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CEATI 10th Annual Grounding & Lightning Conference - Anaheim, CA, USA October 2-3, 2018
Abstract-- The interest on grounding system analysis is related
to the increasing demand on the safety of power systems. A well
designed grounding system can ensure reliable operation of
power systems and the safety of human beings in fault conditions.
The relevance of the problem is increasing with increasing short
circuit fault currents and also with the power systems expansion.
Grounding systems close to the seacoast are very common in case
of industrial or power plants. It is reasonable to suppose that the
sea, with its large volume and its low resistivity, can affects the
GPR “Ground Potential Rise” and the touch and step voltages
distribution of a grounding system. However, it is not evident how
and how much. It is easy to guess that the GPR tends to decrease
due to the effect of the sea, but it is quite surprising to see that
despite this, the touch and step voltages tend to increase and that
close to the seacoast, an otherwise safe grounding system can be
dangerous for people. On the opposite, sea effects seem not
relevant on conditions of insulated pipelines protected with
cathodic protection plants. This paper presents an analytical and
numerical study of this important issues not yet adequately
reported in literature.
Index Terms-- Grounding Systems, Earthing Systems,
Cathodic Protection, Multilayer Soil Models, Computer
Modelling, PEEC.
I. INTRODUCTION
Grounding systems can be calculated using one of the
suitable electromagnetic analysis methods (see [10] for a
complete review). This work relates with some modules
implemented in the XGSLabTM simulation environment [14],
[15]. XGSLabTM is based on the so-called PEEC “Partial
Element Equivalent Circuit” method, a numerical method with
an high computational efficiency. The PEEC method can
readily incorporate electrical components based on a circuit
theory, such as impedances, transmission lines, cables,
transformers, switches, and so on [10].
The XGSLabTM simulation environment may be applied in
many engineering applications, as for instance: grounding,
cathodic protection, electromagnetic fields and interferences,
fault currents distribution and lighting. The program can
consider systems over or below the soil surface and can work
both in frequency and time-domain in a wide frequency range
and also in non-stationary conditions. This so large application
range is due to the very general calculation model adopted
(based on Maxwell equations, Green functions and
This work was supported by SINT Ingegneria Srl which allowed the use of
the software XGSLabTM and provided the financial support.
Sommerfeld integrals), which introduces a limited number of
approximations.
In the Table I are listed the main aspects considered by
XGSLabTM. More details about the used calculation model are
given in literature ([1], [2], [3], [4], [5], [6]).
TABLE I
Aspects taken into account in the used program
Resistive Coupling
Yes
Capacitive Coupling
Yes
Self-Impedance
Yes
Inductive Coupling
Yes
Soil Parameters
ρ, ε = f(ω)
Propagation Law
e-γr/r
The simulation of underground systems represents one of
the most usual applications of XGSLabTM. As known, in this
field the soil modelling represents one of the most crucial
aspects. There is much literature about the criteria to set an
appropriate soil model which can be used to predict the
performances of a grounding system [5].
XGSLabTM allows you to use uniform, multilayer and
multizone soil models (with an arbitrary layers or zones
number) and takes into account not only soil resistivity but
also soil permittivity and frequency dependence of soil
parameters according to the most diffused models [7], [8],
[12].
A uniform soil model should be used only when there is a
moderate variation in apparent measured resistivity but, for the
majority of the soils, this assumption is not valid.
The soil structure and the soil resistivity in general change
both in vertical and horizontal direction (see Fig. 1.1) and only
a 3D map gives an accurate description of real life conditions.
This aspect is more evident close to the seacoast, because the
effects of the sea, a media characterized by a very low
resistivity.
The vertical changings are usually predominant than
horizontal ones, but to correctly model soil conditions, it is
essential to consider grounding system size.
