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In the present context, the asymmetrical multilevel inverter (AMLI) with minimal switches is extensively used to achieve high power quality across a load. The conventional inverter suffers from the disadvantages of large system components, low efficiency, high THD, high losses, etc. The asymmetrical multilevel inverter therefore offers an appropriate alternative to address the key issues of conventional inverters. The present paper aims to analyze the performance comparison of the proposed 15-level AMLI structure with different switching techniques, i.e., NLC, SHEPWM and SPWM. Moreover, loss analysis of the considered AMLI has been performed for different switching techniques. Furthermore, different performance parameters such as conduction losses, switching losses, total losses, THD, efficiency and power delivery of the inverter have been evaluated. It has been observed that the considered inverter topology offers the superior performance with the SHEPWM modulation technique at a modulation index of 0.8. Finally, hardware arrangement of the inverter has also been developed in the laboratory with a real-time Opal-RT 4510 simulator to verify the accuracy of simulation results. [ABSTRACT FROM AUTHOR]

This article presents an innovative asymmetric multilevel inverter (MLI) topology that outperforms conventional counterparts. The introduced topology presents a breakthrough in implementing power electronics control by maximizing specific levels while minimizing switching components. A cutting-edge control scheme for optimal operation of the cascaded half-bridge MLI is presented. The ant lion optimization (ALO) algorithm was implemented to optimize the switching control to reduce the total harmonic distortion (THD) and improve power quality. For verification, the performance and effectiveness of the ALO technique are assessed by comparing its results to those obtained using the simplified sinusoidal pulse width modulation (SSPWM) technique, genetic algorithm (GA), and particle swarm optimization (PSO) in existing literature. Simulation results verified the efficacy of ALO in finding the optimal parameters. The suggested method showcases a remarkable reduction in the THD compared to SSPWM. The quality of the resulting waveform was enhanced, and both filter size and cost were significantly reduced. To meet stringent IEEE standards, an LC filter has been designed with minimal size and proper requirements. Experimental results validation of the suggested scheme, using a dSPACE R&D controller board unequivocally, confirmed its robustness and effectiveness. This groundbreaking study not only introduces a superior asymmetric MLI topology but also validates its exceptional performance through comprehensive analysis and experimentation. The experimental waveforms showed good matching with the simulation outcomes. The findings hold immense promise for advancing the field of power system control and revolutionizing the designing and implementation of efficient and cost-effective inverter systems. [ABSTRACT FROM AUTHOR]

This article describes a novel method for locating and detecting triple line to ground (LLL-G) faults in 110 km of 132 kV transmission lines. To find the transmission line fault, the three phase system currents were first recorded at the appropriate sampling frequency. Then, the total harmonic distortion (THD) and direct current (DC) components were computed using the Fast Fourier transform (FFT). When compared to normal conditions, high values of THD and DC components have been seen in fault situations; fault has been identified as a result. The fault distance in the transmission line has been measured using spline extrapolation or linear interpolation. With this method, very encouraging outcomes have been obtained for fault assessment in transmission line. [ABSTRACT FROM AUTHOR]

Multilevel inverters have gained importance in modern power systems during the last few years because of their high power quality with lower THD. Various topologies developed include the packed U-cell inverter and its different modified versions that have emerged as a compact and efficient solution to distributed energy systems. Most of the available harmonic mitigation techniques, that is, passive filtering and individual optimization techniques, which include GA and PSO, are susceptible to a variety of shortcomings regarding their inherent complexity and inefficiency; hence, finding an appropriate convergence may be quite hard. This paper proposes a hybrid version of the GA-PSO algorithm that exploits the exploratory strengths of GA and the convergence efficiencies of PSO in determining the optimized switching angles for SHM techniques applied to modified five-level and seven-level PUC inverters. By utilizing the multi-objective optimization method, the approach minimizes THD while keeping voltage and efficiency constraints. Simulated in MATLAB/Simulink, the results were experimentally verified using hardware-in-the-loop testing on OP5700. A large THD reduction in both MPUC7 (11.68%) and MPUC5 (17.61%) was obtained. The proposed hybrid algorithm outperformed the standalone approaches of GA and PSO with respect to robustness and with precise harmonic suppression. Other appealing features are reduced computational complexity and improved waveform quality; hence, the method is highly suitable for both grid-tied and standalone renewable energy applications. This work lays a basis for efficient inverter designs that can adapt well under dynamic load conditions. [ABSTRACT FROM AUTHOR]

