation of the elaborated model and main equations describing this model are presented and discussed. Correctness of elaborat...

Temperature is an essential factor affecting the operation of light-emitting diodes (LEDs), which are often used in circuits containing multiple devices influencing each other. Therefore, the thermal models of such circuits should take into account not only the self-heating effects, but also the mutual thermal influences among devices. This problem...

This paper proposes a model of an electrolyser in the form of a subcircuit dedicated for SPICE. It takes into account both the electric static and dynamic properties of the considered device and is devoted to the optimisation of the parameters of the signal feeding this electrolyser, making it possible to obtain a high productivity and efficiency o...

This article concerns the problem of light-emitting diode (LED) compact thermal modeling. The methods currently used to generate such models either require some proprietary information from a device manufacturer or the resulting model element values that do not have any physical interpretation. The methodology proposed in this article allows the ge...

This study proposes an electrothermal averaged model of the diode–transistor switch including insulated gate bipolar transistor (IGBT) and a rapid switching diode. The presented model has the form of subcircuits dedicated for simulation program with integrated circuit emphasis (SPICE) and it makes it possible to compute characteristics of DC–DC con...

This paper presents a compact nonlinear thermal model of pulse transformers. The proposed model takes into account differentiation in values of the temperatures of a ferromagnetic core and each winding. The model is formulated in the form of an electric network realising electrothermal analogy. It consists of current sources representing power diss...

In this paper the problem of modelling thermal properties of the IGBT using a non-linear compact thermal model is considered. This model has the form of an electrical network. In the proposed model influence of internal temperature of this transistor on efficiency of heat dissipation is taken into account. The elaborated model form is presented and...

The effect of the microstructure of solder joints on the thermal properties of power LEDs is investigated. Solder joints were prepared with different solder pastes, namely 99Sn0.3Ag0.7Cu (as reference solder) and reinforced 99Sn0.3Ag0.7Cu–TiO2 (composite solder). TiO2 ceramic was used at 1 wt.% and with two different primary particle sizes, which w...

Purpose The purpose of this paper is to present and discuss the results of measurements illustrating influence of the area of a thermal pad and the kind of the used base on thermal and optical parameters of LED modules. Design/methodology/approach LED modules including six power LEDs are designed. In the layout of these modules, different areas of...

In the paper, a new compact electrothermal model of the impulse transformer is proposed. This model has a form of a subcircuit dedicated for SPICE and could be used for low power impulse transformers applicable in switch‐mode power supplies used in electronics. It takes into account simultaneously electric, thermal, and magnetic phenomena occurring...