In case of small systems, as for instance grounding systems
with a size up to a few hundred meters, soil model is not
significantly affected by horizontal changings in soil resistivity
and usually a multilayer soil model is the most appropriate
model [13]. The layers number depends on the soil resistivity
Sea Effects on Grounding Systems
An Analytical and Numerical Study
A.S. Bretas, University of Florida, USA, and R. Andolfato – D. Cuccarollo, SINT Ingegneria, Italy
CEATI 10th Annual Grounding & Lightning Conference - Anaheim, CA, USA October 2-3, 2018
variations in vertical direction. Literature states that the double
layer soil model is adequate in about the 20% of cases, while
in the 80% of cases a model with three or more layers is
required [13].
In case of systems of intermediate size, as for example
grounding systems with a size up to a few kilometers, soil
model is affected by both horizontal and vertical changings in
soil resistivity and usually an equivalent double or triple layer
soil model is appropriate [13].
The parameters of the multilayer soil model can be
calculated based on soil resistivity measurements [11].
In case of larger systems, soil model is usually significantly
affected by horizontal changings in soil resistivity and a
multizone soil model which takes this aspect into account is
more appropriate than a multilayer soil model [14].
Fig. 1.1. A typical “real life” soil cross section
Close to the seacoast, soil have some unique characteristics.
The sea resistivity is usually about 0.20 Ωm, thus much lower
than the soil resistivity. The current spread to the earth by a
grounding system close to the seacoast tends to flow towards
the sea with relevant effects on GPR, earth surface potential
and touch and step voltages distribution.
The sea can be represented as a large volume of low
resistivity material at the potential of the remote earth, that is
null. The sea effects can be simulated in a different way to the
interfaces between layers. The sea effects can be represented
with an upper surface corresponding to the interface air sea
and a bottom surface corresponding to the seabed. The PEEC
method using a suitable model, can simulate the sea effects in
a very realistic way.
Multilayer soil model and seabed representation allow a
very realistic simulation of grounding systems close to the
seacoast. In particular, seabed and seacoast shapes can be
chosen arbitrarily (see Fig. 1.2).
Still, multizone soil model allows a good simulation the
seacoast suitable in case of very large systems. In this case, the
seabed is assumed at an infinite depth (see Fig. 1.3).
The remainder of this paper is as follows. In the first
theoretical part of the paper, a synthetic description of the
implemented method is given together with its application
limits and range. The second part is propaedeutic to the
simulation of the sea and describes the simulation of an
arbitrary low resistivity finite volume close to a grounding
system. The differences of GPR, earth surface potential and
touch and step voltages distribution without and with this
volume (at floating or imposed to zero potential) are analyzed.
The third part describes the simulation of the effects of the sea
on a grounding system close to the seacoast. The soil is
represented with a multilayer soil model and seabed is
simulate in a realistic way. The differences of GPR, earth
surface potential and touch and step voltages distribution
without and with the presence of the sea are analyzed. The
fourth part describes the simulation of the effects of the sea on
a cathodic protection system with impressed current close to
the seacoast. The soil and the sea are represented with a
multizone soil model. The differences on protection conditions
with and without the presence of the sea are analyzed.
Fig. 1.2. Cross section of a multilayer soil model close to the seacoast
Fig. 1.3. Cross section of a multizone soil model close to the seacoast
II. THEORY
In the following, a short description of the model’s
derivation and considered in this study are presented. The
considered approach for this study is 3D space modelling. The
conductor’s network is partitioned into small thin and straight
elements (current and charge cells) [10].
Using the vector and scalar potentials, Maxwell equations
can be written as in the following (Helmholtz equations):
2
2q
UU
A A J
(1)
where
A
(Vs/m) is the vector potential,
U
(V) is the scalar
potential,
()jj
(1/m),
(S/m)
(H/m) and
(F/m) are the propagation coefficient, conductivity,
permeability and permittivity of the medium respectively, and
q
(C/m3) and
J
(A/m2) are charge and current density
distribution on the sources respectively.
Solution of (1) for sources with linear current and charge
density distribution are given by the following equations:
CEATI 10th Annual Grounding & Lightning Conference - Anaheim, CA, USA October 2-3, 2018
4
1
4
r
L
r
L
e
A I dl
r
e
U q dl
r
(2)
where
I
(A) and
q
(C/m) are the current and charge density
distribution respectively.
