Nashriyyah -i Muhandisi -i Barq va Muhandisi -i Kampyutar -i Iran: 109 (1)

Open Access Article

1 - Analysis of the Effects of Different Cyber Attacks on the Secondary Controller in Island Microgrids
Abdollah Mirzabeigi ali kalantarnia

With the advancement of science, in many control methods, the neighbor system is used to better control and synchronize between different information of microgrids. There are problems in accessing and transmitting information through communication links. In this article More

With the advancement of science, in many control methods, the neighbor system is used to better control and synchronize between different information of microgrids. There are problems in accessing and transmitting information through communication links. In this article, vulnerability and acceptance of secondary control methods are distributed. Also, denial-of-service (DoS) cyber-attacks, sensors and actuators, and hijacking on the island microgrid have been investigated. In addition to stability, synchronization is also analyzed in this article. Multi-agent systems have been used for synchronization. Cyber-attacks are mathematically formulated in the controller. A suitable controller is designed to eliminate the attacks. In the stability and synchronization of frequency and voltage, the Lyapunov function is presented and simultaneous analysis of stability and synchronization has been done with practical proofs. The resilience factor has been calculated for different attacks. It is shown that the system is resilient against cyber-attacks. A case study has been simulated in MATLAB/Simulink to approve the theoretical issues. Manuscript profile

Open Access Article

2 - Optimal Design and Analysis of Fault Current Limiter Based on Variable Air-Core Series Reactor
Moslem Amini Faskhoodi Aliakbar Damaki Aliabad

With the ongoing growth of the power networks and the increase of the short circuit current level in the power network, it’s necessary to use the equipment for limiting the short circuit faults. One of these equipment is fault current limiters (FCLs) based on variable r More

With the ongoing growth of the power networks and the increase of the short circuit current level in the power network, it’s necessary to use the equipment for limiting the short circuit faults. One of these equipment is fault current limiters (FCLs) based on variable reactor that they have simple structure and effective performance. This paper presents an optimal design of new fault current limiter based on variable series reactor. It is very important to obtain the optimal dimensions of the proposed FCL to achieve the best performance with considering parameters of the FCL such as performance time, initial inductance and final inductance. Hence, at the first, the proposed plan is introduced and then an analytical modeling based on equations of the reactor is used to evaluate and optimize the proposed FCL. Finally, the results of optimization are compared with results of primary design. These results confirm that the performance of optimal plan is much better than the primary plan. Manuscript profile

Open Access Article

3 - Comparison of FCS-MPC Predictive Control and Predictive Control Based on Lyapunov Theory in Seven-Level PUC Rectifier
Alimohammad Mohammadpour Behbid Mohammad Reza Alizadeh Pahlavani Arash Dehestani Kolagar Alireza Davari

In this paper, two predictive control methods for dual output multilevel rectifier are compared. The investigated structure is a seven-level PUC rectifier, which was selected based on high reliability and low cost. Increasing the number of input voltage levels helps to More

In this paper, two predictive control methods for dual output multilevel rectifier are compared. The investigated structure is a seven-level PUC rectifier, which was selected based on high reliability and low cost. Increasing the number of input voltage levels helps to reduce the amount of harmonics and consequently reduce the size of power filters. On the other hand, current conduction in this converter is performed continuously and the problems of current discontinuity such as complexity in analysis and the requirement to use large induction filters on the DC side are solved. First, the design is accomplished based on the FCS-MPC method and two different output voltages with ratios of 1 and 3 are obtained. Also, the control of output DC voltages and unity input power factor is well provided. Then, to achieve better stability, the MPC method based on Lyapunov theory has been utilized. In this method, the target variables are defined in the Lyapunov function and the cost function is derived from the same Lyapunov function. The advantages of this approach compared to the conventional MPC method are no need for gain adjustment, easier implementation and fewer sensors (the load current is estimated using the PUC7 rectifier mathematical model). The simulation of both FCS-MPC and predictive control based on Lyapunov method is carried out using Matlab/Simulink and the results of both methods are presented and compared with each other. Finally, it can be seen that in the Lyapunov-based method, the tracking of the reference current is smoother and with less fluctuations, and the seven-level rectifier voltage also has a more regular and sinusoidal waveform. Manuscript profile

Open Access Article

4 - Localization of Mobile Robot Using Smooth Two-Part Kalman Filter
Ramazan Havangi S. H.

The most important issue for a mobile robot is orientation. Success in localization is one of the four main needs in orientation, which include: perception, localization, recognition and movement control. How to provide an accurate localization solution for mobile robot More

The most important issue for a mobile robot is orientation. Success in localization is one of the four main needs in orientation, which include: perception, localization, recognition and movement control. How to provide an accurate localization solution for mobile robots is essential in many IoT applications. To achieve this goal, in this article, a method based on two-part Kalman filter is proposed for localization of mobile robot. The proposed algorithm consists of two parts, the first part is statistical linear regression and the second part is a Kalman filter with state error vector. The proposed method is tested in comparison with the new hybrid TLNF/UK method on circular, rectangular and z-shaped motion paths that are accompanied by noise. The experimental results show that the proposed method has been able to achieve better localization accuracy and it is also observed that the estimation errors in the proposed method are less and it has been able to increase the estimation accuracy compared to the combined TLNF/UK method. Manuscript profile

