Estimation of power losses in a high-frequency planar transformer using a thermal camera

Abstract

This paper presents the implementation of a thermal camera for the quantitative estimation of power losses in a high frequency planar transformer (100 kHz/ 5600 VA). The methodology is based on the observation of the transient temperature rise and determination of the power losses by means of curves representing the derivative of temperature as a function of power losses dissipated in the transformer. First, the thermal calibration characteristics had to be obtained from a simple experiment, where power losses are generated by DC current in the ferrite core and windings. Next, experimental investigations focused on the determination of the transformer power losses for a short circuit and no load, with a resistive load and with the rectifier as a load were carried out. Finally, to verify the obtained results, analytical calculations based on Dowell's and modified Steinmetz's equations were additionally made, which showed a good convergence. The proposed method is easy to implement and can be used as an alternative to the calorimetric method which is time-consuming and requires a complicated measurement setup.

Influence of the Size and Shape of Magnetic Core on Thermal Parameters of the Inductor

“…where is power dissipated in a heating component (core or winding), Rth0, Rth1 and b are the model parameters. Of course, for each of the three transient thermal impedances (1), there is a different set of parameter values describing thermal capacitances and thermal resistances. Changes of individual components of thermal resistance are modelled using the controlled current sources Gi according to the Equation [33]: This model consists of four subcircuits.…”

“…Inductors are important components of switch-mode power converters. These components are used to store electrical energy [1][2][3][4][5]. Properties of these components indeed depend on physical phenomena occurring in the winding and in the ferromagnetic core contained in the inductor [1,[6][7][8][9][10].…”

“…These components are used to store electrical energy [1][2][3][4][5]. Properties of these components indeed depend on physical phenomena occurring in the winding and in the ferromagnetic core contained in the inductor [1,[6][7][8][9][10]. At present, producers of ferromagnetic cores offer many types of cores made of different ferromagnetic materials.…”

“…When an inductor operates in switched mode power converters an increase in power losses in this component is observed, which is the effect of current flowing through the winding of the inductor and remagnetisation of its core [1,[5][6][7][8][9][10][11][12][13][14][15][16]. Power losses in the inductor are converted into heat.…”

Fault Diagnosis of Three Phase Induction Motor Using Current Signal, MSAF-Ratio15 and Selected Classifiers

“…The early detection of faults prevents financial loss and downtimes. In the literature researchers developed methods of fault detection based on acoustic [1][2][3][4][5][6][7][8][9][10][11][12][13], thermal [14][15][16][17][18][19][20] and vibration signals [21][22][23][24][25][26][27][28][29]. An acoustic signal is difficult to process because microphone records many sounds from environment.…”