Maxwell equations give the following relation between
electric field
E
(V/m) and scalar and vector potentials:
gradU j
EA
(3)
where
(rad/s) is the angular frequency.
Considering that the electric field and vector potential on
the surface of a conductor are parallel to the conductor axis,
(3) can be rewritten along the conductor axis as follows:
U
E j A
l
(4)
On the other hand, the tangential electric field on the
surface of a conductor, considering their self impedance per
unit length
z
(Ω/m), gives:
E zI
(5)
Combining (4) and (5), the following fundamental
differential equation is obtained:
0
U
zI j A l
(6)
Equation (6) is derived directly from the Maxwell equations
and is then valid in all conditions, also non stationary. In
practical cases, (6) can be solved only in a numerical way.
As anticipated, the conductor’s network is partitioned into a
suitable number of elements. Each element has to be very short
if compared to both wavelength and system size. Therefore,
the right elements number depends on propagation media,
characteristic frequency of input source and grounding system
size.
Each element is oriented from its start point (in) and its end
point (out). Integrating (6) between the ends of an element,
replacing the vector and scalar potential with (2) and
rearranging, the following linear equation is obtained:
0
i i ij j outij inij j
ji
Z I M I W W J
(7)
where
Z
(Ω) is the self-impedance of the element,
M
(Ω) and
W
(Ω) are the partial mutual coupling and partial potential
coefficients between elements respectively,
I
(A) and
J
(A)
are longitudinal and leakage currents respectively.
The calculation of the self and mutual impedances and
potential coefficient with a uniform and infinite extended
propagation media is quite simple. In this case, the following
equations can be used:
4
out out r
ij i j
in in
je
M dl dl
r
(8a)
4
out r
outij j
in out
e
W dl
lr
(8b)
4
out r
inij j
in in
e
W dl
lr
(8c)
The presence of a non-uniform media introduces a strong
complexity in previous equations. As known, the rigorous and
general formulation in the presence of a propagation media
with a conducting half space involves Green functions and
Sommerfeld integrals [1], [3]. At low frequency,
simplifications can be introduced.
Writing a linear equation for each element, the Maxwell
equations are then reduced to a linear system.
Each element is represented with a simplified “T”
equivalent circuit as shown in Fig. 2.1 and introduces the
following unknowns: input and output currents, and leakage
current and potential of the middle point.
Fig. 2.1. Equivalent circuit of the generic element “i”
The resulting linear systems can be written as follows:
ze
e
U W J
E E Z M I
J A I J
(9)
where:
-
W
= matrix of partial potential coefficient
-
Z
= matrix of self-impedances
-
M
= matrix of partial mutual impedances
-
A
= incidence matrix
-
U
= array of potentials
-
I
= array of currents
-
J
= array of leakage currents
-
z
E
= array of voltage drops
-
e
E
= array of forcing electromotive force
-
e
J
= array of injected currents
The linear system (9), provides the distribution of currents,
potentials and leakage currents along the conductor’s network.
From these main results, it is possible to calculate other
important distributions as for instance: earth surface potentials
and then touch and step voltages, electric and magnetic fields.
The calculation model above described is suitable for the
frequency domain but also for the time domain by using the
CEATI 10th Annual Grounding & Lightning Conference - Anaheim, CA, USA October 2-3, 2018
direct and inverse discrete Fourier transforms. As known a
time domain transient can be considered as a superposition of
many single frequency signals as follows:
N
nk
j
N
kk
c
nefS
tN
ts
2
1
0
1
)(
n = 0, 1, … N-1 (10)
where:
-
)( n
ts
= discrete Fourier transform
-
k
fS
= coefficient of the nth harmonic
- N = sampling number
-
c
t
= sampling time interval
The
k
fS
values can be calculated by using a direct discrete
Fourier transform. In practical cases the maximum harmonics
number in (10) is limited to N values depending on the
frequency spectrum of the input transient.
