Strengthening of Power Grid Protection Systems Against Cyber-Attacks: A Comprehensive Review

per Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452025-01223159173articleStrengthening of Power Grid Protection Systems Against Cyber-Attacks: A Comprehensive ReviewZahra Pourahmadz.pourahmad@eng.ui.ac.ir1R. Hooshmandhooshmand_r@eng.ui.ac.ir2S. Mohammad Madanim.madani@eng.ui.ac.ir3Electrical Engineering Dept. University of Isfahan, Isfahan, IranElectrical Engineering Dept., University of Isfahan, Isfahan, Iran Protective systems constitute the most vital defensive element of power networks against unusual conditions. Therefore, any malfunction caused by cyber-attacks may cause huge consequences for power networks such as widespread blackouts. Among the most critical protective systems vulnerable to cyber intrusions are generator protection, transmission lines, and transformers. Cyber sabotages can be mitigated through strategic proceedings to reduce their impact on the network. This paper provides a comprehensive review of the methods of strengthening the protection system against cyber-attacks, given the importance of power network protection systems. For this purpose, in the first step, protection-based methods for strengthening the power network against cyber-attacks are presented. Then, in the second step, detection-based methods are described to reveal a possible cyber-attack. Since there is no definite guarantee against cyber intrusions, it is possible to prevent the progress of the attack by using attack detection methods. To this end, two types of data-based and model-based algorithms are utilized. In data-based algorithms, network knowledge and information can be optimally used to detect the conditions of cyber-attack compared to the conditions without cyber-attack. In model-based algorithms, parameters of the network are estimated by executing state estimation algorithms based on system relations. Then, data manipulation and cyber intrusions are detected despite the discrepancy between the estimated values and the measured values. Consequently, the use of defense and detection methods to deal with cyber intrusion leads to an increase in the cyber security of the power grid protection system. In this regard, it is very important to use various defense and detection algorithms in combating cyber-attacks.http://ijece.org/Article/47772Cyber-attack resilience power network protection system relay.per Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452025-01223174184articleMessage Extraction for 9th Pulse Standard of eLoran Navigation SystemMehri Lotfalizadelotfalizadeh@mut.ac.ir1Morteza Shafiee NeyestanakMshafiee_n@yahoo.com2Mohammad Bagher Nezafatinezafati@ipm.ir3Maalek Ashtar University of TechnologyInstitute for Research in Fundamental Sciences (IPM)In the Standard of 9th pulse enhanced Loran (eLoran) system, an additional pulse is incorporated into the navigation pulse group for data transmission. The process of extracting messages from the Loran signal involves two stages: first, determining time delay of the data pulse relative to its original position, and second, decoding the data. This paper proposes a method for message extraction using the 9th pulse standard. Time delay of the data pulse is calculated in two steps, involving envelope shift and phase shift utilizing matched and fractional filters, respectively. Following this, Reed-Solomon (RS) decoding is applied, leading to final message extraction. Furthermore, to enhance pulse delay estimation, particularly in noisy and interference conditions, the reference pulse is chosen as average of the eight pulses preceding the data pulse, resulting in a unique reference pulse for each symbol extraction. Evaluation results show that the error rate before decoding decreases from 0.08 to 0.003 as the signal-to-noise ratio increases from 7 to 15 dB, with a significant reduction in errors after RS correction.http://ijece.org/Article/461549th pulse eLoran envelope shift phase shift enhanced Loran (eLoran) Pulse Position Modulation (PPM).per Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452025-01223185196articlePilot Contamination Reduction Using Weighted Graph Coloring and Soft Pilot ReuseAmir Rostaeiamirroostaei21@gmail.com1Hossein Khaleghibizaki@yahoo.com2Emam Hossein UniversityMassive MIMO cellular networks, despite their ability to serve multiple users simultaneously, face a significant challenge due to pilot contamination. This paper presents an innovative two-stage algorithm to reduce this contamination and increase user data rates in both uplink and downlink. The key innovation of the proposed method lies in the intelligent integration of three techniques: Soft Pilot Reuse (SPR), optimal pilot sequence selection algorithm, and Weighted Graph Coloring (WGC). This combination simultaneously addresses three fundamental issues: contamination in SPR due to fixed thresholds, increased pilot overhead in WGC, and the problem of maximizing the data rate of the user with the lowest rate. The proposed algorithm operates in two stages. In the first stage, users are divided into center and edge groups, and optimal pilot sequences are determined based on their data rates. In the second stage, using the WGC algorithm and creating an Edge-Weighted Interference Graph (EWIG), pilot contamination is reduced based on the intensity of user interference. Simulation results show that this method significantly improves system performance compared to the best existing method (WGC). In the downlink, an 11 dB improvement in Signal-to-Interference-plus-Noise Ratio (SINR) and a 0.16 bps/Hz increase in average achievable rate are observed. In the uplink, a 2.4 dB improvement in SINR and a 0.46 bps/Hz increase in average achievable rate are achieved. In terms of computational complexity, the