فهرست مطالب

Smart Electrical Engineering - Volume:12 Issue: 1, Winter 2023

International Journal of Smart Electrical Engineering
Volume:12 Issue: 1, Winter 2023

  • تاریخ انتشار: 1401/11/12
  • تعداد عناوین: 8
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  • Hossein Ghaemzadeh Ebli, Mohammadali Nekoui *, Mohammad Teshnelab Pages 1-9
    In the present paper, multirate control method is used for mechanical robotic manipulators. Also, the process of designing the reference state vector for mechanical manipulators is presented in this paper. For this purpose, a prototype robot is assumed in which highly precise rotary encoders are mounted at the outer side of the joints. The robot dynamics is time-continuous while the relevant controls are time-discrete. Since these systems are always exposed to unwanted disturbances, the present paper introduces a passivity-based control that, in contrast to the reverse dynamic controls, doesn't require linearization. In this regard, first, the modified form of the Lyapunov-based control and, then, the discretized equations are presented. The multirate controller is implemented on the discretized structure and, thereby, its effect on the estimation precision of the angles of the joints is examined in comparison with the single-rate controls. The present paper introduces a practical method for designing and executing the multirate feedforward control of robotic me-chanical manipulator. First, to eliminate the effect of disturbance, a passivity-based con-trol was designed and it was shown that it, unlike the reverse dynamic control, didn't require linearization.
    Keywords: Multirate control, Robotic Manipulator, Network Control System, Disturbances, Lyapunov based Control
  • Keivan Navi *, Neda Ghoreishi, Reza Sabbaghi-Nadooshan, Mohammad Esmaeildoust Pages 11-21
    In junctionless nanowire transistors, drain-channel-source doping is of the same type and level. Therefore, fabricating junctionless transistors is less complicated than inversion mode transistors. However, the reduced ratio of on current to off-state current (ION/IOFF) in junctionless nanowire transistors has made their operation difficult due to the high impurity scattering in the channel. The larger ION / IOFF ratio indicates an increase in transistor switching speed. In this study, the use of gate oxide engineering is proposed to increase of ION / IOFF ratio. The proposed oxide thickness is 1.5nm, which is a buffer layer with K = 5.7 and a thickness of 0.5nm, and the oxide with a high permittivity factor with K = 29 and a thickness of 1nm. The proposed structure is called GAA-JL-FET-with-oxide buffer layer. In GAA-JL-FET-with-oxide buffer layer, the ION / IOFF ratio has been improved by about 106 and 102 times compared to the structure with K = 3.9 and K = 7.5, respectively. Due to the high switching speed, the GAA-JL-FET-with-oxide buffer layer is applied to design the multiple-valued logic (MVL) interconnection network in the voltage mode for the first time using the mixed-mode tool in Silvaco software. The results reveal improving subthreshold parameters of the simulated device significantly enhance the average power, max delay and power delay product (PDP) of the proposed interconnection networks.
    Keywords: Smart Computer networks, Junctionless FET, Multiple-Valued Logic, Interconnection Network, High speed
  • Seyed Mahdi Behinnezhad, Ghazanfar Shahgholian *, Bahador Fani Pages 23-30
    In this paper, a control method based on internal current control loop and dc link voltage regulator for three-phase photovoltaic (PV) system connected to the distribution network is presented. Current control method, the dynamics of the PV system separate it from the dynamics of the grid and the loads in it, and dc link voltage control improves control and increases the output power of the PV system. Also, a feedback control method is proposed to adjust the dc link voltage in order to improve the transient response of the PV system, which distinguishes the dynamics of the PV system from the nonlinear characteristics of solar cells and enables the design and optimization of system controllers in a wider range of workstations. In order to achieve a constant voltage level, a dc/dc converter is recommended to prevent the transfer of voltage harmonics to the inverter. The proposed method is investigated using a simulation of a PV system connected to the distribution network in the MATLAB software environment.
    Keywords: Distribution network, Feedback control method, Output Power, Photovoltaic system
  • Hamideh Jashn, Behnaz Mahipour, Elaheh Moharamkhani *, Behrouz Zadmehr Pages 31-41
    One of the most important technologies that has affected our lives today is cyberspace. On the other hand, one of the most important problems of social networks is the disclosure of users' information, i.e. the violation of their privacy. Therefore, protecting the privacy of users is very important, so the use of encryption methods is an important tool in ensuring the privacy and security of shared data users. The proposed framework of this paper is based on AES and RSA algorithms. This framework is designed to be decentralized and takes advantage of the AES and RSA algorithms to provide a framework that prevents unauthorized entities from accessing users' data and messages. Any safe method must be designed in such a way that there is no escape route for attackers and unauthorized entities. Therefore, our focus is on two important parts of secure methods, namely key management and privacy, which the results of this article show, the security assessment proved that our proposed framework is designed to be completely safe and correct, and increased security and efficiency.
