Paweł Górecki

Modelling the influence of self-heating on characteristics of IGBTs

The paper refers to modelling characteristics of IGBT in SPICE software with self-heating taken into account. The form of the electrothermal model of the considered transistor and equations describing this model are proposed. The correctness of the proposed model is verified experimentally during the operation of the examined transistor at different cooling conditions. Particular attention is paid to the non-typical course of characteristics of the considered device at weak excitation and the shape of the obtained characteristics is discussed.

The influence of a mounting manner of power MOS transistors on characteristics of the Totem-Pole circuit with RLC load

Purpose The paper aims to consider the problem of the influence of mounting power metal-oxide semiconductor (MOS) transistors operating in the Totem–Pole circuit on energy losses in this circuit. Design/methodology/approach Using the computer simulation in SPICE software, the influence of such factors as on-state resistance of the channel of the MOS transistor, the self-heating phenomena in this transistor and resistance of wires connecting transistors with the other part of the circuit on characteristics of the considered circuit operating with resistor, inductor and capacitor (RLC) load is analyzed. The selected results of calculations are compared with the results of measurements. Findings On the basis of the obtained results of calculations, some recommendations concerning the manner of mounting the considered transistors, assuring a high value of watt-hour efficiency of the process of energy transfer to the load are formulated. Research limitations/implications The investigations were performed in the wide range of the frequency of the signal stimulating the considered circuit, but the results of calculations were presented for 2 selected values of this frequency only. Practical implications The considered analysis was performed for the circuit dedicated to power supplied of an elecrolyser. Originality/value Presented results of calculations prove that in some situations, the value of watt-hour efficiency of the considered circuit is determined by the length and the cross-section area of the applied wires bringing the signal to the connectors of the transistors and to load. On the other hand, self-heating phenomena in the power MOS transistors can lead to doubling power losses in these devices.

Voltage regulators for the laptop's power supply station with photovoltaic modules

In this paper project and measured characteristics of the laptops power supply station with photovoltaic module are presented. This device consists of two switch-mode voltage regulators, photovoltaic module and the lead-acid battery. In the following sections step-down and step-up switch-mode voltage regulators are described and the measured by the author characteristics of voltage regulators and the whole power supply station are presented.

Modelling and the Analysis of the Power Supply System for the Generator of Hydrogen

In the paper the manner of characterising properties of the generator of hydrogen and the form of the computer model of this generator are presented. The model was formulated in the form of a subcircuit for SPICE software. The structure of this model is described and the values of parameters of the model are presented. With the use of the proposed model some dc and frequency characteristics of the considered generator are calculated and compared to the measured characteristics. Some results of analyses of the considered generator operating in different supply conditions are presented and discussed.

The Use of Photo-Voltaic Panels to Charge Mobile Electronic Devices

In the paper the circuit to charge mobile electronic devices and the results of measurements of this circuit are presented. The construction of the presented circuit is analysed and the influence of the selection of the photovoltaic panel and optical power density on its surface on current efficiency of the considered circuit are discussed. The directions of the development of the worked out and constructed circuit are pointed.

Modelling dynamic characteristics of the IGBT with thermal phenomena taken into account

Purpose This paper aims to propose the electrothermal dynamic model of the insulated gate bipolar transistors (IGBT) for SPICE. Design/methodology/approach The electrothermal model of this device (IGBT), which takes into account both electrical and thermal phenomena, is described. Particularly, the sub-threshold operation of this device is considered and electrical, and thermal inertia of this device is taken into account. Attention was focused on the influence of electrical and thermal inertia on waveforms of terminal voltages of the considered transistor operating in the switching circuit and on waveforms of the internal temperature of this device. Findings The correctness of the presented model is verified experimentally and a good agreement of the calculated and measured electrical and thermal characteristics of the considered device is obtained. Research limitations/implications The presented model can be used for different types of IGBT, but it is dedicated for SPICE software only. Originality/value The form of the worked out model is presented and the results of experimental verification of this model are shown.

Modelling simple photovoltaic systems with thermal phenomena taken into account

The paper refers to modelling characteristics of a simple photovoltaic system with thermal phenomena taken into account. This system consists of a photovoltaic panel, battery and two switched-mode voltage regulators. The electrothermal models of all the components of such systems are presented. These models are dedicated to electrothermal dc and transient analyses. The correctness of the models of all components of the photovoltaic systems is verified experimentally. Finally, the results of measurements and calculations of characteristics of the considered system are compared and discussed for different operating modes.

Thermal model of the IGBT module

In the paper the dynamic compact thermal model of the IGBT module is proposed. This model makes it possible to calculate internal temperatures of diodes and transistors included in the considered IGBT module with selfheating in each device and mutual thermal couplings between them taken into account. The form of this model and the method of estimation of its selected parameters are described. Some results of measurements and calculations illustrating the usefulness of this model are shown and discussed.

Investigation of the influence of thermal phenomena on characteristics of IGBTs contained in power modules

This paper concerns the impact of mutual thermal coupling between transistors and diodes contained in one power module and self-heating phenomenon on dc characteristics of these devices. For each type of the device, located inside the module, characteristics were measured for three different values of the power dissipated in the other devices, which are located in the same module. Particular attention was paid to the influence of mutual thermal coupling at the limits of safe operation area of the transistors and the maximum current of diodes contained in the module.

The Power Supply of the Hydrogen Generator

In the paper the circuit supplying the hydrogen generator is considered. The idea of operation of this circuit, its simulation schema and the results of computations are presented. These computations were performed for a wide range of frequency of the supplying current. The correctness of the idea of operation of the supplying circuit is shown and the dependence of efficiency of the hydrogen generator on frequency of the supplying current is presented.