Conference PaperPDF Available

Risk and Resiliency Assessments of Renewable Dominated Edge of Grid Under High-Impact Low-Probability Events -A Review

Authors:

Figures

Content may be subject to copyright.
Risk and Resiliency Assessments of Renewable
Dominated Edge of Grid Under High-Impact
Low-Probability Events —A Review
Tossaporn Surinkaew, Rakibuzzaman Shah, Member, IEEE, and Syed Islam, Fellow, IEEE
Centre for New Energy Transition Research (CfNETR),Federation University, Mt Helen, VIC-3350, Australia
E-mail: t.surinkaew@federation.edu.au; m.shah@federation.edu.au; s.islam@federation.edu.au
Abstract—Low-probability high-impact (HILP) events such
as windstorms, earthquakes, wildfires, and floods, which can
cause significant damages to power systems, are inevitable and
unpredictable. Besides, uncertainties from distributed renewable
energy resources may prevent conventional techniques to improve
reliability of power grids. In previous research works, several
strategies have been introduced to investigate risk and resiliency,
and to find effective solutions to improve system reliability under
such extreme events. In this paper, a critical review of these
strategies is presented. Modelings of the HILP events are dis-
cussed. In the conclusion, this paper pinpoints significant findings
and give directions for robustly protecting power systems.
Index Terms—High-impact low-probability events, power sys-
tem resiliency, risk assessment, microgrids.
I. INTRODUCTION
Historical natural disasters such as earthquakes in countries
located closed to the edge of the Pacific Ocean, windstorms
in America, flooding events in the United Kingdom, bushfires
in Australia, etc., highlight their impacts on power system
reliability and resilience. For example, according to National
Centers for Environmental Information, America has experi-
enced 28 drought events, 33 flooding events, 9freeze events,
132 severe storm events, 52 tropical cyclone events, 18 wildfire
events, and 19 winter storm events in the last 40 years,
with severe impacts and major power system failures [1].
These phenomena are generally known as high-impact low-
probability (HILP) events [2]. Since the emergence of such
events is quite rare, power system planners, regulators, and
policy makers may not recognize them within network reliabil-
ity standards [3]. The HILP events are particularly challenging
to identify and understand. In comparison to ordinary power
supply disruptions, the relationships between cause and effect
are more complicate, the uncertainties are greater and it is
more challenging to deal with events, which are believed to
be unimaginable [4]. As reported by [5], Table I summarizes
critical power outages worldwide during 2011 2016.
As a result, their impacts on techno-economic and reliability
aspects ignite electrical engineers, researchers, planner, and
those who are interested to seek suitable assessment methods
and resilient strategies to mitigate the HILP events.
On the one hand, modern power systems comprise dis-
tributed energy resources (DERs) with the ability of per-
forming individually, i.e., either in an islanded mode or a
grid-tied mode. These scenarios have been hailed as a game
TABLE I: Major power outages worldwide due to HILP events
during 2011 2016 [5]
Date Location HILP events Affected
customers
February 2011 Christchurch,
New Zealand
Earthquake 160,000
June 2012 Ohio, United
States
Thunderstorm 3,800,000
July 2012 Northern
Area, India
Monsoon 600,000,000
October 2012 Eastern
Area, United
States
Hurricane
Sandy
8,100,000
January 2013 SE
Queensland,
Australia
Cyclone Os-
wald
250,000
February 2013 Northeastern
Area, United
States
The North
American
Blizzard
650,000
March 2013 Greater
Belfast,
Northern
Ireland
Heavy snow 200,000
April 2013 Poland Heavy snow 100,000
December 2013 Ontario,
Canada
Ice Storm 300,000
July 2014 Luzon,
Philippine
Typhoon
Rammasun
13,000,000
November 2015 Vancouver,
Canada
Windstorm 700,000
November 2015 Washington,
United
States
Windstorm >161,000
September 2016 Florida,
United
States
Hurricane
Hermine
300,000
September 2016 South
Australia,
Australia
The Blyth
Tornado
1,700,000
changer across energy industries in the transition to renewable-
dominated power systems [6]. Consequently, the effects of the
HILP events are intensified by the increasing complexity and
uncertainties of the power system due to integration of DERs.
It is ubiquitously accepted that the efficacy of a microgrid
significantly depends on the energy management systems [7].
Therefore, the optimal economic operations and electricity
generations can reduce the related costs of implementations
and planning, consequently enhancing the overall system re-
siliency [8].
Aiming at the HILP events, the number of publications
on techno-economic risk and resiliency assessment in mod-
ern power systems has relatively increased. These published
papers examine the technical and economical features of
modern power systems with uncertain DERs, and introduce
innovative methodologies for their effective operation man-
agements. Thus, the goal of this review paper is to explore
these publications focused on i) modelings of the HILP events,
ii) summarizing risk assessments and resilient strategies to
mitigate effects of the HILP events, and iii) suggesting future
research gaps and directions regarding on this timely topic.
II. MODELINGS OF HILP EV EN TS
Recently, world have been critically affected by catastrophic
phenomena such as windstorms, earthquakes, wildfires, and
floods. Major infrastructures including power systems are
severely damaged [9], [10]. During such events, the conse-
quences frequently go beyond conventional system design, as
these events lead to prolonged outages for large numbers of
customers and major loads in the systems [9], [10]. This may
eventually leads to wide-area blackouts. In this section, the
modelings of such HILP events are discussed.
Generally, risk assessment index (IR)can be formulated
according to [11] as,
RHI LP =SHI LP ×PHI LP ,(1)
where PHI LP [0 1] is the probability of failure under an
HILP event and SHILP Ris the severity of an HILP event.
In (1), PHI LP can be obtained by the facility curves
described in Section II-E, while SEis calculated from several
factors as demonstrated in Sections II-A, II-B, II-C, and II-D.
A. Windstorm Modeling
Current climate changes have created major windstorms,
which is able to cause high damages to power grids [12]. The
increased severity of windstorms will subject the power grids
to more serious levels of risk. Wind speed is the key factor and
it is the most destructive force of a windstorm. The probability
of failure of each branch/subsystem can be evaluated by
matching the wind speed at a peak value to the fragility
curves of feeders/transmission lines and/or towers in each
area [12]. In [13], very high wind speeds during windstorms
are gauged by means of a geographical random field, thus
allowing for spatial auto-correlation, which is adjusted with
earlier or historical data of the corresponding windstorm.
