This paper presents a new control strategy for optimal energy consumption in microgrids based on forecasting and load shedding method. In islanded mode, only local generation resources are usable. In this mode, the availability of resources is very influenced by meteorological factors. In order to achieve a high availability of energy, microgrid has to satisfy high requirements on intelligent power management. The main objective of this study is to develop a control based on the forecast of production and the priority of loads to ensure high availability of electrical power for critical loads. A mathematical model for the proposed strategy is developed. The simulation of this model on Matlab Simulink for different cases of microgrid topology (sources and loads) shows clearly a high improvement of degree of availability of electrical power supply distribution in microgrid.
Multi agent oriented solution for forecasting-based control strategy with loa...Mohamed Ghaieth Abidi
To improve the power supply availability in an island microgrid, this paper proposes a new approach that integrates distributed energy sources economically, reliably and efficiently. In an island mode, a microgrid must ensure its self-sufficiency of energy production since it cannot make an energetic exchange with a main grid. However, in this mode, the random behavior of the resources affected by meteorological factors presents a major constraint. The challenge related to the power availability in microgrids is to find a solution that faces the operation of intermittent power sources. The microgrid should guarantee a useful power management in order to achieve a high availability of energy. In this paper, we present a mathematical model to describe the influence of the meteorological factors on the sources production. We propose a multi-agent control strategy based on the production forecasting and load shedding for a high availability of the microgrid power supply. The proposed multi-agent system uses the master-slave model in which the communication and negotiation between the defined agents are performed by a concept of tokens. The developed control system is implemented on Spartan 6 FPGA-Board. The paper's contribution is applied to a Tunisian petroleum platform where several blackouts are recorded between 2012 and 2014. Simulation and experimental results show clearly a high availability as a performance of the proposed control strategy.
Stochastic control for optimal power flow in islanded microgridIJECEIAES
The problem of optimal power flow (OPF) in an islanded mircrogrid (MG) for hybrid power system is described. Clearly, it deals with a formulation of an analytical control model for OPF. The MG consists of wind turbine generator, photovoltaic generator, and diesel engine generator (DEG), and is in stochastic environment such as load change, wind power fluctuation, and sun irradiation power disturbance. In fact, the DEG fails and is repaired at random times so that the MG can significantly influence the power flow, and the power flow control faces the main difficulty that how to maintain the balance of power flow? The solution is that a DEG needs to be scheduled. The objective of the control problem is to find the DEG output power by minimizing the total cost of energy. Adopting the Rishel’s famework and using the Bellman principle, the optimality conditions obtained satisfy the Hamilton-Jacobi-Bellman equation. Finally, numerical examples and sensitivity analyses are included to illustrate the importance and effectiveness of the proposed model.
Transient Stability Assessment of Hybrid Distributed Generation Using Facts D...IJMERJOURNAL
ABSTRACT: Due to increasing integration of new technologies into the grid such as hybrid electric vehicles, distributed generations, power electronic interface circuits, advanced controllers etc., the present power system network is now more complex than in the past. Consequently, the recent rate of blackouts recorded in some parts of the world indicates that the power system is stressed. The real time/online monitoring and prediction of stability limit is needed to prevent future blackouts. The aggravated increase in energy demand has posed a serious problem for the power system’s stability and reliability, and hence has become of major concern. The shortcomings of conventional source of energy have paved way for renewable energy sources. The latter can form a part of a standalone system or grid connected system. A single renewable source of energy When integrated with other sources of energy it is termed as hybrid system. This thesis deals with PV, Wind, Hydro system. In this thesis an active power control strategy has been developed such that when the wind alone is not able to meet the energy demand, without compromising the frequency a transition occurs to wind diesel mode so that the energy demand is met. The mathematical model considered uses a STATCOM to meet the reactive power need upon sudden step change in power. The performance and the analysis is done in a user friendly MATLAB/Simulink environment.
Integration Planning and Operation Scheduling of Distribution Generation for ...IJERA Editor
Use of distributed renewable energy sources for domestic energy consumption will increase in near future due to
its advantages as being clean and infinite energy generation possibility. This trend allows more efficient energy
consumption because of reducing distribution losses and dependence of domestic appliances to grid distribution.
Electrical energy is an essential ingredient for the development of a nation. In this paper, it is proposed grid
connected solar PV without and with battery at domestic level to minimize the load on live grid during peak
time, excess power export to the grid when the PV generation is more compared to connected load and increase
the participation of renewable energy sources in our daily energy consumption. The decision support program
enables the consumer to implement the most efficient electricity management strategy while achieving the goal
of minimizing the electricity bill and to supply the quality power. The cost of investment and payback periods
are computed for PV system using cost benefit analysis
This paper discusses about a LabVIEW based controller for the hybrid renewable energy system operated AC-DC microgrid with the major objectives of: i) predicting the power generation potential of the solar–PV and wind generators ii) effective power management iii) load scheduling based on the available power with the renewable sources and iv) grid/islanding mode of operation of the microgrid. In order topredict the output power of wind generator and Solar-PV system, an artificial neural network is developed.The laboratory-scale model of three phase, 400 V, 10 kVA microgrid structure is developed at National Institute of Technology Calicut, India. The developed LabVIEW based controller has been tested successfully for a real-time load and source in the laboratory environment. Test results show that the designed controller is effectively managing the output powerof the primary energy sources under different scenarios.
optimization of the managed electrical energy within a hybrid renewable energ...INFOGAIN PUBLICATION
Hybrid energy applications based on renewable energy sources are becoming more and more desirable every day. They have increased the economic attractiveness of renewable electric energy generation. Because of the sudden fluctuations of the load requirements, the main attribute of such Hybrid Systems is to be able to generate energy at any time by optimally using each source. In this article, we have proposed a combination between a sizing study and a control one for the aim of solving the complex optimization problem of finding the optimal combination of size and storage to make the best use of the renewable power generations and to become more independent of rising electricity costs. Additionally, an improvement in the induced optimization algorithm is introduced in this paper so as to compute the optimal size and the operation control of the system with the aim of minimizing as much as possible the cost while responding to the load energy requirements taking into account the environmental factors.
Performance analysis of grid-tied photovoltaic system under varying weather c...IJECEIAES
Model and simulation of the impact of the distribution grid-tied photovoltaic (PV) system feeding a variable load with its control system have been investigated in this study. Incremental Conductance (IncCond) algorithm based on maximum power point tracking (MPPT) was implemented for the PV system to extract maximum power under different weather conditions when solar irradiation varies between 250 W/m 2 and 1000 W/m 2 . The proposed system is modelled and simulated with MATLAB/Simulink tools. Under different weather conditions, the dynamic performance of the PV system is evaluated. The results obtained show the efficacy of the proposed MPPT method in response to rapid daytime weather variations. The results also show that the surplus power generated is injected into the grid when the injected power from the PV system is higher than the load demand; otherwise, the grid supplies the load.
Multi agent oriented solution for forecasting-based control strategy with loa...Mohamed Ghaieth Abidi
To improve the power supply availability in an island microgrid, this paper proposes a new approach that integrates distributed energy sources economically, reliably and efficiently. In an island mode, a microgrid must ensure its self-sufficiency of energy production since it cannot make an energetic exchange with a main grid. However, in this mode, the random behavior of the resources affected by meteorological factors presents a major constraint. The challenge related to the power availability in microgrids is to find a solution that faces the operation of intermittent power sources. The microgrid should guarantee a useful power management in order to achieve a high availability of energy. In this paper, we present a mathematical model to describe the influence of the meteorological factors on the sources production. We propose a multi-agent control strategy based on the production forecasting and load shedding for a high availability of the microgrid power supply. The proposed multi-agent system uses the master-slave model in which the communication and negotiation between the defined agents are performed by a concept of tokens. The developed control system is implemented on Spartan 6 FPGA-Board. The paper's contribution is applied to a Tunisian petroleum platform where several blackouts are recorded between 2012 and 2014. Simulation and experimental results show clearly a high availability as a performance of the proposed control strategy.
Stochastic control for optimal power flow in islanded microgridIJECEIAES
The problem of optimal power flow (OPF) in an islanded mircrogrid (MG) for hybrid power system is described. Clearly, it deals with a formulation of an analytical control model for OPF. The MG consists of wind turbine generator, photovoltaic generator, and diesel engine generator (DEG), and is in stochastic environment such as load change, wind power fluctuation, and sun irradiation power disturbance. In fact, the DEG fails and is repaired at random times so that the MG can significantly influence the power flow, and the power flow control faces the main difficulty that how to maintain the balance of power flow? The solution is that a DEG needs to be scheduled. The objective of the control problem is to find the DEG output power by minimizing the total cost of energy. Adopting the Rishel’s famework and using the Bellman principle, the optimality conditions obtained satisfy the Hamilton-Jacobi-Bellman equation. Finally, numerical examples and sensitivity analyses are included to illustrate the importance and effectiveness of the proposed model.