The above described frequency domain model can be used
for each harmonic and, at the end, N different output in the
frequency domain will be obtained. The time domain output
can be obtained from these outputs by using the inverse
discrete Fourier transform.
Calculations in the time domain using a frequency domain
approach (the described approach) if compared to the direct
methods are characterized by increased accuracy because they
are based strictly on the principles of electromagnetism, and
the least errors are made [9]. Moreover, these methods allow
considering the frequency dependence of the soil parameters in
a rigorous way. The only requirement to apply this approach is
the linearity of the model in the considered frequency range.
These methods are anyway suitable also for nonlinear
phenomena like soil ionization with accuracy acceptable for
engineering applications.
III. SIMULATION OF FINITE VOLUMES
The simulation of low resistivity volumes is propaedeutic to
the simulation of the sea effects. The sea will be represented
with a very large finite volume, a virtually infinite volume.
A low resistivity finite volume can represent a buried tank,
the basement of a building with reinforced concrete foundation
or also a cavity full of sea water and so on.
If the resistivity of the finite volume is much lower than the
soil resistivity, the finite volume can be simulate using a metal
cage with the same shape of the external surface of the volume
to simulate.
In order to make evident the effects of this finite volume,
the scenario of Fig. 3.1 has been considered.
The grid size is 50 x 50 m with meshes 10 x 10 m and depth
1 m, the finite volume is a parallelepiped 50 x 20 x 10 m close
to the soil surface. The minimum distance between grid and
parallelepiped is 10 m. The current injected in the earth is 10
kA, the frequency is 60 Hz and the soil model is uniform with
resistivity 100 Ωm and relative permittivity 6.
Without additional data input, the finite volume is assumed
at floating potential. The program allows forcing the potential
of the finite volume to zero, so to the potential of the remote
earth.
The soil surface potential distributions on a rectangular area
lying on the soil surface with and without the finite volume are
represented in Fig. 3.2.
Fig. 3.1: Layout of grid (green) and finite volume (blue)
Fig. 3.2: Soil surface potential distributions
Upper without finite volume
Mid with floating finite volume
Bottom with finite volume at potential zero
The soil surface potential and touch and step voltages
distributions on a line lying on the soil surface with and
without the finite volume are represented in Fig. 3.3 and Fig.
3.4 (with the same scale of potential for convenience).
CEATI 10th Annual Grounding & Lightning Conference - Anaheim, CA, USA October 2-3, 2018
Fig. 3.3: Line calculation
Fig. 3.4: Soil surface potential (green) and touch (red) and step (blue)
voltages distributions
Upper without finite volume
Mid with floating finite volume
Bottom with finite volume at potential zero
The effects of the finite volume on soil surface potential
and touch and step voltages distribution are evident from Fig.
3.2 and 3.4.
The GPR of the grounding system are: 9575 V without
finite volume, 9341 V with finite volume at floating potential
and 8303 V with finite volume at potential zero.
Overlapping the results in Fig. 3.4 without finite volume
and with finite volume at potential zero the following results
can be obtained: the touch voltages tend to grow in all
peripheral parts of the grid, the step voltages tend to grow in
the zones between grid and finite volume.
If the cage used to simulate the finite volume is at floating
potential, the GPR of the cage (3014 V in the specific case)
depends on the conductive coupling between grounding system
and cage and then on their layout, mutual position and on soil
resistivity. The total leakage current on the cage is of course
null. The cage draws current from the ground near the
grounding system and returns it far.
If the cage used to simulate the finite volume is at potential
zero, the total leakage current on the cage in this case is not
null.
The finite volume effects reduce when volume size
decrease or when distance between grounding system and
volume increases. The effects of the finite volume at potential
zero is much stronger than when potential is floating.
