Distribution Systems
P. Niranjan; N.K. Choudhary; N. Singh; R.K. Singh
Abstract
Conventional overcurrent protection schemes may not be sufficient to provide the complete protection of microgrids, especially in the islanded mode (ISM) of operation. Directional overcurrent relays (DOCRs) in microgrid may malfunction due to significant changes in fault current level and change in topology ...
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Conventional overcurrent protection schemes may not be sufficient to provide the complete protection of microgrids, especially in the islanded mode (ISM) of operation. Directional overcurrent relays (DOCRs) in microgrid may malfunction due to significant changes in fault current level and change in topology from grid-connected mode (GCM) to ISM. The novel contribution of this study is to determine the optimal settings of time-voltage-current-based dual-setting DOCRs with mixed inverse characteristics, valid in both GCM and ISM, without any miscoordination of relay pairs. The relay coordination problem is formulated as a mixed integer non-linear programming (MINLP) problem and optimally solved using an improved environmental adaption method (IEAM). The proposed relay coordination scheme has been tested on a 7-bus microgrid, the low-voltage section of the modified IEEE-14 bus benchmark system. The performance of the proposed protection scheme has been compared with the existing schemes, considering conventional DOCRs, time-voltage-current-based DOCRs, and dual-setting DOCRs.
Distribution Systems
F. Jabari; M. Shabanzadeh; M. Zeraati
Abstract
Distribution system state estimation (DSSE) is widely used for real-time monitoring of power grids, where different types of metering devices such as phasor measurement units, smart meters, power quality meters, and etc. are installed. The accuracy of estimated states and the system observability level ...
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Distribution system state estimation (DSSE) is widely used for real-time monitoring of power grids, where different types of metering devices such as phasor measurement units, smart meters, power quality meters, and etc. are installed. The accuracy of estimated states and the system observability level depends on the type, number and location of meters and since there are many nodes and branches in such large networks, a highly redundant measurement infrastructure is practically unattainable due to the limited investment budget. Hence, this paper proposes a novel meter placement algorithm aiming to minimize the distribution system state estimation error and enhance the system observability level considering the limited number of available meters or investment cost. To this end, on one hand, Monte Carlo simulation (MCS) is applied to a weighted least squares (WLS) based DSSE to find the nodal voltage magnitude and angle as the state variables under the uncertainty of measurements. A MCS and WLS-DSSE hybrid iterative nonlinear optimization mesh adaptive direct search (NOMADS) algorithm is proposed to obtain the best locations of the voltage measuring units considering a trade-off between the DSSE performance and the investment cost. The uncertainties associated with the voltage measurements are modeled using random errors with normal probability distribution function. The efficiency and applicability of the proposed method are analyzed by its implementation on a 25-node unbalanced radial distribution system and numerical results demonstrate that this method technically outperforms other heuristic algorithms in the literature which are usually computationally intractable or more demanding in finding the optimal meter places under uncertainties. Compared to other recently developed algorithms, the accuracy of the estimated states as well as the runtime of the proposed algorithm are improved significantly especially under severe measuring errors. Moreover, it is capable to find the minimum number of voltage meters ensuring that the system observability criterion and the expected DSSE accuracy are fulfilled under the uncertain operating conditions.
Distribution Systems
N. Kumar; D.K. Jain
Abstract
The integration of distributed generations (DGs) can disrupt the distribution system's radial configuration, leading to potential coordination issues with the existing protection scheme. Disparate operating modes of microgrids render traditional protection schemes ineffective and insecure. This highlights ...
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The integration of distributed generations (DGs) can disrupt the distribution system's radial configuration, leading to potential coordination issues with the existing protection scheme. Disparate operating modes of microgrids render traditional protection schemes ineffective and insecure. This highlights the need for alternative approaches to ensure the reliability and security of microgrids. To mitigate the relay coordination problem in microgrids, this paper puts forth a solution in the form of an adaptive protection scheme. The proposed method is based on fault current and integrates the use of adaptive numerical directional overcurrent relays (ANDOCRs). The proposed adaptive protection strategy encompasses a microgrid central protection controller (MCPC) equipped with communication capabilities. This feature enables MCPC to communicate with intelligent field electronics devices (IFEDs). The MCPC receives data from the IFEDs and updates the ANDOCRs' settings according to the operation mode. This paper suggests a modified objective function specifically tailored to tackle the nonlinear optimization problem for relay coordination in microgrids to strengthen the coordination between primary and backup relays. The proposed adaptive protection scheme also incorporates a quick online fault detection algorithm to identify the faulty feeder precisely. The proposed method is assessed for its performance using a highly unbalanced IEEE-13 node distribution system in MATLAB/Simulink.
