IRANIAN ELECTRIC INDUSTRY JOURNAL OF QUALITY AND PRODUCTIVITY (IEIJQP)
Year:2019 | Volume:7 | Issue:2 (14) |Papers Count:10

Electric vehicles(EV) are the most important technology that can be used in a Smart Grid environment. These vehicles can have many benefits to the network. In order to engage EV owners in the proposed plans of the utility, there must be sufficient and attractiveness conditions such as economic profitability. On the other hand, due to the transfer of vehicles to special parking lot, the mileage of EVs to these parking lot should be reduced as much as possible. On the side of the utility, charging and discharging planning should be such that the system objectives are improve. This scheduling depends on to the number of EV in each parking lot. Therefore, in this paper, using the optimal area of EV lot, as well as scheduling of charging and discharging EV, will increase the profitability of the EV owners and utility at the lowest possible losses, and reducing the mileage of vehicles to the parking lot. Then, due to importance of such load as economic, medical or security center, the effect of the location of these loads is examined on parking area and scheduling of charging and discharging EV.

Distribution network is a part of power systems’ general structure which is considered as the last chain in energy generation and transmission to the consumers. One of the most important issues in distribution lines is occurrence of a fault; regarding the innate structure of distribution networks and their numerous branches, fault location is of high importance. Impedance methods are the most common way used to locate the fault. This method faces problems such as multi-response properties, not being able to recognize the correct fault section and not being able to provide a single correct response. In the present study, possible fault locations are recognized first using the improved impedance method. Then, its natural frequencies are determined. Since there are more than one possible fault locations, it is necessary to identify the fault section in order to determine the fault location accurately. The fault section and its main location are determined through simulating the fault in each section of possible locations by small steps and through accommodating the determined frequency to the existing natural frequency registered in the original fault voltage form. The aforementioned method was applied in Salim’ s 11-node network in which effect of fault inception angles, effect of different resistors and fault type were tested. Accuracy and efficiency of the proposed method has been verified.

The utilization of distributed generators such as the renewable energies together with electrical vehicle are increasing because of the environmental and economic challenges. Irregular and yet large-scale use of either of these two technologies can have devastating effects on electrical grid. However, with planning and appropriate management of these technologies along with energy storage resources can reduce their detrimental effects. In this regard, integrated cumulative effect of electrical vehicles to the grid for the process of charging or discharging and also network instability caused by that – in particular during peak times-have been discussed as a fundamental challenge of utilizing these vehicles. Inconsistent and uncontrolled charging in these vehicles at the large scale on traditional grids can lead to overload, bigger fluctuations in generator speed, rise in voltage deviation of distribution buses, and increased power losses; which these consequences result in lower reliability and smart grid security. Thus, management of production or consumption in these vehicles are investigated. This study adopts Genetic algorithm (GA) to optimize uncoordinated and coordinated PEVs charging stations with renewable distributed generation resources. The proposed model is applied to IEEE 33– bus network. The output results have shown the efficiency and robustness of the proposed model.

Due to technological advancement and environmental and economic considerations, the penetration of renewable energy has been increased in today’ s power systems and the energy management importance has gotten more attention. According to the importance of energy management in one hand, and necessity to emission pollution reduction in other hand, the operation of microgirds considering these both objective has become an important problem. Moreover, the high penetration of renewable energy encourages the system operators to using new advanced operation methods. Different definitions have been presented for energy management concept, however the main definition is an approach to reach a solution with low energy consumption without reducing the quality and reliability of electricity using new management strategies. In this paper, a new method based on game theory is presented for probabilistic energy management of a distribution network that is connected to different microgirds. A two-layers optimization framework is presented that the first layer is optimized using PSO algorithm, while the second layer is optimized using the game theory method. The simulation results show the overall operation cost of the distribution network is reduced considerably.

Social capital one of the important aspects of sustainable development. It can be used to solve problems of social capital as the main source of problem solving and correction of existing processes. The purpose of this paper is to examine the simultaneous effect of social capital, economic and environmental variables on electricity consumption in the household sector of Iranian provinces. In this regard, using the GMM method, during the period of 2000-2015, the explanation of the effect of social capital index on household electricity consumption has been studied. The results showed that social capital had a negative and significant effect on household electricity consumption. Social capital embedded in the relationships between individuals and, consequently, their participation in protecting national and natural capital is one of the factors that investment in this field can reduce the loss of energy sources such as electricity. Reducing administrative corruption, encouraging popular institutions, reducing the breakdown between government and people, education; among other things, it can be done to increase social capital. Other results of the paper also showed that per capita income, cooling demand, household size and consumption of the previous period have a positive effect on the household electricity consumption. Electricity consumption of the previous period had the most impact on the household electricity consumption. The price elasticity of household electricity consumption has been negatively evaluated, so rising electricity prices have reduced electricity consumption. The variable heating and household gas prices do not have a significant effect on electricity consumption.

