List of Articles
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Open Access Article
1 - Placement of AVRs and Reconfiguration of Distribution Networks Simultaneously and Robust Considering Load Uncertainty
M. R. Shakarami Y. Mohammadi Pour: In this paper, optimal locating for AVRs and reconfiguration of distribution networks were assessed simultaneously as an optimization problem. A new objective function was introducing which incorporated several electrical indices including real power losses, reactive More: In this paper, optimal locating for AVRs and reconfiguration of distribution networks were assessed simultaneously as an optimization problem. A new objective function was introducing which incorporated several electrical indices including real power losses, reactive power losses, reliability, voltage profile, voltage stability, and load capacity of lines (MVA). Various load levels were incorporated into the objective function to make sure that switch status in reconfiguration and AVR taps and locations would be robust against load variations. This paper also introduced a new method for calculating the load levels with respect to load uncertainty. It also considered all loads based on a voltage-dependent model. Several scenarios are defined to thoroughly assess the proposed approach. Integer particle swarm optimization algorithm (IPSO) was used to solve the mentioned optimization problem. The results obtained by the simulation of 33-bus and 69-bus standard IEEE .radial power distribution networks demonstrated the effectiveness of the proposed approach Manuscript profile -
Open Access Article
2 - Transmission Expansion Planning in a Deregulated Power System Using Multiobjective Differential Evolution Algorithm
f. rashidiTransmission lines are widely used for transferring electrical energy from power plants to loads, interconnecting load centers and improving reliability of power systems. Due to recent society developments, the need for electrical energy has increased which in turn requ MoreTransmission lines are widely used for transferring electrical energy from power plants to loads, interconnecting load centers and improving reliability of power systems. Due to recent society developments, the need for electrical energy has increased which in turn requires more investment in constructing additional electrical transmission lines. Power system restructuring and deregulation has increased uncertainties in transmission expansion planning and made investment in electrical transmission lines more complicated and less appealing for private parties. This paper proposes a new approach for transmission line expansion planning in deregulated networks. To do that, a multi objective programming problem which consists of various objective functions such as minimizing capital investment for constructing new transmission lines, minimizing congestion in transmission lines and maximizing the investment from private parties is suggested such that access to competitive, economic and reliable energy market is facilitated. To solve the proposed multi objective optimization problem, the Pareto differential evolution algorithm is used. Applying this algorithm to the proposed multi objective programming problem generates set of optimal plans that shows the best compromise between objective functions. The final plan, among the generated plans, is selected using a max-min fuzzy decision making. The proposed method is applied on the IEEE 24 bus test system and effectiveness of the proposed method is verified. Manuscript profile -
Open Access Article
3 - Optimal Sitting and Sizing of Renewable Energy Sources and Charging Stations Simultaneously Based on Improved GA-PSO Algorithm
M. Rezaei Mozafar M. Rezaei MozafarDue to the stochastic nature of renewable energy sources (RES) and electric vehicles (EV) load demand, large scale penetration of these resources in the power systems can stress the reliable network performance, such as reducing power quality, increasing power losses, a MoreDue to the stochastic nature of renewable energy sources (RES) and electric vehicles (EV) load demand, large scale penetration of these resources in the power systems can stress the reliable network performance, such as reducing power quality, increasing power losses, and voltage deviations. These challenges must be minimized by optimal planning based on the variable output from RES to meet the additional demand caused by EV charging. In this paper, a novel method for optimal locating and sizing of RES and EV charging stations simultaneously and managing vehicle charging process is provided. A multi-objective optimization problem is formulated to obtain objective variables in order to reduce power losses, voltage fluctuations, charging and demand supplying costs, and EV battery cost. In this optimization problem, the location and capacity of RES and EV charging stations are the objective variables. Coefficients which are dependent on wind speed, solar radiation, and hourly peak demand ratio for the management of the EV charging pattern in low load hours are introduced. GA-PSO hybrid improved optimization algorithm is used to solve the optimization problem in five different scenarios. The performance of the proposed method on IEEE 33-bus system has been investigated to validate the effectiveness of the novel GA-PSO method to optimal sitting and sizing of RES and EV charging stations simultaneously Manuscript profile -
Open Access Article
4 - A Generalized Relationship for Calculation of Critical Inductance in an n-Input Buck DC-DC Converter
