ریزشبکه

Open Access Article

1 - Designing a Self-Tuning Frequency Controller Based on ANNs for an Isolated Microgrid
F. Habibi H. Bevrani J. Moshtag

20.1001.1.16823745.1391.10.3.3.1

Increasing electrical energy demand, as well as fossil fuel shortages and environmental concerns have caused to use uncommon sources such as distributed generations (DGs) and renewable energy sources (RESs) into modern power systems. A microgrid (MG) system consists of More

Increasing electrical energy demand, as well as fossil fuel shortages and environmental concerns have caused to use uncommon sources such as distributed generations (DGs) and renewable energy sources (RESs) into modern power systems. A microgrid (MG) system consists of several DGs and RESs which is responsible to provide both electrical and heat powers for local loads. Due to the MGs nonlinearity/complexity which is imposed to the conventional power systems, classical and nonflexible control structures may not represent desirable performance over a wide range of operating conditions. Therefore, more flexible/intelligent control methods are needed most of the past. Hence, in this paper addresses to design an online/self-tuning PI-controller based on artificial neural networks (ANNs) for optimal regulating the MG systems frequency. Manuscript profile

Open Access Article

2 - Multi Objective Network Reconfiguration for Distribution System with Micro-Grids Power Exchange using Max-Min Fuzzy Method and Particle Swarm Optimization Algorithm
A. Fattahi Meyabadi H. Sohrabiani

20.1001.1.16823745.1394.13.3.4.3

A group of small generators and energy storages in the low or medium voltage distribution systems beside of consumers emerge to a new power system called micro grid. Micro grids are designed to have secure and economic operation isolated and connected to the network and More

A group of small generators and energy storages in the low or medium voltage distribution systems beside of consumers emerge to a new power system called micro grid. Micro grids are designed to have secure and economic operation isolated and connected to the network and exchange electrical energy with distribution system. Hence, they may impact on planning and scheduling of distribution systems. In this case, network reconfiguration is a considerable issue after presenting of micro grids to the system. In the previous studies regarding to this issue, micro grid is considered as a distributed generation which should only produce electricity to the network. In this paper, micro grid is modeled as a power exchanger in the distribution network to study the effect of it on the network reconfiguration. For this purpose, reconfiguration is formulated as a multi objective optimization problem using max-min fuzzy method. In this problem, power loss reduction and load balancing among feeders are two independent objectives and voltage profile, lines congestion, radial network structure and load flow are equality and inequality constraints. Particle swarm algorithm is applied to solve the optimization problem and the reconfiguration over two 33 and 70 buses IEEE test network is shown. Results demonstrate that replacing traditional distribution systems by modern active networks and exchanging power with micro grids can lead to increase the reliability of system and more economic operation. Manuscript profile

Open Access Article

3 - Design and Implementation of a New Adaptive Sliding Mode for Current Control in Islanding Mode Operation
M. M. Ghanbarian M. Nayeripour A. H. Rajaei

20.1001.1.16823745.1395.14.3.5.1

This paper proposes a new modified adaptive sliding mode controller in order to control the inverters of DGS in the voltage and current (power) control modes in a microgrid. An observer is used to estimate the uncertain parameters in controller design and considering t More

This paper proposes a new modified adaptive sliding mode controller in order to control the inverters of DGS in the voltage and current (power) control modes in a microgrid. An observer is used to estimate the uncertain parameters in controller design and considering these estimated values, the controller is adapted to new condition. In the power management strategy, one of inverter controls the voltage and the other inverter controls the load current and balances the active power. Due to delays in startup power electronic converter and sliding mode controller, the result of controller implementation with classical controllers does not meet the requirement and so, considering these delays with adaptive controller, the performance will be improved considerably and the reference signal will be tracked with lower steady state error in comparison with classical sliding mode controller. Moreover, this controller reduces the total harmonic distortion and improves the rms and peak value tracking. Implementation of system using DSP/TMS320F28335 as well as MATLAB simulation validates the performance of system in different conditions. Manuscript profile

Open Access Article

4 - Optimal Economic Scheduling of Islanding Microgrid Considering Renewable Energy Sources (Wind Turbine and Photovoltaic System), Battery and Hydrogen Storage System in the Presence of the Demand Response Program
A. Mehdizadeh N. Taghizadegan