Abstract: In this paper, generation expansion planning is considered with integration of wind and hydroelectric generating units. Multi-state models are introduced for electrical load, wind farms and hydroelectric power plants. Reliability evaluation is considered in the presence of wind and hydro units in a stochastic programming problem. Recovering time of generation outages is taken into account. In this way, optimal capacities of fast response units such as gas and hydro units are determined. A bender decomposition method is utilized, the impacts of reliability level and emission penalties are taken into account on wind and hydro powers integration. Total cost and pollution level are decreased with increasing wind and hydro powers and decreasing thermal power. The proposed method is applied ti IEEE 24-bus reliability test system and its performance is demonstrated by determining optimal combination of generation units for supplying the forecasted load.

The present research was carried out with the aim of studying the characteristics of the Accounting Information System of West Azarbaijan Electric Power Distribution Company and preparing the SWOT matrix considering the strengths and weaknesses of the system and the opportunities and threats to improve the system. The research period was the one-year period of 1396 and the spatial domain includrd the CEOs of the West Azarbaijan Electricity Distribution Company, the four districts of Urmia and the provincial districts. The present study was an applied and descriptive-case study. The data gathering tool was a combination of library and field tools. Data were collected through deep interviews and questionnaires. 100 in-organizational questionnaires and 16 out-of-organizational questionnaires were distributed. 84 in-organizational questionnaires and 11 out of organizational questionnaires were available. The results of the research hypotheses tests using statistical analysis: Excel, SPSS and the MINITAB revealed that the accounting information system of the company produces useful information which have the qualitative characteristics required for decision making by managers in the organization, but not for the external users. In addition, managers' curriculum is effective in using data from the system. Using the Shah model, it was concluded that there is a good acceptance in improving the accounting information system and relatively good ability in this field, but there is not much power. Finally, the SWOT model and its strategic prosedures were developed, as the threats were overcome by the opportunities to the improvement of the accounting information system, while the strengths and weaknesses were almost equall.

Optimal power flow with transient stability is a nonlinear optimization problem with algebraic and differential equations. In this paper, using the imperialist competition algorithm as an evolutionary optimization algorithm and artificial neural network, a robust and effective two-stage design for solving the TSCOPF problem (transient stability constrained optimal power flow) has been proposed. In hybrid model, an artificial neural network was introduced to predict the transverse stability margin of the rotor angle and then to estimate the transient stability of the rotor angle bound to the optimal load distribution. To solve the problem of TSCOPF (transient stability constraint optimal power flow), imperialist competition algorithm optimization has been used. The function of the proposed method is based on the three-machine system, the WSCC (Western System Coordinating Council) and the IEEE cases under different loading conditions and error mode.

This paper presents a novel appropriate load modeling for decreasing the load levels and evaluating the reliability of smart distribution system including various distributed generations by using the analytical method. Because of several uncertainties in a smart distribution system, the computing time and complexity of calculations in evaluating the reliability indices are the major challenges. Hence by decreasing the computing time of reliability evaluation methods, it is possible to solve the large optimization problems according to the accelerated methods. During the decrement of computing time, it is necessary to achieve a reasonable accuracy. In the proposed method, three scenarios for reliability-based load modeling are presented. The time-based aggregation without any default, time-based aggregation according to several assumptions, and amplitude-based aggregation are the three presented scenarios. Providing the mathematical modeling for implementation of the discussed scenarios is one of the contributions of this article. The proposed method has been applied to the IEEE 33-Bus Test Distribution System and an actual distribution system from Esfahan Province Electrical Distribution Company (EPEDC). The obtained results illustrated the effectiveness of the proposed method. The results show that, by choosing an appropriate load level reduction scenario (time-based or amplitude-based aggregation scenarios), the 90% of the required time for reliability calculations can be saved, while less than 1% error has occurred. Performing the sensitivity analyses in order to determine the more important parameters in the proposed load level reduction methodology is another advantage of this article. The sensitivity analyses results imply that due to increment in load variance of the distribution system in presence of other uncertain parts, the more comprehensive and smart studies are needed.

The uncertainty in connection status of distributed generation and network structure complicates the adjustment of the overcurrent relays in distributing network. With the increase in number of modes of operation, the investigation area faces limitations and becomes even pointless, making it almost impossible to reach a unified host of setting applicable for all possible modes. Yet, the conditional situations could be overlooked and the investigation could be objective-oriented once the differential protection is maintained and the faults are taken care of instantly. The differential protections must be installed with the minimum number and in the proper places so that the incompatible conditions would be eliminated. As such, a new approach based on additional methods with regard to the nature of differential protection and its impact on identifying incompatible conditions is recommended. The outcome of such approach is a set of candid lines for installing the differential protections and thus the convergence of protective coordination of overcurrent relays. This approach has been simulated for the ringed distributed active network and, as the outcome reveals, the recommended approach with the proper placement of differential protections along with the unified setting for all relays makes the constant protection coordination possible.