Distribution Systems
S.S. Halve; S.S. Raghuwanshi; D. Sonje
Abstract
Distribution systems play a crucial role in delivering power to customers and bridging the gap between bulk power transmission and end-users. Increasing energy demand due to factors like industrial development and population growth necessitates efficient distribution system management. A low X/R ratio ...
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Distribution systems play a crucial role in delivering power to customers and bridging the gap between bulk power transmission and end-users. Increasing energy demand due to factors like industrial development and population growth necessitates efficient distribution system management. A low X/R ratio in distribution networks leads to higher real power losses, lower voltage profiles, and reduced system reliability. Selecting optimal combinations of sectionalizing and tie switches for network reconfiguration is a complex and time-consuming task. This article introduces the Modified load flow (MLF) method, which combines the backward/forward sweep method with an effective approach for selecting sectionalizing and tie switches to minimize real power loss. The MLF method offers advantages such as ease of implementation, requiring fewer control parameters, and scalability to large distribution systems. The proposed MLF method is compared with particle swarm optimization (PSO) and other existing algorithms in literature such as the cuckoo search algorithm (CSA), Improved sine cosine algorithm (ISCA), and Improved harmony search algorithm (IHSA). Results obtained from MLF and PSO to IEEE-33, 69, and 118 bus radial distribution systems demonstrate significant reductions in real power loss, with MLF outperforming PSO in terms of efficiency and effectiveness. Voltage profiles at critical buses before and after network reconfiguration are examined, showing improvements in MLF better than the PSO method. Various reliability indices are evaluated to assess system performance before and after network reconfiguration, demonstrating improvements in system reliability. Overall, the proposed modified load flow method offers a promising approach to address the challenges of real power losses and system reliability in radial distribution systems.
Distribution Systems
S. Panjeie; A. Fakharian; M. Sedighizadeh; A. Sheikhi fini
Abstract
Microgrid operators (MGOs) try to restore as much demand as possible when they are faced with electrical power outages corre-sponding to extreme events. This work suggests an outage management strategy (OMS) to improve microgrid resilience by using two optimal actions that are distribution feeder reconfiguration ...
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Microgrid operators (MGOs) try to restore as much demand as possible when they are faced with electrical power outages corre-sponding to extreme events. This work suggests an outage management strategy (OMS) to improve microgrid resilience by using two optimal actions that are distribution feeder reconfiguration (DFR) and scheduling of the distributed energy resources (DERs). Later happening a line fault, the radial network topology is determined by the proposed model using an evaluation of the inci-dence matrix. The presented work handles the uncertain behavior of non-dispatchable DERs and the electrical loads which model by the robust optimization approach. To expand the flexibility of the proposed model, the demand response program (DRP) is treated as the curtailed demand. The aim of optimization is the minimization of the total cost for dispatchable DER operation and electrical load decrease. The recommended robust linear problem (RLP) model is simulated by the CPLEX solver in GAMS software. Applying the suggested model in the 69-bus unbalanced test system demonstrate that the proposed model averagely decreases total operation cost and execution time by 10.62% and 22.23% on all scenarios in comparison with the de-terministic model.
Distribution Systems
S. Behzadi; N. Osali; A. Younesi; A. Bagheri
Abstract
Nowadays, with the detrimental impacts of air pollution on human health and its significant societal expenses, it has been imperative to utilize renewable energy sources (RESs) and energy storage systems (ESSs). This study introduces a new objective function aimed at achieving a long-term optimal plan ...
