International Journal on Electrical Engineering and Informatics - Volume 10, Number 2, June 2018

Modern Electrical Insulations for Power Cables Using

Multi-nanoparticles Technique

Ahmed Thabet1, Nourhan Salem1 and Essam E. M. Mohamed2

1Nanotechnology Research Center, Department of Electrical Engineering,

Faculty of Energy Engineering, Aswan University Egypt 2Department of Electrical Engineering, Faculty of Engineering, South Valley University, Egypt

athm@aswu.edu.eg, nourhansalem50@gmail.com, essam.mohamed@eng.svu.edu.eg

Abstract: This paper presents an investigation on the enhancement of electrical insulations of

power cables materials using a new multi-nanoparticles technique. It has been studied the

effect of adding specified types and concentrations of nanoparticles to polymeric materials

such as XLPE for controlling on electric and dielectric performance. Prediction of effective

dielectric constant has been done for the new nanocomposites based on Interphase Power

Law (IPL) model. The multi-nanoparticles technique has been succeeded for enhancing

electric and dielectric performance of power cables insulation compared with adding

individual nanoparticles. Finally, it has been investigated on electric field distribution in the

new proposed modern insulations for three-phase core belted power cables.

Keywords: Nanoparticles, nanocomposites, effective dielectric constant, interphase,

electrostatic field.

1. Introduction

Nanotechnology science reinforced properties of tradition industrial polymers such as

optical, electrical and dielectric properties. The improvements in dielectric properties of

polymeric nanocomposites have enhanced insulation power cables and general/industrial

applications. Among many high technological manufacture products, polymer nanocomposites

are one of vital technologies in engineering science for exhibiting superior properties. Several

approaches are used to modify properties of polymeric nanocomposites different industries

applications [1, 2]. Cross-linked polyethylene (XLPE) has been created by thermochemical

action; the benefit of cross-linking is to inhibit the movement of molecules with respect to each

other for enhancing stability at various temperatures compared with the thermoplastic materials.

This action permits higher operating temperatures and current rating than polyvinyl chloride.

Nanotechnology science gives polymer matrix a reduction in the values of effective permittivity

as nanocomposites materials [3-10]. Nowadays, electric and dielectric properties of power

cables insulation materials can be controlled using nanotechnology techniques under various

thermal conditions [11-21]. This paper explains novel industrial materials with enhanced

dielectric characteristics of new multi-nanocomposites industrial materials by Interphase Power

Law (IPL) model. The proposed model takes into account interactions between the components

of multi-nanocomposites system in the form of interphase regions. The dielectric characteristics

of the interphase region have been explored on new industrial materials based on individual and

multi-nanocomposites. Also, this paper discusses the electrostatic field distribution in the new

modern dielectric insulations of three-core belted power cables based on charge simulation

method (CSM). Also, this research success for specifying optimal arrangements of variant types

of multi-nanoparticles for enhancing polymeric power cables insulations.

2. Recent Followed Models

A. Multiple Nanocomposite Insulation Materials Technique

Maxwell-Garnett dilute concentration solution for the dielectric constant has been explained

Received: August 19th, 2017. Accepted: June 23rd, 2018

DOI: 10.15676/ijeei.2018.10.2.6

271

For an inhomogeneous interphase region surrounding each inclusion. Power law relationships

used in dielectric modeling of composite systems [22-24]. The determination of the interphase

thickness for individual polymeric nanocomposites is further described in detail in [25-28];

whatever, the interphase region of new polymeric multi-nanocomposites has been illustrated in

Figure.1. In multi-nanoparticles technique, reduction in the effective interphase volume fraction

has been considered many times from nearby of multi-nanoparticles together and the overlap of

interphase regions surrounding each nanoparticle. Approximations have been developed to

estimate the overlap of such particles using analytical solutions to percolation models [29, 30].

