ali reza reisi

Various methods have been proposed for modeling solar panels, but modeling solar power plants using them is associated with challenges. In equivalent circuit-based methods, the modeling depends on factory data that changes over time. Modeling of voltage-current characteristic using intelligent methods such as neural network was less considered due to the low accuracy of modeling. In this article, a method independent of the manufacturer's data for modeling the solar power plant is presented, so that it is possible to accurately model the solar power plants that have been installed for several years. The proposed method consists of two steps, in the first step, open circuit voltage, maximum power point and short circuit current are modeled according to atmospheric conditions using neural network. In the second step, the unknown parameters of the equivalent circuit are determined by circuit analysis relations and using neural network outputs. Finally, to evaluate the proposed method, a 3-kW solar power plant was modeled, and the results show the appropriate accuracy of the proposed method for modeling the solar power plant.

The production of electricity from the pressure difference inside the water transmission lines is one of the new issues in the renewable energy fields, which is achieved by replacing pressure relief valves with micro-hydropower.  For this purpose, extensive research has been done for the technical and economic evaluation of the construction of micro-hydropower on different points of water transmission lines. The main challenge in conducted studies is that these studies cannot be generalized to other points. In other words, considering that the hydraulic parameters of the lines and their operating conditions are completely different, so each line needs feasibility and separate studies. To this end, in this paper, different stages of designing micro-hydropower from a technical and economic point of view were described; then, these steps were carried out for a real case study, that is, the Kohrang-Shahrkord water transmission line. The design of micro-hydropower in this paper was done with the cost function of the ratio of income to initial capital. The results of the designs for different scenarios showed the importance of studying the daily flow rate changes that may have been affected by climate change. Also, the results showed that by choosing the Crossflow turbine for the points with large flow rate changes, the highest value of the profit index was obtained at the cost of 1.92, which led to the production of 2742,000 kW-hr of energy per year. In similar hydraulic conditions, with the choice of Torgo turbine, the value of this index was 1.34 and the annual energy production was 2141,000 kW-hr.

The 12-pulse diode rectifier (12-PDR) fails to comply with the limits of total harmonic distortion (THD) of supply current to be less than 5% specified in the IEEE Standard 519. Passive harmonic suppression circuits (PHSCs) have been observed to be a viable and cost-effective solution to improve the THD of AC-mains current at a reduced cost. PHSCs increase the number of rectification pulses without leading to significant changes in the installations and yield harmonic reduction in both AC and DC sides. This paper presents a comparative analysis of two novel PHSCs connected at the DC-bus of 12-PDR. One is PHSC-I based on four tapped reactors (FTRs) and four auxiliary diodes; the other is PHSC-II, with two tapped reactors (TTRs) and two auxiliary diodes. The operation modes and optimal parameters of both PHSCs are analyzed with similar inputs (AC side) and outputs (DC side). Both 12-PDR are connected to the same AC source as input, and both PHSCs supplied similar DC loads at their outputs, thus leading to an accurate and fair comparison between the two PHSCs. The results show that the input current THD of a 12-PDR with PHSC-II is lower than that of a PHSC-I and lower than existing passive harmonic suppression circuits. In addition, PHSC-II leads to lower connection losses, current stress, and cost than PHSC-I, so in industrial applications that require low input current THD, low connection losses/current stress, and low cost, PHSC-II is highly recommended.

Restructuring of power systems and integration of different renewable energy sources with complex dynamic behaviors and high structural uncertainties has made the issue of load frequency control more important. For a hybrid power system that includes a thermal power plant taking into account nonlinear limitations such as the governor dead band and generator rate constraints and renewable energy sources including a wind turbine, solar-thermal power plant, electrolyzer, fuel cell, and plug-in electric vehicle, this paper proposes an adaptive wavelet neural network fractional order PID controller (AWNNFOPID) based on self-recursive wavelet neural networks and fractional order PID controller. To compare the performance of the proposed AWNNFOPID controller, four different scenarios are considered and the simulation results are compared with traditional I, PI, and PID controllers as well as with the optimized FOPID controller. The simulation results show that the proposed AWNNFOPID controller has better performances than the other control strategies used for the studied hybrid power system based on performance indicators such as settling time, rise time, maximum overshoot, maximum undershoot, integral time absolute error (ITAE), and integral absolute error (IAE).