critical inductance is one of the factors that decides continuous, boundary or discontinuous conduction mode of dc-dc converters. In applications like mining, the Continuous Conduction Mode (CCM) and consequently safety of converter can be guaranteed by proper selection Morecritical inductance is one of the factors that decides continuous, boundary or discontinuous conduction mode of dc-dc converters. In applications like mining, the Continuous Conduction Mode (CCM) and consequently safety of converter can be guaranteed by proper selection of inductance. So, calculation of critical inductance and proper sizing of inductor is an important issue in designing of dc-dc converters. In this paper, a non-isolated n-input buck dc-dc converter is introduced. Then, the operational modes and energy transfer process is investigated and discussed in detail. The critical inductance is calculated for 3 and 4-input versions. Using the inductive reasoning, a generalized relationship is proposed for calculation of critical inductance of converter with any number of inputs (n-input version). The proposed generalized relationship not only reduces the amount and time of calculation in design stage, but also presents a better view of performance of converter. The 3 and 5-input version of converter has been modeled and simulated in PSCAD/EMTDC software. Also, the 3-input version of converter has been practically implemented. The obtained simulation and experimental results confirm the validity of proposed generalized relationship for critical inductance calculation of n-input buck dc-dc converter. Manuscript profile -
Open Access Article
5 - A Generalized Relationship for Calculation of Critical Inductance in an n-Input Buck DC-DC Converter
K. Varesi S. H. Hosseini M. Sabahi E. Babaeicritical inductance is one of the factors that decides continuous, boundary or discontinuous conduction mode of dc-dc converters. In applications like mining, the Continuous Conduction Mode (CCM) and consequently safety of converter can be guaranteed by proper selection Morecritical inductance is one of the factors that decides continuous, boundary or discontinuous conduction mode of dc-dc converters. In applications like mining, the Continuous Conduction Mode (CCM) and consequently safety of converter can be guaranteed by proper selection of inductance. So, calculation of critical inductance and proper sizing of inductor is an important issue in designing of dc-dc converters. In this paper, a non-isolated n-input buck dc-dc converter is introduced. Then, the operational modes and energy transfer process is investigated and discussed in detail. The critical inductance is calculated for 3 and 4-input versions. Using the inductive reasoning, a generalized relationship is proposed for calculation of critical inductance of converter with any number of inputs (n-input version). The proposed generalized relationship not only reduces the amount and time of calculation in design stage, but also presents a better view of performance of converter. The 3 and 5-input version of converter has been modeled and simulated in PSCAD/EMTDC software. Also, the 3-input version of converter has been practically implemented. The obtained simulation and experimental results confirm the validity of proposed generalized relationship for critical inductance calculation of n-input buck dc-dc converter. Manuscript profile -
Open Access Article
6 - Optimal and Simultaneously Compensation of Active, and Reactive Powers in Power System Using of Plug in Electric Vehicle
f. rashidi H. Feshki FarahaniPlug in electric vehicles besides environment pollution reduction can help power system operation. One of the most important capabilities of them is providing activeand reactive power. This paper considers grid constraints, technical concerns and market price and propos MorePlug in electric vehicles besides environment pollution reduction can help power system operation. One of the most important capabilities of them is providing activeand reactive power. This paper considers grid constraints, technical concerns and market price and proposes a framework to allocate the PEV capacity such that operational cost paid by distribution system operator (DSO) to power provider of active and reactive power is minimized. For this purpose, an objective function is defined that includes the payment for each power provider. This objective function is minimized based on particle swarm optimization subject to grid and vehicles constraints. In this framework, the PEVs compete with generator to produce active and reactive power. In order to accelerate the optimization process and prevent the algorithm from being trapped in local optima, new heuristic approaches are included to the original PSO algorithm. To evaluate the effectiveness of the propose method, it is implemented on the low voltage with 134 customer and including the other power providers and the amount of each participants production and payment cost to each component is determined. Manuscript profile -
Open Access Article
7 - Analysis and Expansion of a Compact Model of Propagation Delay Time for Nano-CMOS NAND Gates in Response to Statistical Variability of Fabrication
