Majlesi Journal of Energy Management
Volume:9 Issue: 3, Sep 2020

In the present paper, the effect of transient fault location on voltage profile at different points of distribution network is investigated. Since fault occurrence is inevitable in the power grids, it is necessary to investigate various faults in the power grid to minimize their effects by protective equipment. Both the permanent and transient faults, as two categories of faults, have different effects on power grids; but, since the cause of the permanent fault is visible and can be rectified in most cases, this study will investigate transient faults in a 20 kv distribution network. Transient faults affect all components and equipment, but where this fault occurs in the network, it has a different effect on the distribution network and its components. Hence, these faults' effects on voltage profile as a critical characteristic of the power distribution networks are examined in this study. Then, the DIGSILENT software is applied to simulate the transient fault behavior at different distances on the voltage profile of a sample distribution network, and simulation results are presented in tables.

Power transmission information technology is one of the growing technologies in many developed countries of the world. In addition to hot power lines, the power line telecommunication system also uses cold lines as a data telecommunication channel and has transformed the power transmission system from a single-purpose distribution network to a multi-purpose voice transmission channel and various data services, especially the Internet. Models of distribution network transmission specifications for computer simulations consistent with appropriate system design are of great interest. The channel specifications depend on the design of the low voltage power transmission line system in Iran as well as the location of the transmitter and receiver in the power line infrastructure. The channel is provided. In this article, different methods of power line modeling are examined and the advantages and disadvantages of each are discussed. By examining them, the most complete modeling method can be selected that can evaluate the effect of effective parameters in the power line channel.

In this paper, fine-tuning of the controller gain using artificial neural networks to increase the output power of the wind turbine is studied. Aerodynamics curves play an important role in design of wind turbine controllers. The nonlinear nature of these curves has made the design of the wind turbine controllers a challenging problem. Modeling methods for these curves are not accurate enough since the data has inherent inaccuracy and has a discrete nature due to sampling.  These disadvantages are the reason why the controller design is not very precise. In this work, to solve this problem, artificial neural networks are used to increase the accuracy of the aerodynamics curves, especially power coefficient (Cp). A relatively more accurate model of this curve can be obtained by using artificial neural. In this paper, below rated wind speed of wind turbine is studied. The simulations indicate that the total power obtained can be increased with no additional cost using this new controller gain.

In this paper, a hierarchical control structure with an unbalanced voltage compensation scheme in an island ac microgrid is proposed to improve the quality of the critical load bus voltage (CLB) and problems related to inaccurate power sharing are addressed. The hierarchical design includes the primary and secondary control levels. The primary controls typically include droop controllers, voltage and current controllers, selective virtual impedance loops, and unbalanced voltage compensation. The virtual impedance loop has positive and negative virtual sequence loops at the main frequency and the harmonic impedance loop is the virtual variable under the harmonic frequencies. The secondary control is designed to recover the frequency and voltage range of the CLB. In order to compensate for the CLB voltage, an unbalanced compensator is provided to switch the reference voltage of the distributed generation units (DG). This strategy uses the low bandwidth communication (LBC) method to send appropriate signals to the secondary controller through microgrid control center (MGCC) for primary control. To evaluate the performance of the proposed control strategy, two simulations are performed for two different islanded microgrid. The obtained results show the effect of the proposed control structure with the unbalanced and harmonic compensator CLB voltage and the appropriate sharing of active and reactive power and the unbalanced and harmonic power between the DG units.

Population growth and the indiscriminate consumption of natural resources to maintain economic prosperity, in addition to destroying the ecosystem, have led to a shortage of viable butter. This article estimates the ecological footprint of water and energy consumption (electricity and natural gas) of the household sector in the 22 districts of Tehran and estimates these resources’ environmental capacity. In this paper, in addition to estimating the ecological footprint as a method based on the apparent consumption of resources, the amount of environmental capacity is estimated based on land efficiency. The ecological gap in the concept of lack of access to resources is also estimated obtained. Estimation of the ecological footprint of water and energy (electricity and natural gas) used in the household sector in Tehran indicates a negative relationship between the continuity of household sector activities and the ecological gap of these resources, which according to the results and their analysis, the ecological gap is more than 4 million hectares resulting from excessive consumption of water, electricity and natural gas is available in the household sector of Tehran.

Due to the large integration of wind generation in power system, the inclusion of more novel approaches in the planning of power system operation can be considered as of paramount importance and has spurred a significant amount of research. This study presents a novel framework to study the impacts of demand response programs in order to increase the flexibility and wind power owners' benefits in power market. The operational planning encourages risk due to the intermittent nature and wind generation volatility and the high investment cost. So, in this paper, a modified model is developed to integrate operational planning of wind generation along with implementing demand response programs. One of the most important problems of wind power operation in a competitive electricity market is providing its incentive cost. So, the impact of implementing demand response programs on wind’s incentive cost is investigated in this study. The framework is then implemented on a test system to show the effectiveness of our proposed approach.