This first case highlights the effects of a low resistivity
finite volume close a grid in a simple case. Of course, the
program can simulate more complex scenarios, with irregular
layout of grounding system and finite volume, multiple
grounding systems or finite volumes, multilayer or multizone
soil model and so on. This will be shown in the following in
order to simulate the effects of the sea in two typical cases.
IV. SEA EFFECTS ON GROUNDING SYSTEMS
The simulation of the sea effects on a grounding system
close to the seacoast is very interesting for practical
applications. The sea effects can be evident also when distance
between grounding system and seacoast is significant. The
study of the distance to which the sea effects are negligible
requires a parametric study but in the first approximation, this
distance is of the same order of magnitude of the system size.
If as usually happen, the resistivity of sea (about 0.20 Ωm)
is much lower than the soil resistivity, the sea can be simulated
using a metal grid with the same shape of the seabed extended
up to a distance a few times the maximum size of the system.
The grid potential can be imposed null, as the remote earth.
The scenario of Fig. 4.1 has been considered.
Fig. 4.1: Layout of grid (blue) and seabed (green)
The grid is triangular with a maximum size about 200 m
CEATI 10th Annual Grounding & Lightning Conference - Anaheim, CA, USA October 2-3, 2018
and depth 1 m and a minimum distance to the seacoast about
40 m. The current injected in the earth is 5 kA, the frequency
is 60 Hz and the soil model is a four layer soil model with the
following parameters (see Fig. 4.2):
Layer 1: resistivity = 100.0 Ωm, thickness = 2.000 m
Layer 2: resistivity = 50.00 Ωm, thickness = 6.000 m
Layer 3: resistivity = 200.0 Ωm, thickness = 15.00 m
Layer 4: resistivity = 75.00 Ωm
Fig. 4.2: Apparent soil resistivity of the used four layers soil model
The soil surface potential and touch and step voltages
distributions on a line lying on the soil surface with and
without sea are represented in Fig. 4.4 and Fig. 4.5 (with the
same scale of potential for convenience).
The GPR of the grounding system is 1906 V and 1662 V
without and with sea respectively.
The effects of the sea on the earth surface potential and
touch and step voltages distribution are evident from Fig. 4.5.
Overlapping the results in Fig. 4.5 without and with sea the
following results can be obtained: the touch voltages tend to
grow in all peripheral parts of the grid, the step voltages tend
to grow only close to the seacoast. The step voltages can grow
in all areas between grid and seacoast if the distance between
grid and seacoast is much lower but anyway with values
seldom dangerous.
The sea effects are quite evident if the calculation is
performed using a constant current to earth but is more evident
if the calculation is performed using a constant GPR.
Fig. 4.4: Line calculation
Fig. 4.5: Soil surface potential (green) and touch (red) and step (blue)
voltages distributions
Upper without sea
Mid with sea and constant current
Bottom with sea and constant GPR
This is also evident in Fig. 4.6. where the safe areas without
and with sea are represented.
In Fig. 4.6 a clearing time 0.5 s and a body weight 50 kg
has been considered, so the permissible touch and step
voltages according to the IEEE Std 80 – 2013 are 189.7 V and
266.8 V respectively.
In the specific case, the safe conditions are related only to
the touch voltages because as usual, step voltages are not
dangerous.
CEATI 10th Annual Grounding & Lightning Conference - Anaheim, CA, USA October 2-3, 2018
Figure 4.6: Safe areas (green)
Upper without sea
Mid with sea and constant current
Bottom with sea and constant GPR
V. SEA EFFECTS ON CATHODIC PROTECTION PLANTS
Cathodic protection is one of the most used methods to
prevent or limit the corrosion of buried or submerged metals.
Cathodic protection uses a flow of direct current to interfere
with the activity of the electrochemical cells responsible for
corrosion. Corrosion is prevented by coupling the metal being
protected with a more active metal when both are immersed in
an electrolyte and connected with an external path. In this
case, the entire surface of the metal being protected becomes a
cathode, thus the term “cathodic protection”.
