احسان اکبری

Harmonic voltage and current, power factor or reactive power, equilibrium state of three-phase system and voltage drop or voltage regulation are important factors of power quality issue in distribution network. Also, these factors cause serious damage to the indicators of the network and its equipment. To solve this issue, these cases should be corrected by different compensators at the level of the distribution network. Therefore, this paper presents the compensation of destructive indicators of linear and non-linear loads using D-STATCOM based on conventional power theory (CPT) in the distribution network. It is worth mentioning that in this paper, two methods of CPT and momentary active and reactive power theory (PQ) are used for    D-STATCOM control strategy. Finally, the proposed design is applied on a three-phase system consisting of linear and non-linear loads using PSIM software, and then the capabilities of the proposed design are evaluated.

Today, renewable resources have become important due to the reduction of pollution and cost compared to fossil fuels. Microgrid structure is used for better management and efficiency of these resources. In this article, improving power quality and reducing harmonics in hybrid microgrids using Interlinking converters (ILC) are discussed. For this purpose, a network backup converter has been used to improve power and reduce disturbances. The desired microgrid components include distributed generation units, AC loads, DC loads, the energy storage system (battery), and parallel connecting converters. In the hybrid AC/DC microgrid topology that is investigated in this article, there are two main converters, one is the network forming converter which is an intermediate converter and is used to control the microgrid voltage. The second converter is the VSC converter, which is placed between the DC link (including the DC microgrid and battery) and the AC micro-grid. The control system of a hybrid microgrid was implemented and simulations were carried out in MATLAB software for four different scenarios related to the active and reactive power of the microgrid. After the operation of the harmonic compensation control part in the microgrid, the THD is about 1.87% and even lower than the initial.

The use of FACTS devices is increasing due to the improvement of the transmission capacity of lines and the reduction of losses and costs related to the power system, and for this reason, new devices are used. One of these tools is the of interline power flow controller (IPFC), whose main task is to control the inter-line power of the transmission system, and it is one of the newest FACTS tools. In this article, the placement and regulation of the controllable parameters of IPFC has been discussed in an optimal way. The main goal of this optimal placement of IPFC in a multi-objective manner in the power network is to simultaneously reduce system losses, cost, and also improve system load taking into account the relevant constraints. In order to carry out placement studies, the selection algorithm based on beam forming or PESA_II has been used, and the placement process has been carried out on the IEEE 30-bus network. The results show that all indicators have improved so that compared to the case where IPFC is not present in the network, active power loss (%) is reduced by 59.43, load capacity (%) is increased by 32.08, reactive power loss ( 26.63% reduction and power plant fuel cost has decreased 59.01%.document.

Following the scarcity of non-renewable resources such as oil, gas and coal, more research is focused on the issue of high energy consumption and society's dependence on fossil fuels. The use of renewable energy and the development of microgrids can be necessary to reduce dependence on fossil fuels. Photovoltaic systems play a key role in microgrids as a source of renewable energy supply. In these systems, the output voltage of the cell is usually much lower than the voltage required by the DC bus, and as the output current increases, the amount of this voltage decreases significantly. Therefore, the presence of a step-up DC-DC converter with a wide input voltage range is necessary to connect the low-voltage cell source and the high-voltage DC bus connected to the inverter. In this paper, a new structure is presented for non-insulated DC-DC boost converters based on voltage lift technique. The proposed converter has a proper voltage gain at output and an acceptable voltage stress on switch and diodes in comparison with recent references. The proposed converter has a switch with easier control and high reliability due to the input source common point and the output load of the converter. Analysis of the voltage stress as well as selection of suitable elements along with converter analysis in continuous mode are performed and calculation validity is confirmed by presented laboratory results.