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Nowadays, with the detrimental impacts of air pollution on human health and its significant societal expenses, it has been imperative to utilize renewable energy sources (RESs) and energy storage systems (ESSs). This study introduces a new objective function aimed at achieving a long-term optimal plan where it contrasts the outcomes of meeting network load demand with and without the integration of renewable/non-renewable distributed energy resources (DERs). The analysis considers installation and operational costs, addressing uncertainties through Monte-Carlo and scenario-based methodologies. The proposed problem is structured as a convex optimization model. Simulations are conducted on the IEEE 33-bus system, showcasing the model’s efficacy through cost efficiency and reduced emission expenses. The study confirms that the investment in renewable energy resources and ESS units can be recouped in less than five years. It was observed that in the long-term, there is a cost reduction of 29.4\% when DER units are incorporated. Also, the emission cost for the horizon year is diminished by 43.2\% compared to the case where the DERs are absent.
Distribution Systems
A. Khorshidi; T. Niknam; B. Bahmani
Abstract
In this work, a new control scheme for synchronization of AC microgrids with upstream power grid is presented. The effects of V2Gs (vehicle to grid) dynamics on synchronization process is studied. This new control approach is based on the optimal fractional calculus and has been developed for synchronization ...
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In this work, a new control scheme for synchronization of AC microgrids with upstream power grid is presented. The effects of V2Gs (vehicle to grid) dynamics on synchronization process is studied. This new control approach is based on the optimal fractional calculus and has been developed for synchronization of the microgrid. The V2Gs effect on the dynamics of the microgrid is analyzed through small signal stability and simulations. This effect is also considered in synchronization process by considering a PHEV-dominated-microgrid. The proposed control scheme is a coordinated control of distributed resources and provides a soft and reliable synchronization for microgrid. In the proposed control scheme, the fractional order proportional-integral-derivative (FOPID) controllers have optimally been tuned and implemented using the genetics algorithm (GA). The simulation results confirm the effectiveness of the proposed control strategy in soft and swift synchronization of the microgrid.
Distribution Systems
S. Ghasemi; A. Khodabakhshian; R. Hooshmand
Abstract
After extreme events such as floods, thunderstorms, blizzards and hurricanes there will be devastating effects in the distribution networks which may cause a partial or complete blackout. Then, the major concern for the system operators is to restore the maximum critical loads as soon as possible by ...
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After extreme events such as floods, thunderstorms, blizzards and hurricanes there will be devastating effects in the distribution networks which may cause a partial or complete blackout. Then, the major concern for the system operators is to restore the maximum critical loads as soon as possible by available generation units. In order to solve this problem, this paper provides a restoration strategy by using Distributed Generations (DGs). In this strategy, first, the shortest paths between DGs and critical loads are identified. Then, the best paths are determined by using a decision-making method, named PROMOTHEE-II to achieve the goals. The uncertainties for the output power of DGs are also considered in different scenarios. The IEEE 123-node distribution network is used to show the performance of the suggested method. The simulation results clearly show the efficiency of the proposed strategy for critical loads restoration in distribution networks.
Distribution Systems
H. Yousefi; S.A. Gholamian; A. Zakariazadeh
Abstract
In this paper, a distributed method for reactive power management in a distribution system has been presented. The proposed method focuses on the voltage rise where the distribution systems are equipped with a considerable number of photovoltaic units. This paper proposes the alternating direction method ...
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In this paper, a distributed method for reactive power management in a distribution system has been presented. The proposed method focuses on the voltage rise where the distribution systems are equipped with a considerable number of photovoltaic units. This paper proposes the alternating direction method of multipliers (ADMMs) approach for solving the optimal voltage control problem in a distributed manner in a distribution system with high penetration of PVs. Also, the proposed method uses a clustering approach to divide the network into partitions based on the coupling degrees among different nodes. The optimal reactive power control strategy is conducted in each partition and integrated using ADMM. The proposed method is tested on a 33 bus IEEE distribution test system and a modified IEEE 123-node system. The result evidence that the proposed method has used the lower reactive power if compared to the conventional method.
Distribution Systems
H. Fateh; A. Safari; S. Bahramara
Abstract
Distributed energy resources (DERs) including distributed generators (DGs) and controllable loads (CLs) are managed in the form of several microgrids (MGs) in active distributions networks (ADNs) to meet the demand locally. On the other hand, some loads of distribution networks (DNs) can be supplied ...