    Keywords: Social networks, privacy, Security, Encryption, decryption
  • Shima Nasr Azadani, Hamid Mahmoodian * Pages 43-49
    Controlling the rate of insulin injection is very important in diabetic patients who are equipped with an insulin pump. The challenges of proper insulin injection into the body can be exacerbated by the presence of uncertainties (due to different physiological differences in individuals) and the different daily activities of each person. Insulin control has also become more complex due to the delayed effect of carbohydrate entry on the body's blood sugar levels, and may lead to dangerous conditions of hyperglycemia or hypoglycemia. In this paper, the aim is to reduce the effect of inherent uncertainties in the patient. The patient model is based on the Hurca mathematical model. General type 2 fuzzy controllers with alpha cuts are proposed. A neural network system with a linear regression model is used to predict blood sugar levels in the following hours. Also the adjustment of a number of controlling parameters has been done using genetic algorithm. To investigate the controlling behavior, several disturbances in the model and the entry of carbohydrates into the closed-loop system have been considered. The simulation results show that the proposed controller can control blood sugar under different conditions. The designed controller also prevents the occurrence of two dangerous states of hyperglycemia and hypoglycemia.
    Keywords: control insulin injection rate, fuzzy control, Genetic Algorithm, Neural network
  • Naser Taheri * Pages 51-59
    The use of high voltage direct current (HVDC) transmission lines in power systems not only increase the capacity of electrical power transmission systems, but also strengthen the stability of the power network. In order to optimize the HVDC influences on voltage-frequency stability, it is necessary to design supplementary controllers in the most optimal path between input-output signals of the whole power system. The supplementary controllers are added to the local control loop of HVDC to improve active-reactive power flow. In this paper, an optimized method based on the controllability concept is proposed for the coupling of the input-output (IO) signals of the power system equipped with voltage source converter (VSC)-based HVDC. Then, the optimal path is used for supplementary damping controller design based on a novel adaptive recurrent neural network (ARNN). The ARNN is trained online Using a new training algorithm. The simulation results, which are carried on using MATLAB software, show the effectiveness of the control strategy to improve the voltage profile and dynamic stability of the power system.
    Keywords: Power system dynamic stability, Oscillation Modes Controllability, Supplementary Damping Controller, Recurrent neural network, VSC HVDC
  • Mohammad Maghsoudi *, Roohollah Barzamini, Mehdi Siahi, Payam Rabbanifar Pages 61-68
    Demand for electricity generation is increasing day by day, and power stations must be able to meet these demands. There are several ways to generate power, such as thermal power plants. There are many variables in a thermal power plant boiler unit (steam unit), but the boiler drum level is one of the most important variables that has a very complex dynamics and it is necessary that the control system can keep it in a safe range. In this paper, two time-varying transfer functions are considered for the drum level (output) to water and steam (inputs). In the presence of parametric uncertainties in the model, the three controllers, Sliding Mode Controller (SMC), Model Reference Adaptive Control (MRAC) and PID Controller are compared to track the desired level of the drum-boiler to different inputs. The results show that the SMC has relatively better tracking results, but the control signal in MRAC is more optimal than the other two controllers and is more suitable for practical applications.
    Keywords: sliding mode control, adaptive, MRAC, Uncertainty Model, Power plant, Drum level
  • Yadullah Shafiei, Faramarz Faghihi *, Amir Hossein Salemi, Hossein Heydari Pages 69-78
    In this article, the most important factors affecting the discharge characteristics of high voltage insulators will be investigated. The type and severity of pollution, geographical and climatic conditions such as fog, rain, and wind, as well as the height above sea level, and finally the appearance and constituent materials of insulators will be studied as the main influencing factors in causing flashes on their surface. In addition to its severity, the type of pollution has a great effect on the electrical properties of insulators. This issue is discussed in the first section of the article for common types of pollution with different severities. Furthermore , a mixture of pollutants in the air is also examined, and the insulation waste is also shown in the case of design only based on sea salt, which is the worst type of pollution.In the next part, a review on the influence of climatic and geographical conditions has been performed, and in it, the effect of frost, wind, humidity and altitude on the start of electric discharge is discussed as the most important of them.And finally, the effect of appearance and its associated parameters as well as the constituent materials of insulators in pollution conditions are the last factors that will be considered. In addition, in this study, it has been shown how by intelligently changing these two factors, leakage current and discharge intensity can be reduced in contaminated insulators and their premature aging and failure can be delayed.
    Keywords: Electrical Discharge, pollution, high voltage insulators, climatic conditions, appearance of insulators, field strength