The proposed structure of this article is a hybrid wind-solar-storage system with fault tolerance that reduces output power fluctuations and voltage drop in the system caused by faults. In the proposed topology, the solar system is connected to the DFIG through a DC-DC converter, thus eliminating the need for a special inverter for the solar system and reducing the cost. The power management in this system is done using the converters of the rotor section and the DC-DC controller related to the DC link using the phased method, which is why there is no need to use a compensator in the system. The better the control system works, the better and sooner the fault detection and compensation will be done, and this will prevent the system from being damaged and unstable, and will not cause serious damage to the system. In this thesis, the simulation results for two scenarios were investigated. In both scenarios, the active power decreases during 0.3 seconds when a sudden voltage drop occurs, but the reactive power increases due to the compensation of the created error. With the occurrence of an error and a sudden voltage drop in the system, the wind turbine has not reached an unstable state and a sudden increase in torque has not occurred, and the control system has worked well. Therefore, in this research, the proposed system was able to perform fault detection and voltage drop compensation through DC link voltage stabilization and reactive power injection in order to improve the voltage drop. It should be noted that all simulations were done in MATLAB/Simulink software.

The power quality of power systems is one of the concepts that have always been the focus of electrical engineers and specialists. Electrical power quality disturbances of the power system refer to any problem that causes changes in voltage, current or frequency and affects the performance of equipment and consumers. Electric arc furnaces are one of the large loads whose voltage-current characteristics are nonlinear, variable with time and somewhat random. Wide harmonic spectrum, high range of produced harmonics, low power factor and large changes in active and reactive power consumption are among the most important characteristics of this type of loads. One of the ways to overcome problems and harmonic disturbances and improve the power quality of the power system is to use harmonic filters. One of these filters that is used in this article is a composite filter that has several important functions in one place. In this study, the improvement of power quality in the electric arc furnace distribution network has been investigated using a composite filter, which is controlled using a fractional order controller. The obtained results show that in the case where the composite filter (active and passive) is placed in the circuit, the percentage of network harmonic distortion (THD) decreases to 0.26%, which shows the improvement of the power quality of the system. Therefore, the power quality results in this research show that the combined filter proposed in this research has been able to improve the power quality of the distribution network investigated in this research so that the THD of the system related to voltage and current in this case is greatly Dropped.

Due to the ever-increasing development of the electricity industry and the growth of consumption demand, the use of clean energy sources is increasing. In this regard, the use of wind energy as a clean and free source for the production of electrical energy is expanding day by day, and according to predictions, 20% of the world's energy will be obtained through wind by 2030. But in addition to all the advantages of wind energy, using them in the form of wind turbines in power grids in order to provide the required power can be considered a negative factor from the point of view of stability in power systems. The purpose of this article is to use the predictive control method based on logger functions to check the small signal stability of a hybrid network, including synchronous generators, wind farms and parallel STATCOM compensator. In this method, by using logger functions, the computational time in model-based predictive control has been reduced, so that the accuracy of tracking control signals can be increased and the stability of the system can be improved. The proposed method for controlling the active and reactive powers in the rotor side converter related to DFIG and the type of compensator used has been done in such a way that the performance of the power system can be increased by applying appropriate switching in the corresponding inverter. The simulation results using MATLAB software have been evaluated in the time domain, and its superiority has been clearly shown in order to improve the damping of power system fluctuations.

By developing the distributed generation units, the hybrid micro-grids usage besides the energy storage systems has changed the future of the electricity industry. In addition to the many benefits of the micro-grids, they can undermine security, reliability, stability, and other network indices if not properly scheduled. In this paper, a new attractiveness index is defined in order to optimal schedule the DGs generation and charging/discharging of the energy storage system (ESS) in a hybrid micro-grid. Also, the pollutant emission of the units is considered as the second objective along with the proposed attractiveness index, which constitutes a two-objective optimization problem. To solve this nonlinear and non-convex optimization problem, the Non-Dominated Sorting Genetic Algorithm (NSGA-II) has been used. The main advantages of this algorithm are the ability to escape the local optimal traps and fast convergence. For further comparison, the Quantum Particle Swarm Optimization (QPSO) algorithm has been implemented. The performance of both algorithms in solving the proposed optimization problem is evaluated on a standard hybrid micro-grid. The results show faster convergence and better performance of the NSGA-II algorithm in terms of the final optimization solution.

