IRANIAN JOURNAL OF ELECTRICAL AND ELECTRONIC ENGINEERING

Lyapunov-Based Adaptive Sliding Mode Controller for Active Power Filter

Hadi Chahkandi Nejad

In this paper, a Lyapunov-based adaptive 2nd-order sliding mode controller is proposed to control the current in an active power filter (APF). The penetration of APFs has been exponentially increased because of their high flexibility and fewer resonance problems. Moreover, they can compensate high range of current harmonics and reactive power. The voltage and current control loops have always been interesting areas for researchers since the satisfactory performance of the APF is highly dependent on these control loops. A sliding mode controller (SMC) is a mighty controller when uncertain conditions are considered. However, in order to reduce the chattering- high-frequency switching- and improve the steady state operation, stability, and robustness of the controller, it is usually decided to adaptively tune the gains of the controller. In this paper, a simple-structure adaptive SMC (ASMC) is proposed which can be implemented easily. This ASMC is shown to be stable using the Lyapunov theorem and proved with SIMULINK simulation that it has less steady state error, less chattering, and faster dynamic response compared to the conventional SMC.

Design of the PD-FOPID Controller Based on Rain Optimization Algorithm to Improve Virtual Inertia Control Performance in Islanded Microgrids

Farhad Amiri

Low inertia is one of the most important challenges for frequency maintenance in islanded microgrids. To address this issue, the innovative concept of Virtual Inertia Control (VIC) has emerged as a promising solution for enhancing frequency stability in such systems. This paper presents an advanced controller, the PD-FOPID, as a highly effective technique for improving the efficiency of VIC in islanded microgrids. By leveraging the Rain Optimization Algorithm (ROA), this approach enables precise fine-tuning of the controller's parameters. A key advantage of the proposed method is its inherent resilience to disruptions and uncertainties caused by parameter fluctuations in islanded microgrids. To evaluate its performance and compare it with alternative control methods, extensive assessments were conducted across various scenarios. The comparison includes VIC based on an H-infinity controller (Controller 1), VIC based on an MPC controller (Controller 2), Adaptive VIC (Controller 3), VIC based on an optimized PI controller (Controller 4), conventional VIC (Controller 5), and systems without VIC (Controller 6). The results demonstrate that the proposed methodology significantly outperforms existing approaches in the field of VIC. The simulations were conducted using MATLAB software.

A New Procedure Based on Continuous RTU Measurement to Estimate Multi-port Thevenin Equivalent Circuit Parameters of an External Power System

Nabiollah Ramezani

In this paper, a novel method is presented that can accurately estimate the Thevenin equivalent circuit parameters of an external power system by RTUs. The presented method is based on the simultaneous measurements of the desired points in the boundary system, which includes the bus voltage amplitude, the current amplitude of the boundary transmission lines, as well as active and reactive power, and is continuously active until the Thevenin equivalent circuit model would be available online. The practical application of the proposed method is related to online monitoring and control of wide-area power systems as well as their development design. Also, the innovation of the method is the accurate estimation of the Thevenin equivalent circuit model from part of the power network where information is not available. In the proposed method, an additional measurement and the least squares method are used to eliminate measurement errors in order to accurately estimate the parameters of the equivalent circuit model. In order to avoid providing the wrong equivalent circuit model due to external system changes, a method is presented that can track the correct system changes to continuously monitor the disturbances. The proposed method performance has been implemented and validated by DigSILENT software.

A Dynamic Control Approach for AC Micro-Grids Including Non-Inverter and Inverter Based Energy Resources

Mehdi Radmehr

Microgrids harness the benefits of non-inverter and inverter-based Distributed Energy Resources (DER) in grid-connected and island environments. Adoption of them with the various types of electric loads in modern MGs has led to stability and power quality issues. In this paper, a two-level control approach is proposed to overcome these problems. A state-space dynamic model is performed for Micro-Grids, for this goal, the state-space equations for generation, network, and load components are separately developed in a local DQ reference frame, and after linearization around the set point, then combining them into a common DQ reference frame. In the first level, the control of inverter-based DERs and some types of loads with fast response are activated, and in the second level, the control of synchronous diesel generator resources with slower response is used. In order to validate and evaluate the effectiveness of the proposed control approach, numerical studies have been established on a standard test MG under normal and symmetrical three-phase fault conditions. Finally, the simulation results are summarized.