Besides, an uncertainty of zonal wind-speed-specific set can be
applied to create the spatiotemporal dynamics of windstorms
[12], [13]. Therefore, the windstorm hazard index (W HI )is
directly depend on wind speed (vw)and wind-related factors
(p1, p2,· · · ), as formulated by,
W H I =f(vw, vw(p1, p2,· · · )) .(2)
B. Earthquake Modeling
The earthquake disaster can ruin power supply networks,
substations, power transmission lines, and related electrical
apparatus [14]. System planners should activate effective mea-
sures to improve the earthquake-related reliability. To model
the hazard index from earthquake EHI, major factors such
as a proper characterization of the ground motions (GM)and
peak ground acceleration (P GA)at various sites/areas/zones
are considered as,
EH I =f(GM , P GA).(3)
In (3), the variable P GA can be observed from the ground
motion time-history at a site and it can be modeled as a non-
stationary random mechanism with probability distribution,
frequency content, and period of P GA [14]. Gaussian white
noise can be applied to explain the possibility of time-histories
ground movement [14]. Besides, the work in [15] also employs
a fault tree analysis to investigate impact of earthquake-related
reliability in power systems. The work in [16] represents a
recursive decomposition method for evaluating exclusive safe
and insecure paths of a corresponding power network under
earthquake.
C. Wildfire Modeling
Modeling the wildfire distribution is the key parts to investi-
gate its techno-economic risk on power networks. As reported
by [17], effects of wildfire on power networks (IW )can
be determined by observing the severity of wildfire events
(I W E), grid exposure (GE), and grid susceptibility (GV )
as follows,
IW =IW E ×GE ×GV. (4)
Recently, in [18], a fire weather index (FWI)is applied
to emulate wildfire risk distribution in a period of two years.
The FWI is a function of meteorological parameters such
as temperature (T),vw, relative humidity (Hr), and 24-hr
precipitation (P). A forest fire danger index (F F DI ), which
is a function of T,vw,Hr, drought factor (DF ), and rainfall
(RF ), can be alternatively use to evaluate the severity of the
wildfire. The FWI and F F DI are generally represented in
the following forms,
FWI =f(T, vw, Hr, P ),(5)
F F DI =f(T, vw, Hr, DF, RF ).(6)
where frepresents the nonlinear function.
In (5) and (6), the FWI [0 )and F F DI [0 100]
can be categorized into six levels, i.e., very low, low, moderate,
high, very high, and extreme [19]. These indices also result
in the same warnings for wildfire. In [20], [21], [22], the
FWI can be used to evaluate fire risk irrespective of ignition
resources. Some resilient measures (i.e., losses of load and
energy expectations and probabilities, system resiliency during
a wildfire) with Monte Carlo simulation can be indirectly used
to evaluate the effects of wildfires [23]. In addition to the men-
tioned models, wildfire behavior can be created by physical,
quasi-physical, empirical, quasi-empirical, mathematical, and
simulation models [24].
TABLE II: Summary of HILP modelings
Model Considering Factors
Windstorm Wind speed, related factors to wind speed, etc.
Earthquake Ground motion and peak ground acceleration.
Wildfire Intensity of wildfire, gird exposure, grid vulnera-
bility, temperature, windspeed, relative humidity,
precipitation level, drought, rainfall
Flood Outdoor inundation, indoor electrical compo-
nents, indoor water depth, etc.
D. Flood Modeling
For reliability enhancement of power systems, alleviating
flooding aftermaths and quickly restoring to a pre-flood state
(or stable operating point) are to be regarded as high impor-
tance [25]. In this aspect, floods are considered as functions
of the changing rate of the water levels at the locations of grid
components [26]. The flood hazard causing failure of electrical
network components is developed in [27] by observing several
factors such as outdoor inundation (OI), indoor electrical
components (IEC), indoor water depth (I W D), and so on
[28], [29], [30]. In [31], the geographical information system
(known as GIS) is applied to examine the danger of flooding
events. Moreover, windstorms are correlated with flooding
events [2]. One can simply write flooding hazard index (F HI )
by,
F H I =f(OI , IEC, IW D, · · · ).(7)
Other factors can be used to determine the value of F HI
in (7) depending on available data.
Summary of the HILP modelings is given in Table II.
E. Fragility Curve
A fragility function is widely used to find the probability
of failure of either related structure or component relating to
the potential intensity of a hazard of each HILP event [2]. The
fragility curve can be acquired from i) identification of a big
data set of previous failures, ii) a structural simulation model,
iii) expert judgment, or iv) a combination of i) to iii) [2].
Examples of fragility curve of an HILP event is simply demon-
strated in Fig. 1. Let n=F actor 1, F actor 2,· · · , F actor n is
the counter for considered factor for the fragility curve of each
HILP event and k=V ariable 1, V ar iable2,· · · , V ariable k,
the probability vector of occurrence of event kwith factor n,
Pn
HI LP (k|n)in (1) can be obtained by,
Pn
HI LP (k|n) =
0,if k < k1
Pn
HI LP (k),if k2< k < k3
.
.
.
1,if k > k4
,(8)
where k1,· · · , k4is the range of k.
It should be noted in (8) that the calculation and conditions
of Pn
HI LP (k)are significantly different depending on the
corresponding HILP event. Formulations of the fragility curve
can be found in [27], [26], [31] for flooding events, [32],
[33], [12] for windstorms, [34] for wildfires, and [35], [36] for
earthquakes. Details regarding the fragility curve development
can be found in [2].
Fig. 1: Examples of fragility curve of an HILP event [2].
Fig. 2: Illustrative strategy toward resilient power system during
HILP events [37].
III. STR ATEG IE S TO MITIGATE EFF EC TS O F HILP EVENTS
Several previous research works proposed effective strate-
gies to mitigate the effects of the HILP events. Fig. 2
demonstrates an illustrative process of a resilient power system
subjected to HILP events. As summarized by [37], i) a resilient
power system is appropriately designed and expected to better
resist the HILP events than those of the traditional systems,
ii) the system can mitigate the effects of the disasters through
system hardening, and iii) resilient strategy applied to the
system can be recognized as efficient resource dispatching
methods, and more progressive restoration methods, such as
novel controls of islanded microgrid, will be applied in a
timely operation to recover the system to a new operating
point closing to normal performance level.
A. Mitigation of Windstorm Effects
Several research works have been conducted to mitigate
effects of windstorms. A double-layer robust and resilient
model for the optimal operation of an active distribution net-
work to enhance its operational resilience against windstorms
is utilized in [12]. The proposed method in [12] can pro-
vide higher resilience against windstorms compared to other
conventional methods, i.e., tri-level adaptive robust optimiza-
tion, and duality- and Karush–Kuhn–Tucker-based methods. In
[13], a criteria is defined to rank single components according
to windstorm influences on the overall system reliability.
It is found that component importance associated to initial
failures is ignited by the windstorms, which subsequently
leads to potential cascading failures. The obtained results in
[13] demonstrate that the proposed procedure can provide an
efficient basis for planning network improvements in terms of
i) strengthening vulnerable line segments against wind loads
and ii) increasing line capacities to limit cascading failures.
In [38], a demand side management program considered
weather condition in a real time pricing framework is proposed
to control the customer’s electricity consumption behavior
according to windstorm conditions. The outcome of [38] is
a better complement to the existing resilience enhancement
approaches, which can guide the utility to effectively employ
the existing power infrastructure and modern smart grid op-
eration and strategy to address the challenge of windstorm
hazards. Also, the proposed method is beneficial to the power
system resilience improvement and risk mitigation to lessen
adverse effects caused by severe windstorm conditions. Other
methods such as i) metrics and quantitative framework [39],
ii) component importance assessment [40], iii) resilience-
oriented proactive management approach [41], and iv) multi-
phase assessment and adaptation strategies, can be also used
to evaluate impacts of windstorms and mitigate their effects
on power system and microgrid reliability.