A single-phase multilevel inverter with a switched-capacitor multilevel (SC-MLI) configuration is developed to provide 13-level output voltages. An improved genetic algorithm (GA) with adaptive mutation and crossover rates is employed to achieve robust harmonic mitigation by avoiding local optima and ensuring optimal performance. The topology introduces an SC-MLI that generates AC output voltage at desired levels using only two capacitors, two asymmetrical DC sources, one diode, and 11 switches. This allows the inverter to use fewer gate drivers and, hence, increases the power density of the converter. A significant challenge in the normal operation of SC-MLI circuits relates to the self-voltage balance of the capacitors, which easily becomes unstable, particularly at low modulation indices. The proposed design addresses this issue without the need for ancillary devices or complex control schemes, ensuring stable self-balanced operation across the entire spectrum of the modulation index. In this context, the harmonic mitigation technique optimized through GA applied in this inverter ensures low harmonic distortion, achieving a total harmonic distortion (THD) of 6.73%, thereby enhancing power quality even at low modulation indices. The performance of this SC-MLI is modeled under various loading scenarios using MATLAB/Simulink® 2023b with validation performed through an Opal-RT real-time emulator. Additionally, the inverter's overall power losses and individual switch losses, along with the efficiency, are analyzed using the simulation tool PLEXIM-PLECS. Efficiency is found to be 96.62%. [ABSTRACT FROM AUTHOR]

This paper presents a comparative analysis of interior permanent magnet synchronous motor (IPMSM) drives powered by symmetrical and asymmetrical cascaded H-bridge multilevel inverters. The asymmetric topology operates using multiple DC sources with different voltage values, generating a voltage waveform with more output voltage levels than its traditional counterpart, all while maintaining the same hardware configuration. The main goal is to demonstrate that asymmetrical multilevel inverters are a promising option for improving the performance of electric drives while maintaining cost-efficiency and reliability. The proposed comparison is conducted through simulations in the MATLAB/Simulink R2024a environment, which allows an in-depth analysis of the dynamic performance of the electric drive. Additionally, the variation of the DC link input power of each H-bridge and the Total Harmonic Distortion (THD) of the voltage and current of the output of the converters were studied for different operating conditions in both cases. The obtained results were confirmed through real-time validation, demonstrating the applicability of electric drives powered by asymmetric converters and the advantages, in terms of efficiency, harmonic content and dynamic performance, in certain conditions of operation in terms of speed and applied load. [ABSTRACT FROM AUTHOR]

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The method of utilizing switched capacitors stands as an effective approach to achieve elevated voltage levels while minimizing the requirement for numerous DC sources through efficient utilization of stored energy in capacitors. This poses a significant challenge when designing high-voltage multilevel inverters with a reduced number of sources and switches. This study introduces a new boost-type multilevel inverter named the "nine-level switched capacitor–high-voltage gain boosting inverter" (9LSC-HVGBI). Notably, this specific configuration substantially reduces the DC source and capacitor count, necessitating only ten switches and a single DC source, along with two capacitors and three diodes, to produce a nine-level output. The described architecture offers several notable advantages, including a fourfold amplification capacity in voltage, automated balancing of capacitor voltages, and efficient management of inductive loads. Consequently, it demonstrates superior performance compared to other switched capacitor multilevel inverters in terms of minimal switch conduction at each level, restricting voltage stress on the switches to twice the input voltage, and optimizing efficiency. The proposed design is grounded in an intelligent series and parallel connection of switched capacitors. The study explores the operational concepts, with a specific focus on the mechanism for preserving capacitor voltage balance. The comprehensive loss evaluations and thorough comparisons with state-of-the-art alternatives substantiate its superior performance. Furthermore, the performance of the proposed 9LSC-HVGBI is validated through detailed simulation results across diverse test scenarios and experimental data collected in a well-equipped laboratory. [ABSTRACT FROM AUTHOR]

