@article { author = {Shiripour, Saber and Mohammadnejad, Mohammad}, title = {A linear mathematical programming model for optimization of the energy consumption in construction projects}, journal = {Journal of Energy Management and Technology}, volume = {6}, number = {2}, pages = {63-72}, year = {2022}, publisher = {Iran Energy Association (IEA)}, issn = {2588-3372}, eissn = {2588-3372}, doi = {10.22109/jemt.2021.250917.1259}, abstract = {In this study, a linear mathematical programming model is formulated to manage the consumption of electrical energy and fossil fuels in the construction projects simultaneously. The aim is to determine at what time period and for how long each electric machine is employed in the whole project, the optimal number of periodic services for the machines with fossil fuels and optimal service time so that the total objective function value is minimized. The objective function of the proposed problem is the sum of electricity consumption costs, service costs and fossil fuel consumption costs in the whole project. In the proposed model, different intervals are considered for electrical energy consumption and the effects of the average speed of each machine with fossil fuel consumption and the time required to these machines in each day are also applied in decisions-making. For solving the mathematical model, the LINGO optimization software package is employed. For a better understanding of the behavior of the proposed problem, sample problems with different sizes are investigated and the results are interpreted graphically. The results show that the objective function value of the proposed problem increases with an increment in the project completion time and number of machines, the consumption cost of the fossil fuels machines accounts for a significant portion of the objective function value in all samples and also, the contribution of service costs is more than that of the electric machines. Also, the proposed model is implemented for a sample problem and its sensitivity to some parameters are tested. The results of sensitivity analysis show that by increasing the project completion time, the number of intervals selected for the daily use of electric machines, number of service times required for the fossil fuel machinery and consequently the amount of objective function are increased. Also, the model solving time increases logarithmically with an increment in the project completion time.}, keywords = {Linear mathematical programming model,Energy consumption management,Electric Machines,fossil fuel machines,LINGO optimization software}, url = {https://www.jemat.org/article_128414.html}, eprint = {https://www.jemat.org/article_128414_a56bfd63c8345510747ec0ff9b084f27.pdf} } @article { author = {Younesi, Aria and Tohidi, Sajad and Feyzi, Mohammad Reza}, title = {Fixed switching frequency scheme for current predictive control of DFIG}, journal = {Journal of Energy Management and Technology}, volume = {6}, number = {2}, pages = {73-82}, year = {2022}, publisher = {Iran Energy Association (IEA)}, issn = {2588-3372}, eissn = {2588-3372}, doi = {10.22109/jemt.2021.276331.1286}, abstract = {This paper suggests a new current predictive control algorithm for the wind-driven doubly-fed induction generator (DFIG) based on space vector modulation (SVM) with fixed switching frequency. Combining the current predictive controller and SVM has the benefits of a predictive controller, and fixing the switching frequency improves the output waveform quality. However, if classical predictive control is used, the computational burden will still be high. The proposed algorithm uses SVM to fix the switching frequency of the rotor side converter. Additionally, by using an incremental algorithm, the proposed technique prevents examining all inputs over the prediction horizon. As a result, in the proposed current predictive algorithm the computational time is significantly reduced. The detailed state-space model of DFIG and rotor side converter are used to execute the predictive algorithm. The proposed algorithm uses the rotor current to predict the next behavior of the DFIG, and then, by using SVM, the duty cycles of 2-level voltage source inverter are obtained. Finally, the proposed controller's responses are compared to those of the SVM-based field-oriented control strategy. Simulation results of the proposed controller on a two-level voltage source inverter under a balanced three-phase power system illustrate the satisfactory active and reactive power tracking and improved quality of the inverter outputs.