B. Mitigation of Earthquake Effects
Power system seismic design is used to mitigate earthquake
effects on power system reliability [42]. System performance
under earthquake characteristics depends on i) level of power
system, ii) regional coverage of power system, iii) character-
istics of power system network, iv) dynamic characteristics of
electrical equipment, and v) system robustness against external
disturbances [43], [16]. A systematic method incorporating
substation retrofit and imposing outages to the customers
under earthquake hazards is proposed in [44]. Here, a case
study of historical earthquake events is contemplated. In this
study, the Monte Carlo simulation is applied to track the
stochastic failures of affected substation components. The
results demonstrate that the affected power transformers and
circuit breakers at medium voltage level are the most critical
components in the retrofitting approaches. In [45], novel
assessment framework with component criticality, which can
rank the severity of earthquakes to the affected components,
is proposed. This method can substantially strengthen the
resilience of the system against seismic events.
C. Mitigation of Wildfire Effects
Mitigating the risk of wildfires is potentially one of the
biggest challenge of power system and microgrid reliability
[24]. Impacts of wildfire on power system in USA can cause
from around $M8to $M16,500 [46], [47], [24]. It is widely
known that wildfire can ignite from i) power systems by
an accidental fault or other catastrophic failures [48] (As
they are related to power system caused fire ignitions, this
phenomenon is reported and studied in Refs. [49], [50], [51])
TABLE III: Summary of wildfire mitigation techniques [24]
Techniques Fault of fail-
ure preven-
tion
Acr-ignition
prevention
Wildfire im-
pact mitiga-
tion
Moving line to
underground
Structural hard-
ening
Asset
inspections
Waveform ana-
lytic
Vegetation man-
agement
Sensitive protec-
tion
Disabled
reclosers
Proactive opera-
tion
Weather model-
ing
Fire surveillance
Emergency
planning
and ii) and natural wildfires. According to [24], wildfire
mitigation techniques can be categorized into three groups,
i.e., fault prevention, arc-ignition prevention, and fire response
and impact mitigation. Table III summarizes techniques of
wildfire mitigation. Several research works have proposed
effective strategies to reduce the wildfire effects on power
systems. According to [52], the actions can be performed,
e.g., situational awareness by forecasting potential risks and
damages before the event, corrective action such as network
reconfiguration and power re-routing during the event, and
restoration such as black start and load restoration after the
event. A novel framework for resiliency improvement of a
power system with electric vehicles under wildfire event is
introduced in [23]. This method includes resiliency analysis
incorporated probabilistic models of load redistribution, which
also takes potential evacuation routes into consideration. A
probabilistic proactive generation re-dispatch strategy to en-
hance the operational resilience of power grids during wildfires
is proposed in [53]. The proposed approach in [53] can
enhance the power grid resiliency under various scenarios of
wildfires.
D. Mitigation of Flooding Effects
Flooding events are indeed problematic for previous trans-
mission substations, since they are installed on or close to
the ground level, resulting in the shutting down condition in
case of flooding [54]. The work in [55] proposes an extended
method with decision flow diagrams for external flooding risk
assessment of a nuclear power plant. The proposed framework
in [55] can facilitate the standardization of the evaluation on
the flooding risk assessment. The work in [31] develops a new
GIS-based tool for evaluating hazard of flood, related cost,
and reliability assessment of power networks. The counter-
measures applied in [31] can reduce the risk index from the
flooding scenario, failure probability, and provoked costs over
50% from their normal levels. Additionally, it is shown that
the levels of the electrical and water utilities are interrelated.
The proposed tool is very beneficial for future infrastructure
planning objectives by distinguishing critical risk areas, eval-
uating the potential costs, and supporting utilities, and finally
achieving their reliability goals in the cases of flooding events.
Moreover, other methods such as i) infrastructure hardening,
such as installing substations on elevated foundation slabs
and installing permanent physical barriers [56], [54], ii) using
energy management system, demand response, and network
reconfiguration to avoid load curtailment [57], iii) substation
failure estimation based on probabilistic approaches [58], iv)
robust protection strategies such as upgrading new structures
[59], and v) a stochastic resource allocation methods for
monitoring power substations in a day-ahead manner [60], are
presented. The advantages and disadvantages of such other
methods are discussed in [60].
IV. CONCLUSIONS AND FUTURE RESEARCH DIRECTIONS
A review of previous risk and resiliency assessments, mod-
elings, and mitigation methods considering the HILP events is
discussed in this paper. To investigate the risks and effects of
the HILP events, modeling of hazard or severity need to be
formulated according to available data. Since extreme events
rarely occur in actual power systems, previous research works
mostly apply probabilistic methods and fragility curves to
predict the HILP events. For future risk and resiliency assess-
ments, the following research directions can be considered as
follows:
1) Novel smart grid technologies such as real-time moni-
toring, smart meters, controllable loads, automatic data
acquisition systems, etc., lead to more flexible directions
for the power system and microgrid operation. However,
these technologies are not properly applied to the pro-
posed frameworks to use their contributions for future
resilience enhancements. Measurements and smart meters
should be applied to report the HILP events by using
dynamic data from the system,
2) Real-time tracking of the HILP events on power systems
in both distributed and centralized levels is important
for improving grid resiliency via targeted and quick re-
sponses. Therefore, more researches on high-performance
HILP, dynamic simulation, and equipment failure models
are indispensable,
3) Since DERs highly penetrate into future power systems,
using such distributed active elements to support elec-
tricity during the HILP events are alternative options and
should be well researched by taken into consideration
optimal techno-economical aspects,
4) A few research works incorporate the knowledge of
power system dynamics and stability into risk and relia-
bility assessment for sustainable system planning. Thus,
the dynamic constraints should be additionally considered
in this regard. Conventional risk and reliability assess-
ment methods may be ineffective under uncertain dynam-
ics of DERs. Few research works consider characteristics
and limitations of DERs under the HILP events. This
paves the way to design novel strategies for using DERs
to mitigate the effects of the HILP events.
REFERENCES
[1] “Electric system planning for extreme weather events: Nerc recommends
actions to protect reliability this summer, https://www.trccompanies.
com/insights/electric-system- planning-for-extreme-weather-events/.
[2] M. Panteli, C. Pickering, S. Wilkinson, R. Dawson, and P. Mancarella,
“Power system resilience to extreme weather: fragility modeling, proba-
bilistic impact assessment, and adaptation measures,” IEEE Transactions
on Power Systems, vol. 32, no. 5, pp. 3747–3757, 2016.
[3] R. Moreno, M. Panteli, P. Mancarella, H. Rudnick, T. Lagos, A. Navarro,
F. Ordonez, and J. C. Araneda, “From reliability to resilience: Planning
the grid against the extremes,” IEEE Power and Energy Magazine,
vol. 18, no. 4, pp. 41–53, 2020.