Open Access Article

5 - Covert Communication Using Jointly Spread Spectrum and Artificial Noise
Morteza Shafiee Neyestanak Iman Kazemi

Covert Communication technique is developed for LPD communication in military and civil applications. Artificial Noise (AN) is the method to confuse eavesdropper and assure data transmission. But, generating AN in wide range of frequencies and times is very challenging. More

Covert Communication technique is developed for LPD communication in military and civil applications. Artificial Noise (AN) is the method to confuse eavesdropper and assure data transmission. But, generating AN in wide range of frequencies and times is very challenging. Furthermore, it reveals the transmitter or challenges it for synchronization to confuse eavesdropper about environmental noise. This paper proposes a method based on Spread Spectrum as well as self-jamming as AN to solve the problems. By spreading the spectrum, we can generate AN in wide range of frequencies and times, at low power and cost-effective manner. Consequently, there is no need to synchronization. Simulation and numerical results indicate, partial band jammer, effectively confuse the eavesdropper by 1.8 dB margin at JSR = -5 dB. In the situations, transmitter and receiver may communicate at BER = 10^-3 for Eb/N > 8.3 dB. The paper simulates the proposed method for various types of jamming and reports the results where, multitone jamming is rejected for this application as artificial noise. Single-tone jammer also can confuse the eavesdropper by 2.6 dB margin at JSR = -5 dB and TRX communications quality equal to BER = 10-3 for Eb/N > 10.9 dB Manuscript profile

Open Access Article

6 - Detection of Quantized Sparse Signals Using Locally Most Power Full Detector in Wireless Sensor NetworkS
Abdolreza Mohammadi Amin Jajarmi

This paper addresses the problem of distributed detection of stochastic sparse signals in a wireless sensor network. Observations/local likelihood ratios in each sensor node are quantized into 1-bit and sent to a fusion center (FC) through non-ideal channels. At the FC, More

This paper addresses the problem of distributed detection of stochastic sparse signals in a wireless sensor network. Observations/local likelihood ratios in each sensor node are quantized into 1-bit and sent to a fusion center (FC) through non-ideal channels. At the FC, we propose two sub-optimal detectors after that the data are fused based on the locally most powerful test (LMPT). We obtain the quantization threshold for each sensor node via an asymptotic analysis of the performance of the detector. It is realized that the quantization threshold depends on the bit error probability of the channels between the sensor nodes and the FC. Simulation results are carried out to confirm our theoretical analysis and to depict the performance of the proposed detectors. Manuscript profile

Open Access Article

7 - Optimal Power Allocation for Maximizing Secrecy Rate in Physical Layer Security Using Frequency Diverse Array Directional Modulation and Artificial Noise
Mahdi Tayyeb Massoud Hossein Khaleghi

The directional modulation is a prominent and practical technique for enhancing the physical layer security in modern communication systems. In this method, the message signal is modulated by an array of antennas and transmitted in a specific direction to the legitimate More

The directional modulation is a prominent and practical technique for enhancing the physical layer security in modern communication systems. In this method, the message signal is modulated by an array of antennas and transmitted in a specific direction to the legitimate receiver, such that in other directions, the signal is destroyed and not receivable by eavesdroppers. By incorporating random frequency diverse array directional modulation, secure communication can be achieved in both angular and distance dimensions for the legitimate receiver. However, when the eavesdropper is located near the legitimate receiver, the confidentiality performance of this solution significantly deteriorates. To address this issue, this paper proposes a novel approach that combines artificial noise with random frequency diverse array directional modulation and optimizes power allocation to attain the maximum secrecy rate. Simulation results demonstrate that our proposed approach improves the secrecy rate of the physical layer security by at least one bit per second per hertz compared to the method without artificial noise, and by at least two bits per second per hertz compared to the phased array directional modulation. Manuscript profile

Open Access Article

8 - Temperature Sensor Based on Terahertz Plasmonic Slot Waveguide Coupled with a Resonator
Alireza Dolatabady

In this paper, the performance of a temperature sensor based on plasmonic structure including a slot waveguide coupled with a stub resonator has been investigated. The results have been attained based on the dependency of dispersion equation, and so, the resonance frequ More

In this paper, the performance of a temperature sensor based on plasmonic structure including a slot waveguide coupled with a stub resonator has been investigated. The results have been attained based on the dependency of dispersion equation, and so, the resonance frequency of the stub, to electric permittivity of the constructing material of the structure, InSb, which is also dependent to the ambient temperature. The design of the structure has been carried out for frequencies in terahertz spectra. The simulation results confirm an approximate linear relation between the resonance frequencies and ambient temperature, between 260-350 Kelvin. Also, a criterion has been assigned for evaluation the sensitivity and the performance temperature span of the proposed sensor. The calculated sensitivity is about 1×10-10 Kelvin per Hertz in the mentioned temperature interval. The sensor measurement resolution depends on the frequency resolution of the detection system. This simple sensor can be utilized in various chemical and bio systems. Manuscript profile

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