}, keywords = {current predictive control,fixed switching frequency,space vector modulation,Doubly fed induction generator}, url = {https://www.jemat.org/article_132251.html}, eprint = {https://www.jemat.org/article_132251_2e3edceb066ae0732d4f5d82cc520645.pdf} } @article { author = {Abbasi Soltani, Behnam and Sabahi, Mehran and Babaei, Ebrahim and Pouladi, Jaber}, title = {An extendable half-bridge dimmable multi-channel LED driver for DC/DC grid lighting applications}, journal = {Journal of Energy Management and Technology}, volume = {6}, number = {2}, pages = {83-90}, year = {2022}, publisher = {Iran Energy Association (IEA)}, issn = {2588-3372}, eissn = {2588-3372}, doi = {10.22109/jemt.2021.273304.1281}, abstract = {In this paper, a light emitting diode (LED) driver with multiple outputs, suitable to use with DC grid supply, is proposed. The proposed LED driver provides the ability to individually control the brightness of each output channel. In order to control the output power of each channel, a burst control mode is employed resulting in reduction of conduction losses. Moreover, the half bridge switches are turned on and off at zero voltage (ZV) with a fixed switching frequency; therefore, the switching losses is reduced and efficiency is further increased. Design and implementation have been simplified by choosing the same structure of the resonant series for outputs. A two-channel DC/DC converter is simulated and tested to verify the theoretical analyses.The presented converter operates above resonant frequency to decrease total harmonic distortion and reduce the size and weight of the components. Therefore, it is suitable for high power application of multi-channel drivers.}, keywords = {DC/DC converter,Driver,Light-Emitting-Diode,Multi-Channel}, url = {https://www.jemat.org/article_135090.html}, eprint = {https://www.jemat.org/article_135090_fba57917493804888a6aed82183539bd.pdf} } @article { author = {Azad, Sasan and Asgharinejad Keisami, Mohammad Hosein and Amiri, Mohammad Mehdi and Mosallanejad, Ali and Ameli, Mohammad Taghi}, title = {Ranking power system contingencies for real-time assessment of voltage stability based on PMU data}, journal = {Journal of Energy Management and Technology}, volume = {6}, number = {2}, pages = {91-97}, year = {2022}, publisher = {Iran Energy Association (IEA)}, issn = {2588-3372}, eissn = {2588-3372}, doi = {10.22109/jemt.2021.270938.1275}, abstract = {Voltage stability has been one of the main challenges for power system operators in recent years. The ranking of contingencies is one of the practical factors in assessing voltage stability. Therefore, the importance of maintaining grid stability necessitates the real-time assessment of voltage stability to protect the system from the risk of instability, and contingency ranking provides a list of essential and critical contingencies in terms of their impact on the network for real-time use. In this paper, a new index for classifying contingencies is presented, which is defined based on the voltage deviation and phase angle of the buses and PMU data. The proposed index has been tested on the IEEE 30-bus network. First, using this index, a contingency study was performed in 1000 operating points, and in the second stage, the results of these studies were compared with a random operation point. Comparing the results obtained from the proposed index with other available indices shows its proper performance for ranking and screening possible contingencies in power systems.}, keywords = {Voltage Stability Assessment,Contingencies,Ranking contingencies}, url = {https://www.jemat.org/article_135594.html}, eprint = {https://www.jemat.org/article_135594_0c3e4836f498b317b06063b75d6eb3d9.pdf} } @article { author = {Jahangir, Mohammad Hossein and Zendehnam, Arman and Alimoradiyan, Hamed}, title = {Exergy and exergoeconomic assessment and multi-objective optimization of a renewable assisted CCHP system}, journal = {Journal of Energy Management and Technology}, volume = {6}, number = {2}, pages = {98-110}, year = {2022}, publisher = {Iran Energy Association (IEA)}, issn = {2588-3372}, eissn = {2588-3372}, doi = {10.22109/jemt.2021.267289.1274}, abstract = {The current study analyzed and optimized a renewable-assisted multi-generation system in energy, exergy, and exergoeconomic. The proposed system is composed of PTCs, a horizontal-axis wind turbine, an organic Rankine cycle, heat recovery heat exchangers, a parallel double-effect LiBr-H$_2$O absorptive chiller, heat recovery heat exchangers, and an electrolyzer. The designed system has been being used for the simultaneous production of electricity, heating, cooling, and hydrogen. Moreover, a thermodynamic model of the defined system has been developed in engineering Equation Solver (EES) software. A Genetic Algorithm (GA) model was also conducted to find the optimum composition of decision variables that efficiently optimize the system performance in terms of cost and exergy.  