[4] H. Khaloie, A. Abdollahi, M. Rashidinejad, and P. Siano, “Risk-based
probabilistic-possibilistic self-scheduling considering high-impact low-
probability events uncertainty,” International Journal of Electrical Power
& Energy Systems, vol. 110, pp. 598–612, 2019.
[5] F. H. Jufri, V. Widiputra, and J. Jung, “State-of-the-art review on power
grid resilience to extreme weather events: Definitions, frameworks,
quantitative assessment methodologies, and enhancement strategies,
Applied energy, vol. 239, pp. 1049–1065, 2019.
[6] M. Sadees, J. P. Roselyn, K. Vijayakumar, and A. Ravi, “Techno
economic analysis of microgrid with an efficient energy management
system and inverter control strategies, Sustainable Energy Technologies
and Assessments, vol. 48, p. 101602, 2021.
[7] H. J. Touma, M. Mansor, M. S. A. Rahman, V. Kumaran, H. B. Mokhlis,
Y. J. Ying, and M. Hannan, “Energy management system of microgrid:
Control schemes, pricing techniques, and future horizons,” International
Journal of Energy Research, vol. 45, no. 9, pp. 12 728–12 739, 2021.
[8] M. Daneshvar, H. Eskandari, A. B. Sirous, and R. Esmaeilzadeh, “A
novel techno-economic risk-averse strategy for optimal scheduling of
renewable-based industrial microgrid, Sustainable Cities and Society,
vol. 70, p. 102879, 2021.
[9] R. Moreno, D. N. Trakas, M. Jamieson, M. Panteli, P. Mancarella, G. Str-
bac, C. Marnay, and N. Hatziargyriou, “Microgrids against wildfires:
distributed energy resources enhance system resilience, IEEE Power
and Energy Magazine, vol. 20, no. 1, pp. 78–89, 2022.
[10] A. Veeramany, S. D. Unwin, G. A. Coles, J. E. Dagle, D. W. Millard,
J. Yao, C. S. Glantz, and S. N. Gourisetti, “Framework for modeling
high-impact, low-frequency power grid events to support risk-informed
decisions,” International Journal of Disaster Risk Reduction, vol. 18,
pp. 125–137, 2016.
[11] W. Li, Risk assessment of power systems: models, methods, and appli-
cations. John Wiley & Sons, 2014.
[12] M. Esfahani, N. Amjady, B. Bagheri, and N. D. Hatziargyriou, “Robust
resiliency-oriented operation of active distribution networks considering
windstorms,” IEEE Transactions on Power Systems, vol. 35, no. 5, pp.
3481–3493, 2020.
[13] A. Scherb, L. Garre, and D. Straub, “Evaluating component importance
and reliability of power transmission networks subject to windstorms:
methodology and application to the nordic grid,” Reliability Engineering
& System Safety, vol. 191, p. 106517, 2019.
[14] I. Vanzi, “Seismic reliability of electric power networks: methodology
and application,” Structural Safety, vol. 18, no. 4, pp. 311–327, 1996.
[15] A. Volkanovski, “On-site power system reliability of a nuclear power
plant after the earthquake,” Kerntechnik, vol. 78, no. 2, pp. 99–112,
2013.
[16] H. Jun and L. Jie, “Seismic reliability analysis of large electric power
systems,” Earthquake Engineering and Engineering Vibration, vol. 3,
no. 1, pp. 51–55, 2004.
[17] D. Crichton, “The risk triangle. natural disaster management: a pre-
sentation to commemorate the international decade for natural disaster
reduction (idndr) 1990–2000,” Ingleton J: Tudor Rose, 1999.
[18] W. Yang, S. N. Sparrow, M. Ashtine, D. C. Wallom, and T. Morstyn,
“Resilient by design: Preventing wildfires and blackouts with micro-
grids,” Applied Energy, vol. 313, p. 118793, 2022.
[19] “Assessing bushfire hazards, https://research.csiro.au/bushfire/
assessing-bushfire-hazards/hazard-identification/fire-danger-index/.
[20] G. J. Van Oldenborgh, F. Krikken, S. Lewis, N. J. Leach, F. Lehner,
K. R. Saunders, M. Van Weele, K. Haustein, S. Li, D. Wallom et al.,
“Attribution of the australian bushfire risk to anthropogenic climate
change,” Natural Hazards and Earth System Sciences, vol. 21, no. 3,
pp. 941–960, 2021.
[21] A. Camia and G. Amatulli, “Weather factors and fire danger in the
mediterranean,” in Earth observation of wildland fires in Mediterranean
ecosystems. Springer, 2009, pp. 71–82.
[22] A. Dimitrakopoulos, A. Bemmerzouk, and I. Mitsopoulos, “Evaluation
of the canadian fire weather index system in an eastern mediterranean
environment, Meteorological Applications, vol. 18, no. 1, pp. 83–93,
2011.
[23] D. L. Donaldson, M. S. Alvarez-Alvarado, and D. Jayaweera, “Power
system resiliency during wildfires under increasing penetration of
electric vehicles,” in 2020 International Conference on Probabilistic
Methods Applied to Power Systems (PMAPS). IEEE, 2020, pp. 1–6.
[24] J. W. Muhs, M. Parvania, and M. Shahidehpour, “Wildfire risk mitiga-
tion: A paradigm shift in power systems planning and operation, IEEE
Open Access Journal of Power and Energy, vol. 7, pp. 366–375, 2020.
[25] J. Leandro, A. Chen, and A. Schumann, “A 2d parallel diffusive wave
model for floodplain inundation with variable time step (p-dwave),
Journal of Hydrology, vol. 517, pp. 250–259, 2014.
[26] L. Souto, J. Yip, W.-Y. Wu, B. Austgen, E. Kutanoglu, J. Hasenbein,
Z.-L. Yang, C. W. King, and S. Santoso, “Power system resilience to
floods: Modeling, impact assessment, and mid-term mitigation strate-
gies,” International Journal of Electrical Power & Energy Systems, vol.
135, p. 107545, 2022.
[27] J. Leandro, S. Cunneff, and L. Viernstein, “Resilience modeling of
flood induced electrical distribution network failures: Munich, germany,”
Frontiers in Earth Science, vol. 9, p. 572925, 2021.
[28] B. Dong, J. Xia, M. Zhou, Q. Li, R. Ahmadian, and R. A. Falconer,
“Integrated modeling of 2d urban surface and 1d sewer hydrodynamic
processes and flood risk assessment of people and vehicles,” Science of
the Total Environment, vol. 827, p. 154098, 2022.
[29] T. Pflugbeil, K. Broich, and M. Disse, “Hydrodynamic simulation of
the flash flood events in baiersdorf and simbach (bavaria)—a model
comparison,” EGU Gen. Assem, vol. 21, p. 15509, 2019.
[30] R. Martins, J. Leandro, A. S. Chen, and S. Djordjevi´
c, “A comparison of
three dual drainage models: shallow water vs local inertial vs diffusive
wave, Journal of Hydroinformatics, vol. 19, no. 3, pp. 331–348, 2017.