Several methods were proposed for the design of power system stabilizer, PSS, based on PI, PID, and FOPID controllers. In these controllers, the degree of freedom increases from two to three and five, respectively. Although increasing the degree of freedom can enhance the convergence rate and the robustness of the controller, it does come with more challenges when it comes to tuning the control parameters. For instance, it is no longer possible to adjust FOPID parameters using trial and error. One of the conventional methods is to use optimization algorithms, but it should be noted that the power system is highly non-linear. This research aimed to propose an algorithm to design the PSS controller based on FOPID, in which the controller coefficients were adjusted based on the system conditions. For this purpose, the controller coefficients were defined based on the gradient of the power system, so that the coefficients were adjusted at any moment by the adaptive-indirect gradient method in such a way that the cost function of the controller was minimized, and as a result, the rate of oscillation damping increased. In the proposed algorithm, an identifier based on self-tuning wavelet neural network with online learning was used to estimate the gradient of the power system. Finally, the proposed adaptive controller was designed for a two-zone, two-machine power system including FACTs devices, SSSC-type, and its performance was evaluated in comparison with other methods. The results confirm the effectiveness of the proposed method.

The existence of deviant behaviors in organizations reduces the effectiveness of the organization. The purpose of this study was to investigate the relationship between professional ethics and job values with deviant organizational behaviors in health care network employees

In this descriptive-analytical study, 148 employees of health centers in Ardal city in Chaharmahal and Bakhtiari province in 2017 were randomly entered into the study and after obtaining informed consent, questionnaires were distributed among them. Data collection tools were three standard questionnaires of professional ethics, job values and deviant organizational behavior. Data were analyzed using IBM SPSS 24 software and descriptive statistics, correlation and multivariate regression tests.

The mean score of professional ethics was 65.02 ±12.85, the mean score of job values was 72.04 ±15.44 and the mean score of deviant organizational behaviors was 42.02 ±12.02. The results of multivariate regression test showed that the variables of professional ethics (p = 0.006) and job values (p = 0.008) are predictors of deviant organizational behaviors and the variable of professional ethics is a stronger predictor. There was a strong and consistent relationship between the mean score of professional ethics and job values (r = 0.183) (p <0.05). There is a strong and inverse relationship between the mean score of organizational deviant behavior with professional ethics (r= -0. 402) and job values (r = -0. 09 ((p <0.05).

The results showed that it is expected to reduce the amount of deviant organizational behaviors in employees by promoting the professional ethics of employees and giving importance to job values.

Respect to the concept of the control structures, the author of this study recently suggested a novel hysteresis damper with named nested-eccentric-cylindrical shells damper (NESD) for increasing the damping in structures.According to the greater ability of the shell structures versus the plate structures, the NESD is designed based on the shell structures. The configuration of the shells in the NESD is designed in such a way that it can be increasing the performance and stability of the device. These members are as well as the multi-springs with the combination of series and parallel form. Also, the configuration of this device is designed by the simple form and with an easy way to install in structures. However, to evaluate the seismic performance of the proposed damper, the NESD used into the structures with various heights with four, eight, and twelve floors and analyzed by dynamic nonlinear time history. The seismic analyses are run with eleven records by particular geography characteristics of seismic hazard zone. In this evaluation, the efficiency of this damper in damping seismic energy and reducing the displacement and base shear responses is approved. In the seismic analysis, Therefore, by modeling this damper in structures, it was found that by using this damper in structures could be a damping of up to 35% of the seismic energy in the structures and reduce an average of 50% in displacement and could cause a reduction of 7 to 27% in the base shear for the structures. However, it was found that the NESD could be better behavior for reducing the response of mid-rise structures.