Transient Stability Assessment of Hybrid Distributed Generation Using Facts D...IJMERJOURNAL
ABSTRACT: Due to increasing integration of new technologies into the grid such as hybrid electric vehicles, distributed generations, power electronic interface circuits, advanced controllers etc., the present power system network is now more complex than in the past. Consequently, the recent rate of blackouts recorded in some parts of the world indicates that the power system is stressed. The real time/online monitoring and prediction of stability limit is needed to prevent future blackouts. The aggravated increase in energy demand has posed a serious problem for the power system’s stability and reliability, and hence has become of major concern. The shortcomings of conventional source of energy have paved way for renewable energy sources. The latter can form a part of a standalone system or grid connected system. A single renewable source of energy When integrated with other sources of energy it is termed as hybrid system. This thesis deals with PV, Wind, Hydro system. In this thesis an active power control strategy has been developed such that when the wind alone is not able to meet the energy demand, without compromising the frequency a transition occurs to wind diesel mode so that the energy demand is met. The mathematical model considered uses a STATCOM to meet the reactive power need upon sudden step change in power. The performance and the analysis is done in a user friendly MATLAB/Simulink environment.
Integration Planning and Operation Scheduling of Distribution Generation for ...IJERA Editor
Use of distributed renewable energy sources for domestic energy consumption will increase in near future due to
its advantages as being clean and infinite energy generation possibility. This trend allows more efficient energy
consumption because of reducing distribution losses and dependence of domestic appliances to grid distribution.
Electrical energy is an essential ingredient for the development of a nation. In this paper, it is proposed grid
connected solar PV without and with battery at domestic level to minimize the load on live grid during peak
time, excess power export to the grid when the PV generation is more compared to connected load and increase
the participation of renewable energy sources in our daily energy consumption. The decision support program
enables the consumer to implement the most efficient electricity management strategy while achieving the goal
of minimizing the electricity bill and to supply the quality power. The cost of investment and payback periods
are computed for PV system using cost benefit analysis
This paper discusses about a LabVIEW based controller for the hybrid renewable energy system operated AC-DC microgrid with the major objectives of: i) predicting the power generation potential of the solar–PV and wind generators ii) effective power management iii) load scheduling based on the available power with the renewable sources and iv) grid/islanding mode of operation of the microgrid. In order topredict the output power of wind generator and Solar-PV system, an artificial neural network is developed.The laboratory-scale model of three phase, 400 V, 10 kVA microgrid structure is developed at National Institute of Technology Calicut, India. The developed LabVIEW based controller has been tested successfully for a real-time load and source in the laboratory environment. Test results show that the designed controller is effectively managing the output powerof the primary energy sources under different scenarios.
optimization of the managed electrical energy within a hybrid renewable energ...INFOGAIN PUBLICATION
Hybrid energy applications based on renewable energy sources are becoming more and more desirable every day. They have increased the economic attractiveness of renewable electric energy generation. Because of the sudden fluctuations of the load requirements, the main attribute of such Hybrid Systems is to be able to generate energy at any time by optimally using each source. In this article, we have proposed a combination between a sizing study and a control one for the aim of solving the complex optimization problem of finding the optimal combination of size and storage to make the best use of the renewable power generations and to become more independent of rising electricity costs. Additionally, an improvement in the induced optimization algorithm is introduced in this paper so as to compute the optimal size and the operation control of the system with the aim of minimizing as much as possible the cost while responding to the load energy requirements taking into account the environmental factors.
Performance analysis of grid-tied photovoltaic system under varying weather c...IJECEIAES
Model and simulation of the impact of the distribution grid-tied photovoltaic (PV) system feeding a variable load with its control system have been investigated in this study. Incremental Conductance (IncCond) algorithm based on maximum power point tracking (MPPT) was implemented for the PV system to extract maximum power under different weather conditions when solar irradiation varies between 250 W/m 2 and 1000 W/m 2 . The proposed system is modelled and simulated with MATLAB/Simulink tools. Under different weather conditions, the dynamic performance of the PV system is evaluated. The results obtained show the efficacy of the proposed MPPT method in response to rapid daytime weather variations. The results also show that the surplus power generated is injected into the grid when the injected power from the PV system is higher than the load demand; otherwise, the grid supplies the load.
COORDINATED CONTROL AND ENERGY MANAGEMENT OF DISTRIBUTED GENERATION INVERTERS...ijiert bestjournal
In modern world,our entire life moves around Computers. Most of our tasks are dependent on the Computers,like Communication,Ticket Reservations,Researches,Printing,and Education etc. When we communicate with each other by using Computers through E Mails,a number of Computers are used for this purpose and the collection of these computers forms a network,which is called a Computer Network. As more and more peoples are going to be connected through the general network (INTERNET),the problem of security arises. Now a day,a number of security issues occur in networks which include Sniffing,Spoofing,Security Attacks,Malwares,Unauthorized Access,etc. This will create havoc for the users,who wants to communicate with each other through these networks. So,to make the communication between two users via the Computer Networks,we have to follow some security measures,which include using the Firewalls,Anti Malicious Software,Intrusion Detection Systems,Cryptography Techniques,et c. This paper is basically focused on how the communication between two users has been performed by using Computer Networks and how to make such a communication
Source resizing and improved power distribution for high available island mic...Mohamed Ghaieth Abidi
A microgrid is a small-scale smart network that contains distributed resources and loads and serves several technical, economic, and environmental aims. In this kind of power system, the energy generated by different sources is often collected in an adequate bus system (ac or dc busses) and transported to loads across a distribution system. In case of islanding operation of a microgrid, each production insufficiency or distribution system fault can cause a partial or total interruption of power supply required by loads of the microgrid. This unavailability can last longer because of the randomness and intermittent behavior of renewable sources and the importance of the maintenance actions of the distribution system. To guarantee high availability of power supply, microgrid must be able to produce and to transfer the power energy requested by loads. The sizing of distributed sources and the design of the distribution system present an important challenge to achieve this goal. This paper offers a new global methodology carried out in two steps: in the first, it aims to optimize the source sizing by adding some microsources for ensuring the balance between sources production and loads requirement, then, in a second step, it aims to enhance the distribution system design by the creation of new paths of power transmission for transferring the produced energy from sources to loads. The proposed optimization methodology aims to achieve the requested availability rate requested by each load (considering their priorities) by taking into account some technical and economic factors. In this methodology based on genetic algorithms, objective functions are defined, and several electrical and economic constraints are formulated. The graph theory is used to represent the architecture of the microgrid distribution system, and Matpower tool of MATLAB is used to model it. An application and implementation of the proposed optimization methodology in a Tunisian petroleum platform indicate that the proposed solution is efficient in optimizing of power supply availability in its microgrid.
Sampling-Based Model Predictive Control of PV-Integrated Energy Storage Syste...Power System Operation
This paper proposes a novel control solution designed to solve the local and grid-connected
distributed energy resources (DERs) management problem by developing a generalizable framework capable
of controlling DERs based on forecasted values and real-time energy prices. The proposed model uses
sampling-based model predictive control (SBMPC), together with the real-time price of energy and forecasts
of PV and load power, to allocate the dispatch of the available distributed energy resources (DERs) while
minimizing the overall cost. The strategy developed aims to nd the ideal combination of solar, grid, and
energy storage (ES) power with the objective of minimizing the total cost of energy of the entire system.
Both ofine and controller hardware-in-the-loop (CHIL) results are presented for a 7-day test case scenario
and compared with two manual base test cases and four baseline optimization algorithms (Genetic Algo-
rithm (GA), Particle Swarm Optimization (PSO), Quadratic Programming interior-point method (QP-IP),
and Sequential Quadratic Programming (SQP)) designed to solve the optimization problem considering the
current status of the system and also its future states. The proposed model uses a 24-hour prediction horizon
with a 15-minute control horizon. The results demonstrate substantial cost and execution time savings when
compared to the other baseline control algorithms.
This article presents the system design and prediction performance of a 1kW capacity grid-tied photovoltaic inverter applicable for low or medium-voltage electrical distri-bution networks. System parameters, for instance, the longitude and latitude of the solar plant location, panel orientation, tilt and azimuth angle calculation, feasibility testing, optimal sizing of installment are analyzed in the model and the utility is sim-ulated precisely to construct an efficient solar power plant for residential applications. In this paper, meteorological data are computed to discuss the impact of environmen-tal variables. As regards ensuring reliability and sustenance, a simulation model of the system of interest is tested in the PVsyst software package. Simulation results yield that the optimum energy injected to the national grid from the solar plant, specific pro-duction, and performance ratio are 1676kWh/year, 1552kWh/kWp/year, and 79.29% respectively. Moreover, the predicted carbon footprint reduction is 23.467 tons during the 30 years lifetime of the system. Therefore, the performance assessments affirm the effectiveness of the proposed research.
Optimal Configuration of Wind Farms in Radial Distribution System Using Parti...journalBEEI
Recently, a wide range of wind farm based distributed generations (DGs) are being integrated into distribution systems to fulfill energy demands and to reduce the burden on transmission corridors. The non-optimal configuration of DGs could severely affect the distribution system operations and control. Hence, the aim of this paper is to analyze the wind data in order to build a mathematical model for power output and pinpoint the optimal location. The overall objective is minimization of power loss reduction in distribution system. The five years of wind data was taken from 24o 44’ 29” North, 67o 35’ 9” East coordinates in Pakistan. The optimal location for these wind farms were pinpointed via particle swarm optimization (PSO) algorithm using standard IEEE 33 radial distribution system. The result reveals that the proposed method helps in improving renewable energy near to load centers, reduce power losses and improve voltage profile of the system. Moreover, the validity and performance of the proposed model were also compared with other optimization algorithms.
