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Heuristic Algorithm Based Dynamic Scheduling Model of Home Appliances in Smart Grid


Abstract and Figures

Smart grid provides an opportunity for customers as well as for utility companies to reduce electricity costs and regulate generation capacity. The success of scheduling algorithms mainly depends upon accurate information exchange between main grids and smart meters. On the other hand, customers are required to schedule loads, respond to energy demand signals, participate in energy bidding and actively monitor energy prices generated by the utility company. Strengthening communication infrastructure between the utility company and consumers can serve the purpose of consumer satisfaction. We propose a heuristic demand side management model for scheduling smart home appliances in an automated manner, to maximise the satisfaction of the consumers associated with it. Simulation results confirm that the proposed hybrid approach has the ability to reduce peak-to-average ratio of the total energy demand and reduce the total cost of the energy without compromising user comfort.
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Heuristic Algorithm Based Dynamic Scheduling
Model of Home Appliances in Smart Grid
Inam Ullah Khan
, Xiandong Ma
, C. James Taylor
, Nadeem Javaid
, Kelum A.A. Gamage
Engineering Department, Lancaster University, Lancaster LA1 4YW, UK
Electrical Engineering Department, COMSATS University Lahore, Pakistan
COMSATS University, Islamabad 44000, Pakistan
School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK;
Smart grid provides an opportunity for
customers as well as for utility companies to reduce
electricity costs and regulate generation capacity. The
success of scheduling algorithms mainly depends upon
accurate information exchange between main grids
and smart meters. On the other hand, customers are
required to schedule loads, respond to energy demand
signals, participate in energy bidding and actively
monitor energy prices generated by the utility
company. Strengthening communication
infrastructure between the utility company and
consumers can serve the purpose of consumer
satisfaction. We propose a heuristic demand side
management model for scheduling smart home
appliances in an automated manner, to maximise the
satisfaction of the consumers associated with it.
Simulation results confirm that the proposed hybrid
approach has the ability to reduce peak-to-average
ratio of the total energy demand and reduce the total
cost of the energy without compromising user comfort.
Keywords: Demand side management, appliance scheduling,
critical peak pricing, household energy management.
Demand side management (DSM) usually refers to those
decisions, which are taken by utility companies at user’s
premises [1]. DSM programs are initiated to use available
energy in a more efficient way without developing new
infrastructure for generation, transmission and
distribution. DSM programs usually encompass demand
response programs, fuel substitution programs, efficient
conservation of energy programs and above all
commercial or residential load management programs [2]-
[4]. Reducing and shifting consumption is one of the main
key design features of the residential load management
program [5]. This can only be achieved if users are
encouraged to build energy efficient buildings and to be
well aware of their energy consumption patterns. A part
from this practical initiative needs to be taken, including
high power appliances shifting from peak hours to off-
peak hours for measurable reduction in peak-to-average
ratio (PAR) in load demand. Load shifting is expected to
be even more important because of high penetration of the
plug-in hybrid electrical vehicles (PHEVs). Usually
PHEVs require 0.2-0.3 kWh charging power for one mile
driving [6]. This significantly enhances new load on the
existing distribution system. Particularly during charging
hours, it doubles average household demand, thus
worsening the existing high PAR. In absence of properly
reinforced system, a high PHEVs penetration can create
unbalanced condition, thus compromising power quality
standards, voltage regulation issues and even prospective
damage to utility and consumer equipment.
Direct load control (DLC) is another useful approach for
residential load management [7]-[9]. By applying DLC
programs, utility company remotely controls energy
consumption and operations of certain household
appliances. For instance, thermal comfort equipment
including heating, ventilating and air conditioning
(HVAC), refrigerators, pumps and light control are well-
known examples of DLC programs. When considering
home automation and residential load control specifically,
users’ comfort is on the top priority and considered as a
hurdle in DLC programs execution [10].
Today dynamic pricing replaces DLC programs features.
In dynamic pricing mechanism, users are motivated to
manage their loads individually on a voluntary basis, e.g.,
shutting and shifting heavy loads from peak hours to off-
peak hours [11]-[13]. Most popular and frequently used
schemes of dynamic pricing includes critical-peak pricing
(CPP), real-time pricing (RTP), inclined block rate (IBR),
time of use pricing (ToUP) and day ahead pricing (DAP)
schemes, etc. With the help of these schemes users are
encouraged to shift appliances from peak hour to off-peak
hours. This helps to achieve a lower PAR and reduces
consumer costs [14].