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Distributed energy resources (DERs) including distributed generators (DGs) and controllable loads (CLs) are managed in the form of several microgrids (MGs) in active distributions networks (ADNs) to meet the demand locally. On the other hand, some loads of distribution networks (DNs) can be supplied by retailers which participate in wholesale energy markets. Therefore, there are several decision makers in DNs which their cooperation should be modeled for optimal operation of the network. For this purpose, a bi-level optimization approach is proposed in this paper to model the cooperation between retailers and MGs in DNs. In the proposed model, the aim of the upper level (leader) and lower level (follower) problems are to maximize the profit of retailers and to minimize the cost of MGs, respectively. To solve the proposed multi-objective bi-level optimization model, multi-objective Particle Swarm Optimization (MOPSO) algorithm is employed. The effectiveness of the proposed bi-level model and its solution methodology is investigated in the numerical results.
Distribution Systems
O. Eghbali; R. Kazemzadeh; K. Amiri
Abstract
State estimation in the energy management center of active distribution networks has attracted many attentions. Considering an increase in complexity and real-time management of active distribution networks and knowing the network information at each time instant are necessary. This article presents ...
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State estimation in the energy management center of active distribution networks has attracted many attentions. Considering an increase in complexity and real-time management of active distribution networks and knowing the network information at each time instant are necessary. This article presents a two-step multi-area state estimation method in balanced active distribution networks. The proposed method is based on the location of PMU measurements of the network. The network is divided into several sub-areas about PMUs in the first step. A local sate estimation is implemented in each sub-area. The estimated values of the first step along with real measurements are used as measurements for second step estimation. The measurements are located in each sub-area using these values based on the ellipse area method, and the best location of measurements is extracted. Therefore, a second step state estimation including integrated state estimation of the whole network is performed by using the measurements obtained and located from the first step. The estimation results of the first step are used in the second step which improve the estimation accuracy. Simulations are performed on a standard IEEE 69-bus network to validate the proposed method.
Distribution Systems
M.A. Tavakoli Ghazi Jahani; P. Nazarian; A. Safari; M.R. Haghifam
Abstract
Network reconfiguration is a nonlinear optimization procedure which calculates a radial structure to optimize the power losses and improve the network reliability index while meeting practical constraints. In this paper, a multi-objective framework is proposed for optimal network reconfiguration with ...
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Network reconfiguration is a nonlinear optimization procedure which calculates a radial structure to optimize the power losses and improve the network reliability index while meeting practical constraints. In this paper, a multi-objective framework is proposed for optimal network reconfiguration with the objective functions of minimization of power losses and improvement of reliability index. The optimization problem is solved by multi-objective grasshopper optimization algorithm (MOGOA) which is one of the most modern heuristic optimization tools. To solve an optimization problem, the suggested algorithm mathematically mimics and formulates the behavior of grasshopper swarms. The modifying comfort zone coefficient needs grasshoppers to balance exploration and exploitation, which helps the MOGOA to find an exact approximation of global optimization and not trapped in local optima. The efficiency of the suggested technique is approved regarding the 33-bus and 69-bus test systems. Optimization results expressed that the suggested technique not only presents the intensified exploration ability but also has a better solution compared with previous algorithms.
Distribution Systems
P. Salyani; J. Salehi
Abstract
The reliability of distribution networks is inherently low due to their radial nature, consequently distribution companies (DisCos) usually seek to improve the system reliability indices with the minimum possible investment cost. This can be known as system-oriented reliability planning (SORP). However, ...
