Calorimetric measurement and modelling of the equivalent series of capacitors

¹ Laboratoire d'Electrostatique et des Matériaux Diélectriques (UMR 5517 du CNRS et UJF), B.P. 166, 38402 Grenoble Cedex 9, France
² Laboratoire d'Electrotechnique de Grenoble (UMR 5529 du CNRS, INPG et UJF), B.P. 46, 38402 Saint-Martin d'Héres Cedex, France

Corresponding author: gosse@labs.polycnrs-gre.fr

Received: 6 August 1998
Revised: 30 September 1999
Accepted: 30 September 1999
Published online: 15 December 1999

Abstract

The equivalent series resistance of polypropylene capacitors has been determined under rated voltage, in the range 1 kHz–1 MHz, between 220 K and 370 K by a calorimetric technique. The original feature of this determination of capacitor losses lies in the use of the isothermal calorimetry and in the measurement of an electrical power and not of a temperature increase. The frequency dependence of the equivalent series resistance, at various temperatures, enables to separate the losses in the conducting material from those in the dielectric and to get their respective variations as a function of frequency and temperature. These variations of the equivalent series resistance with frequency at a given temperature have been reproduced by using an equivalent circuit composed of resistors, inductors and capacitors. This model has been verified for non-sinusoidal waveforms such as those met with in a filtering circuit and is used to evaluate by simulation the losses of the capacitor.