proposed method has lower complexity compared to the WGC scheme. Moreover, energy efficiency analysis confirms the superiority of the proposed method in both uplink and downlink scenarios.http://ijece.org/Article/45982Pilot contamination massive MIMO channel estimation weighted graph coloring (WGC) edge-weighted interference graph (EWIG).per Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452025-01223197207articleA Mathematical Model Based on Electrical and Magnetic susceptibilities for an Ideal Reflective Metasurface - Without Unwanted Waves -Elham Moradie.moradi999@gmail.com1Masoud Movahhedimovahhedi@yazd.ac.ir2Electrical Engineering Department, Yazd University, Yazd, IranYazd UniversityOne of the most useful features of metasurfaces is controlling a plane-wave reflection. However, recent research has shown that realizations of anomalously reflecting surfaces based on simple phase-gradient metasurface designs suffer from limited efficiency, where there are always parasitic reflections to undesired directions. Using a circuit-based approach, it has been shown that a polarizer metasurface can achieve reflection without spurious diffraction. Here, such condition is derived using a medium-based—and hence, more insightful—an approach based on generalized sheet transition conditions and surface susceptibility tensors. Thus, we derive the susceptibility tensors of the metasurface in closed-form equations. Moreover, to determine the performance improvement of this metasurface compared to its common examples, the susceptibility parameters of the metasurface based on the Generalized Snell's law are also obtained. Then, full-wave simulations of two surfaces illuminated by perpendicular Gaussian waves are compared. The obtained susceptibility parameters are considered the macroscopic design of the metasurface.http://ijece.org/Article/45429Anomalous reflection metasurfaces periodic structures reconfigurable intelligent surfaces (RISs) generalized sheet transition conditions (GSTCs).per Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452025-01223208215articleBidirectional Bus Transfer Method for Induction Motors Between Inverter and Grid By Correcting Control References Using Discrete Fourier TransformationAlireza Lahooti Eshkevaria_lahootieshkevari@sbu.ac.ir1Ali Keshavarziana.keshavarzian@ut.ac.ir2Iman Abdolii_abdoli@sbu.ac.ir3Mohammad Farzim.farzi@acecr.ac.ir4Seyed Mohammadreza Zeinalhosseinis.m.r.zeinal@gmail.com5Iranian Research Institute for Electrical EngineeringIranian Research Institute for Electrical EngineeringIranian Research Institute for Electrical EngineeringIranian Research Institute for Electrical EngineeringThis paper presents a new method for bidirectional bus-transfer of an induction motor, between the inverter and the grid, based on discrete Fourier transform. In this method, without affecting the motor control strategy and only by correcting the amplitude and frequency references (or by correcting the flux and torque references), the phase, amplitude, and frequency of the output waveform of the inverter are synchronized with the grid. It enables changing the source of a motor without interruption. Due to the extraction of the fundamental component of the waveforms of both sources, this method is robust against to noises, DC pollution and harmonics. Due to eliminating proportional-integral controllers in determining each of these parameters, there is no need to adjust their coefficients . Also, due to the high accuracy of synchronization, instantaneous parallelization of voltage sources is realized without the need for additional devices. The maximum circulating current caused by parallelization in the worst cases is limited to less than 1.5 times the rated current of the motor. This article, while presenting the proposed method in detail and comparing it with some previous methods, uses laboratory results to evaluate its achievements. Experimental results confirm the above achievements.http://ijece.org/Article/46497Motor bus-transfer variable speed drive induction motor synchronizationper Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452025-01223216223articleProposing an Islanding Detection Index for Distribution Networks with Conventional and Inverter-Based Distributed Generators Amir Hosein Alizadehalizadeh.ah@gmail.com1Seyed Fariborz Zareisf.zarei@gmail.com2Department Electrical and Computer Engineering, Qom University of Technology, Qom, IranThis paper proposes an index based on zero-sequence components that serves as a single indicator for islanding detection. The proposed index demonstrates satisfactory performance, achieving an accuracy of 97.84% using a simple threshold adjustment model. Additionally, this index can be integrated into artificial intelligence-based methods to enhance accuracy further. The results indicate that utilizing the proposed index as a single indicator within a one-dimensional convolutional neural network (1D-CNN) model yields a competitive accuracy of 99.78%. This outcome is noteworthy when compared to more advanced artificial intelligence methods, such as long short-term memory (LSTM) neural networks, which rely on a larger set of features. The data collection for testing encompasses various islanding and non-islanding conditions, including islanding under different loading conditions and power factors, as well as varying quality factor values. Non-islanding scenarios include the activation and deactivation of large loads and capacitor banks, along with the application of various short-circuit faults at different locations and resistances. The results from all tests demonstrate the superiority of the proposed method and index.http://ijece.org/Article/46748Application of power electronics in renewable energies islanding islanding detection 1D convolutional neural networks