[31] D. S. Muñoz and J. L. D. García, “GIS-based tool development for
flooding impact assessment on electrical sector, Journal of Cleaner
Production, vol. 320, p. 128793, 2021.
[32] S. Bjarnadottir, Y. Li, and M. G. Stewart, “Hurricane risk assessment
of power distribution poles considering impacts of a changing climate,
Journal of Infrastructure Systems, vol. 19, no. 1, pp. 12–24, 2013.
[33] A. M. Salman, Y. Li, and M. G. Stewart, “Evaluating system reliability
and targeted hardening strategies of power distribution systems subjected
to hurricanes,” Reliability Engineering & System Safety, vol. 144, pp.
319–333, 2015.
[34] Y.-P. Fang, G. Sansavini, and E. Zio, An optimization-based framework
for the identification of vulnerabilities in electric power grids exposed
to natural hazards,” Risk Analysis, vol. 39, no. 9, pp. 1949–1969, 2019.
[35] G. Andreotti and C. G. Lai, “Use of fragility curves to assess the seismic
vulnerability in the risk analysis of mountain tunnels,” Tunnelling and
Underground Space Technology, vol. 91, p. 103008, 2019.
[36] M. Biglari and A. Formisano, “Damage probability matrices and empiri-
cal fragility curves from damage data on masonry buildings after sarpol-
e-zahab and bam earthquakes of iran,” Frontiers in built environment,
vol. 6, p. 2, 2020.
[37] Z. Bie, Y. Lin, G. Li, and F. Li, “Battling the extreme: A study on the
power system resilience,” Proceedings of the IEEE, vol. 105, no. 7, pp.
1253–1266, 2017.
[38] Y. Li, K. Xie, L. Wang, and Y. Xiang, “Exploiting network topology
optimization and demand side management to improve bulk power
system resilience under windstorms,” Electric Power Systems Research,
vol. 171, pp. 127–140, 2019.
[39] M. Amirioun, F. Aminifar, H. Lesani, and M. Shahidehpour, “Metrics
and quantitative framework for assessing microgrid resilience against
windstorms,” International Journal of Electrical Power & Energy Sys-
tems, vol. 104, pp. 716–723, 2019.
[40] G. Li, G. Huang, Z. Bie, Y. Lin, and Y. Huang, “Component importance
assessment of power systems for improving resilience under wind
storms,” Journal of Modern Power Systems and Clean Energy, vol. 7,
no. 4, pp. 676–687, 2019.
[41] M. Amirioun, F. Aminifar, and H. Lesani, “Resilience-oriented proactive
management of microgrids against windstorms,” IEEE Transactions on
Power Systems, vol. 33, no. 4, pp. 4275–4284, 2017.
[42] L. Tian and Z. Zhe, “Study on earthquake resistance of electric power
system based on system reliability, in 2010 International Conference on
Intelligent System Design and Engineering Application, vol. 2. IEEE,
2010, pp. 437–440.
[43] S. Espinoza, A. Poulos, H. Rudnick, J. C. De La Llera, M. Pan-
teli, P. Mancarella, R. Sacaan, A. Navarro, and R. Moreno, “Seismic
resilience assessment and adaptation of the northern chilean power
system,” in 2017 IEEE Power & Energy Society General Meeting.
IEEE, 2017, pp. 1–5.
[44] M. H. Oboudi, M. Mohammadi, D. N. Trakas, and N. D. Hatziargyriou,
“A systematic method for power system hardening to increase resilience
against earthquakes,” IEEE Systems Journal, vol. 15, no. 4, pp. 4970–
4979, 2020.
[45] S. Espinoza, A. Poulos, H. Rudnick, J. C. de la Llera, M. Panteli,
and P. Mancarella, “Risk and resilience assessment with component
criticality ranking of electric power systems subject to earthquakes,
IEEE Systems Journal, vol. 14, no. 2, pp. 2837–2848, 2020.
[46] M. McGranaghan, M. Olearczyk, and C. Gellings, “Enhancing distri-
bution resiliency: Opportunities for applying innovative technologies,”
Electricity Today, vol. 28, no. 1, pp. 46–48, 2013.
[47] Y. Wang, C. Chen, J. Wang, and R. Baldick, “Research on resilience of
power systems under natural disasters—a review,” IEEE Transactions
on Power Systems, vol. 31, no. 2, pp. 1604–1613, 2015.
[48] B. D. Russell, C. L. Benner, and J. A. Wischkaemper, “Distribution
feeder caused wildfires: Mechanisms and prevention, in 2012 65th
Annual Conference for Protective Relay Engineers. IEEE, 2012, pp.
43–51.
[49] C. D. Zak, The effect of particle properties on hot particle spot fire
ignition. University of California, Berkeley, 2015.
[50] A. Fernandez-Pello, C. Lautenberger, D. Rich, C. Zak, J. Urban,
R. Hadden, S. Scott, and S. Fereres, “Spot fire ignition of natural fuel
beds by hot metal particles, embers, and sparks,” Combustion science
and technology, vol. 187, no. 1-2, pp. 269–295, 2015.
[51] D. Coldham, A. Czerwinski, and T. Marxsen, “Probability of bushfire
ignition from electric arc faults final report,” 2011.
[52] H. Nazaripouya, “Power grid resilience under wildfire: A review on
challenges and solutions,” in 2020 IEEE Power & Energy Society
General Meeting (PESGM). IEEE, 2020, pp. 1–5.
[53] M. Abdelmalak and M. Benidris, “Enhancing power system operational
resilience against wildfires,” IEEE Transactions on Industry Applica-
tions, vol. 58, no. 2, pp. 1611–1621, 2022.
[54] J. Boggess, G. Becker, and M. Mitchell, “Storm & flood hardening
of electrical substations,” in 2014 IEEE PES T&D Conference and
Exposition. IEEE, 2014, pp. 1–5.
[55] T. Bani-Mustafa, R. Flage, D. Vasseur, Z. Zeng, and E. Zio, An
extended method for evaluating assumptions deviations in quantitative
risk assessment and its application to external flooding risk assessment
of a nuclear power plant,” Reliability Engineering & System Safety, vol.
200, p. 106947, 2020.
[56] R. E. Costa and G. R. McAllister, “Substation flood program and flood
hardening case study, in 2017 IEEE Power & Energy Society General
Meeting. IEEE, 2017, pp. 1–5.
[57] M. H. Amirioun, F. Aminifar, and H. Lesani, “Towards proactive
scheduling of microgrids against extreme floods,” IEEE Transactions
on Smart Grid, vol. 9, no. 4, pp. 3900–3902, 2017.
[58] D. Sánchez-Muñoz, J. L. Domínguez-García, E. Martínez-Gomariz,
B. Russo, J. Stevens, and M. Pardo, “Electrical grid risk assessment
against flooding in barcelona and bristol cities,” Sustainability, vol. 12,
no. 4, p. 1527, 2020.