Researchers have recently developed and implemented
different state of the art algorithms in smart grid (SG).
These algorithms successfully analyzed commercial,
residential and industrial buildings in terms of their load
consumption profile. Researchers have focused on
optimizing energy controller and scheduler in such a way
that energy cost is brought to an optimum level for utility
companies and customers. Maximum attention is given to
balancing the supply-demand ratio and reducing customer
cost to a minimum level. Multiple factors are considered
while developing these algorithms: appliance rating,
Proceedings of the 24th International Conference on
Automation & Computing, Newcastle University,
Newcastle upon Tyne, UK, 6-7 September 2018
pricing schemes, utility company priorities and consumer
demand in order to get maximum benefit for all
In reference [9], dynamic price RTP is used for optimally
scheduling smart home appliances. They mainly focus on
reducing unconventional electricity usage, minimizing
cost and maximizing benefits from energy storage.
Electricity cost is reduced to 22.6% and peak price is
reduced to 11.7% as compared to the normal pricing
scheme. However, authors do not pay attention towards
optimizing scheme in their work. While architecting the
DSM model, authors purchase the energy during off-peak
hours and store it in storage bank for peak hours use. Their
main focus is cost minimization and energy storage in
battery bank. Linear programming based optimal
scheduling model is proposed; however, goals remain
Non-deterministic polynomial-time (NP) hardness based
optimal scheduling model is discussed in [12]. The authors
use greedy iterative algorithms to meet the home
scheduling goal. In their work, optimization is achieved
by using linear programming and artificial intelligence
optimization approaches. Lower peak load and lower peak
fluctuation phenomenon is also discussed. Problem
formulation is made not only based on user’s load demand
but also on the generation cost.
In references [11]-[15], authors propose a mixed integer
linear programming based algorithm for scheduling home
appliances in a fascinate way. The real price tariff is used
for scheduling home appliances to reduce cost as well as
peak reduction. In [16], multiple types of users in the
proposed model are evaluated. These users are categorized
as commercial, industrial and residential users. From
simulation results, it can be concluded that the proposed
algorithm contributes significantly to minimization of
PAR and electricity cost.
Genetic Algorithm (GA) based cost minimization
method is used in references [12]-[14]. In these papers,
renewable energy sources (RESs) and battery storage are
integrated into the existing system. RESs are supposed to
charge battery bank for later use, when electricity prices
are high during high demand of energy. For battery
efficiency and life, a controller is developed to monitor the
charging and discharging thresholds associated with the
battery bank. Furthermore, when electricity prices are low,
batteries are supposed to fully charge. Later, when prices
are high then certain high priority appliances are handled
from battery source to save user cost.
In this paper, we propose meta-heuristic optimization
models based on genetic algorithm, grey wolf optimization
(GWO) and a hybrid grey wolf and genetic algorithm
(hybrid G
) for scheduling 12 home appliances. Each day
is divided into 96 time slots (each 15 minutes) instead of
one-hour time slot for appliance operation. This is
necessary because in many cases an appliance requires less
than an hour to complete its operation such as the electric
cattle and dish washer. In this way, users have much
freedom and opportunities to reduce cost, PAR and total
energy demand. Finally, simulation results of the
unscheduled, GA schedule, GWO and hybrid
presented to show the effectiveness of the proposed
model for appliance scheduling in DSM.
In this work, a smart home with multiple smart
appliances is considered. Length of operation time (LoTs)
and power rating (PR) information of all appliances are
already taken from end consumers. The whole system is
divided into three sub-layers, including supply side
management layer (SSML), communication management
layer (CML) and demand side management layer (DSML).
SSML contains all information related to energy
generation. DSML uses energy management controller
(EMC) and appliance scheduler (AS), and schedules
Base Li ne Loads
Regular Loads
Controlla ble Loads
Energy Ma nageme nt
Energy Pr edictor
Load Predi ctor
Utility Control Cent re
Fig. 1 The proposed system architecture
smart appliances on the basis of LOTs defined by the end
users. Purpose of load balancer (LB) is used to delay
appliance operation to minimize demand-supply gap and
not to allow consumer demand to exceed the limit.