20.1001.1.16823745.1396.15.1.1.0

Microgrid (MG) supplied its local load with distributed energy resources at the low voltage system in distribution networks. Microgrid can be used in parts that are not allowed access to the electricity network with low investment cost. The used islanding MG in this res More

Microgrid (MG) supplied its local load with distributed energy resources at the low voltage system in distribution networks. Microgrid can be used in parts that are not allowed access to the electricity network with low investment cost. The used islanding MG in this research includes wind turbine and photovoltaic systems as renewable energy sources and hydrogen storage system (HSS). This paper proposes a new energy management strategy (EMS) for MG in the presence of the HSS considering the power uncertainties of renewable energy sources. The objective of proposed EMS is to minimize the operating costs of batteries, HSS and the costs associated with excess and undelivered energy considering the supplied load constraints. The considered technical constraints in this paper contain renewable energy sources limits and battery and HSS constraints. HSS includes electrolyzer (EL), hydrogen tanks and fuel cell (FC). Demand response program (DRP) is used to flat the load curve and optimal operation of MG. The proposed model on a MG is been implemented in GAMS software. The simulation results show that the operation cost of MG reduced by using of HSS and DRP. Manuscript profile

Open Access Article

5 - Optimal Operation of AC Microgrid in the Presence of Plug-in Electric Vehicles under Demand Side Managemen
A. Mehdizadeh N. Taghizadegan J. Salehi

20.1001.1.16823745.1397.16.3.6.6

In the recent years, integrations of renewable energy sources as well as plug-in electric vehicles are increased in the AC microgrid. Also, demand side management can be used to manage peak load in order to improve optimal performance of AC microgrid. Therefore, this pa More

In the recent years, integrations of renewable energy sources as well as plug-in electric vehicles are increased in the AC microgrid. Also, demand side management can be used to manage peak load in order to improve optimal performance of AC microgrid. Therefore, this paper proposes optimal operation of AC microgrid in the presence of plug-in electric vehicles under demand side management. The proposed model describes optimal operation of microgrid including the exchange power with the upstream grid, the production of DG units including wind turbines, battery storage, diesel generators, charging and discharging of electric vehicles and the manner of participation of large industrial consumers and aggregators of small consumers in demand side management that minimize the operation cost of microgrid. The proposed formulation is considered the mathematical model of various energy sources in a microgrid and the AC load flow constraints and the bus voltage and feeder current limitations has been considered.In the proposed model, charge and discharge management of plug-in electric vehicles and demand side management are simultaneously proposed to reduce operation cost of AC microgrid subject to technical and economic constraints. A 33-bus microgrid is used as test system in order to investigate effects of plug-in electric vehicles and demand side management on optimal operation of AC microgrid. The proposed model is formulated via mixed-integer non-linear programming which is solved using CPLEX solver under GAMS optimization software. Manuscript profile

Open Access Article

6 - Robust Scheduling of a Smart Microgrid Connected to the Grid Considering Air Pollution in the Presence of Controllable Loads
amin namvar NAVID TAGHIZADEGAN KALANTARI

20.1001.1.16823745.1399.18.1.3.3

The microgrid is a set of local energy producers and consumers that can be utilized with low cost and high reliability. In this paper, a robust multi-objective model is proposed to reduce operating costs and carbon emissions in which a smart grid utilizes a wind turbine More

The microgrid is a set of local energy producers and consumers that can be utilized with low cost and high reliability. In this paper, a robust multi-objective model is proposed to reduce operating costs and carbon emissions in which a smart grid utilizes a wind turbine and micro-turbine to feed its connected loads. The microgrid also uses a battery to store electrical energy in off-peak hours and to deliver energy in on-peak hours. On the other hand, it is connected to the main grid and can exchange energy with it. Consumers connected to this microgrid are divided into two groups. The first group is uncontrollable loads with certain load pattern and the second group is controllable loads that have certain energy consumption but can be controlled by the operating time. The proposed model is a mixed-integer linear programming problem and is simulated with the CPLEX solver in GAMS software. The results show that when the price of electricity is low, the loads are often supplied by grid electricity, and when the price of electricity is high, they are often fed by micro-turbines, batteries, and wind turbines. Manuscript profile