Figure 1. Interphase region surrounding the filler particles in multi-nanocomposites system

B. Electric Field Distribution in Three-Phase Core Belted Power Cables

The distribution of the electric field in a three-core cable is very important for the proper

design and the safe operation of power cables. Theoretical model has been detected maximum

high voltage stresses for new insulated three core pelted power cables. In case of using individual

or multiple nanoparticles techniques inside polymer matrix, power law relationships used in

dielectric modeling of composite systems; the composite system have three components (matrix,

interphase region and nanoparticles). There are various techniques have been done to make the

calculations of the electric field in the three-core belted power cables for determining the stress

in cables [31-36]. This paper applied the calculations of the electric field in three-core belted

cables by using the best charge simulation technique which uses less number of charges and

gives small errors and high degree of accuracy achieved [36]. The electrostatic field distribution

in insulation material has been studied within various solid insulation nanocomposites and multi-

nanocomposites around cable conductor whenever, the eight points which shown in Figure 2

Figure 2. Cable configuration its coordinate axis

Interphase

r+∆r

r

T

t

d

Circles of

line

charge

Y

X

Rs

R

Rc S Circles

of

8 7

6

5

4 3 2 1

Ahmed Thabet, et al.

272

can be located within the thickness of solid insulation materials. The values of the charges can

be obtained as follows:

[𝑃]𝑚×𝑛[𝑄] = [𝑉]𝑛 (1)

Where, [P] is the potential coefficient matrix, [Q] is the column vector of values of the unknown

charges, [V] is the potential of the boundary points, and n is the number of simulating charges.

It is assumed that the potential and field don’t vary in z-direction and therefore, the infinite

line charges are used for simulation. It can be estimated the electrostatic field at any point (xk,

yk) within solid insulation materials (pure, or nanocomposites, or multi-nanocomposites) and

around the cable conductor as follows:

=

−

=

TN

iijD

ixkx

o

iqxE

12

.~2

(2)

=

−

=

TN

iijD

iyky

o

iqyE

12

.~2

(3)

Where, qi is the charges which stated in conductors and its images

3. Suggested Nano-materials

Clay nanoparticles are used to reduce the density of product [37]. Aluminum Oxide is strong

high heat-resistance, very stable, high hardness, high mechanical strength, and electrical

insulator. Zinc Oxide (ZnO) is used in paints, coatings, cross linker of rubber and sealants,

Magnesium Oxide has high thermal conductivity and low electrical conductivity, whatever,

Barium titanate is a dielectric ceramic used for capacitors. Cross-linked polyethylene (XLPE) is

the most industrial common form of polymeric insulation for fabrication power cables

insulations [39, 40]. Table 1 depicts details numerical analysis for original and new polymeric

nanocomposites materials.

Table 1. Physical Properties Of Nanocomposites & Multi-Nanocomposites

Nanoparticles

ɛr

Nanocomposites Multi-Nanocomposites

Base

Matrix ɛr Base Matrix ɛr

Clay 2.0

XLPE 2.4

Clay/XLPE

Silica/

XLPE ZnO/ XLPE

SiO2/ XLPE

MgO/ XLPE

TiO2/ XLPE

Al2O3/ XLPE

1.6983

1.2095

1.4233 3.6549

4.0061

4.8920

9.2976

Silica 2.5

ZnO 1.7

SiO2 4.5

MgO 9

TiO2 10

Al2O3 9.5

4. Results and Discussion

This paper discusses the effect of multi-nanoparticles on industrial materials. The effective

dielectric constant of the composite system is discussed in current work with multi-nanoparticles,

and power cables insulations such as XLPE.