Concept of Hybrid Energy Storage Systems in Microgridijtsrd
Public awareness of the need to reduce global warming and the significant increase in the prices of conventional energy sources have encouraged many countries to provide new energy policies that promote the renewable energy applications. Such renewable energy sources like wind, solar, hydro based energies, etc. are environment friendly and have potential to be more widely used. Combining these renewable energy sources with back up units to form a hybrid system can provide a more economic, environment friendly and reliable supply of electricity in all load demand conditions compared to single use of such systems. Energy storages Systems ESS present many benefits such as balancing generation and demand, power quality improvement, smoothing the renewable resource's intermittency, and enabling ancillary services like frequency and voltage regulation in microgrid MG operation. Hybrid energy storage systems HESSs characterized by coupling of two or more energy storage technologies are emerged as a solution to achieve the desired performance by combining the appropriate features of different technologies. A single ESS technology cannot fulfill the desired operation due to its limited capability and potency in terms of lifespan, cost, energy and power density, and dynamic response. Hence, different configurations of HESSs considering storage type, interface, control method, and the provided service have been proposed in the literature. This paper comprehensively reviews the state of the art of HESSs system for MG applications and presents a general outlook of developing HESS industry. Important aspects of HESS utilization in MGs including capacity sizing methods, power converter topologies for HESS interface, architecture, controlling, and energy management of HESS in MGs are reviewed and classified. An economic analysis along with design methodology is also included to point out the HESS from investor and distribution systems engineers view. Regarding literature review and available shortcomings, future trends of HESS in MGs are proposed. Priya | Sukhbir Singh "Concept of Hybrid Energy Storage Systems in Microgrid" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25238.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/25238/concept-of-hybrid-energy-storage-systems-in-microgrid/priya
Performance based Comparison of Wind and Solar Distributed Generators using E...Editor IJLRES
Distributed Generation (DG) technologies have become more and more important in power systems. The objective of the paper is to optimize the distributed energy resource type and size based on uncertainties in the distribution network. The three things are considered in stand point of uncertainties are listed as, (i) Future load growth, (ii) Variation in the solar radiation, (iii) Wind output variation. The challenge in Optimal DG Placement (ODGP) needs to be solved with optimization problem with many objectives and constraints. The ODGP is going to be done here, by using Non-dominated Sorting Genetic Algorithm II (NSGA II). NSGA II is one among the available multi objective optimization algorithms with reduced computational complexity (O=MN2). Because of this prominent feature of NSGA II, it is widely applicable in all the multi objective optimization problems irrespective of disciplines. Hence it is selected to be employed here in order to obtain the reduced cost associated with the DG units. The proposed NSGA II is going to be applied on the IEEE 33-bus and the different performance characteristics were compared for both wind and solar type DG units.
An Higher Case Operation and Analysis of a Multiple Renewable Resources Conne...IJERA Editor
In our nation the usage of electricity is increasing day-by-day. According to that conserdations, the generated
power from the non-renewable sources will not satisfy the demands properly. so for these purpose, by using
multiple renewable sources, it will be very useful to some type of dc applications. The power produced from the
individual renewable sources will not be satisfy the demand at all times. So by integration of a multiple
renewable sources such as wind and solar a huge amount of power will be produced. These power will be
coordinated to the ac grid or directly to dc consumers. For integration of renewable sources an aggregated model
has to be proposed. In according to these operation BESS (battery energy storage system)is equipped with the
system for maintaining the power balance. For obtaining the power balance the adaptive droop control technique
has to be proposed and droop curves are evaluated. The droop characteristics are selected on the basis of the
deviation between the optimized and real-time SOC of the BESS. In these paper, the operational analysis can be
performed when real time soc is higher than the optimised soc and droop curves are plotted.
Harvesting in electric vehicles: Combining multiple power tracking and fuel-c...IJECEIAES
Exploitation of green energy sources is essential to diminish the deterioration of our environment. The energy harvesting, represents an alternative to achieve greater range in electric and hybrid vehicles. An energy management strategy (EMS) must be optimized to obtain the best benefits in such vehicles, which is not a trivial task. If harvesting or energy recovery devices are added, the EMS becomes a dual-purpose algorithm: minimizing fuel consumption and maximizing energy harvest through maximum power point tracking (MPPT) controllers. Known studies consider separate EMS, one for traction and another for regenerative braking, without considering harvest devices such as solar panels, regenerative suspension, thermal generators, among others. Furthermore, the electronic power converters used, are not designed to handle such unequal power levels. In this article, an electronic platform to include multiple energy harvesting devices in a fuel-cell hybrid electric vehicle, was presented together with a multiple MPPT-EMS. The EMS is easily implementable, and considers quasi-constant cell energy extraction and filtering of current transients to the battery bank ensuring the longevity of the devices. A new mathematical model of the platform, a closed loop stability analysis, and numerical and Hardware-in-the-Loop (HIL) validations were presented. Some experimental validation results were also provided.
Comparative Study Improving Residential Load Factor Using Power Shifting and ...TELKOMNIKA JOURNAL
One the problem of electric power stability is due to load fluctuations in distribution system
especialy during peak load conditions. One solution which is applied in Smart Grid scheme is through load
shifting or power shifting. In load shifting the load with high power consumption which operates at peak
load shifted its operations outside of the peak load or s some loads with high power consumption do not
operate at the same time, there is a load whose operating time is shifted to reduce peak power. Power
shifting is used when energy from renewable source not directly suplied to load but storage first and
supplied to reduce high power consumption to reduce peak power. Low load factor, ratio between average
power to peak power, may affect to power system operation. If load factor of residential load can keep in
low, it will be certainly help improve the stabi lity of the power system. In this study we will examine the
comparison of load shifting method with power shifting in improving load factor. Load shifting is done to
water pumps and washing machines, because washing machine is shiftable load. Power shiftin g is made
to the output power of the solar power plant, which is used to reduce peak power from the water pump.
Test results show that power shifting can increase load factor value up to 54,9% while load shifting give
load factor value equal to 43,9%.
Comparing the Dynamic Impact of Hybrid Distributed Generation with Single Sou...IJAEMSJORNAL
Due to the natural intermittent properties of some renewable energies, the grid is subjected to instability, insufficient power delivery and fluctuation. When these renewable energies are combined together to address the challenge of power shortage, increasing energy demand, and voltage drop, the grid is subject to different stabilities issues compare to the single energy source. This paper compares the dynamic behavior of single energy with mixed energy sources. The paper compares the impact of DFIG alone, Solar PV alone and Small Hydro power alone with hybrid type under distributed generation concept on transient stability of power system. To investigate this investigation, a DIgSILENT power factory library models was used as a component model for wind Turbine / Solar PV and small hydropower system. The simulation was carried out on single machine infinite system.
Physical design and modeling of 25 v dc dc boost converter for stand alone so...ecij
As per the present development the shortage in powe
r all over the world seems to be abundance.
Renewable energy sources are the capable energy sou
rce along with the accessible resources of energy.
Among all the renewable resources of energy, solar
PV technology is most acceptable due to its
considerable advantage over other form of renewable
sources. Calculating the output of PV system is a
key
aspect. The main principle of this paper is to pres
ent physical modeling and simulation of solar PV sy
stem
and DC-DC boost converter in SIMSCAPE library of MA
TLAB. The benefit by SIMSCAPE library is that it
models the system physically and the outcome obtain
s from it will be considering all the physical resu
lt. In
this paper the output of solar cell has been interf
aced with the boost converter. The system model in
SIMSCAPE can be directly converted into hardware fo
r implement for actual time application
Active and reactive power sharing in micro grid using droop control IJECEIAES
The development of renewable energy contributes to the global objectives of reducing our greenhouse gas emissions, obtaining and increasing our energy efficiency. In the face of these changes, the electric-network must adapt, while maintaining a high level of reliability and a quality of energy production. To meet this objective, it is recommended to use highly developed electrical network by integrating renewable energy sources in order to adapt the energy consumption to their production, using electrotechnical software information and telecommunications technologies. We are talking about intelligent grids (Smart Grid). The main objective of the work presented in this paper is the contribution to the study of intelligent network for efficient management of energy produced by several sources linked to the AC bus via the voltage inverters. Numerical simulations have been presented to validate the performance of the proposed active and reactive power controller (Droop Control).