By the concept of control structures a new shell configuration for a steel energy dissipative device designed for earthquake protection of structures is proposed in this study. This device is named a nested-eccentric-shells damper (NESD). This device is made of a large cylindrical shell that surrounded three small cylindrical shells. The conventional methods of welding or metal casting can be applied in constructing this damper. The configuration of the shell-type components is designed in such a way that to be able as a combination of series and parallel springs. To assess the performance of this damper, numerical analysis and full-scale testing are run. Hysteretic loops obtained from the analysis with highly ductile performance are applied to determine the behavior of this proposed damper. The results indicate that the nested-eccentric-shells damper is of a stable behavior in hysteretic loops, and can provide appropriate damped energy subject to cyclic loading. However, in order to improve the performance and interaction of the internal members of this damper, a thickness ratio is proposed for the inner shells and the usefulness of using this modification in numerical analysis has been proven in this study.

Demand Response (DR) program is one of the measures, performing with both of Retail Electricity Companies (Recos) and market's operator. This paper aims to provide a novel framework for optimal congestion management via encouraging a collaboration between the independent system operator (ISO) and Retail electricity companies (Recos) in implementing demand response (DR) programs based on the market mechanism. The merit of the paper is to increase the market efficiency. Economic signals specified by the ISO, are used for assisting Recos in evaluating any benefits from implementing DR in various network buses. A Stackelberg game is adopted for designing a DR trade between Recos and demand response aggregators to help Recos identifying their optimal demands in the market which are then used by the ISO to analyze grid congestion and consequently to re-specify the new economic signals. The game is repeated until the Nash equilibrium point, the optimal congestion reduction and the optimal Recos' demands, are obtained. The performance of the proposed framework are assessed using a test power system, The paper demonstrates an effective performance for the proposed framework.

A coupling beam is a type of beam for connecting two adjacent shear walls, with a functioning similar to that of eccentrically braced steel frames (EBF). Seismic characteristics of various types of coupled beams such as diagonally reinforced concrete coupling beam (DBCB), steel coupling beam (SCB), composite steel/concrete beam utilising a vertical web shear plate with headed shear (SPCB), and steel beam with a steel fuse link located at mid span of the beam (FCB) are studied (Fig. 1). Pushover analysis has been performed for chosen frames of up to 20 storeys in order to determine reduction factor as a function of overstrength factor, ductility factor and indeterminacy reduction factor. In this research, novel relations have been proposed for calculating reduction factor, which include the effect of the type of soil and height of the structure. Four 5-, 10-, 15- and 20-storey frames with 3 m-high storeys and five spans have been analysed. There are four concrete bending frame spans, each 5 m long, and a 4 m-long span with two coupling core wall, each 1.4 m long, and a 1.2 m-long coupling beam. ETABS code [1] has been used for the design of structural members, pushover analysis, and the determination of overstrength factor, ductility factor and indeterminacy reduction factor by which reduction factor can be calculated. The effect of four different types of soil has been considered. Effect of variable parameters on reduction factor In order to investigate the effect of variable parameters on reduction factor, two types of frames, i.e. intermediate and special bending frames, four numbers of storeys, i.e. 5, 10, 15 and 20 storeys, and four different types of soil, i.e. types I, II, III and IV [2], have been considered. The sequence of member stiffness increase is from coupling beams towards beams, columns and shear walls and it is more pronounced for lower frames. By increasing the height of the frame, the reduction factor calculated by the proposed equations is decreased until it coincides with the value proposed by the Iranian Earthquake Code [2]. For points higher than the coincidence point, reduction factor is on the safe side. For looser soils, the value of reduction factor increases slightly for points lower than the coincidence point and it decreases slightly for points higher than the coincidence point.