Through CML, energy forecaster (EF) and demand
response manger (DRM) exchange real-time demand-
supply information with SSML and DSML. Home Area
Network (HAN) conducts effective communication
between EMC through Wi-Fi, Z-wave and Zig-Bee
communication protocols. Furthermore, smart appliances
are further categorized into base line loads, regular loads
and controllable loads depending upon whether their
operation can be interrupted or not when activated. EMC
uses appliance interface (AI) which controls on/off
operation tasks of all smart appliances associated with the
system. It is pertinent to mention here that EMC through
AS, stops all scheduling operation of the appliances if the
interrupt is generated by the consumer to enhance the
Three meta-heuristic techniques are adopted in this
paper, including GA, GWO and hybrid
in order to
schedule these smart appliances in home energy
management system (HEMS). Scheduling is performed to
save electricity utilization cost for end users. Knapsack
problem is formulated to establish coordination among
smart appliances at run-time. This gives autonomy to each
consumer for managing appliance operation according to
the comfort.
Home appliances are classified into three sub-categories
based on their operational behavior. Interruptible
appliances are those whose operation can be interrupted or
delayed during operation but their operational time is
unchangeable. Similarly, uninterruptible appliances are
those whose operation cannot be delayed or interrupted
once they are in operating mode. However, these
appliances can be shifted to other time slots before their
operations start.
It is important to shift interruptible and uninterruptible
appliances to other time slots to maintain overall energy
consumption up to an allowed level. It is beneficial to use
the interruptible appliances at low peak hours for saving
electricity cost. On contrary, base appliances are those
which can neither be interrupted nor deferred in home
energy management system (HEMS). For example,
refrigerator, air conditioning, lightening and microwave
oven are such devices whose operation pattern remains
unchanged. All appliances along with their length of
operation time (LOT), power rating and category used in
this study are listed in Table 1.
In this section, we will analytically describe power
system, energy cost and load control model for residential
purpose. Based on these descriptions, we will formulate
three design optimization problems in next section.
A. Power System
We consider a smart power system with various load
consumers and a single energy source which may be a
generator or connection to the main grid through a step
down transformer. Furthermore, we assume that each
consumer is equipped with EMC that is capable of
scheduling different appliances (12 in our model) during
different intervals of time (96 intervals in a complete day,
i.e., 15 minutes each). By making use of appropriate
communication protocol, different smart meters are
interconnected, not only with the grid but also with each
other by sharing the updated information.
Let be the set of users, where for each user let
denotes the total load at time slot    {1,…….T}, where
T = 96. Daily consumed load by a specific user is
denoted by
  [
      
]. This leads us to
calculate the total load of all users in a single time slot
across the whole day  . It is represented as
 (1)
Similarly, daily peak load and average load can be
calculated as
 
From equations (2) and (3), PAR can be calculated as
B. Energy Cost Model
For each time slot    energy cost for electricity
generation or distribution is represented by
Generally, for the same load, cost may differ in different
time slot of a day. It mostly depends upon electrical price
maintained by the utility at generation site. It is worth
mentioning here that cost function being considered in this
paper can represent either the original cost of thermal
generators or artificial cost tariffs maintained by the utility
for proper execution of the load control programs. Actual
energy cost function can be represented in terms of a
quadratic function in equation (5).
 
 
 
 
 at each time slot t 
C. Residential Load Control
For an individual user u U, let
denotes the different
set of appliances, including base, interruptible and
uninterruptible appliances in a home. For scheduling
purposes, we initially define a schedule vector for each
appliance a  
of individual user, where n is the number
of the appliances.
 
       
represents scheduled energy consumption in
one time-slot for appliance by user. We can then
calculate the total load by  user.
, t T (7)
In our proposed model, main task of AS is to determine
an optimum time slot in  user’s smart meter for the
individual appliance. In this way, user can shape its
daily load profile by making use of equation (7). It is
important to mention here that energy scheduler does not
aim to reduce power consumption of different appliances
rather it shifts to other different time slots for minimization
of PAR and energy cost. Initially, a user needs to initiate
start and end time slot in which a particular appliance is
supposed to complete its task. Let beginning time slot be
represented by
  and end time slot is represented
  and
 
Table 1. Appliance parameters
Appliances Lot
Washing machine 20 1.0 Uninterruptible
Clothes dryer
Electric vehicle 36 2.0 Interruptible
Vacuum cleaner
Water heater
Dish washer
Air conditioner
Microwave oven
For example, an electrical vehicle (EV) having
 needs 4 hours to complete its charging cycle for 50
km driving range in a single day. For compiling task, a
user must select a larger time slot because in case of any
interruption, scheduler completes the task by its end time.