The upward continuation was used to obtain the residual RTP magnetic maps at elevations 2, 12, 16 and 22 km. These maps are processed by the Total Horizontal Derivative (THD) technique to detect the main lineaments that represent the boundary of subsurface sources or fractures. The high background of THD in the central part of the study area supports the presence of a group of faults between the western and eastern parts of the area. The obtained lineaments trends were represented on the rose diagram, as were the main trends in the study area. The predominant lineaments (faults) trends in the western part in descending are N55W, N35W, N05W, N65W, N45W, N25W, N05E, N15E, and N35E, respectively, for the four considered upward elevations. The lineament in eastern part found trending N55W, N35W, N35E, N45W, N45E, N05E, N25E, and N05W, respectively. The lineaments of the western and eastern parts indicate that the main trend in shallow sources is NW-SE, which coincides with the Najd fault system (540-620 Ma) in the Arabian Plate. The deep-level lineaments are trending N-S, which coincides with the Nabitah fault system (680-640 Ma). [ABSTRACT FROM AUTHOR]

This article examines a modified multilevel inverter circuit that uses basic units connected in cascade. The suggested circuit can be used with an inverter that is symmetrical or asymmetric. The magnitude of the DC voltage source is determined using a variety of methods in order to generate a large number of voltage levels. For both symmetrical and asymmetrical configurations, the magnitude of two DC sources in basic units can be used. The DC voltage source's magnitude is the same for each unit in the symmetrical configuration. However, in an asymmetrical configuration, the value of the DC source for the fundamental units is inequitable, and their magnitudes are obtained using various techniques. Comparison study demonstrates that the suggested circuit requires minimum components, reduces power loss, and boosts inverter efficiency. Additionally, in comparison to modern topologies, the standing voltage across the switches is acceptable. To verify the effectiveness of the investigated topology, simulation results for 15, 17, 23, and 31-level inverters are analysed. [ABSTRACT FROM AUTHOR]

An inverter is a power electronic device that converts Direct Current (DC) to Alternating Current (AC). A three-leg inverter was used to convert DC to AC in a three-phase form. The increasing need to integrate renewable energy into the power grid has increased the demand for this type of converter. In this paper, a Laguerre-based Model Predictive Controller (LMPC) is proposed to control a three-leg inverter under load variation. The proposed LMPC algorithm was designed to optimize the inverter performance and was compared with traditional Sinusoidal Pulse Width Modulation (SPWM) methods. Simulations were conducted under various load conditions including resistive (R), capacitive (RC), and induction motor loads. The results demonstrate that the LMPC controller outperforms the SPWM methods, providing better performance and lower Total Harmonic Distortion (THD) values. The THDs of the voltage and current achieved by the LMPC controller were below 1.5%, complying with IEEE 519-2014 standards. However, the current THD increased to 7.18% under the induction motor load. [ABSTRACT FROM AUTHOR]

This study provides an extensive overview of recent developments in grid-connected photovoltaic (PV) systems based on five-level Multilevel Inverters (MLIs), with an emphasis on modulation schemes, control approaches, and system architectures. Five-level MLI-based PV systems have become a crucial option as the relevance of renewable energy keeps increasing because of their increased efficiency, less harmonic distortion, and greater power quality. The study looks at several different control strategies, including grid synchronization approaches and Maximum Power Point Tracking (MPPT), to improve PV system performance and grid interaction. Several modulation techniques are also examined, with a focus on how they might lower harmonics and boost system performance. Examples of these techniques include pulse width modulation (PWM) and selective harmonic elimination (SHE). Further analysis of the structural features of five-level MLI-based systems is done, which helps to clarify the trade-offs between complexity, dependability, and cost. This analysis includes component needs and scalability concerns. Researchers and engineers working on the design, control, and deployment of sophisticated MLI-based PV systems in grid-connected applications may learn from this paper.

