Majlesi Journal of Energy Management
Volume:11 Issue: 1, Mar 2022

The main purpose of power system control is to generate electrical power in aninterconnected system so that it is as reliable and economical as possible and at thesame time the voltages and frequencies are within the allowable range. For thispurpose, load-frequency control loop is used in power systems, which has the role ofdamping oscillations between interconnected areas. The rapid growth and penetrationof microgrids and their other capabilities, including load response, have made load-frequency control methods different from traditional methods. The introduction of newmethods of frequency control in such systems has always been of interest toresearchers. Therefore, in this paper, a three-area power system including microgridsbased on DFIG wind turbines and hydrogen energy storage along with load response isinvestigated and to improve its performance, genetic algorithm will be used.

The purpose of this study is to analyze the relationship between cultural values ​​in the pattern of water consumption of families in the city of "Shahinshahr" using the Schwartz model of cultural values. In this regard, in order to explain the importance of the position of cultural values ​​in explaining the reform of water consumption pattern, an attempt was made to compare the explained change in water consumption by cultural values ​​with demographic variables. In this regard, the results of the research, which is based on a descriptive model, show that, firstly, cultural values ​​had more explanatory power compared to demographic variables. Second, by dividing cultural values ​​into four dimensions: readiness for change, protection, self-enhancement, and excellence based on Shuartz theories, the results show that the value of excellence (including the values ​​of cosmopolitanism and benevolence) causes citizens to tend to participatory thinking in reducing consumption. Water is drunk, and people with lower values ​​of excellence tend to consume more.

Exchanger system is widely used in oil, gas and petrochemical plants because it can sustain wide range of temperature and pressure. The main purpose of a exchanger system is to transfer from a hot fluid to a cooler fluid or conversely, so temperature control of outlet fluid is of prime importance. To control the temperature of outlet fluid of the exchanger system a conventional PID controller can be used. Due to inherent disadvantages of conventional control techniques, Fuzzy logic controller is employed to control the temperature of outlet fluid of the exchanger system. The designed controller regulates the temperature of the outgoing fluid to a desired set point in the shortest possible time irrespective of load and process disturbances, equipment saturation and nonlinearity.

Iran has recently launched a project to reform its nuclear policy. The revised nuclear energy policy is looking for possible alternative locations for future nuclear power plants in Iran. At the most basic level, people cannot accurately assess whether they are willing to support nuclear energy unless they have an idea of the possible location of the plants. It has been stated that the choice of facility location is a multi-criteria decision problem that includes both quantitative and qualitative criteria. In this study, considering the multi-criteria nature of the issue of site selection of nuclear facilities, a decision tool is proposed to rank the possible locations of nuclear power plants in Iran. This proposed tool is based on fuzzy entropy and fuzzy programming based on fuzzy programming to deal with the ambiguities of human judgments. At the end, a discussion and conclusion are presented.

The aim of this paper is to achieve maximum voltage sag compensation using direct converter based DVR. The DVR topology has a direct converter and a series transformer. The direct converter is connected between the series transformer and the line in which compensation has to be achieved. In this work, the direct converter topology is a new topology. The direct converter has a two uncontrolled full bridge rectifiers, two unidirectional controlled switches and one bidirectional controlled switch. The DVR is designed to compensate the voltage sag and swell in a phase by taking power from the same phase. One uncontrolled rectifier is used to generate positive unidirectional voltage and the other uncontrolled rectifier to generate negative unidirectional voltage from the supply side voltage. Depending up on the occurrence of sag or swell the two unidirectional controlled switches and the bidirectional switch are alternatively modulated to mitigate the sag and the swell. The control algorithm is very simple and effective as only two controlled switches are operated at a time. In order to achieve maximum compensation the compensating voltage is expressed as a percentage of available voltage at the supply side. With the proposed direct converter topology and the control technique, the proposed DVR is able to mitigate 52% of voltage sag and 100% of voltage swell with the THD less than 5%. MATLAB/Simulink results are presented for validating the analysis.

The proportion of installed capacity of renewable energy sources such as wind power continues to increase. The intermittent and volatility of its output have put tremendous pressure on the power system’s dispatch and operation, and the demand for peak shaving by the power grid is increasingly urgent. The hydrogen production system participates in the optimization model of the auxiliary peak shaving service capacity allocation of thermal power units. The power grid’s waste wind power cannot absorb hydrogen through water electrolysis, improving resource utilization efficiency. Based on the technical and economic model analysis of the peak shaving-oriented hydrogen production system, based on the constraints of thermal power and hydrogen production systems, a control strategy for the hydrogen production system to participate in the auxiliary peak shaving of thermal power is proposed. Considering the comprehensive load of the power grid affected by wind power fluctuations, the optimal allocation plan of the hydrogen production system capacity is obtained. The analysis is carried out in the actual example model to verify the correctness of the theoretical analysis.