COORDINATED CONTROL AND ENERGY MANAGEMENT OF DISTRIBUTED GENERATION INVERTERS...ijiert bestjournal
In modern world,our entire life moves around Computers. Most of our tasks are dependent on the Computers,like Communication,Ticket Reservations,Researches,Printing,and Education etc. When we communicate with each other by using Computers through E Mails,a number of Computers are used for this purpose and the collection of these computers forms a network,which is called a Computer Network. As more and more peoples are going to be connected through the general network (INTERNET),the problem of security arises. Now a day,a number of security issues occur in networks which include Sniffing,Spoofing,Security Attacks,Malwares,Unauthorized Access,etc. This will create havoc for the users,who wants to communicate with each other through these networks. So,to make the communication between two users via the Computer Networks,we have to follow some security measures,which include using the Firewalls,Anti Malicious Software,Intrusion Detection Systems,Cryptography Techniques,et c. This paper is basically focused on how the communication between two users has been performed by using Computer Networks and how to make such a communication
Source resizing and improved power distribution for high available island mic...Mohamed Ghaieth Abidi
A microgrid is a small-scale smart network that contains distributed resources and loads and serves several technical, economic, and environmental aims. In this kind of power system, the energy generated by different sources is often collected in an adequate bus system (ac or dc busses) and transported to loads across a distribution system. In case of islanding operation of a microgrid, each production insufficiency or distribution system fault can cause a partial or total interruption of power supply required by loads of the microgrid. This unavailability can last longer because of the randomness and intermittent behavior of renewable sources and the importance of the maintenance actions of the distribution system. To guarantee high availability of power supply, microgrid must be able to produce and to transfer the power energy requested by loads. The sizing of distributed sources and the design of the distribution system present an important challenge to achieve this goal. This paper offers a new global methodology carried out in two steps: in the first, it aims to optimize the source sizing by adding some microsources for ensuring the balance between sources production and loads requirement, then, in a second step, it aims to enhance the distribution system design by the creation of new paths of power transmission for transferring the produced energy from sources to loads. The proposed optimization methodology aims to achieve the requested availability rate requested by each load (considering their priorities) by taking into account some technical and economic factors. In this methodology based on genetic algorithms, objective functions are defined, and several electrical and economic constraints are formulated. The graph theory is used to represent the architecture of the microgrid distribution system, and Matpower tool of MATLAB is used to model it. An application and implementation of the proposed optimization methodology in a Tunisian petroleum platform indicate that the proposed solution is efficient in optimizing of power supply availability in its microgrid.
Sampling-Based Model Predictive Control of PV-Integrated Energy Storage Syste...Power System Operation
This paper proposes a novel control solution designed to solve the local and grid-connected
distributed energy resources (DERs) management problem by developing a generalizable framework capable
of controlling DERs based on forecasted values and real-time energy prices. The proposed model uses
sampling-based model predictive control (SBMPC), together with the real-time price of energy and forecasts
of PV and load power, to allocate the dispatch of the available distributed energy resources (DERs) while
minimizing the overall cost. The strategy developed aims to nd the ideal combination of solar, grid, and
energy storage (ES) power with the objective of minimizing the total cost of energy of the entire system.
Both ofine and controller hardware-in-the-loop (CHIL) results are presented for a 7-day test case scenario
and compared with two manual base test cases and four baseline optimization algorithms (Genetic Algo-
rithm (GA), Particle Swarm Optimization (PSO), Quadratic Programming interior-point method (QP-IP),
and Sequential Quadratic Programming (SQP)) designed to solve the optimization problem considering the
current status of the system and also its future states. The proposed model uses a 24-hour prediction horizon
with a 15-minute control horizon. The results demonstrate substantial cost and execution time savings when
compared to the other baseline control algorithms.
This article presents the system design and prediction performance of a 1kW capacity grid-tied photovoltaic inverter applicable for low or medium-voltage electrical distri-bution networks. System parameters, for instance, the longitude and latitude of the solar plant location, panel orientation, tilt and azimuth angle calculation, feasibility testing, optimal sizing of installment are analyzed in the model and the utility is sim-ulated precisely to construct an efficient solar power plant for residential applications. In this paper, meteorological data are computed to discuss the impact of environmen-tal variables. As regards ensuring reliability and sustenance, a simulation model of the system of interest is tested in the PVsyst software package. Simulation results yield that the optimum energy injected to the national grid from the solar plant, specific pro-duction, and performance ratio are 1676kWh/year, 1552kWh/kWp/year, and 79.29% respectively. Moreover, the predicted carbon footprint reduction is 23.467 tons during the 30 years lifetime of the system. Therefore, the performance assessments affirm the effectiveness of the proposed research.
Optimal Configuration of Wind Farms in Radial Distribution System Using Parti...journalBEEI
Recently, a wide range of wind farm based distributed generations (DGs) are being integrated into distribution systems to fulfill energy demands and to reduce the burden on transmission corridors. The non-optimal configuration of DGs could severely affect the distribution system operations and control. Hence, the aim of this paper is to analyze the wind data in order to build a mathematical model for power output and pinpoint the optimal location. The overall objective is minimization of power loss reduction in distribution system. The five years of wind data was taken from 24o 44’ 29” North, 67o 35’ 9” East coordinates in Pakistan. The optimal location for these wind farms were pinpointed via particle swarm optimization (PSO) algorithm using standard IEEE 33 radial distribution system. The result reveals that the proposed method helps in improving renewable energy near to load centers, reduce power losses and improve voltage profile of the system. Moreover, the validity and performance of the proposed model were also compared with other optimization algorithms.
Concept of Hybrid Energy Storage Systems in Microgridijtsrd
Public awareness of the need to reduce global warming and the significant increase in the prices of conventional energy sources have encouraged many countries to provide new energy policies that promote the renewable energy applications. Such renewable energy sources like wind, solar, hydro based energies, etc. are environment friendly and have potential to be more widely used. Combining these renewable energy sources with back up units to form a hybrid system can provide a more economic, environment friendly and reliable supply of electricity in all load demand conditions compared to single use of such systems. Energy storages Systems ESS present many benefits such as balancing generation and demand, power quality improvement, smoothing the renewable resource's intermittency, and enabling ancillary services like frequency and voltage regulation in microgrid MG operation. Hybrid energy storage systems HESSs characterized by coupling of two or more energy storage technologies are emerged as a solution to achieve the desired performance by combining the appropriate features of different technologies. A single ESS technology cannot fulfill the desired operation due to its limited capability and potency in terms of lifespan, cost, energy and power density, and dynamic response. Hence, different configurations of HESSs considering storage type, interface, control method, and the provided service have been proposed in the literature. This paper comprehensively reviews the state of the art of HESSs system for MG applications and presents a general outlook of developing HESS industry. Important aspects of HESS utilization in MGs including capacity sizing methods, power converter topologies for HESS interface, architecture, controlling, and energy management of HESS in MGs are reviewed and classified. An economic analysis along with design methodology is also included to point out the HESS from investor and distribution systems engineers view. Regarding literature review and available shortcomings, future trends of HESS in MGs are proposed. Priya | Sukhbir Singh "Concept of Hybrid Energy Storage Systems in Microgrid" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25238.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/25238/concept-of-hybrid-energy-storage-systems-in-microgrid/priya
Performance based Comparison of Wind and Solar Distributed Generators using E...Editor IJLRES
Distributed Generation (DG) technologies have become more and more important in power systems. The objective of the paper is to optimize the distributed energy resource type and size based on uncertainties in the distribution network. The three things are considered in stand point of uncertainties are listed as, (i) Future load growth, (ii) Variation in the solar radiation, (iii) Wind output variation. The challenge in Optimal DG Placement (ODGP) needs to be solved with optimization problem with many objectives and constraints. The ODGP is going to be done here, by using Non-dominated Sorting Genetic Algorithm II (NSGA II). NSGA II is one among the available multi objective optimization algorithms with reduced computational complexity (O=MN2). Because of this prominent feature of NSGA II, it is widely applicable in all the multi objective optimization problems irrespective of disciplines. Hence it is selected to be employed here in order to obtain the reduced cost associated with the DG units. The proposed NSGA II is going to be applied on the IEEE 33-bus and the different performance characteristics were compared for both wind and solar type DG units.
An Higher Case Operation and Analysis of a Multiple Renewable Resources Conne...IJERA Editor
In our nation the usage of electricity is increasing day-by-day. According to that conserdations, the generated
power from the non-renewable sources will not satisfy the demands properly. so for these purpose, by using
multiple renewable sources, it will be very useful to some type of dc applications. The power produced from the
individual renewable sources will not be satisfy the demand at all times. So by integration of a multiple
renewable sources such as wind and solar a huge amount of power will be produced. These power will be
coordinated to the ac grid or directly to dc consumers. For integration of renewable sources an aggregated model
has to be proposed. In according to these operation BESS (battery energy storage system)is equipped with the
system for maintaining the power balance. For obtaining the power balance the adaptive droop control technique
has to be proposed and droop curves are evaluated. The droop characteristics are selected on the basis of the
deviation between the optimized and real-time SOC of the BESS. In these paper, the operational analysis can be
performed when real time soc is higher than the optimised soc and droop curves are plotted.
Harvesting in electric vehicles: Combining multiple power tracking and fuel-c...IJECEIAES
Exploitation of green energy sources is essential to diminish the deterioration of our environment. The energy harvesting, represents an alternative to achieve greater range in electric and hybrid vehicles. An energy management strategy (EMS) must be optimized to obtain the best benefits in such vehicles, which is not a trivial task. If harvesting or energy recovery devices are added, the EMS becomes a dual-purpose algorithm: minimizing fuel consumption and maximizing energy harvest through maximum power point tracking (MPPT) controllers. Known studies consider separate EMS, one for traction and another for regenerative braking, without considering harvest devices such as solar panels, regenerative suspension, thermal generators, among others. Furthermore, the electronic power converters used, are not designed to handle such unequal power levels. In this article, an electronic platform to include multiple energy harvesting devices in a fuel-cell hybrid electric vehicle, was presented together with a multiple MPPT-EMS. The EMS is easily implementable, and considers quasi-constant cell energy extraction and filtering of current transients to the battery bank ensuring the longevity of the devices. A new mathematical model of the platform, a closed loop stability analysis, and numerical and Hardware-in-the-Loop (HIL) validations were presented. Some experimental validation results were also provided.