Advancements and Optimisation Strategies in Building Integrated Photovoltaic Thermal (BIPVT) Systems

Arjun Deo

This paper provides an overview of the current innovations in Building Integrated Photovoltaic Thermal Systems. This paper briefly describes varying performance evaluation techniques, optimisation techniques, and the environmental impact and cost implication of Building Integrated Photovoltaic Thermal systems. The results reveal high energy-pin efficiency with Building Integrated Photovoltaic Thermal systems of over 50% and more efficient than when the two systems are incorporated separately. Exergy analysis is a more insightful means of analyzing system effectiveness than energy analysis. The paper covers the current algorithms for various optimisation algorithms such as Genetic Algorithms and Particle Swarm Optimisation that provide enhanced utilization improvements. An evaluation of the environmental impact of Building Integrated Photovoltaic Thermal in terms of carbon dioxide emission reduction and building energy optimisation is made. The results of the life cycle cost studies show that, even though the initial cost is higher than conventional solutions, the overall economic profit is more significant in the future. Some of the challenges described in the paper include increased initial costs and sophisticated integration procedures. In contrast, possible future developments include new materials, Building Integrated Photovoltaic Thermal system standardization, and integration in smart grids. This review is intended to be a state-of-the-art source of information for researchers, engineers, architects, and policymakers involved in enhancing sustainable building technologies using building-integrated photovoltaic thermal systems.

Modeling and simulation of piezoelectric-based train-induced vibration energy harvester railway track monitoring system

JIA UDDIN

This study aims to evaluate a cantilever beam type piezoelectric energy harvester operating on train-induced vibrations for powering Wireless Sensor Networks (WSNs) used in railway track monitoring systems. Harvester's behaviors under different conditions are simulated in MATLAB using the analytical model. Natural frequency, maximum deflection, and stress are calculated with greater precision using eigen frequency and stationary analysis using COMSOL Multiphysics. At a base excitation of 2 g and a resonant frequency of 4.38 Hz, the simulated results showed that the developed energy harvester prototype could generate up to 14 V of AC output voltage and 550 mW of output power. These findings highlight the promising potential of the proposed energy harvester for transforming train mechanical energy into electrical power. This energy harvester's viability and dependability for real-world applications in monitoring railway tracks are supported by developed analytical and simulation models.

The Effect of Photoplethysmography Signal Denoising on Compression Quality

Mohsen Karimi

Photoplethysmography (PPG) signals provide a non-invasive means of monitoring cardiovascular status during physical exercise; however, they are prone to noise, especially motion artifacts (MA). For specific telemedicine applications, compression is necessary for tasks such as PPG signal generation and secure data transmission. In this study, the investigation focused on determining whether it is better to perform compression before or after noise removal by applying a noise removal method and various compression methods. To achieve the aim, the study explored a subspace-based denoising method called "Maximum Uncorrelated PPG Denoising." Additionally, signal compression methods were examined in nine distinct steps. Compression quality is evaluated using various criteria, such as compression rate (CR) and Percentage Root Mean Square Difference (PRD). The results showed that regardless of the type of compression method, it is better not to remove noise before the compression process because doing so reduces CR and increases PRD.

DRL-based Joint Beamforming and Power Allocation in Beyond Diagonal Reconfigurable Intelligence Surface 6G Systems

Mousa Abdollahvand

This paper introduces a new method for improving wireless communication systems by employing beyond diagonal reconfigurable intelligent surfaces (BD-RIS) and unmanned aerial vehicle (UAV) alongside deep reinforcement learning (DRL) techniques. BD-RIS represents a departure from traditional RIS designs, providing advanced capabilities for manipulating electromagnetic waves to optimize the performance of communication. We propose a DRL-based framework for optimizing the UAV and configuration of BD-RIS elements, including hybrid beamforming, phase shift adjustments, and transmit power coefficients for non-orthogonal multiple access (NOMA) transmission by considering max-min fairness. Through extensive simulations and performance evaluations, we demonstrate that BD-RIS outperforms conventional RIS architectures. Additionally, we analyze the convergence speed and performance trade-offs of different DRL algorithms, emphasizing the importance of selecting the appropriate algorithm and hyper-parameters for specific applications. Our findings underscore the transformative potential of BD-RIS and DRL in enhancing wireless communication systems, laying the groundwork for next-generation network optimization and deployment.