Connecting wind turbines to power networks without adversely affecting system stability is one of the most important future challenges to expand wind farms. In this paper, to improve the power network stability, damping the oscillations caused by torsional modes and increasing the energy conversion efficiency of wind turbines, a new control strategy was proposed for the active power control loop of wind turbines as well as HVDC transmission systems. First, the nonlinear speed-power curve of the wind turbine was shown to be effective in damping coefficients of torsional modes, energy conversion efficiency and the stability of the wind turbine. Accordingly, the use of wind turbine stabilizer in the wind turbine power control loop was proposed. Since the wind power plant is effective in the flow of the active-reactive power components, the use of supplementary damping controllers in the rectifier of VSC HVDC system was proposed to improve the voltage profile and the dynamic stability of the power network. The fractional order PID controllers were used in the proposed control strategy whose coefficients were adjusted using the proposed genetic-bat algorithm. In this algorithm, in order to avoid the rapid convergence of bats to local extremes and the optimal development of the search space, two operators of genetic algorithms, the dynamic mutation based on probabilities and the crossover were used. The simulation results showed that under the proposed control strategy, the stability of the system and the voltage profile in the network were significantly improved.

The use of high voltage direct current (HVDC) technology to connect wind turbines seems to be very convenient, as it provides a cost-effective solution for long-distance energy transfer as well as for offshore wind farms. In this paper, a new method for connecting wind turbine chains with the help of DC link connection is presented. In this method, electronic power converters are used to create HVDC converters distributed between turbines. In the proposed method, in addition to reducing the number of equipment, converters and electronic components of power, it reduces costs and increases efficiency and better voltage stability in wind fluctuations. The simulation results show that the change in wind speed and related fluctuations due to changes in air climate have no effect on the output voltage of the system connected to the transmission network. The results show that the designed controller works well and keeps the voltage constant at 100 kV by controlling the current. It should be noted that all simulations were performed in PSCAD / EMTDC software environment.

In fuel cell vehicles, the output voltage of the fuel cell source is usually much lower than the required voltage of the DC bus; and as the output current increases, the output voltage decreases significantly. In order to match the output voltage of the fuel cell source with the DC bus voltage, a new DC-DC boost converter with a wide input voltage range and high voltage gain is introduced that as a required power interface can reduce the voltage stress across electrical appliances and work with acceptable conversion efficiency. A prototype with 300 W power is designed and implemented; as a result the maximum efficiency of the proposed converter is 95% at 300 W. Experimental results are also presented to confirm the effectiveness of the proposed converter.

The use of agricultural waste is always important; one of the most important processes for increasing their shelf-life is drying. The purpose of this study was to investigate the drying kinetics of carrot pomace and evaluating the antioxidant and color properties of it. For this purpose, the prepared pomace was dried at 50, 60 and 70 °C, and the antioxidant and colorant properties of fresh and dried pomace were studied. The results showed that the best model for predicting drying kinetics of carrot pomace was Midilli-Kucuk model with correlation coefficient (R2) of 0.9994, 0.9994 and 0.9986 and root mean square error (RMSE) 0.0088, 0.0091 and 0.019 for the temperatures of 50, 60 and 70 oC, respectively. During the drying process, the amount of carrot pulps beta-carotene (30.10 ±0.08 at 60 °C) 80.2% was reduced compared to fresh pomace (150.66 ± 1.4 mg/100g), this difference was significant (p<0.005). Also, the temperature of 60 °C had the greatest effect on the reduction of beta-carotene. Reducing the amount of beta-carotene led to the color indicators alterations. An indicator changes showed a high correlation (0.988) with beta-carotene content.