For example, the user may select
 and
 . Mathematically, it is
represented as
 
represents energy consumption vector of
appliance a during t time slot by u. Also, from equation
(8), it is concluded that appliance a schedules balances
according to daily consumption requirement. Similarly,
total energy consumption by all appliances and by all users
can be summed up.
 
Since electronic devices are divided into base, interruptible
and uninterruptible smart appliances, so in case of
uninterruptible appliances strict energy consumption
needs to be adopted. In our case, washing machine (WM)
and clothes dryer (CD) have constraints that once WM task
ends, CD must start its operation immediately. In that case,
 for WM and
= 0 for CD. Similarly, a
refrigerator is on all the time, so in that case
 for
WM and
= 96. Generally, a scheduler has no active
impact on the operation of the non-interruptible
appliances. For a complete energy consumption profile,
standby power of interruptible appliances needs to be
calculated. It is the power which is consumed by
interruptible appliances when they are in idle mode. we
need to calculate minimum
) and maximum
) standby power level for interruptible
appliances. Standby power can be assumed to be such
power which a device is consuming when it is in non
operation mode but ready to start its operation. We can
assume it as:
 
 
We are now ready to calculate different optimal energy
scheduling model by considering equations (1)-(10) in our
proposed hybrid
DSM model.
Traditional optimization methods like integer linear
programming (ILP), mixed integer programming (MILP)
and mixed integer nonlinear programming (MINLP) are
unable to control large number of appliances.
Furthermore, these methods are computationally
inefficient and hence not suitable for real time
optimization, which is deterministic in nature. Instead, the
meta-heuristic optimization technique can provide a best
solution while considering user defined constraints. We
are applying genetic algorithm (GA), grey wolf
optimization (GWO) method and a hybrid of both
techniques to achieve real time optimal results.
GA is inspired from the genes of living organisms.
Initially, binary coded chromosomes are randomly
initialized. Total number of smart appliances are
represented by the length of chromosomes’ and smart
appliances ON/OFF status is identified through
chromosomes binary coded pattern. Once the initial
population is generated, fitness function of GA is
evaluated which is actually an objective function of this
study. Mutation and crossover are performed to generate
new population. Generated population fitness function is
then compared with the previous one and hence, optimum
results are achieved.
On the other hand, GWO algorithm is based on grey
wolves hunting and leadership hierarchy mechanism.
Alpha, beta, delta and omega are four kinds of wolves in
leadership hierarchy. For performing optimization
hunting, searching, encircling and attacking, prey steps are
implemented. In this way, position of the search agents are
updated in the form of position vector towards prey.
Search agents update its position until it reaches to an
optimal position in n-dimensional search space.
The purpose of proposing the hybrid technique is to
achieve a balance between global search and local search.
GA performs well in terms of exploration mode. Also, it
has good convergence rate to reach to optimal solution.
Initially, GA steps are followed for generating initial
population of chromosomes. These chromosomes actually
represent candidate solution to the problem. Furthermore,
a bit of chromosomes represents the ON/OFF state of the
smart appliances. Fitness function is based on objective
function, taken from GWO. The best population is
regenerated through velocity updating step of GWO.
Firstly, it finds a local best solution and on the basis of this
value, it achieves a global best solution. Through an
optimal stopping rule, the cost minimization problem can
be formulated and the best fit value is thus chosen. Based
on crossover and mutation, a new stream of is generated.
Hence new generation population is created which has
completely different characteristics as compared to the
initial generation.
In this section, we present simulation results and assess
the performances of the proposed algorithms. By making
RTP signal for DSM, PAR reduction, cost minimization
and load balancing are key features to be analyzed. The
cost, load and waiting time for each group is represented
in terms of cents, hours and kWh. Fig. 2 shows the load on
grid for a single home using all three approaches according
to RTP. In RTP tariffs, electricity price changes during
different times of a single day. Particularly prices are
higher in the afternoon, hot summer days and cold winter
days. Fig. 3 clearly demonstrates that during the high price
rate hours, if demand is high, then unscheduled load
creates high peaks as compared to the scheduled load. Due
to this reason, electricity cost of unscheduled load is high.
It also depicts that without affecting the overall load, the
proposed fitness function has a greatest effectiveness on
cost and PAR reduction.
Moreover, load profile during multiple time slots for a
complete day is shown in Fig. 4. It demonstrates that the
proposed hybrid model outperforms the GA and GWO
models in terms of load shifting to off-peak hours; hence
reduction can be many folds in terms of PAR and cost. Fig.