Open Access Article

7 - A New Method to Detect Line-to-Ground Faults in DC Microgrids Using Instantaneous Power Changes
Said Abbasi N. Ghaffarzadeh

20.1001.1.16823745.1399.18.2.2.4

With the increasing of sensitive loads such as data centers, the use of DC microgrids has increased. Line to ground fault is the most common type of fault in this type of microgrid, which causes various damages to the DC microgrid. One of the most important challenges i More

With the increasing of sensitive loads such as data centers, the use of DC microgrids has increased. Line to ground fault is the most common type of fault in this type of microgrid, which causes various damages to the DC microgrid. One of the most important challenges in operating a DC microgrid is the lack of effective protection against this faults type. In this paper, by using local measurements such as voltage and current at the beginning of each line, the instantaneous power changes in them are computed and a new protection scheme that is not based on any communication line is presented. The proposed protection scheme has good accuracy and speed of operation and is able to detect line-to-ground faults in DC microgrids with high-speed. The accuracy and precision of the protection scheme has been tested under different conditions. Manuscript profile

Open Access Article

8 - Harmonic Voltage Reduction by using Droop Controller in Inverters Parallel Operation
B. Fani M. Moazzami E. Farhoodi

20.1001.1.16823745.1398.17.2.2.7

Microgrid technology makes possible coordination and effective use of different energy resources for supplying loads. In order to have synchronous operation between inverter resources during the occurrence of islanding condition, the use of droop controller structure wo More

Microgrid technology makes possible coordination and effective use of different energy resources for supplying loads. In order to have synchronous operation between inverter resources during the occurrence of islanding condition, the use of droop controller structure would be beneficial. In this paper, the conventional droop controller is modified to divide proportional power between resources and cause accurate voltage setting in output resources. By providing a model for connected inverter to the nonlinear load, a harmonic droop controller has been designed. By droop controller related to each harmonic, the harmonic voltages are calculated and add to the reference voltage. Therefore the quality of the output voltage is improved. Then the inverter voltage control loop would be modified with resistance impedance in the presence of non-linear loads, so that, in combination with harmonic droop controller, THD of output voltage considerably reduced. Simulation results show the ability of suggested method in reduction of harmonic voltages in inverters parallel operation. Manuscript profile

Open Access Article

9 - Preventive and Probabilistic-Possibilistic Scheduling of Microgrid against the Natural Phenomena in the Presence of Electric Vehicles
Amirhossein Nasri A. Abdollahi M. Rashidinejad

20.1001.1.16823745.1399.18.3.6.0

This paper proposes a preventive and probabilistic–possibilistic framework for day-ahead scheduling of Electric Vehicles (EVs) parking lot and distributed generation in a microgrid. The suggested scheduling is performed in normal and emergency conditions when a natural More

This paper proposes a preventive and probabilistic–possibilistic framework for day-ahead scheduling of Electric Vehicles (EVs) parking lot and distributed generation in a microgrid. The suggested scheduling is performed in normal and emergency conditions when a natural phenomenon appears and the microgrid is disconnected from the upstream network. Furthermore, the uncertainty of EVs number in a parking lot is considered by Z-number as a probabilistic-possibilistic model. Moreover, the uncertainties of photovoltaic units generation, wind turbine output power, market price, and load demand are modeled by Monte Carlo as a probabilistic method. Furthermore, natural phenomena occurrences are modeled by considering multifarious scenarios according to when the phenomenon unfolds and how much it takes. In the suggested framework, the operation of parking lots is based on the uncertainty and EVs charging/discharging schedule. The operational cost in normal condition and load shedding cost in addition to operational cost are considered as the objective functions of the proposed structure. To evaluate the performance of the suggested structure, the modified 33-bus IEEE distribution network is employed. Manuscript profile

Open Access Article

10 - Distributed Control Scheme Based on Model Predictive Control for Supplying Power in an Isolated DC Microgrid
Arash Abedi Behrooz Rezaie Alireza Khosravi مجید شهابی

20.1001.1.16823745.1399.18.4.5.1

In this paper, a control scheme is presented for an isolated DC microgrid including wind turbine connected to permanent magnet synchronous generator, electrical energy storage unit, and variable electrical loads. Energy sources are connected to a common bus through DC b More