A sensitivity analysis also has been applied to measure the effect of decision variables on the exergoeconomic performance of the proposed system. Results show that rising the inlet flow rate and inlet flow temperature to the Organic Rankin Cycle (ORC) turbine has an upward effect on the system's exergy efficiency and production cost rate. In addition, it was found that the increase of the boiler pressure only increases the exergy efficiency to a certain degree, and the exergy efficiency of the proposed system reduces in the pressures above 2600 kPa. With the optimization of the decision variables using a GA model, it was found that there is room to enhance the exergy exploitation rate by 2.6% and reduce the total rate of the production cost of the proposed system by 12.9%.}, keywords = {exergoeconomic,Multi-generation system,Multi-Objective Optimization,Sensitivity analysis,Exergy efficiency}, url = {https://www.jemat.org/article_137503.html}, eprint = {https://www.jemat.org/article_137503_8a87c86cb9f66c979f15d34807ffbd27.pdf} } @article { author = {Ghaffarpour, Reza and Zamanian, Saeid}, title = {Tri-level optimization-based resilient island city distribution network planning against terrorist attacks}, journal = {Journal of Energy Management and Technology}, volume = {6}, number = {2}, pages = {111-118}, year = {2022}, publisher = {Iran Energy Association (IEA)}, issn = {2588-3372}, eissn = {2588-3372}, doi = {10.22109/jemt.2021.292486.1308}, abstract = {Power distribution networks are known as a key infrastructure of smart cities. The safe operation of such networks is generally threatened by terrorist agents to disrupt the activities of smart cities. Therefore, distribution network planners attempt to find a solution for increasing the resilience of a distribution system against terrorist attacks. The hardening of distribution lines and allocation of electrical energy storage units are generally performed for reaching planner goals. However, investment for obtaining a resilient distribution network against terrorist attacks is limited by a hardening budget. This budget can be increased by considering other distribution network plans (such as increasing the expansion of renewable energies) and using the geographical features of the studied distribution networks. This paper proposes a tri-level optimization problem for allocating and sizing the offshore pumped storage units for increasing an Island city distribution network resiliency against terrorist activities and minimizing the network operation cost by solving the stochastic nature of ocean wave generation powers. The proposed tri-level problem is solved based on the Benders decomposition method using primal cuts. The simulating results obtained by using the IEEE distribution test system validate the effectiveness of the proposed tri-level model and highlight that offshore pumped storage units can enhance the resiliency of a distribution system located on an island against terrorist attacks and reduce the total operation cost during normal conditions.}, keywords = {Defender-attacker-defender model,offshore pumped storage,distribution network resiliency}, url = {https://www.jemat.org/article_138660.html}, eprint = {https://www.jemat.org/article_138660_d9d67506c8579fff53e4e5decc45a72c.pdf} } @article { author = {Shojaei, Saeid and Beiza, Jamal and Abedinzadeh, Taher and Alipour, Hasan}, title = {Optimal eco-emission scheduling of a microgrid by considering uncertainties}, journal = {Journal of Energy Management and Technology}, volume = {6}, number = {2}, pages = {119-126}, year = {2022}, publisher = {Iran Energy Association (IEA)}, issn = {2588-3372}, eissn = {2588-3372}, doi = {10.22109/jemt.2021.289829.1306}, abstract = {This paper describes a scheduling problem formulation to optimize and trade-off economic and emission (Eco-Emission) costs of a microgrid (MG). This MG includes solar parking lots (SPL) and local distributed generation (LDG) with a grid-connected bus to exchange power. The output of this work is an operation instruction that is applicable for the operator of MG. This MG operator (MGO), located in the control center of MG, could select either limited power exchange or unlimited power exchange with the main grid. These conditions are considered as two scenarios for the scheduling problem. The proposed bi-objective eco-emission problem is solved by using the $\varepsilon$-constraint and max-min fuzzy decision-making method. In the last section, the input/output power of MG has been studied taking into account demand response (DR). The simulation of the presented framework is carried out in GAMS software. As investigated the obtained results, exchange power with a main grid has a positive effect in decreasing total emission and economic cost of the MG.}, keywords = {Eco-Emission Cost,Uncertainties,Scenario Tree,Scenario Reduction,ε -Constraint Method}, url = {https://www.jemat.org/article_139882.html}, eprint = {https://www.jemat.org/article_139882_991b3a029d47c1e2fc69b6f0e2e4e279.pdf} }