[59] J. C. Aerts, W. W. Botzen, K. Emanuel, N. Lin, H. De Moel, and
E. O. Michel-Kerjan, “Evaluating flood resilience strategies for coastal
megacities,” Science, vol. 344, no. 6183, pp. 473–475, 2014.
[60] M. Movahednia, A. Kargarian, C. E. Ozdemir, and S. C. Hagen, “Power
grid resilience enhancement via protecting electrical substations against
flood hazards: A stochastic framework, IEEE Transactions on Industrial
Informatics, vol. 18, no. 3, pp. 2132–2143, 2021.
... Fig. 2 visually presents the organization and structure of the paper. This paper is developed from our previous paper [3] presented at 2022 IEEE Global Conference on Computing, Power and Communication Technologies (GlobConPT). ...
... However, it should be noted that extreme events, such as wildfires, can impact the power grid without causing direct damage. For instance, soot accumulation caused by a wildfire can lead to high leakage current and line-off [1]- [3]. Additionally, wildfires and the consequent rise in temperature can negatively affect the output of PV generation, resulting in a 7%-30% reduction in their generation [1], [3], [7]. ...
... For instance, soot accumulation caused by a wildfire can lead to high leakage current and line-off [1]- [3]. Additionally, wildfires and the consequent rise in temperature can negatively affect the output of PV generation, resulting in a 7%-30% reduction in their generation [1], [3], [7]. Unfortunately, most previous research on power system resiliency has ignored the constraints of renewable generation during extreme events and the correlation of weather variables with power system events. ...
Article
This research presents a detailed review of high-impact low-probability (HILP) events, like wildfires, earthquakes, windstorms, and floods, which have the potential to cause major damage to power systems. These events are inevitable and hard to predict. Moreover, the uncertainties arising from distributed renewable energy resources can decrease the effectiveness of conventional techniques that aim to enhance the power grid reliability against extreme events. This paper aims to conduct a thorough and critical evaluation of existing practices in modelling extreme events, system components, and system responses, all aiming to improve resiliency. This review serves as a crucial basis for developing modelling techniques that are not only comprehensive and accurate but also computationally efficient. Initially, the paper examines existing technologies used to model the spread of extreme events. Subsequently, it explores various approaches utilized to model the impact of these extreme events on power system components and responses. Additionally, the research addresses the gaps and challenges associated with current modelling approaches and proposes potential solutions to overcome these limitations.
... Climate change has intensified the frequency and severity of natural disasters which significantly impact critical infrastructure systems. The challenge of high-impact low-probability (HILP) events, such as wildfires, earthquakes, windstorms, and floods, is highlighted by Surinkaew et al. (2022). These events pose significant threats to power systems, and the uncertainties they introduce necessitate comprehensive and accurate modeling techniques to improve resiliency. ...
Conference Paper
The growing frequency and intensity of climate-related events and natural disasters present substantial challenges to the resilience and adaptability of critical infrastructure, particularly electricity transmission and distribution networks. This study provides a review of existing literature and incorporates recent research findings to identify the primary factors influencing resilience and adaptability within these networks. The study emphasizes the importance of key areas including technical design strategies, infrastructure investments, facility design considerations, organizational capabilities, operational strategies, and supply chain factors. The findings offer essential insights for stakeholders in the energy sector aiming to enhance the resilience of transmission and distribution networks against climate change impacts and natural disasters. Additionally, the study underscores the importance of establishing standardized resilience metrics and advocates for future research focusing on cost-benefit analyses and data-driven approaches to predict and mitigate cascading failures and high-impact, low-probability (HILP) events. 1. INTRODUCTION Climate change has intensified the frequency and severity of natural disasters which significantly impact critical infrastructure systems. The challenge of high-impact low-probability (HILP) events, such as wildfires, earthquakes, windstorms, and floods, is highlighted by Surinkaew et al. (2022). These events pose significant threats to power systems, and the uncertainties they introduce necessitate comprehensive and accurate modeling techniques to improve resiliency. Electricity transmission and distribution (T&D) networks are particularly vulnerable, which can result in prolonged power outages that cause substantial economic losses and threaten public health and safety (Ekisheva et al., 2020; Fant et al., 2020). Enhancing the resilience and adaptability of these networks is essential to ensure a reliable electricity supply and to mitigate the adverse effects of climate-related events. Recent literature indicates a growing recognition of the challenges posed by climate change to T&D networks. The traditional reliability measures may not suffice for such extreme events, and there is a need for advanced modeling approaches that can capture the complexities associated with HILP events. Addressing vulnerabilities and potential attacks is a significant concern. Valencia et al. (2021) reviewed methodologies for assessing the vulnerability of power systems using multilevel programming. They point out that while most research focuses on transmission systems using linear approximations, there is a need for more comprehensive models that can address vulnerabilities in distribution networks and incorporate defense strategies such as distributed generation and demand response. This aligns with the findings of Erenoğlu et al. (2024), who stress the importance of distinguishing between reliability and resiliency. While reliability focuses on the system's ability to perform under normal conditions, resiliency pertains to the system's capacity to adapt and recover from extreme disruptions. Developing quantitative metrics for resiliency, as they suggest, is essential for better understanding and enhancing this emerging concept. Studies have explored various aspects of resilience, including design strategies, the integration of advanced technologies, and organizational as well as operational aspects. This review study addresses key gaps by providing a comprehensive analysis of the challenges and critical factors affecting the resilience of T&D networks in response to natural disasters. By integrating insights from foundational studies and recent literature, this review aims to identify the challenges and critical factors that influence the resilience of transmission networks in the face of natural disasters. It also underscores the importance of resilience and adaptability in T&D networks, highlighting the need for standardized resilience metrics to improve assessment and response strategies under adverse conditions.
... Such extreme disruptive events are characterised by high impact and low probability causing potentially longer power outages. Consequently, grid planning should not only consider reliability-driven aspects but also other more severe disruptions [19][20][21][22]. In response to this need, the resilience concept has been incorporated into the planning of energy systems, drawing its origins from the field of ecological sciences as first proposed by Holling [23]. ...
Article
Full-text available
The integration of renewable energy sources (RES) is essential for steering our energy systems towards sustainability. This transition, though, coupled with emerging trends such as digitalisation and decentralisation, introduces a number of new challenges and vulnerabilities to our energy infrastructure. To strengthen our energy systems against the uncertainties arising from intermittent RES and decentral organised power grids, battery energy storage systems (BESSs) integrated into sector-coupling strategies might play a crucial role. Such BESSs can enhance system resilience by providing increased flexibility in the face of disruptive events. Yet, the assessment of their resilience contribution is still a nascent field, particularly within the context of multi-energy systems. To address this gap, our study presents an assessment scheme utilising the open source energy system model electricity grid optimisation. We apply this scheme to evaluate the impact of sector-coupled BESS installations with a local district heating network in a mid-sized German city. Our analysis encompasses various scenarios, considering diverse BESS sizes, quantities, seasonal influences, system scales, siting, and the severity of disruptive events. The principal findings are threefold: for energy systems that exhibit high inherent robustness, such as those with existing adaptive capacities and redundancies, hybrid BESS (hBESS) has a low impact on the resilience against single disruptive events. In contrast, for less prepared systems or during simultaneous events, hBESSs can substantially strengthen the resilience of the energy infrastructure, particularly regarding the ‘security of supply’ and ‘cost efficiency’. For instance, during short-lasting disruptive events, hBESS can potentially avert up potential power outages from 1.4% to 45% increasing the security of supply. However, the resilient design principle ‘spatial diversity’ could not improve the system’s resilience in all scenarios. This holistic approach is essential for identifying resilient strategies capable of effectively countering unforeseen disruptive events, thereby ensuring the continued stability and sustainability of our energy systems.