4 illustrates the cost in different time slots during the day,
the consumption pattern by GWO and GA during the peak
price is high as compared to the hybrid
approach. This
affects the overall cost per day for aforementioned
approaches as shown in Fig. 5. It clearly shows that price
using hybrid
is low as compared to GA and GWO.
Using the hybrid
, the proposed approach reduces 20%
cost, which is the best among all three used approaches
Fig. 2 Load profiles
Fig. 3 Energy cost during the time slots
Fig. 4 Cost in different time slots over the day
PAR results are shown in Fig. 6, where the
unscheduled load is very high and for the hybrid
it is
commendable. This shows adeptness of the proposed
approach which is better than GA and GWO. In this case,
about 50% PAR is reduced by hybrid
. While
addressing the cost and PAR, waiting time of different
appliances cannot be overlooked; this is highlighted in Fig.
7. Waiting time has a direct relationship and impact on user
comfort and it is an important parameter for efficiency
measurement in any proposed scheme. It shows that
waiting time for base load appliances for GA and GWO is
higher as compared to the hybrid
Fig. 5 Total cost under different approaches
Fig. 6 PAR under different schemes
Fig. 7 Waiting time for the different approaches
During the simulation, we perceived that GA is best for
maximum number of populations. With the increase in
number of population and generation step, difference
among the lowest and highest point becomes negligible.
On the other hand, GWO shows high performance for
small population under hundred intervals. Fig. 5 and Fig.
6 show that GA outperforms GWO in terms of cost
reduction, peak reduction and PAR. The hybrid
positive influence on both approaches by lowering PAR,
cost and peak load values.
In this paper, we have presented an effective approach
for load management by shifting or balancing home
appliances in an optimum way. The main idea is to
facilitate consumers to reduce electricity cost. From the
simulated results, it is observed that considerable saving in
energy costs can be realized by consumers. To facilitate
consumers, artificial intelligence based optimization
technique is adopted. The results show that through a
carefully designed appliance scheduling model, users can
offer a viable solution to optimal power management
among residential energy users. The proposed approach is
based on a hybrid GA and GWO.
It clearly demonstrates that the hybrid approach
outperforms the GA and GWO. The load is balanced in
such a way that not only load peaks are avoided but also
user comfort is less compromised. It is worth mentioning
that there exists the tradeoff between cost and PAR. Since
cost is minimized at certain time extents the load to off-
peak hours using the proposed model, resulting in
maximizing PAR. Results show the effectiveness of the
proposed hybrid model in terms of cost minimization.
Future work will consider integration and testing RES
along with real-time pricing signal.
The authors would like to acknowledge the funding
support from Lancaster University, UK and COMSATS
University, Pakistan.
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... The local scheduler allocates each task with identity number. The LS runs a script having an ID with range that is changed from the default LS scripts with End-point Management [9,10]. ...
... In this each part of the GS sets priority to the jobs. By using a mapping such priorities are associated with global priorities [9,10]. ...
... The idea is as follows. The local schedular uses local heuristics which assign the resources locally [9]. If the resources are available in the near locality then the resources are allotted for the computation. ...
Full-text available
In recent year, the number of cell phones in the society has increased drastically and they are getting popular due to their computational ability and adaptability. Resource provisioning is an important, but still remains NP hard problem in mobile computational grid. Once the jobs are assigned to the mobile computational grid, the main challenge is how to identify the correct resource according to the job’s requirement and use them to execute the sub-jobs. The heuristic methods such as Min-Min, Max-Min and HEFT can be used to select appropriate resources from Mobile computational grid that is assigned for job execution. Since the computational nodes are static and mobile in nature, the performance of such heuristics is not as expected. Such heuristics suffers from the low throughput and low speedup. The process of localization is used in wireless sensor network with good results. The proposed model uses heuristics and localization process for optimizing the quality of service parameter localization, normalized speedup and throughput in MCG with the concept of grid nodes available in mobile computational grid. The observation shows significant improvement in quality of service parameter localization, normalized speedup and throughput in MCG. The proposed model HGLA and MIN-MIN, MAX-MIN, and HEFT are compared with respect to localization, speedup and throughput. The results reveal that proposed model shows better performance over MIN-MIN, MAX-MIN and HEFT.
... They discovered that changing loads from peak to off-peak hours can cut electricity bills. Authors of [20] presented two heuristics to lower the PAR. Due to the 2-Dimensional (2D) packing issue, these techniques are known as G-MinPeak and Level Match. ...