Generator Rescheduling Based Congestion Management in Power System Deregulation Using the Cheetah Optimization

Dipu Sarkar

Transmission line congestion is more severe and persistent in deregulated power systems than it is in traditionally controlled power systems. In a deregulated power market (DPM) scenario, transmission line congestion is one of the most critical problems. To guarantee the electricity system framework runs consistently and securely, the independent system operator (ISO) controls congestion. Congestion management (CM), which takes into account the inherent uncertainties of the restructured power system, is essential to the functioning and security of DPM. This article demonstrates how to control congestion with generation rescheduling. The system is designed in such a way that it helps the traders to compete and trade using the bid prices. Network security is maintained by keeping all constraints within the allowed limits via the Newton-Raphson load flow. An innovative Cheetah Optimizer is employed to handle the congestion management challenge. The weighted sum approach is used instead of multiobjective optimization to simplify the problem as a single-objective optimization, solve the issue for multiple instances of congestion, and be tested in an IEEE 30 bus system. The MATLAB software serves as a tool for modeling the full process, and the results acquired with the Cheetah optimizer give better results than the conventional optimization technique.

Enhancing Misalignment Tolerance in Inductive Power Transfer System to Maintain Stable Power Transfer and Improve the Efficiency for Battery Charging

M. A. Shamsi-Nejad

This paper proposes an inductive power transfer (IPT) system to maintain stable power transfer and improve efficiency for battery charging performance across a wide range of coupling coefficient variations. The proposed IPT system uses series-series (S-S) and series-inductor-capacitor-inductor (S-LCL) compensation. In both compensation configurations, the rectifier operates in half-bridge (HB) and full-bridge (FB) modes. By using the correct switching pattern between compensation networks and the rectifier, four transfer power-coupling coefficient (P-k) curves are created. A 400 W prototype simulated in MATLAB demonstrates that, with the proposed method, output power fluctuation is limited to only 3% for coupling coefficients varying from 0.1 to 0.4, with system efficiency ranging from 80% to 95.9%. Compared to other methods, the proposed structure provides stable power transfer over an ultra-wide coupling variation and does not require special coil design, clamp circuit design, or complex control.

Voltage Difference-Based Field-Weakening Control of Double-Rotor Hybrid Excitation Axial Flux Switching Permanent Magnet Motor

Behrooz Rezaeealam

This paper investigates the operational performance of a novel Double-Rotor Hybrid Excitation Axial Flux Switching Permanent Magnet (DRHE-AFSPM) machine, combining the strengths of Flux-Switching Machines and Hybrid Excitation Synchronous Machines. The study analyzes the machine's structure and magnetic field adjustment principles, including inductance and flux linkage characteristics. A mathematical model is derived and a vector control-based drive system is established. The loading capacity of the DRHE-AFSPM motor is examined at low speeds using an i_d = 0 control approach based on a stage control strategy. For high-speed operation, a field-weakening control strategy is implemented, with the field-weakening moment determined based on the voltage difference. Simulations and experimental results demonstrate the DRHE-AFSPM motor's ability to fully utilize its torque with id = 0 control, highlighting its strong load capacity. Compared to speed-based field-weakening control strategies, the voltage difference-based approach offers improved inverter output voltage utilization and a broader speed regulation range. These findings suggest that the DRHE-AFSPM motor is a promising candidate for in-wheel motor applications in electric vehicles (EVs).