Comparative Study Improving Residential Load Factor Using Power Shifting and ...TELKOMNIKA JOURNAL
One the problem of electric power stability is due to load fluctuations in distribution system
especialy during peak load conditions. One solution which is applied in Smart Grid scheme is through load
shifting or power shifting. In load shifting the load with high power consumption which operates at peak
load shifted its operations outside of the peak load or s some loads with high power consumption do not
operate at the same time, there is a load whose operating time is shifted to reduce peak power. Power
shifting is used when energy from renewable source not directly suplied to load but storage first and
supplied to reduce high power consumption to reduce peak power. Low load factor, ratio between average
power to peak power, may affect to power system operation. If load factor of residential load can keep in
low, it will be certainly help improve the stabi lity of the power system. In this study we will examine the
comparison of load shifting method with power shifting in improving load factor. Load shifting is done to
water pumps and washing machines, because washing machine is shiftable load. Power shiftin g is made
to the output power of the solar power plant, which is used to reduce peak power from the water pump.
Test results show that power shifting can increase load factor value up to 54,9% while load shifting give
load factor value equal to 43,9%.
Comparing the Dynamic Impact of Hybrid Distributed Generation with Single Sou...IJAEMSJORNAL
Due to the natural intermittent properties of some renewable energies, the grid is subjected to instability, insufficient power delivery and fluctuation. When these renewable energies are combined together to address the challenge of power shortage, increasing energy demand, and voltage drop, the grid is subject to different stabilities issues compare to the single energy source. This paper compares the dynamic behavior of single energy with mixed energy sources. The paper compares the impact of DFIG alone, Solar PV alone and Small Hydro power alone with hybrid type under distributed generation concept on transient stability of power system. To investigate this investigation, a DIgSILENT power factory library models was used as a component model for wind Turbine / Solar PV and small hydropower system. The simulation was carried out on single machine infinite system.
Physical design and modeling of 25 v dc dc boost converter for stand alone so...ecij
As per the present development the shortage in powe
r all over the world seems to be abundance.
Renewable energy sources are the capable energy sou
rce along with the accessible resources of energy.
Among all the renewable resources of energy, solar
PV technology is most acceptable due to its
considerable advantage over other form of renewable
sources. Calculating the output of PV system is a
key
aspect. The main principle of this paper is to pres
ent physical modeling and simulation of solar PV sy
stem
and DC-DC boost converter in SIMSCAPE library of MA
TLAB. The benefit by SIMSCAPE library is that it
models the system physically and the outcome obtain
s from it will be considering all the physical resu
lt. In
this paper the output of solar cell has been interf
aced with the boost converter. The system model in
SIMSCAPE can be directly converted into hardware fo
r implement for actual time application
Active and reactive power sharing in micro grid using droop control IJECEIAES
The development of renewable energy contributes to the global objectives of reducing our greenhouse gas emissions, obtaining and increasing our energy efficiency. In the face of these changes, the electric-network must adapt, while maintaining a high level of reliability and a quality of energy production. To meet this objective, it is recommended to use highly developed electrical network by integrating renewable energy sources in order to adapt the energy consumption to their production, using electrotechnical software information and telecommunications technologies. We are talking about intelligent grids (Smart Grid). The main objective of the work presented in this paper is the contribution to the study of intelligent network for efficient management of energy produced by several sources linked to the AC bus via the voltage inverters. Numerical simulations have been presented to validate the performance of the proposed active and reactive power controller (Droop Control).
Micropower system optimization for the telecommunication towers based on var...IJECEIAES
This study investigates the technical and cost-effective performance of options renewable energy sources to develop a green off-grid telecommunication tower to replace diesel generators in Malaysia. For this purpose, the solar, wind, pico-hydro energy, along with diesel generators, were examined to compare. In addition, the modeling of hybrid powering systems was conducted using hybrid optimization model for energy (HOMER) simulation based on techno-economic analysis to determine the optimal economically feasible system. The optimization findings showed that the hybrid high-efficiency fixed photovoltaic (PV) system with battery followed by 2 kW pico-hydropower and battery are the optimal configurations for powering off-grid telecommunication towers in Malaysia with the lowest net present cost (NPC) and cost of energy (COE). These costs of NPC and COE are more down than diesel generator costs with battery by 17.45%, 16.45%, 15.9%, and 15.5%, respectively. Furthermore, the economic evaluation of the high-efficiency solar fixed PV panels system annual cash flow compared to the diesel generator with the battery system indicated a ten-year payback period.
The decline of competence effectuated by the unreplenishable energy etymology due to the plummet of fossil fuels has created an alternate need for renewable energy sources to play a vital role in providing power at a larger scale. Thus, a new system of distribution of energy resources is introduced to tackle the ever-growing demand for power and safety of the environment using renewable energy sources with the traditional ways of transmitting power. Such challenges can be overcome by using hybrid microgrids which helps in detecting and hegemonizing faults more dexterously sanctioning sharing of load and instinctive switching through various algorithms thus improving the system accuracy and adaptability. This exertion incorporates the modeling of an AC hybrid microgrid system analyzed in the is-landed mode. Fuel stack and the photo-voltaic cell are used as renewable energy power sources. It also includes the PID control method to the solution the most encountered problems in a microgrid. The engaged control modus operandi can modulate and regulate the output voltage at an expected and paradigm value. The whole AC hybrid microgrid and its control are simulated in MATLAB/simulink R2020b.
New solutions for optimization of the electrical distribution system availabi...Mohamed Ghaieth Abidi
This paper deals with the availability in microgrids that are composed of a set of sources (Photovoltaic generators, wind turbines, diesel generators and batteries) and a set of loads (critical and uncritical loads). The energy produced by various sources will be grouped in an alternative bus (AC bus), and it will be distributed on loads through an electrical distribution system. The occurrence of a fault in the system can cause a total or partial unavailability of energy required by the loads. The objective of this paper is to characterize the fault caused by the limited reliability of the components of the electrical distribution system and to propose an new design methodology to optimize the availability of this system (as well as the availability of power supply) by taking into account all the economic constraints. The proposed methodology is based on the redundancy of electrical distribution paths. An application of this optimization to a petroleum platform shows clearly a high degree of supply availability distribution in microgrid.
A review of optimal operation of microgrids IJECEIAES
The term microgrid refers to small-scale power grid that can operate autonomously or in concurrence with the area’s main electrical grid. The intermittent characteristic of DGs which defies the power quality and voltage manifests the requirement for new planning and operation approaches for microgrids. Consequently, conventional optimization methods in new power systems have been critically biased all through the previous decade. One of the main technological and inexpensive tools in this regard is the optimal generation scheduling of microgrid. As a primary optimization tool in the planning and operation fields, optimal operation has an undeniable part in the power system. This paper reviews and evaluates the optimal operation approaches mostly related to microgrids. In this work, the foremost optimal generation scheduling approaches are compared in terms of their objective functions, techniques and constraints. To conclude, a few fundamental challenges occurring from the latest optimal generation scheduling techniques in microgrids are addressed.
Renewable energy allocation based on maximum flow modelling within a microgridIJECEIAES
This paper designs a microgrid-wide energy allocation mechanism on top of a network flow model from distributed generators to consumer entities. Basically, the flow graph consists of a set of nodes representing consumers or generators as well as a set of weighted links representing the amount of energy generation, consumer-side demand, and transmission cable capacity. The main idea lies in that a special node is added to account for the interaction with the main grid and that two-pass allocation is executed. In the first pass, the maximum flow solver decides the amount of the insufficiency, which must be supplemented by the main power network, usually with predefined cost. The second pass runs the flow solver again to fill the energy lack and calculates the surplus of renewable energy generation. The experiment result observes the stability in energy distribution over the microgrid while the amount of the total energy production can be accommodated by the maximum link capacity.
Reactive Power Sharing Droop Control Strategy for DG Units in an Islanded Mic...IJMTST Journal
The proposed method mainly includes two important operations: error reduction operation and voltage
recovery operation. The sharing accuracy is improved by the sharing error reduction operation, which is
activated by the low-bandwidth synchronization signals. However, the error reduction operation will result in
a decrease in output voltage amplitude. Therefore, the voltage recovery operation is proposed to compensate
the decrease., due to increasing the demand of electricity as well as rapid depletion of fossil fuels, and the
government policies on reduction of greenhouse gas emissions , renewable energy technologies are more
attractive and various types of distributed generation sources, such as wind turbine generators and solar
photo voltaic panels are being connected to low-voltage distribution networks. Micro grid is an integrated
system that contain in s distributed generation sources, control systems, load management, energy storage
and communication infrastructure capability to work in both grid connected and island mode to optimize
energy usage. The paper presents a advanced control technique for a micro grid system which works
efficiently under a decentralized control system.
A survey on power management strategies of hybrid energy systems in microgrid IJECEIAES
The power generation through renewable energy resources is increasing vastly, Solar energy and Wind Energy are the most abundantly available renewable energy resources. The growth of small scale distributed grid networks increasing rapidly in the modern power systems and Distributed Generation (DG) plays a predominant role. Microgrid is one among the emerging techniques in power systems. Power Management is mainly required to have control over the real and reactive power of individual DG and for smooth operation, maintaining stability and reliability. This paper presents a survey of the research works already reported focusing on power management of hybrid energy systems such as mainly solar and wind systems in microgrid. Six different approaches have been studied in detail for AC, DC and hybrid AC/DC microgrid.