... The renewable energy sources connected in a distributed manner along with the loads constitute microgrids (MGs). A renewable-rich microgrid is a localized energy system that uses a variety of renewable energy sources to generate electricity [1] and is distinguished from the other MGs by its large dependence on renewable energy sources such as solar, wind, hydro, and geothermal energy to supply a significant amount of its loads. ...
Article
Full-text available
With the intent of reducing carbon emissions, renewable-rich microgrids, in which most of the load is being served by renewable sources, are expanding rapidly to achieve maximum self-sustainability and minimum dependency on the grid. However, the area required to commission such a renewable-rich microgrid is a major constraint, particularly for the long-term planning of microgrids in urban areas, in addition to the criticality of cost and availability. In this connection, this paper presents a framework for optimally planning a renewable-rich hybrid microgrid with area constraints for energy resources. Considering the criticality, the proposed framework includes the formulation for optimization of twin objectives: the cost of the microgrid and the availability of power in the microgrid. The problem is solved using a Multi-objective approach to minimize the cost, maximize availability, and importantly achieve a feasible generation mix subjected to specified area constraints, a first of its kind. Stochastic algorithms based on genetic and swarm techniques are employed to solve the multi-objective optimization problem of planning a renewable-rich hybrid microgrid. From the performance analysis, a superior method is identified which is further applied for expansion planning of the considered hybrid microgrid to meet future requirements with limitations on area constraints while taking advantage of modularity associated with renewable sources, a first of its kind. To handle the uncertainties associated with such renewable-rich microgrids, uncertainty analyses are carried out by constructing the utility function and validated using Monte Carlo simulations to rationalize decision-making on system design. It is to note that the results from the proposed method of microgrid planning are found to be effective over the known normal distribution of the considered uncertainty as well. The modeling, decision-making, and uncertainty analyses, are carried out with the help of MATLAB environment.
Conference Paper
Cyber-physical distribution systems (CPDS) have emerged from the integration of information technology into distribution systems. While offering substantial benefits, this integration also introduces vulnerabilities. The interaction between cyber networks and distribution systems renders CPDS susceptible to disasters. To ensure critical load supply and system resilience, rapid post-disaster load restoration is required. The paper proposes a critical load restoration (CLR) framework in CPDS using a network reconfiguration approach that exploits the existing post-disaster resources to restore critical loads within the shortest possible time. Using graph theory, the cyber network and distribution system are integrated into a single digraph, minimizing the CLR complexity in CPDS. A cost metric is also defined to satisfy network-specific objectives and constraints. A heuristic is proposed to guide the load restoration process using the cost metric within the integrated digraph. Simulation results confirm the framework’s superiority over existing literature, which either overlooks cyber components or prolongs restoration with additional resource deployment.
Article
Full-text available
This paper proposes a strategy for managing wildfire risks and preventing blackouts using microgrids. To demonstrate this approach, not seen in previous literature, we use the power network of Victoria, Australia, in December 2019 as a case study. The Fire Weather Index (FWI) is a crucial indicator of global fire behaviour both spatially and temporally, as proved with its robust analysis within many previous studies. The FWI is applied to a Wildfire-Energy System for the first time, contributing to a higher spatial and temporal resolution to position the wildfire risk in a grid. A novel method is proposed to automatically correlate the wildfire risk index and the power network model using geographical information of the transmission lines. The optimal power flow and grid performances are obtained from a grid model which incorporates wildfire risk distributions. It is shown that a system with installed microgrids can maintain operation under severe fire-related conditions without scheduled or unplanned outages. Finally, a cost-benefit analysis is conducted, which demonstrates that 68% of system costs can be recuperated by implementing networked microgrid solutions.
Article
Full-text available
In recent years, countries around the world have been severely affected by catastrophic wildfires with significant environmental, economic, and human losses. Critical infrastructures, including power systems, have been severely damaged, compromising the quality of life and the continuous and reliable provision of essential services, including the electricity supply.
Article
Full-text available
Natural disasters, such as floods, may damage power system assets and lead to widespread and long outages. The impact of flood can be alleviated by preventive actions such as installing tiger dams around power substations before the flood. In this regard, it is imperative that critical substations are identified in terms of the connected load and imposed costs to the system. This paper presents a stochastic resource allocation approach for protecting power substations against flood events a day ahead of the event. Flood probability distribution functions are used to generate several flood scenarios at each substation. Using flood scenarios and substations' fragility, damage, and repair time curves obtained from historical data, the failure probability, damage percentage, damage cost, and repair time of substations are estimated. A day-ahead risk-aware stochastic scheduling model is proposed to identify the critical substations whose protection by tiger dams maximizes grid resilience. The risk-aware approach prevents high cost and low resilience if a particular scenario with a low probability is realized. A scenario reduction method is developed to generate representative substation failure scenarios and reduce the computational cost of the optimization problem. The simulation results on a realistic 30-substation system show the effectiveness of the proposed model.
Article
In order to accurately simulate the whole urban flooding processes and assess the flood risks to people and vehicles in floodwaters, a 2D-surface and a 1D-sewer integrated hydrodynamic model was proposed in this study, with the module of flood risk assessment of people and vehicles being included. The proposed model was firstly validated by a dual-drainage laboratory experiment on the flood inundation process over a typical urban street, and the relative importance of model parameters and model uncertainties were evaluated using the GSA-GLUE method. Then the model was applied to simulate an actual urban flooding process that occurred in Glasgow, UK, with the influence of the sewer drainage system on flood inundation processes and hazard degree distributions of people and vehicles being comprehensively discussed. The following conclusions are drawn from this study: (i) The proposed model has a high degree of accuracy with the NSE values of key hydraulic variables greater than 0.8 and the GSA indicates that Manning roughness coefficients for surface and sewer flows, inlet weir and orifice discharge coefficients, are the most relevant parameters to influence the simulated results; (ii) vehicles are vulnerable to larger water depths while human stability is significantly influenced by higher flow velocities, with the overall flood risk of people being less than that of vehicles; and (iii) about 88.7% of the total inflow volume was drained to the sewer network, and the sewer drainage system greatly reduced the flood risks to people and vehicles except the local areas with large inundation water depths, where the sewer drainage increased the local flow velocity leading to higher flood risks especially for people.
