66 research outputs found

    The Impact of Currency Shocks on Sanandaj Municipality Revenues in Iran

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    Exchange rate fluctuations have been affecting economic demand in recent years. The purpose of this study is to review the effects of exchange shocks on Sanandaj Municipality Revenues. The statistical population is Sanandaj municipality during 2006-2018 and SPSS, Eviews softwares were used for data analysis. The results show that since the correlation test is not significant at the level of 0.95, there is no significant relationship between two variables of municipality income and exchange fluctuations. Thus, the main hypothesis is rejected. In other words, exchange shocks have no impact on Sanandaj municipality revenues. Also based on the correlation test, since the correlation test is not significant at the level of 0.95, the relationship between the two variables of municipality income and negative exchange fluctuations is not significant and the sub-hypothesis (1) is rejected, and finally based on correlation test, since the correlation test is not significant at the level of 0.95, the relationship between two variables of municipality and positive exchange fluctuations is not significant. Thus, the sub-hypothesis (2) is rejected as well. It could be concluded that, Sanandaj municipality revenues do not follow the currency rate fluctuations

    Smart Grid in China, EU, and the US: State of Implementation

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    Depletion of fossil fuel deposits is the main current issue related to the world's power generation. Renewable energy sources integrated with energy efficiency represent an effective solution. The electrification of end-use coupled with renewable power generation integration is considered as an important tool to achieve these tasks. However, the current electric power system does not currently have the suitable features to allow this change. Therefore, in the future, it has to allow two-way direction power flows, communication, and automated controls to fully manage the system and customers. The resulting system is defined as the smart grid. This article analyses the smart grid state of play within China, the US, and the EU, assessing the completion state of each smart grid technology and integrated asset. The analysis related to these countries presented here shows that the smart grid overall state of play in China, the US, and the EU are equal to 18%, 15%, and 13%, respectively, unveiling the need related to further efforts and investments in these countries for the full smart grid development

    Ocean Wind Energy Technologies in Modern Electric Networks: Opportunity and Challenges

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    Wind energy is one of the most important sources of energy in the world. In recent decades, wind as one of the massive marine energy resources in the ocean to produce electricity has been used. This chapter introduces a comprehensive overview of the efficient ocean wind energy technologies, and the global wind energies in both offshore and onshore sides are discussed. Also, the classification of global ocean wind energy resources is presented. Moreover, different components of a wind farm offshore as well as the technologies used in them are investigated. Possible layouts regarding the foundation of an offshore wind turbine, floating offshore, as well as the operation of wind farms in the shallow and deep location of the ocean are studied. Finally, the offshore wind power plant challenges are described

    A Model for Reconfiguration and Distributed Generation Allocation Considering Reduction of Network Losses

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    615-620This paper proposes a new model for reconfiguration and distributed generation allocation in distribution network conceding reduce network losses. The objective function involves minimizing losses using the new Ant Lion Optimizer (ALO) algorithm. The proposed reconfiguration on the unbalanced 33-bus IEEE base grid with and without Distributed Generation Sources (DGRs) as well as the use of capacitors have been investigated. In this study, a branching technique with an optimization method is used to determine the best network arrangement. Simulation studies are carried out under different scenarios. In each of the scenarios, the losses before and after the optimization are compared. The results indicate that, through using the proposed method the rate of the losses in the case study is reduced

    A harmonic compensation strategy in a grid-connected photovoltaic system using zero-sequence control

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    Mitigation of harmonics for a grid-connected inverter is an important element to stabilize the control and the quality of current injected into the grid. This paper deals with the control method of a three-phase Grid-Connected Inverter (GCI) Photovoltaic (PV) system, which is based on the zero-sequence current adjuster. The proposed method is capable of removing the harmonic current and voltage without using any active and passive filters and without the knowledge of the microgrid topology and also impedances of distribution bands and loading conditions. This concept is adopted for the control of a Distributed Generator (DG) in the form of grid-connected inverter. The proposed control can be applied to the grid connected inverter of the PV. The fast dynamic response, simple design, stability, and fast transient response are the new main features of the proposed design. This paper also analyzes the circuit configuration effects on the grid connected inverter capability. The proposed control is used to demonstrate the improved stability and performance

    Improved voltage unbalance and harmonics compensation control strategy for an isolated microgrid

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    This paper suggests an enhanced control scheme for a four-leg battery energy storage systems (BESS) under unbalanced and nonlinear load conditions operating in the isolated microgrid. Simplicity, tiny steady-state error, fast transient response, and low total harmonic distortion (THD) are the main advantages of the method. Firstly, a new decoupled per-phase model for the three-phase four-leg inverter is presented. It can eliminate the effect of power stage coupling on control design; thus, the three-phase four-leg power inverter can be viewed as three single input single output (SISO) control systems. Then, using an improved orthogonal signal generation method, the per-phase model of the four-leg inverter in the stationary and synchronous frame is derived. As the second step, a per-phase multi-loop control scheme for the four-leg inverter under unbalanced load conditions is suggested. The proposed control strategy has the ability to provide balanced output voltages under unbalanced load conditions by avoiding the need to deal with the symmetrical components. Finally, a multi-resonant harmonic compensator is used to actively prevent low-order harmonic currents to distort the output voltages of the three-phase four-leg grid-forming power converter. Simulations results are also presented to verify the performance of the suggested control strategy
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