In this paper, a control scheme is presented for an isolated DC microgrid including wind turbine connected to permanent magnet synchronous generator, electrical energy storage unit, and variable electrical loads. Energy sources are connected to a common bus through DC buck and buck-boost converters. The local distributed controllers are located in the first control layer. These controllers are designed based on a Lyapunov stability analysis and thereby its stability is guaranteed. Moreover, the current and voltage, injected to the network, are adjusted by controlling the switching functions of the converters. The decentralized secondary controllers determine the contribution of the local units for supplying the local loads. In this control layer, a model predictive controller for the wind generation unit as well as a proportional-integral controller for preserving the bus voltage are proposed to determine the reference currents for the local controllers. In addition to the practical simplicity, complete isolation of the secondary controllers, minimum requirements to data transfer, and providing a control structure without any need to change in development plan are the important advantages of the proposed control scheme. The performance of the controllers is investigated and verified using the simulations in MATLAB software performed for different cases. Manuscript profile

Open Access Article

11 - Comprehensive Optimal Management System of Distributed Resources Using Dynamic Neural Network in Modeling of Electricity Consumption Uncertainty for Grid-Connected Microgrids
Mohammad Veysi محمدرضا سلطانپور jafar Khalilpour hadi niaei

20.1001.1.16823745.1400.19.1.4.1

In this paper, to enhance the optimal planning for power management of micrigrids, a strategy is proposed using power sharing through coordination between microgrids and the neighborhood system, which has no additional costs for generating units. The uncertainty values More

In this paper, to enhance the optimal planning for power management of micrigrids, a strategy is proposed using power sharing through coordination between microgrids and the neighborhood system, which has no additional costs for generating units. The uncertainty values of electrical consumers are modeled by dynamic neural network, considering the implementation process and high accuracy of forecasting. In another view, to supply the electrical energy of microgrid, diesel generator, renewable energies such as solar energy and wind energy and so, battery energy storage are used, in addition to the upstream grid connection. As well as, using of the reliability factors, along with a detailed assessment of current costs will improve the performance of microgrid. Hence, the loss of power supply probability (LPSP) and loss of load expectations (LOLE) are expressed as factors for assessing the accuracy of current costs. The proposed model is implemented in GAMS and MATLAB environment and the simulation results clearly demonstrate the desired performance of the proposed algorithm, and leads to gaining revenue for the under-study system. Manuscript profile

Open Access Article

12 - A Two-Step Stochastic Linear Programming Approach for Microgrid Resources and Energy Storage Management with Real-Time Pricing Program Using Salp Swarm Optimization Algorithm
Mohsen Sarami مجيد معظمي غضنفر شاهقلیان

20.1001.1.16823745.1401.20.1.14.8

Integrating renewable resources to provide local load has created a concept called microgrid. With the widespread introduction of microgrids, energy management and system utilization and resources in the electricity market are important tasks of microgrid management. In More

Integrating renewable resources to provide local load has created a concept called microgrid. With the widespread introduction of microgrids, energy management and system utilization and resources in the electricity market are important tasks of microgrid management. In this paper, the problem of microgrid utilization is modeled taking into account economic, technical and uncertainties related to power consumption, wind speed and solar radiation in electricity market conditions. One of the most important issues in the electricity market is the discussion of the participation of units in real price conditions. In this paper, a framework for the exploitation of electricity and the consumption of controllable loads through integrated utilization of distributed energy sources of uncertainty is presented from a consumer perspective. The optimization problem is a two-step stochastic linear programming that minimized the cost of microgrid operation and expected cost of consumers considering the consumer’s requirement for controllable loads in the desire time interval and distribution company constraints that solved by using Salp swarm optimization algorithm. RBT and IBR tariffs are employed for modeling retail power market for better reflection of wholesale price volatility and avoid of the concurrent use of consumers. In this method price announced to the consumers by retailers only is limited specific later hours instead of the entire operation period. In this condition any timing of controllable loads need to price forecasting, while this forecasting have some uncertainties. These uncertainties are modeled using Monte Carlo method for stochastic price variable scenario generation. MATLAB software is employed for simulation and verification of the proposed method. Manuscript profile

Open Access Article

13 - Synchronverter with the Capability of Damping Enhancement for the Suppression of Power and Frequency Oscillations in Inverter-Based Micro-Grids
kambiz Mehrdadian Seyed Mohammad Azimi