Improving photovoltaic systems to better withstand variations in temperature and irradiance, lessen steady-state ripples, maintain high efficiency, require less tracking time, and have minimal complexity is becoming increasingly important. The PV array's overall power output is negatively impacted by partial shading because the shaded cells produce less power and consume less power overall, which lowers efficiency and creates localized hotspots. Although bypass diodes may be used to counteract these impacts by rerouting current around cells that are shaded, they can result in several peaks, which complicates maximum power point tracking (MPPT). To manage several peaks and optimize power output, metaheuristic algorithms are compulsory. A recently developed game-based optimization methodology known as Golf Optimization Approach (GOA) is used in this study to find a way to MPPT in a grid-connected photovoltaic (PV) system under partial shading conditions (PSCs). Additionally, the same suggested approach is applied to get optimal parameters for the inverter with the goal of optimizing its voltage and current regulators. It aims to evaluate a plan to lower the output voltage and current's total harmonic distortion and DC voltage error. The proposed technique is contrasted to other tracking approaches such as the traditional Perturb & Observe (P&O), Gray Wolf Optimization (GWO), and Sea-gull Optimization Approach (SOA). Simulation is performed in MATLAB R2022b/SIMULINK environment. The obtained outcomes demonstrate the ability of the suggested technique to enhance the utility grid's power quality and improve the tracking system under various partial shading effects and temperature alterations. The proposed technique achieves a tracking efficiency of 99.8 %, surpassing the effectiveness of both of the previous methods which are at 97.2 % and 96.7 %.

This article presents information about harmonic distortion and resonance in distribution networks. The theory behind harmonics and resonance is presented. Examples from the literature and the results of power quality measurements, as well as the authors' experiences connected with significant changes in harmonic distortions, are presented. The harmonic resonance phenomenon is explained, and the risk of resonance in a distribution system network is highlighted. Attention is paid to the connection of a new power plant to the network; however, other risks, e.g., those connected to network reconfiguration, are also highlighted. Further simulation case studies are presented to show interactions between volt/VAR control and harmonic distortion. Simulations consider a few scenarios: impact of voltage change on impedance characteristics and resulting harmonics amplitudes, the impact of a capacitor on impedance characteristics, and the impact of network expansion on harmonic distortion. The final part presents alternative, low-cost harmonics mitigation methods. The concept of the utilization of phase-shifting transformers for two twin-type 1 MW plants located next to each other is verified by on-site measurement. The concept of adapting the harmonics spectrum of new devices to impedance characteristics is presented. Finally, an alternative concept for active mitigation of harmonics under resonance conditions is provided. The concept is based on the reactive power correction in order to change the harmonics phase shift. A comparison of harmonic mitigation methods and general recommendations are provided. Further research is outlined. [ABSTRACT FROM AUTHOR]

Symmetry is a fundamental property of many natural systems, which is observable through signals. In most out-of-equilibrium complex dynamic systems, the observed signals are asymmetric. However, for certain operating modes, some systems have demonstrated a resurgence of symmetry in their signals. Research has naturally focused on examining time invariance to quantify this symmetry. Measures based on the statistical and harmonic properties of signals have been proposed, but most of them focused on harmonic distortion without explicitly measuring symmetry. This paper introduces a new mathematical framework based on group theory for analyzing signal symmetry beyond time invariance. It presents new indicators to evaluate different types of symmetry in non-stochastic symmetric signals. Both periodic and non-periodic symmetric signals are analyzed to formalize the problem. The study raises critical questions about the completeness of symmetry in signals and proposes a new classification for periodic and non-periodic signals that goes beyond the traditional classification based on Fourier coefficients. Furthermore, new measures such as "symmetrometry" and "distorsymmetry" are introduced to quantify symmetry. These measures outperform traditional indicators like Total Harmonic Distortion (THD) and provide a more accurate measurement of symmetry in complex signals from applications where duty cycle plays a major role. [ABSTRACT FROM AUTHOR]

In the realm of electrical distribution, managing power quality is critical due to its significant impact on infrastructure and customer satisfaction. Addressing issues such as voltage sags and swells, along with current and voltage harmonics, is imperative. The innovative approach proposed in this paper centers on a dual-phase control strategy using a Universal Power Quality Conditioner that integrates series and parallel compensations to rectify these disturbances simultaneously. Our methodology introduces a hybrid control scheme that employs adaptive dynamic neural networks (ADNN), a sinusoidal tracking filter (STF), and a proportional-integral (PI) controller optimized via an improved krill herd (IKH) algorithm. The first phase utilizes the ADNN-based adaptive integrated estimator for quick and accurate disturbance detection and estimation. Subsequently, the second phase employs the STF, omitting the Low Pass Filter and employing a Phase Locking Loop to generate precise reference voltages and currents for the series and parallel active filters based on dynamic load and source conditions. This advanced control mechanism not only enhances system efficacy but also reduces the need for extensive computational resources. Furthermore, the performance of both series and parallel inverters is finely tuned through a PI controller optimized with the IKH algorithm, improving the DC link voltage regulation. Our extensive testing under various conditions, including voltage imbalances and harmonic disturbances, demonstrates the robustness of the proposed solution in both transient and steady-state scenarios. [ABSTRACT FROM AUTHOR]