The current flow can be provided by a source commonly
called anode. Anode made from active metal are commonly
called “sacrificial”, as the anode material is sacrificed to
protect the structure under protection. Anode made from inert
metal are commonly called “impressed current anodes”, as an
external energy source is used to impress a current onto the
structure under protection. The cathodic protection plants with
impressed currents are the preferred when systems to be
protected are large.
The operative criterion for cathodic protection consists in
forcing the potential on the system surface within a given
range, for example “-900 mV < U < -350 mV”. This can be
obtained by suitably positioning the anodes and suitably
adjusting the protection current. Under protection implies
corrosion but also overprotection implies damages to the
pipeline.
In Fig. 5.1 is represented a long pipeline (length > 150 km)
and the corresponding multizone soil model (with 35 zones)
without considering the presence of the sea.
Fig. 5.1: Layout of pipeline (blue), multizone soil model without sea and
cathodic protection plants
The pipeline can be protected by using only three feeders
placed for instance as represented in the Fig. 5.1 with a red
flash. The distribution of the potential along the pipeline is
represented in Fig. 5.2a and 5.2b.
Fig. 5.2a: Potential distribution
Fig. 5.2b: Potential distribution without sea
The potentials distribution meets the criterion “-900 mV <
V < -350 mV”, so the pipeline is correctly protected.
Now the effects of the sea are included in simulations. In
Fig. 5.3 is represented the same scenario considering the
presence of the sea.
CEATI 10th Annual Grounding & Lightning Conference - Anaheim, CA, USA October 2-3, 2018
Fig. 5.3: Layout of pipeline (blue) and multizone soil model with sea
In the same conditions (same anodes and same protection
currents), the distribution of the potential along the pipeline is
represented in Fig. 5.4.
Fig. 545: Potential distribution with sea
The sea effects are negligible on potential distribution. This
because assuming a constant impressed current, the pipeline
potential is related mainly to the coating effects and the effects
of soil resistivity is limited. The presence of the sea has no
significant effects on the distribution of potential on the
pipeline.
VI. CONCLUSION
This paper presents a study of the sea effects on grounding
systems close to the seacoast. The numerical study has been
extended also to the sea effects on cathodic protection systems
because of great interest on real-life applications.
The paper shows how modern programs are able to
represent a complex scenario with grounding systems with any
shape, buried in soil represented with a multilayer or multizone
model close to the seacoast with an arbitrary shape of the
seabed in a very realistic way.
The sea effects are usually evident depending on soil
resistivity, grounding system shape and in particular on
distance to the seacoast. The simulation of the sea effects is in
general required when distance between grounding system and
seacoast is of the same order of magnitude of the system size.
If the calculation is performed assuming a constant current
to earth, the presence of the sea reduces the GPR of the
grounding system but surprisingly, it increases touch voltages
in all peripheral parts of the grid. If the calculation is
performed assuming a constant GPR value, the increasing of
the touch voltages can be relevant.
The effects of the sea in the step voltages are evident only
in the area between grounding system and seacoast and only if
the distance between grid and seacoast is limited.
The paper confirms the importance of a realistic simulation
of the sea effects when a grounding system lie close to the
seacoast.
The only requirement for the simulation of the sea is that
the sea resistivity is much lower than the soil resistivity, as
usually happen. In this case, simulation can be very realistic.
Conversely, sea effects are substantially negligible on
potential distribution along an insulated pipeline protected
with a cathodic protection system. In these cases, assuming a
constant impressed current, the presence of the sea if not
relevant in results.
VII. REFERENCES
[1] E.D. Sunde, Earth Conduction Effects in Transmission Systems,
first ed., D. Van Nostrand Company Inc., New York, 1949.
[2] G. F. Tagg, Earth Resistance, first ed., George Newnes Limited,
London, 1964.
[3] S. Ramo, J.R. Whinnery, T. Van Duzer, Fields and Waves in
Communication Electronics, first ed., Wiley International Edition,
New York and London, 1965.
