This article concerns the indirect thermographic temperature measurement of a die of the semiconductor diode D00-250-10. The article shows how the goal was achieved. The methodology of selecting the point at which thermographic measurements of the temperature of the diode cases were performed is discussed. The method of thermographic measurement of the case temperature and the measuring system used is described. The method of simulations making it possible to obtain the die’s temperature on the basis of thermographic casing temperature measurement is presented. In order to enable a better understanding of the discussed issues, the construction of the diode used and the heat flow equation are described. As a result of the work carried out, the point at which the temperature is closest to the die temperature was indicated on the diode case. It is shown that the difference between the casing temperature and the die temperature does not exceed 2 °C at the point indicated. An indirect measurement of the die’s temperature is carried out for different values of the power dissipated on the die.

An increase in reactive power consumption results in an increase in electricity costs. This negative phenomenon can be prevented by using reactive power compensation methods. One of them is the installation of capacitors. These capacitors are exposed to external conditions, such as temperature and humidity. As a consequence, the aging process occurs. Another negative phenomenon is the corrosion that occurs inside the capacitor as a result of moisture absorption. As a result of this phenomenon, the capacitor can be damaged. One of the symptoms of the ongoing corrosion of the inside of the capacitor is an increase in temperature. Capacitors designed for reactive power compensation operate at mains voltage. They are often placed in a switchgear. For this reason, the use of contact methods of temperature measurement is difficult and dangerous. An alternative is thermographic measurement. Determining the internal temperature of the capacitor by thermographic measurement of the temperature of the case is possible with the use of numerical methods. One of them is FEM (Finite Element Method). The temperature results on the capacitor housing obtained from the simulation work were verified by comparing them with the result of thermographic temperature measurement. Both values differed by 0.2 °C. On the basis of the defined model, the differences between the temperature inside the capacitor housing and the temperature on the capacitor housing were determined by simulation. A simplification was proposed by replacing the cylinder made of layers with a homogeneous cylinder.

This article concerns the indirect thermographic measurement of the junction temperature of a D00-250-10 semiconductor diode. Herein, we show how the temperature of the semiconductor junction was estimated on the basis of the heat sink temperature. We discuss the methodology of selecting the points for thermographic measurement of the heat sink temperature and the diode case. The method of thermographic measurement of the heat sink temperature and the used measurement system are described. The simulation method used to obtain the temperature of the semiconductor diode junction on the basis of the thermographic measurement of the heat sink temperature, as well as the method of determining the emissivity and convection coefficients, is presented. In order to facilitate the understanding of the discussed issues, the construction of the diode and heat sink used, the heat flow equation and the finite element method are described. As a result of the work carried out, the point where the diode casing temperature is closest to the junction temperature was indicated, as well as which fragments of the heat sink should be observed in order to correctly estimate the temperature of the semiconductor junction. The indirect measurement of the semiconductor junction temperature was carried out for different values of the power dissipated in the junction.

This paper presents aspects related to the indirect thermographic measurement of a C2M0280120D transistor in pulse mode. The tested transistor was made on the basis of silicon carbide and is commonly used in many applications. During the research, the pulse frequency was varied from 1 kHz to 800 kHz. The transistor case temperature was measured using a Flir E50 thermographic camera and a Pt1000 sensor. The transistor die temperature was determined based on the voltage drop on the body diode and the known characteristics between the voltage drop on the diode and the temperature of the die. The research was carried out in accordance with the presented measuring standards and maintaining the described conditions. The differences between the transistor case temperature and the transistor die temperature were also determined based on simulation work performed in Solidworks 2020 SP05. For this purpose, a three-dimensional model of the C2M0280120D transistor was created and the materials used in this model were selected; the methodology for selecting the model parameters is discussed. The largest recorded difference between the case temperature and the junction temperature was 27.3 °C. The use of a thermographic camera allows the transistor’s temperature to be determined without the risk of electric shock. As a result, it will be possible to control the C2M0280120D transistor in such a way so as not to damage it and to optimally select its operating point.

The supply of energy with the correct parameters to electrical appliances is possible with the use of energy converters. When a direct current is required, rectifier bridges are needed. These can be made using rectifier diodes. The problem of excessive junction temperatures in power diodes, which are used to build rectifier bridges and power converters, was recognized. For this reason, research work was carried out to create a model of a rectifier diode placed on a heat sink and to analyze the heat dissipation from the junction of this diode under forced convection conditions. The results obtained from the simulation work were compared with the results of thermographic temperature measurements. The boundary conditions chosen for the simulation work are presented. A method is also presented that determined the convection coefficient under forced convection conditions. The difference between the simulation results and the results of the thermographic measurements was found to be 0.1 °C, depending on the power dissipated at the junction and the air velocity around the diode.

The contact resistance of the current path in a mechanical connector increases with rising current frequency due to the skin effect, which causes the current to concentrate near the surface of the conductor. This phenomenon is particularly significant in circuits with distorted current waveforms, often found in systems with non-linear loads. The increase in resistance leads to higher power losses within the contact system and the entire current path, contributing to excessive heating. As a result, the operational reliability and lifespan of the connector can be significantly reduced. To address this issue, this study determines a correction factor that allows for proper adjustment of the rated current in the mechanical connectors used in such conditions, ensuring improved performance and durability in practical applications.