... [19] 2018 Energy harvesting is minimized. [20] 2018 Balancing property is achieved by deploying the optimization quickly to calculate the impact in real-time. [21] 2014 Load is balanced [22] 2008 ...
... The GA and Grey Wolf Optimization (GWO) algorithms are proposed in [54]. The aim of these proposed algorithms in this work is to minimize the peak load of SHs. ...
... SHEM [51] electricity cost is minimized They cannot consider PAR and CC in their proposed work BPSO, GA and Cuckoo search [52] to reduce the peak load and electricity price Still, the electricity bill can be reduced further GA and PSO [53] reduction of peak during peak hours and it also affects the electricity bill the CC is compromised GA and Grey Wolf Optimization (GWO) [54] reduction in the load and electric bill the performance is decreased MILP [55] Made system more efficient and gives the offer of to use electricity in fewer rates in specific hours ...
The energy demand is increasing every day due to the huge amount of residential appliance’s energy consumption. As the energy demand for consumption is comparably higher than the generation of energy, which produce the shortage of energy. Industrial and commercial areas are also consuming large amount of energy, however residential energy demand is more flexible as compared to other two. Many of the existing schemes are developed to fulfill the consumer demand. Nowadays, many of the techniques are presented for scheduling of residential appliances to reduce the Peak to Average Ratio (PAR) and consumer delay time. However, they did not consider the total cost of electricity and waiting time for the consumer. This critical issue has been resolved by Demand Side Management (DSM) in the Smart Grid (SG), Smart Home (SH) is considered to manage with many solutions. Home Energy Management System (HEMS) is able to use different kind of meta-heuristic techniques for scheduling of home appliances. In this thesis, we reduce the cost through load shifting techniques. In order to achieve above objective, we employed some feature of Jaya Algorithm (JA) on Bat Algorithm (BA) to develop Candidate Solution Updation Algorithm (CSUA). Simulation was conducted to compare the result of existing BA and JA for single smart home with 15 smart appliances. We used Time of Use (ToU) and Critical Peak Price (CPP) for electricity cost estimation. The result depicts that successful achievement of load shifting from higher price time slot to lower price time slot, which basically bring out the reduction in electricity bills. In this thesis, we also proposed our another meta-heuristic algorithm Runner Updation Optimization Algorithm (RUOA) to arrange the consumption behavior of residential appliances. We compared the results of our scheme with other meta-heuristic algorithms Strawberry Algorithm (SBA) and Firefly Algorithm (FA). CPP and Real Time Price (RTP) are the two electricity pricing scheme that we used in this thesis to calculate cost of electricity. The main objective of this thesis is to reduce the electricity cost and PAR. However, consumer comfort is not satisfied. Afterward, when our system done with an efficient optimization at consumption side, then come across the area of utility to generate electricity with better and accurate prediction of their price. Like in the electricity market, electricity price has some complicated features like high volatility, non-linearity and non-stationarity that make very difficult to predict the accurate price. However, it is necessary for markets and companies to predict accurate electricity price. In this paper, we enhanced the forecasting accuracy by combined approaches of Kernel Extreme Learning Machine (KELM) and Autoregression Moving Average (ARMA) along with unique and enhanced features of both models. Wavelet transform is applied on prices series to decompose them, afterward test has performed on decomposed series for providing stationary series to AMRA-model and non-stationary series to KELM-model. At the end series are tuned with our combine approach of enhanced price prediction. The performance of our enhanced combined method is evaluated by electricity price dataset of New South Wales (NSW), Australian market. The simulation results show that combined method has more accurate prediction than individual methods.
... Ref [13] examined the most effective operating strategies in microgrids using the enhanced swarm optimization algorithms and adaptive evolutionary algorithms. Ref [14] examined the optimum planning method for domestic devices, utilizing the DAP signals in the smart home. With the algorithm, optimal costs are reduced by 22.6%, and normal prices are reduced by 11.7%. ...
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The use of smart grids has enabled a number of planning methods to be developed to optimize energy costs, Peak to Average Ratios (PARs), and consumer satisfaction for load management in industrial, commercial, and domestic sectors. From a technical point of view, achieving optimal outcomes requires Demand Side Management (DSM). In smart grids, utility companies and electric users communicate two-way using digital technology to make a sustainable and economic system. This paper proposes a novel framework within which an Energy Management Controller (EMC) keeps track of each appliance, its operational time, and the costs associated with them. Customers of smart grids are motivated to shift their Off-Peak Hours (OPH) from Peak Hours by presenting incentives in OPH. The metering devices would also save customers costs by preventing load shifting between high- and low-cost periods. In addition, the study proposes the bacterial foraging algorithm and grasshopper optimization algorithm for lessening power price and PAR without compromising user comfort (UC) through appliance planning. The simulation results on a practical test system advocate the high effectiveness and reliable performance of the proposed model.