A. Effect of individual and multi-nanoparticles technique on dielectric constant of cross linked

polyethylene (XLPE)

As shown in Figure’s (3-5) that show the behavior of effective dielectric constant of

XLPE nanocomposites with various volume fractions of nanoparticles. It is obvious that clay,

ZnO and silica nanoparticles reduce the dielectric constant of XLPE insulation materials,

whatever, TiO2, and Alumina nanoparticles increases dielectric constant property of XLPE

Modern Electrical Insulations for Power Cables Using

273

insulation materials. Using multi-nanoparticle technique can be changing the arrangement of

nanoparticles; hence, controlling of dielectric insulation is more easy and efficient as shown

graphically.

Figure 3. Effect of ZnO, Silica and Alumina on effective dielectric constant of XLPE

Figure 4. Effect of ZnO, SiO2 and TiO2 on effective dielectric constant of XLPE

0

5

10

15

20

25

30

35

0 0.2 0.4 0.6 0.8 1

Eff

ecti

ve

Die

lect

ric

Con

stan

t

Volume Fraction

XLPE + ZnO XLPE + Al2O3

XLPE + Silica (XLPE + ZnO) + Al2O3

(XLPE + ZnO) + Silica (XLPE + Al2O3) + ZnO

(XLPE + Al2O3) + Silica (XLPE + Silica) + ZnO

(XLPE + Silica) + Al2O3

0

3

6

9

12

15

0 0.2 0.4 0.6 0.8 1

Eff

ecti

ve

Die

lect

ric

Co

nst

ant

Volume Fraction

XLPE + ZnO XLPE + SiO2

XLPE + TiO2 (XLPE + ZnO) + SiO2

(XLPE + ZnO) + TiO2 (XLPE + SiO2) + ZnO

(XLPE + SiO2) + TiO2 (XLPE + TiO2) + ZnO

(XLPE + TiO2) + SiO2

Ahmed Thabet, et al.

274

Figure 5. Effect of MgO, Silica and TiO2 on effective dielectric constant of XLPE

B. Electric field distribution in new modern insulations of three-phase core belted power cables

Figure (6, 7) show the effects of nanoparticles and multiple nanoparticles for changing

electrostatic field distribution around cores of three-phase core belted power cables. It is obvious

that MgO and SiO2 nanoparticles increases the electric field distribution whatever, TiO2

nanoparticles decreases the electric field distribution. Arrangement of nanoparticles inside multi-

nanocomposites is more efficient procedure for controlling in the electric field distribution in

insulation of power cables.

Figure 6. Effect of MgO, SiO2 and TiO2 on electric field distribution in

Three-phase core belted power cables

0

3

6

9

12

15

0 0.2 0.4 0.6 0.8 1

Eff

ecti

ve

Die

lect

ric

Co

nst

ant

Volume Fraction

XLPE + MgO XLPE + Silica

XLPE + TiO2 (XLPE + MgO) + Silica

(XLPE + MgO) + TiO2 (XLPE + Silica) + MgO

(XLPE+ Silica) + TiO2 (XLPE + TiO2) + MgO

(XLPE + TiO2) + Silica

0

0.2

0.4

0.6

0.8

1

1.2

0 60 120 180 240 300 360

Ele

ctro

stat

ic f

ield

dis

trib

uti

on

Theta

XLPE + MgO XLPE + SiO2

XLPE + TiO2 (XLPE + MgO) + TiO2

(XLPE + SiO2) + MgO (XLPE + SiO2) + TiO2

(XLPE + TiO2) + MgO

Modern Electrical Insulations for Power Cables Using

275

Figure 7. Effect of TiO2, SiO2 and Al2O3 on electric field distribution in

Three-phase core belted power cables

5. Trends of Polymeric Multi-nanocomposites

Multi-nanoparticles technique has been investigated the best new trends for enhancing the

effective dielectric constant with respect to using individual nanoparticles; therefore, the new

nanocomposites should be having multi- nanoparticles for enhancing the effective dielectric

constant of base matrix dielectric material. Arrangement and concentrations of nanoparticles in

polymeric base matrix are controlling in dielectric characterization. The proposed study on

electric field distribution in the new modern insulations of three-phase core belted power cables

shows that multi-nanoparticles technique is more efficient for controlling on electric field

distribution in insulation of three-core belted power cables.