20.1001.1.16823745.1401.20.3.14.2

Nowadays, due to the advances made in power electronics and the desire to use renewable energy resources, micro-grids have been developed considerably. One of the challenging operation modes of Micro-grids is named islanded mode, where the control of power and frequency More

Nowadays, due to the advances made in power electronics and the desire to use renewable energy resources, micro-grids have been developed considerably. One of the challenging operation modes of Micro-grids is named islanded mode, where the control of power and frequency is a challenging problem. Many distributed energy resources are operated based on electronic power converters and these converters have no inertia unlike synchronous generators, as a result, the issue of power and frequency control in micro-grids is considered as a serious problem. This issue will cause severe frequency fluctuations following to power changes which can lead to system instability. In this paper, first a sample micro-grid is simulated and modeled in synchronous reference frame then using the idea of inertia in synchronous machines, a novel control method with the capability of damping enhancement during system transients is proposed. The control scheme utilizes the idea of virtual inertia injection during the power and frequency fluctuations based on the synchronverter model. Finally, the effectiveness of the proposed method is verified using a set of the time domain simulations carried out in Matlab/Simulink software in an inverter based multi-source micro-grid operating in the island mode, and the results are compared with the vector control method implemented in the rotating reference frame under different scenarios. Manuscript profile

Open Access Article

14 - Stabilizing and Synchronizing the Islanded Microgrid with the Presence of Sensor and Actuator Fault and Cyber-Attack with Secondary Controller Design
Abdollah Mirzabeigi Ali Kazemy Mehdi Ramezani Seyed Mohammad Azimi

In many microgrid control methods, the output information of sensors and actuators of neighbouring distributed generators (DGs) is used to stabilize and synchronize voltage and frequency. Many problems such as disturbances, uncertainty, unmodeled dynamics, cyber-attacks More

In many microgrid control methods, the output information of sensors and actuators of neighbouring distributed generators (DGs) is used to stabilize and synchronize voltage and frequency. Many problems such as disturbances, uncertainty, unmodeled dynamics, cyber-attacks, noise, time delay, and measurement errors cause invalid data problems and errors in the system. Better microgrid control depends on the quality of data measured or sent from the output of sensors and actuators. In this paper, according to the advantages of the Cooperative distributed hierarchical control, it is used for control and synchronization in the islanded microgrid with the presence of sensor and actuator error. To synchronize DGs with multi-agent systems and communication channels, it is modeled with graph theory. To stabilize and synchronize, sensor and actuator error in the DG model is mathematically formulated. In the proof of stability and synchronization, the appropriate Lyapunov candidate is presented and the conditions of stability and synchronization are proved. Finally, to show the effectiveness of the designed controller in solving communication channel problems and verifying the presented theory, a case study is simulated in the MATLAB/Simulink software environment with the presence of error and cyber-attack of sensors and actuators. Manuscript profile

Open Access Article

15 - Multi-Objective Economic-Environment Scheduling of Microgrids in the Presence of Hybrid Electric Vehicles and Demand Response to Smooth the Distribution Nodal Prices
ali mirzaei NAVID TAGHIZADEGAN KALANTARI Sajad Najafi Ravadanegh

Today, with the growing demand for hybrid electric vehicles in microgrids, electricity supply, environmental issues, and rescheduling are among the challenges of microgrids that must be solved and suitable solutions provided. To overcome these challenges, this paper int More

Today, with the growing demand for hybrid electric vehicles in microgrids, electricity supply, environmental issues, and rescheduling are among the challenges of microgrids that must be solved and suitable solutions provided. To overcome these challenges, this paper introduces a new multi-objective optimization model, which in the first objective, minimizes the total operation cost of the microgrid, and in the second objective, improves the reliability index by reducing the amount of energy not supplied. Due to these two objectives, a multi-objective evolutionary seagull optimization algorithm is used to find the optimal global solutions. In this regard, hybrid electric vehicles and demand response programs are used to smooth out distribution nodal prices and reduce CO2 emissions. The 69-bus distribution network has been used to evaluate the efficiency of the proposed method. Manuscript profile

Current Issue

Published Issues

Menu

Browse

List of Articles ریزشبکه