© 2021 UNIVERSITY OF ZILINA COMMUNICATIONS 23 (1) C1-C6
ORIGINAL RESEARCH ARTICLE Electrical Engineering in Transport C1
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The paper proposes a design and construction of a special plated capacitor
exhibiting very good high-frequency characteristics. The capacitor is designed
to minimize the parasitic parameters like ESR (equivalent series resistance)
and ESL (equivalent series inductance) and to be suitable for power industry
applications. The paper describes the fabrication process and discusses technical
issues related to technology of manufacturing and assembling. It also provides
an experimental verifcation and the quality evaluation based on frequency
characteristics compared to existing commercial high-quality capacitor.
DESIGN AND CONSTRUCTION OF HIGH-QUALITY CAPACITOR
FOR HIGH FREQUENCY AND POWER APPLICATION
Martin Zavřel
1
, Vladimír Kindl
1,
*, Tomáš Kavalír
2
, Pavel Drábek
1
1
Regional Innovation Centre for Electrical Engineering, Faculty of Electrical Engineering, University of West Bohemia,
Pilsen, Czech Republic
2
Regional Technological Institute, Faculty of Mechanical Engineering, University of West Bohemia, Pilsen, Czech Republic
*E-mail of corresponding author: vkindl@kev.zcu.cz
Article info
Received 26 May 2020
Accepted 8 June 2020
Online 27 October 2020
Keywords:
capacitor,
high quality,
high power,
high frequency,
parasitics,
construction design,
testing
Available online: https://doi.org/10.26552/com.C.2021.1.C1-C6
ISSN 1335-4205 (print version)
ISSN 2585-7878 (online version)
neglecting infuence of the insulation resistance (is too
high), one may write:
Q
f
I ESR
C
I
RC
2
2
2
1
1
m
m
2
2
2
r
~
~
= = . (1)
In Equation (1), ~ represents the angular frequency of
the power supply, I
m
is the magnitude of the current through
the capacitor C and R represents its ESR. As obvious from
Equation (1), the energy loss starts to dominate at higher
frequencies, therefore the high Q factor capacitors must
be used to prevent any performance issues. This could be
achieved by special design having the ultra-low ESR and so
ESL. This high-quality capacitor will fnd its purpose in any
industrial-, electronics- or medicine application [14-17] that
are using frequencies even higher than tens of MHz.
This paper proposes a design of high-quality, high-
frequency and high-power capacitor and describes step-by-
step manufacturing and assembling process. The capacitor
properties are compared to the equivalent high-quality
capacitor available on the market [18].
2 Design of the capacitor
As mentioned in previous section, to demonstrate
the quality of this design, the properties of the capacitor
are compared to the existing one developed by Vishay
1 Introduction
Increasing the power density of electrical passive
components, such as a capacitor [1-3], inductor or resistor,
incorporated into modern power systems, is a common
technical goal for many power applications. Higher power
density brings better material utilization, lower weight
and lower equipment cost. Many power applications are
using the high frequency and sometimes the resonance,
e.g. wireless power transfer [4-5], high-pass, low-pass and
EMI (electromagnetic interference) flters [6-7], induction
heating [8-9] etc.
In these applications, the compensation capacitors
play a very important role, since they must carry very high
electrical current and are being stressed with relatively
high voltage. In that case, the quality factor (Q factor) of
the capacitor is one of the most important characteristics
in a power circuit design [10]. Besides the capacitance
(the main parameter), the practical capacitor consists
of equivalent series resistance (ESR), equivalent series
inductance (ESL) and insulation resistance (R
g
) [11-13]. The
electrodes and the terminals of a capacitor contribute the
resistive component and the inductive component, while
the dielectric material contributes the insulation resistance.
The ESR component causes energy loss in a form
of heat and the ESL parameter creates a magnetic feld
interfering with how the current rises to the peak and
falls back. The Q factor then represents effciency of
a given capacitor in terms of its rate of energy loss. When