Optimal power scheduling of renewable energy sources in micro-grid via distri...TELKOMNIKA JOURNAL
This research is mainly focusing on the optimal power management by controlling the charging and discharging modes of the battery storage of the micro-grid (MG). A droop-based controller or battery controller is proposed for this work in order to optimize the power management of the battery. Charging and discharging modes are controlled by the droop-based characteristic where it will perform as a battery controller for the battery storage. Furthermore, the charging and discharging rates will depend on the signal from the MG at power secondary and its signal will be read by the battery controller and choose either to charge or discharge the battery storage where it will suffice the energy demand by loads in the micro-grid. The simulation results show the effectiveness of the controller to control sharing the power based on the desired energy from the battery storage to the loads at the MG. Moreover, all the critical cases have been advised, such as sudden decrease or disturbance of any generating unit. The result has been observed that due to sudden decrease or disturbance of any generating unit, the battery controller manages to control the charging and discharging rate based on the insufficient energy caused by the disturbance to fulfil the demand at MG.
Voltage Stability Analysis of Micro-grid Based on double Data CenterIJRESJOURNAL
ABSTRACT : The double data center is introduced into the micro-grid to adjust the whole system, and the double data center placement method is analyzed, and the optimal distribution strategy is designed in the whole micro-grid system. Using the load adjustable featuresofthe data center to keep the micro-grid maintenance. First, due to the new energy and the residents load is a key problem leading to micro-grid imbalance, in the new energy access and residential load nodes around the placement of data centers to achieve demand response. Then,analyzing the influence of new energy fluctuation and residential electricity load on micro-grid, the load adjustment strategy of data center is established. Because the distribution of new energy and resident load is located at different positions of micro-grid, double data center is used to carry out maintain the micro-grid in a balanced state. Finally, the establishment of double data center interactive compensation strategy to achieve demand response and the maintenance of micro-grid stability.
Analysis and Implementation of Power Quality Enhancement Techniques in Hybrid...ijtsrd
With the growth in global warming, renewable energy based distributed generators DGs play a prominent role in power generation. Wind, solar energy, biomass, mini hydro, and the usage of fuel cells and microturbines will provide substantial impetus in the near future. Environmental friendliness, expandability, and flexibility have made distributed generation, powered by a variety of renewable and unconventional energy sources, an appealing alternative for building contemporary electrical systems. A microgrid is made up of a group of loads and dispersed generators that work together to form a single controlled system. Microgrids, as an integrated energy delivery system, may function in tandem with or independently of the main power grid. The microgrid idea reduces the number of reverse conversions in a single AC or DC grid while also making it easier to link variable renewable AC and DC sources and loads to power systems. The connectivity of DGs to the utility grid through power electronic converters has raised concerns regarding equipment safety and protection. The microgrid may be configured to fulfil the customers specific needs, such as greater local dependability, reduced feeder losses, local voltage support, greater efficiency via waste heat usage, voltage sag correction, or uninterruptible power supply. The performance of a hybrid AC DC microgrid system in grid tethered mode is examined in this paper. For the creation of a microgrid, a solar system, a wind turbine generator, and a battery are utilized. Control methods are also included to allow the converters to appropriately coordinate the AC sub grid with the DC sub grid. The MATLAB SIMULINK environment was used to achieve the findings. Tarun Jaiswal | Ashish Bhargava "Analysis and Implementation of Power Quality Enhancement Techniques in Hybrid AC/DC Microgrid" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46296.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/46296/analysis-and-implementation-of-power-quality-enhancement-techniques-in-hybrid-acdc-microgrid/tarun-jaiswal
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Hybrid Micro Grid Architectures and ChallengesIJMTST Journal
The distribution system is part of the electric power system that links the bulk transmission system and the
individual customers. Increasing environmental concerns, consumer expectations in terms of reliability &
better quality of power supply and improving economics of distributed energy resources (DER) based on
renewable, is making Micro Grid a viable proposition. Present electrical distribution system offers many
technical & operational glitches for successful integration of Micro Grid Technologies. Modern Power systems
are smart, interconnected, interdependent, load sharing and phased mission systems. Micro grids are
composed by distributed generators, energy storage devices, intelligent circuit breakers and local loads. In
this paper, a review of the main micro grid architectures proposed in the literature has been carried out. The
micro grid architectures are first classified regarding their AC or DC distribution buses. Besides, more
complex micro grid architectures will be discussed. Both advantages and disadvantages of each one of the
micro grid families will be discussed.
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Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
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This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
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It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
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New forecasting-based solutions for optimal energy consumption in microgrids with load shedding: Case study: Petroleum platform
1. New Forecasting-based Solutions for Optimal Energy Consumption in
Microgrids with Load Shedding
Case Study: Petroleum Platform
Mohamed Ghaieth Abidi, Moncef Ben Smida and Mohamed Khalgui
LISI Lab, INSAT Institute, University of Carthage, Carthage, Tunisia
Keywords: Microgrid, High Availability, Forecasting, Weather Condition, Control, Load Shedding.
Abstract: This paper presents a new control strategy for optimal energy consumption in microgrids based on forecasting
and load shedding method. In islanded mode, only local generation resources are usable. In this mode, the
availability of resources is very influenced by meteorological factors. In order to achieve a high availability of
energy, microgrid has to satisfy high requirements on intelligent power management. The main objective of
this study is to develop a control based on the forecast of production and the priority of loads to ensure high
availability of electrical power for critical loads. A mathematical model for the proposed strategy is developed.
The simulation of this model on Matlab Simulink for different cases of microgrid topology (sources and loads)
shows clearly a high improvement of degree of availability of electrical power supply distribution in microgrid.
1 INTRODUCTION
Microgrid system is a new concept that aims to inte-
grate decentralized energy sources efficiently and re-
liably. A microgrid consists mainly of distributed en-
ergy resources, energy storage devices, flexible loads
and energy controllers. A microgrid can operate in a
connected mode if is interconnected to the main grid,
or in an island mode if is disconnected from. In island
mode, the main constraints to ensure a high avail-
ability are the intermittent behaviour of distributed
generation sources and their possible unavailability
when they are required to product. To improve the
availability, several studies are interested in the use
of hybrid sources and power management strategies
based on balancing between loads demand and pro-
duction sources. In order to achieve a high availabil-
ity of energy and minimize the influence of intermit-
tent behaviour of sources, an intelligent power man-
agement based on forecasting production and loads
shedding methods should be used. The proposed con-
trol strategy in this paper is based on the using of
the forecast weather information to predict the avail-
ability of renewable sources and the ability of refu-
elling of programmable sources in an island micro-
grid. This method gives to the microgrid management
system the ability to make the right decision about
the achievement refuelling and to choose between us-
ing the energy produced to supply total loads or us-
ing the load shedding method to store the energy in
storage devices for use thereafter in order to supply
main loads. In this paper, a mathematical approach is
presented to show the different relationships between
the different components of microgrid and the influ-
ence of their yields by the meteorological factor (in-
solation and wind). This mathematical approach is
used to show the advantage of the new forecasting
based control strategy in the improvement of avail-
ability. Several simulations on matlab Simulink of
the mathematical model of the proposed strategy are
developed for different cases of microgrid topology
(sources and loads). The simulation results show a
high improvement of availability of electrical power
supply distribution in microgrid. Comparing to the
control strategy without forecasting and load shed-
ding, this new control strategy allows to increase the
availability value from 85% to 100%. This paper is
organized as follows: Section 1 presents the state of
the art of microgrid power availability. The second
Section explains the case study and the problem. Sec-
tion 3 proposes the new control solution for optimal
availability. In Section 4, we evaluate the proposed
solution. Finally, Section 5 summarizes this paper.
2 STATE OF THE ART
Nowadays, many human activities depend critically
289
Abidi M., Ben Smida M. and Khalgui M..
New Forecasting-based Solutions for Optimal Energy Consumption in Microgrids with Load Shedding - Case Study: Petroleum Platform.
DOI: 10.5220/0005244002890296
In Proceedings of the 5th International Conference on Pervasive and Embedded Computing and Communication Systems (PECCS-2015), pages
289-296
ISBN: 978-989-758-084-0
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2. on a secure supply of energy. With Growing con-
cern about the availability of primary energy, rising
electricity demand, use of renewable energy sources
such as wind and solar become an obligation (Bhoyar
and Bharatkar, 2013). The new generation of electric
networks should integrate renewable energy into the
electrical grid (Hatziargyriou, 2014). Thus, system
security, environmental protection, quality of electric-
ity, cost of supply and energy efficiency should be
considered in new ways to meet the changing needs
in a liberalized market environment. Microgrid is a
contained network of distributed generation sources
and energy storage devices that are connected to the
loads. The generation can be from renewable sources,
that reduce (or cancel) the need to conventional en-
ergy sources. The potential for improving the avail-
ability of Microgrid power supply is one of the main
motivations behind the development and deployment
of microgrids. Because of the importance of the avail-
ability of electrical energy for various applications
and the fluctuating availability of renewable energy
sources, a lot of research are interested in different
kinds of power sources hybridisation and their avail-
ability. The adequate choice of sources is the most
important step to improve availability. The hybridi-
sation can be on the type of sources (renewable or
programmable source, energy storage devices) or on
kind of the same type of source energy storage de-
vices (wind turbine and PV, fast-dynamic storage de-
vices and long-term storage devices, fuel cell, diesel
generator) or on both of them. After an adequate
choice, the sizing of these sources plays a mattering
role in the guarantee of the continuity of service (Lo-
genthiran and Raj, 2010). Many optimizing method-
ologies are proposed to calculate the optimum size of
energy source and storage system considering avail-
ability criterion (Y. Nian and Liu, 2013). Some pa-
pers explores how microgrids availability is impacted
by the different topology design choices for the power
electronic interfaces between the distributed genera-
tion (DG) sources and the rest of the microgrid. This
work focuses on the effect of DC or AC architec-
ture choice, converter design on system availability.