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The reliability of distribution networks is inherently low due to their radial nature, consequently distribution companies (DisCos) usually seek to improve the system reliability indices with the minimum possible investment cost. This can be known as system-oriented reliability planning (SORP). However, there can exist some customers that are not satisfied by their reliability determined by adopting the SORP and they may be eager to have a higher level of reliability. Therefore, other planning in addition of SORP is required to concern the customer viewpoint reliability. This paper introduces the customer-oriented reliability planning (CORP) in medium voltage network which is an innovative approach in the context of load point reliability. To this end, first a SORP is conducted to improve the distribution system reliability index. Then the strategy is revised and the CORP is adopted by DisCo considering involving the results obtained in SORP and the customers that have declared to reduce their expected energy not supplied (EENS). Since the surplus investment cost stem from the planning revision is received from the requestor customers, CORP can provide a proper and acceptable mechanism to fairly allocate the surplus cost to those customers. Furthermore, this problem is studied under the probabilistic nature of distribution network. Simultaneous placement of distributed generators (DGs) and automatic sectionalizing switches is implemented too with a new defined load shedding mechanism in order to enhance the reliability level for both mentioned planning frameworks.
Distribution Systems
M. Alilou; D. Nazarpour; H. Shayeghi
Abstract
The optimal management of distributed generation (DG) enhances the efficiency of the distribution system; On the other hand, increasing the interest of customers in optimizing their consumption improves the performance of DG. This act is called demand side management. In this study, a new method based ...
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The optimal management of distributed generation (DG) enhances the efficiency of the distribution system; On the other hand, increasing the interest of customers in optimizing their consumption improves the performance of DG. This act is called demand side management. In this study, a new method based on the intelligent algorithm is proposed to optimal operate the demand side management in the presence of DG units and demand response. Firstly, the best location and capacity of different technologies of DG are selected by optimizing the technical index including the active and reactive loss and the voltage profile. Secondly, the daily performance of multi-DG and grid is optimized with and without considering the demand response. The economic and environmental indices are optimized in this step. In both steps, the non-dominated sorting firefly algorithm is utilized to multi-objective optimize the objective functions and then the fuzzy decision-making method is used to select the best result from the Pareto optimal solutions. Finally, the proposed method is implemented on the IEEE 33-bus distribution system and actual 101-bus distribution systems in Khoy-Iran. The obtained numerical results indicate the impact of the proposed method on improving the technical, economic and environmental indices of the distribution system.
Distribution Systems
R. Afshan; J. Salehi
Abstract
This paper proposes a novel hybrid Monte Carlo simulation-genetic approach (MCS-GA) for optimal operation of a distribution network considering renewable energy generation systems (REGSs) and battery energy storage systems (BESSs). The aim of this paper is to design an optimal charging /discharging scheduling ...
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This paper proposes a novel hybrid Monte Carlo simulation-genetic approach (MCS-GA) for optimal operation of a distribution network considering renewable energy generation systems (REGSs) and battery energy storage systems (BESSs). The aim of this paper is to design an optimal charging /discharging scheduling of BESSs so that the total daily profit of distribution company (Disco) can be maximized. In this study, the power generation of REGSs such as photovoltaic resources (PVs) and the network electricity prices are studied through their uncertainty natures. The probability distribution function (PDF), is used to account for uncertainties in this paper. Also, the Monte Carlo simulation (MCS) is applied to generate different scenarios of network electricity prices and solar irradiation of PVs. Optimal scheduling of BESSs can be performed by genetic algorithm (GA). In this paper, firstly, the charging and discharging state of BESSs (positive or negative sign of battery power) is determined according to the variable amount of the electricity prices and power produced from PVs, which have been obtained from the Monte Carlo simulation. Then by using the GA, optimal amount of BESSs is determined. Therefore, a hybrid MCS-GA is used to solve this problem. Numerical examples are presented to illustrate the optimal charging/discharging power of the battery for maximizing the total daily profit.
Distribution Systems
A. Bagheri; R. Noroozian; J. Gholinezhad
Abstract
In the most recent heuristic methods, the high potential buses for capacitor placement are initially identified and ranked using loss sensitivity factors (LSFs) or power loss index (PLI). These factors or indices help to reduce the search space of the optimization procedure, but they may not always indicate ...