In this study, the kinetics of total antioxidant activity changes by DPPH radical evaluation, brown pigment formation (BPF), and phenol total with folin–ciocalteu reagent intestinal tract in heated alfalfa honey at different temperatures (45, 55 and 65 °C) over a period of 10 days it placed. The results showed that the amount of antioxidant activity, BPF, and total phenol content increased with increasing temperature and time. Also, the kinetics of changes in BPF and total phenol showed that these parameters follow zero-order kinetics and the activation energy was 86.1 and 71.7 kJ / mol, respectively, at 45-65 °C. However, due to the diversification of antioxidant activity at different temperatures, second order, first order, and zero order kinetics were obtained at 45, 55 and 65 ° C, respectively. Honey heating at 65 ° C was more effective than 45 ° C and 55 ° C for all three parameters. The results showed that antioxidant activity was associated with an increase in both browning factors and total phenol, and also with increasing brown pigment formation, the total phenol content increased so that the highest amount of phenol was related to the darkest honey sample.

In this research, the physicochemical and antimicrobial properties of propolis from honeybee beehives around Mashhad and the content of active compounds in propolis were determined by high pressure liquid chromatography (HPLC) both quantitatively and qualitatively. Physicochemical properties of the propolis sample (such as ash, moisture, soluble solids and insoluble solids and existing metal elements) were measured. The total phenolic and flavonoids compounds in the ethanolic extract of propolis were 40.126 mg/g (gallic acid) and 26.46 mg/g (quercetin), respectively. Antimicrobial tests showed that the minimum inhibitory concentration (MIC) of the extract against Staphylococcus aureus was 100 mg/mL, while in the applied concentration MIC did not achieve against Escherichia coli. Also, the results of the minimum bactericidal concentration (MBC) test indicated that propolis extract on Staphylococcus aureus had only inhibitory effects. Evaluation of the content of phenolic and flavonoid compounds in propolis extract by HPLC indicated that the flavonoid compounds included flavones (13.33 mg/g), flavonoids (6.375 mg/g), flavonols (8.235 mg/g) and flavanones (16.825 mg/g). Based on the results, propolis can be used in various food and pharmaceutical industries.

Due to the low voltage level and as a result of high current, the distribution networks have high losses and high voltage drop, which has always been the biggest contributor to the losses and reduced reliability of the electricity distribution network. Various methods have been proposed to reduce losses, improve voltage profiles and increase reliability in these networks, one of which is redistribution. Rebuilding Distribution Networks with Switching Keys is to find the best combination of all switches in the network to minimize power losses and load balancing in situations where load distribution constraints, grid radial topology and The minimum voltage required is a very cost-effective and low cost method that reduces losses, improves voltage profiles and increases reliability in power distribution networks without adding additional equipment to the grid. Reliability calculations have used the Cut-Set method to speed up compared to the Monte Carlo method. The rearrangement of distribution networks is a large-scale nonlinear hybrid optimization problem involving a number of constraints. In this paper, a new meta-heuristic algorithm based on the behavioral pattern of wild mice is used to reconfiguration of power distribution networks to reduce losses, improve voltage profiles and increase reliability. The wild mice colony algorithm is a suitable algorithm for finding the optimal answer to complex problems. The effects of  distribution system reconfiguration on two distribution networks 33 Bus and 69 Bus of IEEE standard are implemented and the results are evaluated.