Power management strategy (Wang Haiyan and BiY-
ing, 2011) also have a significant impact on the avail-
ability of electrical energy, especially in the case of in-
sufficient production of energy or hardware problem.
Several research works have been interested in the im-
pact of the strategy of control on the different crite-
ria of microgrid power supply (WANG, 2013), espe-
cially the power-quality and the availability of elec-
trical produced energy (Thang, 2012). Whatever the
approaches of control (centralized/decentralized ap-
proaches) and especially in island mode, they require
Figure 1: Petroleum platform in Gulf of Hammamet in
Tunisia.
forecasting of the generation from renewable power
sources, electricity demand (and heat demand in some
cases). Prediction of the evolution of this quantity al-
lows us to face unsafe situations and optimize produc-
tion costs and power supply availability (H.X. Yang
and Burnett, 2003) (V. and K.U, 2014) . Therefore,
forecasting options may have a direct impact on the
economic viability and supply availability of micro-
grids, since they allow them to enhance their compet-
itiveness compared to centralized generation. To have
a wider degree of freedom on control strategy of elec-
trical power supply distribution in microgrid compar-
ing to the control based on forecasting (V. and K.U,
2014) and the control based on load shedding (Lee
and Huang, 2013), we propose a new optimized con-
trol strategy combining these two aspects by taking
in consideration the priority of the load supply. The
basic idea of our proposed strategy is to use the fore-
casted weather information to predict the availability
of renewable sources of refuelling of programmable
sources in an island microgrid. We aim in this paper
to make the right decision about the achievement re-
fuelling and load shedding.
3 CASE STUDY AND PROBLEM
We will describe in this section the Microgrid archi-
tecture and the climate values and we will introduce
the problem.
3.1 Microgrid Architecture
The Microgrid investigated in this paper is an abstrac-
tion of a petroleum platform (Figure 1) islanded lo-
cated on the Tunisian Coast. This Microgrid concep-
tion adopted for this case study is composed of PV
arrays, a wind turbine, a diesel generator with its fuel
tank, a storage device (batteries) and two loads (Fig-
ure 2). The Microgrid is designed as follows:
• Each renewable energy source (PV, Wind turbine)
is sized to be able to generate the electrical power
supply required by both loads and batteries in
favourable weather conditions,
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3. Figure 2: Microgrid.
• Diesel generator is dimensioned to be able to pro-
duce electrical energy required by the load. The
autonomy of this source is proportional to the
level of fuel in its tank and its produced energy,
• Battery is sized to be able to provide the electri-
cal power supply required by both loads with an
autonomy proportional to its charge level and the
electrical power request by loads. The battery be-
comes another load in her charging phase,
• load 1 is a critical load, it must be always con-
nected to the grid. Load 2 is a secondary load, it
can be disconnected in some cases.
The problem in this case is the intermittent nature
of all the sources of energy in this islanded microgrid.
The availability of sources is relative to the meteoro-
logical terms (Gooding, 2013). Based on sizing solu-
tions, the system - especially the elements of storage
- must be oversized; price and weight are the weak
points of this solution. We can increase the availabil-
ity by hybridisation of sources with other sources that
can operate in the bad times, such as the waves en-
ergy sources. This solution decreases the weight sup-
ported by the platform, but it is very expensive and
this type of energy is still in the process of study and
development. In this case, an adequate management
of energy can ensure or at least improve the availabil-
ity of electrical energy for the critical loads without
needs of new sources and new weight on the platform.
This strategy can minimize the aspect of intermittent
sources of energy by the use of the forecast of the me-
teorological factors and can act accordingly.
3.2 Climate values
The proposed Microgrid management systems must
be enhanced with forecasting technical functionalities
able to predict the power production of distributed
production sources in the next hours or days. To that
purpose, historical measurements database are needed
to generate the forecasting models. In Tunisia, you
can get this data from the National Institute of Mete-
orology1.
3.3 Problem and Discussion
In the island function mode of a microgrid, the avail-
ability of power supply is very influenced by the in-
termittent behaviour of its distributed sources. With
a view to improve this availability, the hybridisation
and the oversizing of sources represents a good tech-
nical solution, but this solution is very expensive. In
economical point of view, the solutions based on con-
trol strategy are always the cheapest. This kind of
solution is characterized by its flexibility and ability
to be adapted to the climate change. For this reason,
a microgrid must have an intelligent control strategy
based on forecasting methods that can minimize the
impact of weather conditions on the renewable and
programmable sources availability. The strategy of
control should minimize the impact of the unavail-
ability of renewable sources by increasing the avail-
ability of backup sources (programmable sources and
storage devices).
4 CONTRIBUTION
Our contribution consists in the development of the
new forecasting-based solution for optimal energy
consumption in microgrids with Load Shedding. This
contribution is based on mathematical formulation of
the electrical network structure of Tunisian offshore
petroleum platform existing in the Gulf of Hammamet
with taking into account the weather condition.
4.1 Architecture
A microgrid is composed of Photovoltaic Cells, Wind
turbine, Battery, Diesel Generator and loads. All
the sources are sized so that each of them - when is
available- is able to meet the energy demand loads.
The availability of renewable sources depends on cli-
matic factors (insolation and wind). The availability
of the battery depends on the charge level. The battery
can be charged and discharged through the microgrid.
The diesel generator is available when the tank is not
empty. The tank can be filled with refuelling in case
of good weather. There are two types of loads in the
microgrid: (i) critical load that should be supplied all
the time, (ii) and uncritical load that can be discon-
nected from network in the case of load shedding.
1http://www.meteo.tn
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4. 4.2 Optimal Energy Consumption
In this subsection, we will describe the notation and
the problem formulation.
4.2.1 Notation
We denote in the following by:
PV Photovoltaic Generator
WT Wind Turbine
B Battery
GE Diesel Generator
PSource(t) Electrical power exchanged between the
source and the rest of network
PLoad1(t) Electrical power consumed by critical load
PLoad2(t) Electrical power consumed by uncritical load
En Insolation
VV Wind speed
Echarge Battery charge level
Eclim Sea State
NCharge Level of the fuel in the tank of the diesel
generator
Eclim0
Nominal sea State
ψ(t) Electrical power produced by this source
4.2.2 Problem Formulation
In term of availability A(t) (Equation 1), all electrical
energy sources can have two states:
• 1: available energy producer.
• 0: unavailable energy producer.
In its charging phase, the battery acts as a load that
may consume excess production. The battery can
have a third state:
• -1: load state of battery.
APV (t) = 1;0
AWT (t) = 1;0
AB(t) = 1;0;−1
AGE(t) = 1;0
(1)
Only available sources can be connected to the
grid. The state of penetration of sources C(t) to the
network is defined by equation(2):
CPV (t) = En
En0
−1
CWT (t) = ( VV
VV0
−1).APV (t)
CB(t) = (
ECharge
ECharge0
−1).AWT (t).APV (t)
CGE(t) = (
NCharge
NCharge0
−1).AB(t).AWT (t).APV (t)
(2)
Where:
En0(t), VV0 (t), Ncharge0
(t) and Eclim0
(t) are the nominal
values from which the sources are capable of produc-
ing energy.
The electrical power supplied by different sources to
the microgrid is equal to:
PPV (t) = CPV (t).ψPV (t)
PWT (t) = CWT (t).ψWT (t)
PB(t) = CB(t).ψB(t)
PGE(t) = CGE(t).ψGE(t)
(3)
The power produced in the microgrid may not be
sufficient to satisfy the totality of power demand for
all the time. For this reason, we should be allocated a
specified priority for each load. In this study, we have
two levels of priority:
• Load 1: critical load, it must be supplied most of
the time,
• Load 2: uncritical load. It can be disconnected in
the load shedding phase (CLoad2 = 0).
To ensure the availability of power supply, the pro-
duced power must check the following inequation:
PPV (t)+PWT (t))+PB(t)
+PGE(t) ≥ PLoad1(t)+PLoad2(t).CLoad2
(4)
In case of basic load shedding (without forecast-
ing), the load shedding method takes into considera-
tion only the real-time information about production
and consumption.
CLoad2(t) = f(PPV (t),PWT (t),
Echarge,Ncharge,PLoad1,PLoad2)
(5)
In the case of a load shedding based on the
forecasting, the uncritical load can be disconnected.