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In the most recent heuristic methods, the high potential buses for capacitor placement are initially identified and ranked using loss sensitivity factors (LSFs) or power loss index (PLI). These factors or indices help to reduce the search space of the optimization procedure, but they may not always indicate the appropriate placement of capacitors. This paper proposes an efficient approach for the optimal capacitor placement in radial distribution networks with the aim of annual costs minimization based on the sequential placement of capacitors and calculation of power loss index. In the proposed approach, initially, the number of capacitors location is estimated using the total reactive power demand and the average range of capacitors available in the market. Then, the high potential buses can be identified using sequential power loss index-based method. This method leads to achieve the optimal or near optimal locations for the capacitors and decrease the search space of the optimization procedure significantly. The particle Swarm Optimization (PSO) algorithm takes the final decision for the optimum size and location of capacitors. To evaluate the efficiency of the conducted approach, it is tested on several well-known distribution networks, and the results are compared with those of existing methods in the literature. The comparisons verify the effectiveness of the proposed method in producing fast and optimal solutions.
Distribution Systems
S. Ghaemi; K. Zare
Abstract
The determination of practical and coherent policy to pin down the price in restructured distribution networks should be considered as a momentous topic. The present paper introduces a new method of distribution marginal price (DMP) calculation. The main aim of this paper is to evaluate the DMP for both ...
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The determination of practical and coherent policy to pin down the price in restructured distribution networks should be considered as a momentous topic. The present paper introduces a new method of distribution marginal price (DMP) calculation. The main aim of this paper is to evaluate the DMP for both producers and consumers separately. For this purpose, the first part of the procedure emphasizes a price by which the producers should sell their power. To meet this target, the share of each node plays a significant role in the total active loss of the network. The producers will make a substantial profit when their efficiency leads to decreasing the share of the node that is associated with the total loss. In the second part of the procedure, DMP is computed for the consumers. In this part, based on the distribution system operator’s decision about the obtained profit allocated to the consumers, their payment has been reduced. This method has been applied to the 33-Bus Distribution System. The results demonstrate the characteristic of the method which tends to encourage the distributed units to increase their output powers. This is the reason why the penetration of these units in the networks is an opportunity for consumers from an economic aspect in such a way that merchandising surplus (MS) becomes zero.
Distribution Systems
A. Lashkar Ara; H. Bagheri Tolabi; R. hosseini
Volume 4, Issue 2 , December 2016, , Pages 93-103
Abstract
In this paper, a combination of simulated annealing (SA) and intelligent water drops (IWD) algorithm is used to solve the nonlinear/complex problem of simultaneous reconfiguration with optimal allocation (size and location) of wind turbine (WT) as a distributed generation (DG) and dynamic voltage restorer ...
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In this paper, a combination of simulated annealing (SA) and intelligent water drops (IWD) algorithm is used to solve the nonlinear/complex problem of simultaneous reconfiguration with optimal allocation (size and location) of wind turbine (WT) as a distributed generation (DG) and dynamic voltage restorer (DVR) as a distributed flexible AC transmission systems (DFACT) unit in a distribution system. The objectives of this research are to minimize active power loss, minimize operational cost, improve voltage stability, and increase the load balancing of the system. For evaluation purposes, the proposed algorithm is evaluated using the Tai-Power 11.4-kV real distribution network. The impacts of the optimal placement of the WT, DVR, and WT with DVR units are separately evaluated. The results are compared in terms of statistical indicators. By comparing all the testing scenarios, it is observed that the multi-objective optimization evolutionary algorithm is more beneficial than its single-objective optimization counterpart. Also, the obtained results show that the proposed SAIWD method outperforms the IWD method and other intelligent search algorithms such as genetic algorithm or particle swarm optimization.
Distribution Systems
A. Najafi; R. Aboli; H. Falaghi; M. Ramezani
Volume 4, Issue 2 , December 2016, , Pages 153-164
Abstract
Utilizing capacitor banks is very conventional in distribution network in order for local compensation of reactive power. This will be more important considering uncertainties including wind generation and loads uncertainty. Harmonics and non-linear loads are other challenges in power system which complicates ...