Exploring the Potential of Cloud Fertilization through Electromagnetic Wave Scattering Analysis

Seyed Hosein mousavi

Electromagnetic waves, with their unique properties, offer promising solutions to environmental challenges. This paper explores the utilization of electromagnetic scattering by droplets for cloud fertilization purposes. Specifically, a linearly polarized plane wave is deployed to stimulate a heterogeneous cloud medium composed of spherical droplets with varying size parameters. Through the application of Generalized Mie Theory (GMT) and Discrete Dipole Approximation (DDA) at a frequency of 28 GHz, multiple scattering phenomena and local electric fields are meticulously computed. Various scenarios of scattering, encompassing droplet diameters ranging from 500 µm to 700 µm and diverse volume fractions, are meticulously examined. Employing DDA and dyadic calculations, the exerted forces on individual spherical droplets are rigorously evaluated, with precise determination of force direction and components. The simulations robustly affirm the viability of droplet manipulation via plane wave excitation, thereby enhancing the likelihood of droplet collision and consequent cloud fertilization, ultimately leading to precipitation. Furthermore, the parameters of the incident wave can be deliberately adjusted to steer droplets towards denser regions, thereby augmenting the likelihood of successful fertilization events.

Enhancing Load frequency control in power systems using Puma Optimizer – Proportional Integral Derivative Method

Thanh Long Duong

Frequency instability is one of the causes of severe disturbances in the power system, including load shedding and widespread blackouts. Especially in modern power systems, frequency instability has even more serious consequences due to the propagation occurring in interconnected regions. Load frequency control (LFC) is a powerful tool in power system operation to ensure that the frequency is always within the allowable limits. The control parameters of LFC must be optimally adjusted for stable system operation. However, researchers are currently unable to find a suitable and robust method for optimal tuning of LFC control parameters. The paper proposes the Puma Optimizer (PO) algorithm to optimize the parameters of PID, FOPID, and FOPTID+1 controllers for solving the LFC problem. The proposed PO algorithm is evaluated through two models of single-area and two-area power systems with different power sources, including thermal power, hydropower, and gas power. The simulation results show that the integral time absolute error (ITAE) value of the proposed PO method is smaller by 5.25%, 18.16%, 28.35%, and 59.92% compared to Particle Swarm Optimization (PSO), Crested Porcupine Optimization (CPO), Newton-Raphson-based optimization (NRBO), and Global Neighborhood Algorithm (GNA), respectively. The results obtained demonstrate that the PO algorithm is a reliable and efficient tool for finding solutions to the LFC problem.

The Lightning Protection Assessment of Distribution Lines with Considering Frequency Grounding System

Masume Khodsuz

Ensuring the protection of all components within power systems from lightning-induced overvoltage is crucial. The issue of power interruptions caused by both direct and indirect lightning strikes (LS) presents significant challenges in the electrical sector. In medium voltage distribution feeders, the relatively low dielectric strength makes them susceptible to insulation degradation, which can ultimately lead to failures in the distribution system. Therefore, implementing effective protective measures against LS is vital for maintaining an acceptable level of reliability in distribution systems. This paper presents an analytical assessment of LS-induced system overvoltage through high-frequency modeling of components within a 20kV distribution system. The study utilizes EMTP-RV software for precise component modeling, including the grounding system, surge arresters, and distribution feeders. Additionally, the operational impacts of protective devices, such as ZnO surge arresters, shield wires, and lightning rods, are evaluated to mitigate LS-induced overvoltage. A frequency grounding system is implemented using the method of moments (MOM) to analyze the grounding system's influence on LS-induced overvoltage. Furthermore, eight different scenarios are explored to assess the anti-LS capabilities of the 20kV distribution system. Each scenario involves evaluating dielectric breakdown and overvoltage across the insulator chain while proposing suitable protective solutions. The results indicate that the absence of shielding wires and surge arresters leads to higher breakdown voltages, with the lowest breakdown voltage occurring when surge arresters are installed during LS events. Additionally, the use of a frequency grounding system, due to its accurate modeling, yields more precise results compared to a static resistor approach. The MOM simulation reveals a 50% reduction in breakdown voltage under the worst-case scenario, and overall overvoltage experiences a 2% decrease.