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As the energy demand for consumption is comparably higher than the generation of energy, which produce the shortage of energy. Many new schemes are being developed to fulfill the energy consumer demand. In this paper, we proposed our meta-heuristic algorithm Runner Updation Optimization Algorithm (RUOA) to schedule the consumption pattern of residential appliances. We compared the results of our scheme with other meta-heuristic algorithm Strawberry Algorithm (SBA) and Firefly Algorithm (FA). Critical Peak Price (CPP) and Real Time Price (RTP) are the two electricity pricing scheme that we used in this paper for calculation of electricity cost. The main objective of this paper is to minimize the electricity cost and Peak to Average Ratio (PAR). However, consumer comfort is not satisfied.
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In this paper, we design a controller for home energy management based on following meta-heuristic algorithms: teaching learning-based optimization (TLBO), genetic algorithm (GA), firefly algorithm (FA) and optimal stopping rule (OSR) theory. The principal goal of designing this controller is to reduce the energy consumption of residential sectors while reducing consumer’s electricity bill and maximizing user comfort. Additionally, we propose three hybrid schemes OSR-GA, OSR-TLBO and OSR-FA, by combining the best features of existing algorithms. We have also optimized the desired parameters: peak to average ratio, energy consumption, cost, and user comfort (appliance waiting time) for 20, 50, 100 and 200 heterogeneous homes in two steps. In the first step, we obtain the optimal scheduling of home appliances implementing our aforementioned hybrid schemes for single and multiple homes while considering user preferences and threshold base policy. In the second step, we formulate our problem through chance constrained optimization. Simulation results show that proposed hybrid scheduling schemes outperformed for single and multiple homes and they shift the consumer load demand exceeding a predefined threshold to the hours where the electricity price is low thus following the threshold base policy. This helps to reduce electricity cost while considering the comfort of a user by minimizing delay and peak to average ratio. In addition, chance-constrained optimization is used to ensure the scheduling of appliances while considering the uncertainties of a load hence smoothing the load curtailment. The major focus is to keep the appliances power consumption within the power constraint, while keeping power consumption below a pre-defined acceptable level. Moreover, the feasible regions of appliances electricity consumption are calculated which show the relationship between cost and energy consumption and cost and waiting time.
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In Smart Grid (SG), integration of renewable energy sources such as solar and wind is a challenging task due to their intermittent nature. Most of the existing Demand Side Management (DSM) techniques are based on Day Ahead Pricing (DAP) or Time of Use (TOU) pricing which can deviate from Real Time Pricing (RTP) due to unpredictable energy consumption trends and electricity prices. This paper presents opportunistic scheduling algorithms in a RTP environment based on Optimal Stoping Rule (OSR). We classify different users and assign priorities based on energy demand. In order to minimize the electricity bill and appliance waiting time cost, we modify the First Come First Serve (FCFS) scheduling algorithm. Regarding comfort maximization, Priority Enable Early Deadline First (PEEDF) scheduling algorithm is proposed which schedules the appliances based on minimum length of operation time and priority constraints. Simulation results validate the effectiveness of the proposed algorithms in terms of electricity cost reduction and user comfort maximization.
Traditional power grid and its demand-side management (DSM) techniques are centralized and mainly focus on industrial consumers. The ignorance of residential and commercial sectors in DSM activities degrades the overall performance of a conventional grid. Therefore, the concept of DSM and demand response (DR) via residential sector makes the smart grid (SG) superior over the traditional grid. In this context, this paper proposes an optimized home energy management system (OHEMS) that not only facilitates the integration of renewable energy source (RES) and energy storage system (ESS) but also incorporates the residential sector into DSM activities. The proposed OHEMS minimizes the electricity bill by scheduling the household appliances and ESS in response to the dynamic pricing of electricity market. First, the constrained optimization problem is mathematically formulated by using multiple knapsack problems, and then solved by using the heuristic algorithms; genetic algorithm (GA), binary particle swarm optimization (BPSO), wind driven optimization (WDO), bacterial foraging optimization (BFO) and hybrid GA-PSO (HGPO) algorithms. The performance of the proposed scheme and heuristic algorithms is evaluated via MATLAB simulations. Results illustrate that the integration of RES and ESS reduces the electricity bill and peak-to-average ratio (PAR) by 19.94% and 21.55% respectively. Moreover, the HGPO algorithm based home energy management system outperforms the other heuristic algorithms, and further reduces the bill by 25.12% and PAR by 24.88%.