H. Jooypa D. DidebanWith shrinking transistor dimensions into nano meter scale, electrical parameters of transistors become more sensitive against statistical or random variations. Moreover, accurate estimation of these variations using “atomistic simulators” is time consuming and not a co MoreWith shrinking transistor dimensions into nano meter scale, electrical parameters of transistors become more sensitive against statistical or random variations. Moreover, accurate estimation of these variations using “atomistic simulators” is time consuming and not a cost effective approach. In this paper for the first time, analytical models have been used to study the impacts of statistical variability of fabrication process on propagation delay time in a 35 nm CMOS NAND gate. With selecting appropriate set from analytical model’s parameters, the impact of statistical variability on the propagation delay time have been modeled and extended. Moreover, target analytical model has been benchmarked against statistical variability of fabrication process. The results obtained from extension of this model have been compared with the accurate atomistic simulations. It is observed that by applying different sets of parameters the maximum error of propagation delay time reaches to 8.7% against accurate atomistic simulations but by applying our proposed approach, Standard Deviation (SD) error of propagation delay is estimated to 2.4%. Also the SD error of propagation delay reaches to 9.9% when normal regenerated parameters have been used. Eventually using proposed algorithm which encompasses regenerated Gaussian parameters while taking the correlation factor into account, the SD error decreases to 1.6%. Manuscript profile -
Open Access Article
8 - A Game Framework for Congestion Management Based on Generators Re-Dispatching and Demand Response
Ali R. Reisi S. M. HosseinianThis paper proposes a new algorithm for addressing the congestion problem in the network through generation and demand rescheduling. A demand response market based programming is developed for demand rescheduling by capturing the benefit of retailers. In the proposed al MoreThis paper proposes a new algorithm for addressing the congestion problem in the network through generation and demand rescheduling. A demand response market based programming is developed for demand rescheduling by capturing the benefit of retailers. In the proposed algorithm two tasks are implemented by the ISO for controlling network security and spark prices. In the case of any network defect, generator re-dispatching is conducted by the ISO and in the case of any spark price, retailers’ demands in specific buses decrease via some economic signals, sent by the ISO. Having such economic signalsthe retailers then participate in a demand response trade with demand response aggregators (DRAs) to optimize their incomes and next to resubmit their demands to the ISO. A Stackelberg game is employed to capture the interplay among retailers, the leaders, and DRAs, the followers. Retailers choose their strategies, the amount and price of required demand response. Then, DRAs compete based on the retailers’ strategies to maximize their payoffs and to choose their strategies, the demand response sale amount. An IEEE bus test network with 14 buses is considered to demonstrate the feasibility of the proposed method. The paper demonstrates that the proposed method enables to alleviate the congestion problem while the retailers’ incomes increase. Manuscript profile -
Open Access Article
9 - Double-band Hysteresis Current Controller to Reduce Switching Losses of BLDC Drive and Its Comparison with Single-Band Hysteresis
H. Torkaman M. R. Hassanzadeh AghdamIn this paper, a double-band hysteresis current controller (DBHCC) as a new switching method in feeder inverter of a BLDC motor is proposed and implemented. Then, it is compared with the single-band hysteresis current controller (SBHCC). It has been shown that in the pr MoreIn this paper, a double-band hysteresis current controller (DBHCC) as a new switching method in feeder inverter of a BLDC motor is proposed and implemented. Then, it is compared with the single-band hysteresis current controller (SBHCC). It has been shown that in the proposed method, the average switching frequency of switches is reduced compared to SBHCC by preserving other advantages. Thus, switching losses are reduced and the lifetime of switches is increased. In addition, it has desirable effects on reducing electromagnetic interferences and noise. In addition, speed control, torque, current ripple and transient states are investigated in both states. Three-phase reference currents for hysteresis switching are obtained using a PI regulator and integrating with output signals from Hall-effect sensors. BLDC motors are used widely in the industry due to more advantages in comparison with others. In order to drive this motor, a three-level cascade half-bridge voltage source inverter with constant DC link for each phase is used. Simulation results are obtained and analyzed using MATLAB/Simulink environment. Manuscript profile -
Open Access Article
10 - Multi-Criteria Operation Optimization of Combined Cool, Heat and Power (CCHP) Generation Systems in a Microgrid
M. Setayeshnazar F. AmiriEnergy efficiency is one of the most important issues in the power system studies and many methods are used to improve power systems efficiency. Combined cool, heat and power (CCHP) systems are one of the most important technologies that can improve power system efficie MoreEnergy efficiency is one of the most important issues in the power system studies and many methods are used to improve power systems efficiency. Combined cool, heat and power (CCHP) systems are one of the most important technologies that can improve power system efficiency and these systems use their excess heat for supplying heat and cool loads. This paper presents a framework for optimal operation of CCHP systems in a microgrid. At first the unit cost functions are used to optimize operation of CCHP units. Then the algorithm determines the optimal operating strategy of microgrid units. A multi-criteria operation optimization method is proposed that uses primary energy consumption, pollution emissions and operating costs as criteria. The case study is performed for a nine bus microgrid and the results are compared with reference articles results and the advantage of the proposed method is investigated. Manuscript profile