6. Conclusions

• Individual nanoparticles like, Clay, ZnO, and Silica are interested in decreasing the effective

dielectric constant of polymeric insulation. Whatever, SiO2, MgO, TiO2, and Alumina have

interested in increasing dielectric characterization. The use of multiple nanoparticles is more

efficient for controlling both dielectric properties and physical properties of power cables

materials.

• Electric field distribution inside insulation materials of three core belted power cables has

been enhanced by using individual and is controlled by using multi-nanoparticles technique.

• The arrangement position of nanoparticles (Clay, ZnO, Silica, SiO2, and TiO2) inside host

matrix is an efficient parameter for controlling in the effective dielectric constant of multi-

nanocomposites.

7. Acknowledgements

The present work was supported by Nanotechnology Research Center at Aswan University

that is established by aided the Science and Technology Development Fund (STDF), Egypt,

Grant No: Project ID 505, 2009-2011.

0

0.2

0.4

0.6

0.8

1

1.2

0 60 120 180 240 300 360

Ele

ctro

stat

ic f

ield

dis

trib

uti

on

Theta

XLPE + SiO2 XLPE + Al2O3

XLPE + TiO2 (XLPE + SiO2) + Al2O3

(XLPE + SiO2) + TiO2 (XLPE + Al2O3) + TiO2

(XLPE + TiO2) + Al2O3

Ahmed Thabet, et al.

276

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Ahmed Thabet was born in Aswan, Egypt in 1974. He received the BSc (FEE)

Electrical Engineering degree in 1997 and an MSc (FEE) Electrical

Engineering degree in 2002 both from Faculty of Energy Engineering, Aswan,

Egypt. PhD degree had been received in Electrical Engineering in 2006 from

El-Minia University, Minia, Egypt. He joined with an Electrical Power

Engineering Group of Faculty of Energy Engineering in Aswan University as

a Demonstrator at July 1999, until; he held Full Professor Position at October

2017 up to date. His research interests lie in the areas of analysis and developing

electrical engineering models and applications, investigating novel nanotechnology materials via

addition nano-scale particles and additives for using industrial branch, electromagnetic materials,

electroluminescence and the relationship with electrical and thermal ageing of industrial

polymers. Many of mobility’s have investigated for supporting his research experience in UK,

Finland, Italy, and USA …etc. On 2009, he had been a Principle Investigator of a funded project

from the Science and Technology development Fund “STDF” for developing industrial materials

of ac and dc applications of nanotechnology techniques. He has been established first

Nanotechnology Research Center in the Upper Egypt.

Nourhan Salem was born in Aswan, Egypt and received the BSc degree in electrical engineering

from Faculty of Energy Engineering, Aswan University, Egypt. She is MSc student in Electrical

Engineering from Faculty of Energy Engineering, Aswan University, Egypt, in 2014.

Essam E. M. Mohamed was born in Qena, Egypt, in 1974. He received the

BSc and MSc degrees in electrical power and machines engineering from

Faculty of Energy Engineering, Aswan University, Aswan, Egypt, in 1997 and

2003 respectively. He received the PhD degree in electrical engineering from

the University of Sheffield, Sheffield, United Kingdom in 2011. In 1999, he

joined the Department of Electrical Engineering, Faculty of Energy

Engineering, Aswan University, as a Demonstrator, as a Lecturer Assistant in

2003, and as a Lecturer in 2011. Since 2013, he has been with the Department

of Electrical Engineering, Faculty of Engineering, South Valley University, Qena, Egypt. His

current research interests include power electronics, electrical machines design and control,

electric drives, multi-phase electrical machines, multilevel inverters and renewable energy

systems. Dr. Mohamed is a member of IEEE and founder and manager of the South Valley

University IEEE student branch.

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