In this paper, we comparatively evaluate the performance of home energy management controller which is designed on the basis of heuristic algorithms; genetic algorithm (GA), binary particle swarm optimization (BPSO) and ant colony optimization (ACO). In this regard, we introduce a generic architecture for demand side management (DSM) which integrates residential area domain with smart area domain via wide area network. In addition, problem formulation is carried via multiple knapsack problem. For energy pricing, combined model of time of use tariff and inclined block rates is used. Simulation results show that all designed models for energy management act significantly to achieve our objections and proven as a cost-effective solution to increase sustainability of smart grid. GA based energy management controller performs more efficiently than BPSO based energy management controller and ACO based energy management controller in terms of electricity bill reduction, peak to average ratio minimization and user comfort level maximization.
This paper studies the power scheduling problem for residential consumers in smart grid. In general, the consumers have two types of electric appliances. The first type of appliances have flexible starting time and work continuously with a fixed power. The second type of appliances work with a flexible power in a predefined working time. The consumers can adjust the starting time of the first type of appliances or reduce the power consumption of the second type of appliances to reduce the payments. However, this will also incur discomfort to the consumers. Assuming the electricity price is announced by the service provider ahead of time, we propose a power scheduling strategy for the residential consumers to achieve a desired trade-off between the payments and the discomfort. The power scheduling is formulated as an optimization problem including integer and continuous variables. An optimal scheduling strategy is obtained by solving the optimization problem. Simulation results demonstrate that the scheduling strategy can achieve a desired tradeoff between the payments and the discomfort.
In this paper, an algorithm for energy management system (EMS) based on multi-layer ant colony optimization (EMS-MACO) is presented to find energy scheduling in Microgrid (MG). The aim of study is to figure out the optimum operation of micro-sources for decreasing the electricity production cost by hourly day-ahead and real time scheduling. The proposed algorithm is based on ant colony optimization (ACO) method and is able to analyze the technical and economic time dependent constraints. This algorithm attempts to meet the required load demand with minimum energy cost in a local energy market (LEM) structure. Performance of MACO is compared with modified conventional EMS (MCEMS) and particle swarm optimization (PSO) based EMS. Analysis of obtained results demonstrates that the system performance is improved also the energy cost is reduced about 20% and 5% by applying MACO in comparison with MCEMS and PSO, respectively. Furthermore, the plug and play capability in real time applications is investigated by using different scenarios and the system adequate performance is validated experimentally too.
Conference Paper
We propose a method about power consumption scheduling for shaving peak load at home area using linear programming technique. Problems caused by peak load such as blackout and rolling blackout has occurred recently in the world because hourly peak load consumption is increased rapidly in the same time. So to solve these problems is using ESS. Especially, the most effective method is to utilize ESS and V2G. Electricity of the battery of parked PHEV at home area transmits through V2G to the ESS. The stored electricity in the ESS is optimized by using linear programming. This optimization reduces the hourly peak load consumption.
This paper proposes a novel load management solution for coordinating the charging of multiple plug-in electric vehicles (PEVs) in a smart grid system. Utilities are becoming concerned about the potential stresses, performance degradations and overloads that may occur in distribution systems with multiple domestic PEV charging activities. Uncontrolled and random PEV charging can cause increased power losses, overloads and voltage fluctuations, which are all detrimental to the reliability and security of newly developing smart grids. Therefore, a real-time smart load management (RT-SLM) control strategy is proposed and developed for the coordination of PEV charging based on real-time (e.g., every 5 min) minimization of total cost of generating the energy plus the associated grid energy losses. The approach reduces generation cost by incorporating time-varying market energy prices and PEV owner preferred charging time zones based on priority selection. The RT-SLM algorithm appropriately considers random plug-in of PEVs and utilizes the maximum sensitivities selection (MSS) optimization. This approach enables PEVs to begin charging as soon as possible considering priority-charging time zones while complying with network operation criteria (such as losses, generation limits, and voltage profile). Simulation results are presented to demonstrate the performance of SLM for the modified IEEE 23 kV distribution system connected to several low voltage residential networks populated with PEVs.