Article
Catastrophic impacts of wildfires on the performance of power grids have increased in the recent years. Though various methods have been applied to enhance power grid resilience against severe weather events, only a few have focused on wildfires. Most previous operational-based resilience enhancement methods have focused on corrective or restorative strategies during and after extreme events without proactively preparing the system for forecasted potential failures. Also, the propagation behavior of wildfires among system components induces further complexities resulting in a mathematically involved problem accompanied with many modeling challenges. During sequential failures, operators need to make decisions in a fast-paced manner to maintain reliable operation and avoid cascading failures and blackouts. Thereby, the complexity of decision processes increases dramatically during extreme weather events. This article proposes a probabilistic proactive generation redispatch strategy to enhance the operational resilience of power grids during wildfires. A Markov decision process is used to model system state transitions and to provide generation redispatch strategies for each possible system state given component failure probabilities, wildfire spatiotemporal properties, and load variation. For a realistic system representation, dynamic system constraints are considered including ramping rates and minimum up/down times of generating units, load demand profile, and transmission constraints. The IBM ILOG CPLEX optimization studio is utilized to solve the optimization problem. The IEEE 30-bus system is used to validate the proposed strategy under various impact scenarios. The results demonstrate the effectiveness of the proposed method in enhancing the resilience level of power grids during wildfires.
Article
A microgrid comprises of distributed energy resources with the capability of operating independently as an islanded mode or in a grid connected mode. The efficacy of a microgrid is based on the performance of the control strategy and the energy management strategy. Therefore, in this paper the feasibility of an efficient inverter control strategy and energy management strategy for microgrid are studied. The proposed microgridis implemented with master-slave energy management control and battery management system for effective power flow control in an islanded and grid connected mode. A three-layer hierarchical energy management strategy comprising of master-slave system to provide continuous supply at all conditions and effective switchover operations between grid connected and islanded modes of operation is proposed. The voltage-frequency control under standalone mode of operation and P-Q control using hysteresis current control under grid-connected mode of operation are developed and the system parameters like real power, reactive power and voltage at the PCC are analyzed after the implementation of proposed controllers under islanded and grid connected modes of operation. The proposed model achieves voltage and frequency regulation under varying system operating conditions. Also, a techno-economic analysis is performed in HOMER software where the cost of energy and return on investment are studied for the proposed microgrid system by which levelized cost and payback period is reduced. The proposed control algorithms are implemented through MATLAB simulation and tested in a real-time for 1 kW grid-connected solar PV system.
Article
This article presents a methodology aimed at improving mid-term power system resilience at transmission substations in areas potentially affected by floods, combining hardening strategies and quantitative metrics. It takes into account flood forecasts from a hydrological model and the location of electrical equipment to perform impact assessment “as is” and with resilience planning strategies. Thus, the impact of floods on the grid is evaluated over a range of realistic flood scenarios, based on the accumulated cost and load energy unserved as metrics together with future transmission system expansion capacity projections. The mixed-integer linear programming formulation is aimed at minimizing accumulated cost and load energy unserved with optimal hardening of substations, assuming that any non-hardened substation disabled by flooding must be repaired. Furthermore, the methodology is demonstrated in the coastal area of Texas with simulations of floods based on the rainfall of Hurricane Harvey in 2017. Ultimately, the choice of the most appropriate mitigation strategies shall optimize resilience metrics and/or cost indicators with robustness over a range of scenarios.
Article
Due to climate change, extreme weather events are increasing in frequency and intensity. Thus, critical infrastructures as power distribution must be secure and resilient to respond to and mitigate the impacts caused by extreme events. Accounting that the most valuable assets, human lives, are currently hosted in cities, these are considered as the most sensible and critical zones and are also constituted as the main focus of study. This statement is reflected in the increasing interest in making cities more resilient against extreme events, becoming a key research topic worldwide. Trying to tackle this goal, this paper focuses on the development of a GIS-based tool oriented to help decision-makers in planning while providing unitary and global views of the electric assets of a network considering their interrelations in a failure case. The study follows three main steps to achieve this purpose. First, the flood risk assessment while evaluating the flood depth hazard (taking into account the Average of Water Depth found in the flooded areas), the exposure of the assets (using Affected Area Rates), and their vulnerability (with the integration of Fragility curves), putting all the elements together into Failure Probabilities considering the interrelation between assets and the potential cascade effects. Second, calculating a cost assessment (from damage, business interruption, auxiliary cost, and non-supplied energy). Finally, calculating electrical network reliability indices, which provides highly valuable information about the status of the grid and the interruptions to customers when considering scenarios of extreme flooding events. Intending to prove the use and performance of the tool developed, this tool is applied to a real case study in Barcelona city. This case of study is constituted by two flooding scenarios (Current situation and Climate change with RCP 8.5) previously modeled and validated in other projects, and the Climate change scenario with measures applied to the water sector (increasing the drainage capacity of the city, and improving capacities of the sewer system). It is demonstrated how the improvements introduced by measures are interrelated and considerably improve the safety of the electrical network, mitigating consequences provoked by flooding extreme events by 60% in case of Average of Water Depth, 50% the failure probability, and 77% the costs provoked.
Article
The tremendous engagement of electric energy consumers and the advent of smart grids have left more complexity and challenges in terms of energy management system. Recently, microgrid is a preferable choice to cope with these challenges as small‐scale power system and so close to consumers. However, there is a crucial need to find more compatible solutions to achieve economic, environmental, and reliable objectives of energy management system, since most current solutions are based on optimal scheduling of generating units at the supply side. Demand side management develops more opportunities to achieve these objectives by efficiency programs and demand response programs (pricing techniques). Therefore, this article reviews and assesses demand side management, particularly pricing techniques, in the light of energy management system as a part of control system of microgrid. Furthermore, the aspects of control schemes are discussed including centralized and distributed controls. Finally, this article identifies a number of shortcomings in the current research that concern demand side management and highlights future horizons of research.
Article
Nowadays, increasing concerns regarding the harmful effects of fossil fuel-based energy production systems have accelerated the decarbonization efforts particularly in equipping the electric power grid with a high level of renewable energy sources. In deregulated energy networks with a high share of renewables, adopting an effective strategy for appropriately dealing with intermittences of stochastic producers is necessary to provide a continuous and reliable energy supply. This paper proposes a novel techno-economic risk-averse strategy for optimal scheduling of the industrial microgrid considering both the technical and economical objectives. The robustness function of the information gap decision theory method is exerted for developing the risk-averse strategy aiming to properly manage the fluctuations of uncertain parameters in the system. The demand-side energy management is carried out by developing the price and load response schemes as the demand response programs. The industrial microgrid equipped with renewable energy sources and energy storage systems is intended as a real case study for examining the effectiveness of the proposed strategy. The problem is studied under two models, which Model I assesses the scheduling of the industrial microgrid without intending the stochastic behaviors of uncertain parameters while Model II models uncertainties based on the proposed strategy. The results indicated the effectiveness of the proposed strategy in realizing robustness condition for the renewable-based industrial microgrid to supply reliable and continuous energy in the deregulated environment.