[4] A. Banos, Dipole Radiation in the Presence of a Conductive Half-
Space, first ed., Pergamon Press Inc., Oxford – London –
Edinburgh - New York, Paris and Frankfurt, 1966
[5] R. G. Van Nostrand, K. L. Cook, Interpretation of Resistivity Data,
first ed., United States Government Printing Office, Washington:
1984
[6] R. Andolfato, L. Bernardi, L. Fellin, Aerial and Grounding System
Analysis by the Shifting Complex Images Method, IEEE
Transactions on Power Delivery, Vol. 15, No. 3, July 2000, pp.
1001 – 1009.
[7] R. Alipio, S. Visacro, Frequency Dependence of Soil Parameters:
Effect on the Lightning Response of Grounding Electrodes, IEEE
Transactions on Electromagnetic Compatibility, 2012
[8] R. Alipio, S. Visacro, Frequency Dependence of Soil Parameters:
Experimental Results, Predicting Formula and Influence on the
Lightning Response of Grounding Electrode, IEEE Transactions
on Power Delivery, Vol. 27, no. 2, April 2012
[9] J. He, R. Zeng, B.Zhang, Methodology and Technology for Power
System Grounding, first ed., John Wiley & Sons Singapore Pte.
Ltd., 2013
[10] CIGRE WG C4.501 June 2013 “Guideline for Numerical
Electromagnetic Analysis Method and its Application to Surge
Phenomena”
[11] J. Q. Keji Chen, J. Xu, X. Wen, Z. Pan, Q. Yang, Comparative
Study of Different Parameter Inversion Methods, Proceedings of
the World Congress on Engineering and Computer Science 2014
Vol I, WCECS 2014, 22-24 October, 2014, San Francisco, USA
[12] D. Cavka, N. Mora, F. Rachidi, A Comparison of Frequency
Dependent Soil Models: Application to the Analysis of Grounding
Systems, IEEE Transactions on Electromagnetic Compatibility,
Vol. 56, no. 1, February 2014
[13] IEEE Std 80™-2013 “IEEE Guide for Safety in AC Substation
Grounding”
[14] “XGSLabTM rel. 8.3.1 User’s Guide” SINT Ingegneria Srl.
[15] “XGSLabTM rel. 8.3.1 Tutorials” SINT Ingegneria Srl.
Sea
Sea
Sea
CEATI 10th Annual Grounding & Lightning Conference - Anaheim, CA, USA October 2-3, 2018
VIII. BIOGRAPHIES
Arturo Bretas is a professor at the department of
electrical and computer engineering of the
University of Florida. His research interests include
power systems operation, protection and control. He
has held visiting positions at universities all over the
world, including the Grenoble Institute of
Technology, Grenoble France during 2003-2004
where he was a CNRS Scholar. Since 2002, he has
been involved as a PI/CPI on more than 17
RD&D projects funded by the industry and the
government. These projects concern, for example, cyber-physical
system security, new technologies to enhance power system control and
monitoring, distribution systems reliability optimization and planning under
deregulation. Dr. Bretas has published up to date more 253 scientific papers
in international conferences and journals.
Roberto Andolfato received a Dr. Ing. and Ph.D.
degree in electrical engineering from University of
Padua, Italy in 1990 and 1998, respectively. He is
an invited lecturer of structured seminars at the
University of Padua. His main fields of interest are
grounding systems and electric and magnetic fields,
with specific emphasis on developing numerical
procedures for simulating the electromagnetic field
generated by complex geometry in dispersing media
or in the air, in both frequency and time domain. He
is also a Professional Consultant Engineer and a member of the Italian
Electrical and Electronic Association (AEIT). Dr. Andolfato has published up
to date more 16 scientific papers in international conferences and journals.
Daniele Cuccarollo received a Dr. Ing. degree in
electrical engineering from University of Padua,
Italy in 2009. His main fields of interest are
grounding systems and electric and magnetic fields,
with specific emphasis on developing numerical
procedures for simulating the electromagnetic field
generated by complex geometry in dispersing media
and in the air in both frequency and time domain.