The labour procedure system in Iran is based on the consideration of special or quasi-judicial authorities to the differences between the labourer and the employer, and the structure and competence of these institutions are explained in Articles 157 to 166 of the Labour Code and the Rules of Procedure of Labour, approved in 2012. Based on the above legal standards, the settlement of labourer and employer disputes in the legal system of Iran takes place within the framework of three institutions of reconciliation, the Delegation of Delegation and the Dispute Resolution Board, and the organization of these three main institutions also follows the common principles governing labour proceedings, including the principle The simple consideration of the lack of formalities and the participation of the parties in the relationship of work in the formation of these references has been carried out. However, by studying the documents of the International Labour Organization and an comprative approach to the structure and jurisdiction of labour courts in Iran and the world, it can be seen that the labour system in Iran has important legal deficiencies due to its structure, jurisdiction and treatment, which is the lack of The full realization of structural autonomy, the lack of general jurisdiction, the conflict of jurisdiction with other specific authorities, the failure to comply with the standards of civil procedure, and the non-compliance of the structure and jurisdiction of the competent authorities with the principles of fair trial and the principles of labour law, among the most important examples are the number they are going.

In recent years with the advancement of military technology, societies have become decadent and observation of the ethical principles has declined; different countries attacking each other. One of the most important defensive strategies that have been taken into account by many developed countries, is using passive defense principles for the design of hidden systems according to the patterns of deception and camouflage. The built-in camouflage, has significant advantages compared to the additive camouflage, and it is considered in the original layout when new systems are being designed. This camouflage is a component of system composition and there is no need for personnel effort to activate it. The main objective of this research is to present new patterns for design of hidden buildings and development of resistant structures by the passive method as a defensive strategy. Another goal is to increase the possibility of continuity of their activity in the face of military and terrorist attacks.

The purpose of this research was to investigate the effects of spirituality in the workplace component of desire to change the attitude according to the mediating role of organizational commitment. This research based on its goal is considered a practical research which consumed a descriptive and correlative research based on data gathering. The oil pipelines and telecommunications company of Fars district employees' (350 persons) were the statistical population of this research. The number of samples was counted 125 persons using the Cochran formula, and sampling was done by simple random method. Data collection was done by combination of three standardized questionnaires in a Likert 5 scales score. The research data was analyzed by using lisrel 8.5. All variables affecting the desire to change attitudes by employees in the oil pipelines and telecommunications company of Fars district were evaluated based on a conceptual model. Finally, the conceptual model according to indices of goodness of fit was approved. According to the estimates of the coefficients of the direct and indirect effects, the highest direct effect on willingness to change attitudes was related to “continuance commitment” (.35) and the lowest indirect effect have been “working interest” (.08).

The judicial review of the Administrative Justice Court on the votes of the commissions and parliaments is set out in paragraph 2 of Article 10 of the Law on the Organization and Procedure of the Administrative Justice Court. Accordingly, and in view of the non-existence of the cases mentioned in this paragraph, The objection was cast on all subjectivist authorities in the Administrative Justice Court. However, the law of the city of land, by referring to the term "Saleh Court" as the point of reference for the review of the committee's vote under Article 12 of this law, has created an ambiguity in the history of the concept of the term. Proceedings No. 473- 1389/10/27 The General Court of the Court of Justice has interpreted the term "competent court" to the public court of justice in its statement of purpose, and has been disqualified in this regard. However, the content of this vote is largely criticized, given the nature of the Commission's Article 12 of the Law on Urban Land, the lack of grounds for the application of judicial review by the public courts to the commission's decision, and the lack of attention to the inherent jurisdiction of the Administrative Justice Court and the public courts.

With the growth of communities and the increasing need for electricity, and because of the many benefits of renewable energy sources, the wind turbine has become a completely commercial and inevitable process, with increasing penetration into the electricity grid. Distribution networks, on the other hand, are subject to fault that cause power fluctuations and outflow of wind units. In order to continue to use these units and not to leave them out of the grid, it is important for them to improve Low voltage Ride-Through. In this paper, two Dynamic Voltage Restorer (DVR) and Superconducting Magnetic Energy Storage (SMES) systems under four different scenarios are used to improve DFIG's low voltage ride-through and uninterrupted performance by maintaining its controllability during the faults. The performance and comparison of the performance of the four scenarios to improve the LVRT and reduce the DC and DC link voltage fluctuations have been studied. The simulation results in the MATLAB/SIMULINK software environment demonstrate the high accuracy and real-time performance of these two equipments in reducing the adverse effects of distribution grids LVRT on wind turbine based DFIG.