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Utilizing capacitor banks is very conventional in distribution network in order for local compensation of reactive power. This will be more important considering uncertainties including wind generation and loads uncertainty. Harmonics and non-linear loads are other challenges in power system which complicates the capacitor placement problem. Thus, uncertainty and network harmonics have been considered in this paper, simultaneously. Capacitor placement has been proposed as a probabilistic harmonic problem with different objectives and technical constraints in the capacitor placement problem. Minimizing power and energy loss and capacitor prices are considered as objectives. Particle Swarm Optimization (PSO) and Differential Evolution (DE) algorithms have been used to solve the optimization problem. Loads are subjected to uncertainty with normal probabilistic distribution function (PDF). Auto Regressive and Moving Average (ARMA) time series and two point estimate method have also been utilized to simulate the wind speed and to perform the probabilistic load flow, respectively. Finally, the proposed method has been implemented on standard distorted test cases in different scenarios. Monte Carlo Simulation (MCS) has also been used to verify the probabilistic harmonic power flow. Simulation results demonstrate the efficiency of the proposed method.
Distribution Systems
B. Mohammadzadeh; A. Safari; S. Najafi Ravadanegh
Volume 4, Issue 2 , December 2016, , Pages 165-174
Abstract
This paper presents a new and useful methodology for simultaneous allocation of sectionalizer switches and distributed energy resources (DERs) considering both reliability and supply security aspects. The proposed algorithm defines the proper locations of sectionalizer switching devices in radial distribution ...
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This paper presents a new and useful methodology for simultaneous allocation of sectionalizer switches and distributed energy resources (DERs) considering both reliability and supply security aspects. The proposed algorithm defines the proper locations of sectionalizer switching devices in radial distribution networks considering the effect of DER units in the presented cost function and other optimization constraints such as providing the maximum number of costumers to be supplied by DER units in islanded distribution systems after possible outages. In this paper, the main goal of cost function is to minimize the total cost of expected energy not supplied (EENS) with regard to impacts of load priority and optimum load shedding in the both grid connected and islanding states after possible outages. The proposed method is simulated and tested on a case study system in both cases of with DER and non DER situations. Also, this paper evaluates the number and amount of DER, switch and different DER penetration percentage effects in cost function value. For solving of mentioned problem, this paper uses a new and strong method based on imperialist competitive algorithm (ICA). Simulation and numerical results show the effectiveness of the proposed algorithm for placement of switch and DER units in the radial distribution network simultaneously.
Distribution Systems
Soheil Derafshi Beigvand; Hamdi Abdi,
Volume 3, Issue 2 , December 2015, , Pages 102-115
Abstract
This paper proposes an Optimal Power Flow (OPF) algorithm by Direct Load Control (DLC) programs to optimize the operational cost of smart grids considering various scenarios based on different constraints. The cost function includes active power production cost of available power sources and a novel ...
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This paper proposes an Optimal Power Flow (OPF) algorithm by Direct Load Control (DLC) programs to optimize the operational cost of smart grids considering various scenarios based on different constraints. The cost function includes active power production cost of available power sources and a novel flexible load curtailment cost associated with DLC programs. The load curtailment cost is based on a virtual generator for each load (which participates in DLC program). To implement the load curtailment in the objective function, we consider incentive payments for participants and a load shedding priority list in some events. The proposed OPF methodology is applied to IEEE 14, 30-bus, and 13-node industrial power systems as three examples of the smart grids, respectively. The numerical results of the proposed algorithm are compared with the results obtained by applying MATPOWER to the nominal case by using the DLC programs. It is shown that the suggested approach converges to a better quality solution in an acceptable computation time.
Distribution Systems
Hossein Shayeghi; Masoud Alilou
Volume 3, Issue 2 , December 2015, , Pages 131-146
Abstract
In this paper, simultaneous placement of distributed generation, capacitor bank and protective devices are utilized to improve the efficiency of the distribution network. The objectives of the problem are reduction of active and reactive power losses, improvement of voltage profile and reliability indices ...
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In this paper, simultaneous placement of distributed generation, capacitor bank and protective devices are utilized to improve the efficiency of the distribution network. The objectives of the problem are reduction of active and reactive power losses, improvement of voltage profile and reliability indices and increasing distribution companies’ profit. The combination of firefly algorithm, particle swarm optimization and analytical hierarchy process is proposed to solve the multi-objective allocation problem. The proposed method is implemented on IEEE 69-bus and also an actual 22-bus distribution systems in Tehran-Iran. Test results approve the effectiveness of the proposed method for improved reliability and network performance of the distribution network.