CLoad2 can be re-written as:
CLoad2(t) = βGE(t).βB(t) (6)
With
βGE(t) = (
∑n
i=1 .EClim(i)
n.EClim0
−1).(
∑n
i=1 .NR(i)
n.NR0
−1)
βB(t) = (
∑n
i=1 .En(i)
n.En0
−1).(
∑n
i=1 .VV (i)
n.VV0
−1)
.(
∑n
i=1 .NCharge(i)
n.NCharge0
−1)
(7)
βGE(t) and βB(t) are predictive probabilistic in-
dex about the state of the diesel generator and battery
availability in the future. These two indexes will be
used in order to optimize the load shedding and the
refuelling system decision.
5 EVALUATION
In this section, we will deal with the power sys-
tem model as well as the simulation result of the
petroleum platform.
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5. 5.1 Power System Modelling
We present in this subsection the photovoltaic gen-
erator, the wind turbine, the diesel generator and the
battery.
5.1.1 Photovoltaic Generator
The behaviour of photovoltaic generator (PVG) can
be presented by the following equation:
ψPV (t) = ηPVG.APVG.Gir (8)
With:
• APVG(m2) is the PVG surface,
• ηPVG is the PVG conversion efficiency given by:
ηPVG= ηr[1-β.(Tc-Tcref)]
5.1.2 Wind Turbine
As seen in equation(9), the energy of wind turbine
.ψWT and mechanical output power of wind turbine
Pm.
ψWT (V) =
Pn. V−Vdem
Vn−Vdem
,Vdem ≤ V ≤ Vn
Pn,Vn ≤ V ≤ Vmax
0,Otherwise
(9)
Pm(t) = 1
2 .Cp(λ,β).ρ.AV3 (10)
With:
• ρ: Air density (Kg/m3),
• A: Turbine swept area (m3),
• V: Wind speed (m/s), Vn: Nominal wind speed,
VMax: Maximal wind speed, Vdem: Startup Wind
speed,
• Cp(λ,β): Performance coefficient of the turbine,
• λ: Tip speed ratio of the rotor blade tip speed to
wind speed,
• β: Blade pitch angle (deg).
5.1.3 Diesel Generator
The used model is a very simple. If its tank is not
empty, the diesel generator is a generator able to pro-
vide an electrical power Pgen. After each unit of time
T of operation of generator, the fuel level decreases
by a quantity proportional to T and Pgen.
5.1.4 Battery
There are many models to charge and discharge the
batteries. For the problems of sizing, it is enough to
use models that feel the State Of Charge (SOC) of the
battery in a simple manner.
5.2 Simulation Result
In this subsection, a number of simulation results that
highlight the influence of: (i) the strategy of com-
mand and (ii) the oversizing of backup sources on the
availability of electrical energy are presented and dis-
cussed. We will focus mainly on calculating the avail-
ability of energy: (i) at the level of critical loads, (ii)
at the level of the entire system. We will focus also on
the evolution of the charge level of the battery and the
fuel level in the tank of diesel generator. The instanta-
neous availability may have only two values, 1 in the
case of availability and 0 in the opposite case. The
average Availability AA(t) is the mean value of the
instantaneous availability between time=0 and time=t
(Taylor and Ranganathan, 2013).
AA(t) =
1
t
t
0
A(x)dx (11)
The rate of load shedding is also an important index.
It gives us the idea about the availability of electrical
energy at the level of uncritical load and also at the
entire system.
5.2.1 Case 1: Without Forecasting and Load
Shedding
This case does not address the paper’s contribution. It
deals with a simulation without forecasting and load
shedding. Two types of load are considered: both
powered or both unpowered. Note that the refuelling
occurs only in the good weather if the tank is empty.
Table 1 shows the power supply availability index for:
(i) critical loads, (ii) entire system and (iii) the load
shedding rate for uncritical loads. Since there is no
Table 1: Availability values.
Power supply availability for the main loads 0.8517
Power supply availability for all the system 0.8517
Load shedding rate 0%
load shedding, so the power supply availability for
the main loads and the power supply availability for
all the system are equal. The calculation of availabil-
ity at the level of charges has given an availability
rate equals to 85.17 %. That it may be considered
as a mediocre value. Figure 3 presents the evaluation
of the instantaneous and average power availability at
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6. Figure 3: Instantaneous and average availability.
Figure 4: State of penetration of sources.
Figure 5: State of charge of the battery.
the level of critical load. Figure 4 shows the state of
penetration of sources (to the microgrid) which pro-
vide energy for consumers (Equation 2).
Note that: at each moment, only one source can be
penetrated to the network. We can also see the evo-
lution of the state of charge in the battery on Figure
5.
Figure 6 gives us information about the possibil-
ity of refuelling, the act of refuelling and the evolu-
tion of level of fuel in the tank of the diesel generator.
According to this figure, we have three times of refu-
elling.
5.2.2 Case 2: Without Forecasting and with
Load Shedding
This case is interested in a simulation that we did
without forecasting but with load shedding, if the sys-
tem is powered by the non-renewable energy sources,
there is automatically a load shedding. Comparing
with the previous value of simulation without load
shedding, we note that the power supply availability
rate for critical loads increases more than 9% but the
power supply availability rate for the entire system is
decreased by 7% (Table 2). Using the strategy of load
Figure 6: Good weather, refuelling and fuel level.
Figure 7: Instantaneous and average availability.
Figure 8: Good weather, refuelling and fuel level.
Table 2: Availability values.
Power supply availability for the main loads 0.9433
Power supply availability for all the system 0.7883
Load shedding rate 36.67%
shedding, we note that the supply system becomes to-
tally unavailable only once (Figure 7). The gain that
we obtain in Case 2 comparing to Case 1 is the im-
provement of power availability at the level of critical
loads. The reader can observe this improvement by
comparing Figure 7 to Figure 3. Table 2 shows that
the application of load shedding without forecasting
desceases the power supply availability of the system
from 0.85 to 0.78.
Despite that the availability rate of the power supply
for critical loads increases, we note that the number of
refuelling act decreases. This presents an economic
gain in term of fuel and its transport (Figure 8).
Figure 9 shows the influence of load shedding on
the rate of the connected loads.
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7. Figure 9: Load(pu).
Figure 10: Instantaneous and average availability.
5.2.3 Case 3: With Load Shedding and
Forecasting Only for Refuelling
Case 3 is interesting in the paper’s contribution that
deals with the prediction of the future weather con-
ditions to manage the current energy consumption to
optimize the refuelling process. Using the same pre-
vious strategy of load shedding, we can optimize the
values of availability (Figure 10), if we improve the
refuelling decision system taking into consideration
the present state of tank and the provisional state-
ments of all the sources of microgrid. This fore-
cast helps the system to take the right decision of re-
fuelling: Figure 11 shows three times of refuelling
which improve the availability of the diesel generator.
Thanks to this new solution of Case 3, the power sup-
ply availability is increased from 0.94 to 0.98 (com-
pared to Case 2) thanks to the proposed Equation 7.
Table 3: Availability values.
Power supply availability for the main loads 0.9847
Power supply availability for all the system 0.809
Load shedding rate 36.67%
5.2.4 Case 4: With Forecasting and Load
Shedding
In this case, we present the paper’s contribution that
deals with the forecasting and load shedding. Table 4
and Figure 12 show a full availability of power supply
thanks to the proposed forecasting solution with load
shedding. Figure 13 shows the state of penetration
of sources and Figure 14 shows the state of charge
of the battery. Figure 15 shows the influence of the
load shedding on the rate of the connected loads. The
reader can observe the gain that we get by applying
Figure 11: Good weather, refuelling and fuel level.
Figure 12: Instantaneous and average availability.
Figure 13: State of penetration of sources.
Figure 14: State of charge of the battery.
Figure 15: Load(pu).
the forecasting with load shedding. Figure 16 gives
us information on the possibility of refuelling, the act
of refuelling and the evolution of the level of the fuel
in the tank of the diesel generator. In Case 4 compared
to Case 3, the power supply availability is increased
from 0.98 to 1 thanks to the proposed Equation 6 and
7.
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8. Figure 16: Good weather, refuelling and fuel level.
Table 4: Availability values.
Power supply availability for the main loads 1
Power supply availability for all the system 0.809
Load shedding rate 38.12%
5.2.5 Result
According to the results obtained, it can be seen that:
• The type of hybridisation affects the availability.
But when we choose the sources, the reconfigura-
tion is costly and takes time,
• Note that the load shedding is a very important
strategy to increase the availability of electric
power in the priority loads, but it decreases the
rate at secondary loads and the system as a whole,
• Load shedding may be based on real-time infor-
mation or forecasts or of course both. The right
choice of this command and forecasting methods
provide a very high availability level of critical de-
vices, which can reach 100%.
6 CONCLUSION
In order to ensure a high availability in the is-
landed and autonomous microgrid, we propose a new
forecasting-based solution for optimal energy man-
agement. The major problem of this solution is the
probabilistic aspect of the forecasting data on which
the strategy is based on to make its decision. The load
shedding increase the availability in the level of crit-
ical loads; but in return, this method decreases the
availability in the level of uncritical loads. Despite
their problems, this strategy provides good results in
a case study. Predictive control strategy can help the
microgrid to improve the power supply availability for
its user by proactive control. Comparing with existing
solutions, our new solution presents several econom-
ical and technical benefits and it can be implemented
easily. The implementation of this proposed solution
and its experimental result will be published nearly.
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