The legitimacy and acceptance are modern and new words. Although these words not used during ancient ages but its concepts had special significance for the kings. The terms " admissibility or qualify " can be described as the best alternative for concept of legitimacy during ancient times. The Achaemenid Empire, one of the largest empires in the ancient world, ruling over ancient large urban centers of civilized world that had long history in the governing and managing, was much more than the Achamenians. The fact that the Achaemenids how was able to satisfy the civilized nations under their reliance, and take legitimacy for crown prince among other princes. Second matter is as important as first. These cases wasn’t studied before our research. Based on the study of the inscriptions of the Achaemenid kings, it was found that a complex set of factors played a role in this matter, such as: Divine Verdict, Descent, Positive Moral Characteristics, Intelligence and Politics, Warrior Victory and Avoiding lying. These most important factors lead that after war and military conquering other regions, people accept victor kings as theirs, and obey the commands without military pressure or forces.

Nowadays, food adulteration is important to marketing and production. The purpose of this study was to classify different types of honey (Thyme, Chaste tree, Jujube, Coriander, Barberry, Acacia and Alfalfa) with different herbal origin based on color characteristics, salinity, electrical resistance and total dissolved solids (TDS). For classification of honey, principal component analysis (PCA), linear discriminant analysis (LDA) and cluster analysis (CA) of chemometrics method, were used. The results showed the two principal components (PC1 and PC2) comprise 77.69% of the total variance, which indicates the distinction between different honeys based on physicochemical characteristics. It was also shown in the LDA method was able to classify different honeys with an accuracy of 75%. On the other hand, the method of CA in the distance of 85.58, honey was placed in 7 groups that contained thyme, coriander, acacia, barberry and jujube honey in separate groups and alfalfa honey and chaste tree honey were scattered among the groups.

Unified Power Flow Controller (UPFC) is one of the FACTS devices which plays a crucial role in simultaneous regulating active and reactive power, improving system load, reducing congestion and cost of production. Therefore, determining the optimum location of such equipment in order to improve the performance of the network is significant. In this paper, WCA algorithm is used to locate the optimal placement of UPFC. The concepts and ideas underlying this approach are inspired by nature and are based on observations of water and the process of the water cycle and the formation of rivers and streams and their flow to the sea in the real world. This algorithm has a high potential for escaping local optimizations as well as speeding up global optimization. For UPFC modeling, the power injection model has been used and the OPF-UPFC problem has been solved with various objective functions such as generators fuel cost, network losses and system loading, both single-objective and multi-objective. Also, the results obtained from different objective functions are compared with other references. The results acquired show the efficiency and speed of the water cycle algorithm compared to some other intelligent algorithms. The computer program has been written in the MATLAB software environment and implemented on the IEEE 14-bus network.

The legitimacy and acceptance are modern and new words. Althoughthese words not used during ancient ages but its concepts had specialsignificance for the kings. The terms " admissibility or qualify " can bedescribed as the best alternative for concept of legitimacy duringancient times. The Achaemenid Empire, one of the largest empires inthe ancient world, ruling over ancient large urban centers of civilizedworld that had long history in the governing and managing, was muchmore than the Achamenians. The fact that the Achaemenids how wasable to satisfy the civilized nations under their reliance, and takelegitimacy for crown prince among other princes. Second matter is asimportant as first. These cases wasn’t studied before our research.Based on the study of the inscriptions of the Achaemenid kings, it wasfound that a complex set of factors played a role in this matter, such as:Divine Verdict, Descent, Positive Moral Characteristics, Intelligenceand Politics, Warrior Victory and Avoiding lying. These mostimportant factors lead that after war and military conquering otherregions, people accept victor kings as theirs, and obey the commandswithout military pressure or forces.Keywords: Achaemenid, legitimacy, inscription, descent