Single-phase lines are typically used to distribute electricity economically to remote or rural locations. This system can handle three-phase loads in addition to single-phase loads. However, these distribution lines are vulnerable to issues with declining power quality on both the single-phase source and the three-phase load due to their length and inherent environmental faults. The goal of the project is to use the Sugeno Fuzzy Inference System (FIS) method to enhance the power quality performance of a single-phase-to-three-phase (1Ph-3Ph) unified power quality conditioner (UPQC) supplied by a photovoltaic (PV) array. The 1Ph-3Ph-UPQC-PV system is powered by a PV array that is connected to the system without needing a DC-link capacitor circuit. To maintain a steady voltage connected to the DC-link 1Ph-3Ph-UPQC series and provide active power to the load during disturbances, the PV array serves as a replacement for the DC-link capacitor. When figuring out the ideal parameters for proportional and integral (PI) constants, the Sugeno-FIS approach is utilized to get beyond the drawbacks of PI. A single linear load (L) and a single non-linear load (NL) are linked to each of the three system configurations (1Ph-3Ph-UPQC-PV) with 6 interference modes. Each combination of 1Ph-3Ph-UPQC-PV, using the Sugeno FIS Method, is compared with PI, resulting in a total of 12 modes of interference. In the 1Ph-3Ph-UPQC-PV with Modes 1-6, Sugeno FIS control is capable of producing three-phase load voltage THD and single-phase source current THD, which are lower than PI control and both comply with IEEE Standard 519. Modes 1-6, using PI, are able to generate a load voltage THD in the range of 1.14% to 5.19%. Otherwise, with the Sugeno-FIS, modes 1-6 are able to reduce the load voltage THD to between 1.11% and 3.70%. Modes 1-6 are capable of producing the source current THD between 0.50% and 2.40%. Otherwise, using the Sugeno-FIS, modes 1-6 are able to reduce the source current THD between 0.08% and 1.08%. The Sugeno FIS control in the system 1Ph-3Ph-UPQC-PV is able to improve the source power factor better than the PI control in all fault modes. Modes 1-6 with PI are able to maintain a source power factor between 0.99971 and 0.99999. Otherwise, using Sugeno FIS, modes 1-6 are able to improve the source power factor between 0.9999 and 1.0. The 1Ph-3Ph-UPQC-PV system using the PI/Sugeno FIS method connected to a non-linear load containing high distortion in Modes 4-6 is able to reduce the source current THD significantly. Mode 6 using FIS Sugeno is able to reduce the load current THD on phase A to source current THD of 882.05% into 0.09%, respectively. [ABSTRACT FROM AUTHOR]

Inverter-based systems encounter significant challenges in mitigating common-mode voltage (CMV) and minimizing inverter losses. Despite various space vector pulse-width modulation (SVPWM) techniques proposed to address these issues, a comprehensive comparative analysis has been lacking. This paper addresses this gap through an experimental and simulation-based evaluation of nine SVPWM techniques. A new discontinuous SVPWM technique, DSVPWM-K4, is introduced, which involves reversing the use of the two zero vectors in DSVPWM-K3. DSVPWM-K3 delivers superior performance in terms of CMV reduction, total harmonic distortion (THD), and inverter losses across all modulation indices (MI = 1, 0.75, 0.5, and 0.25), making it the most effective overall. Although DSVPWM-K4 is a novel approach, it ranks second in effectiveness. The RSPWM technique achieves the lowest CMV with a zero peak-to-peak value but is most effective at lower modulation indices (0.25 and 0.5) due to higher harmonic distortion at higher modulation indices. AZSPWM performs optimally at higher modulation indices, providing a 66.66% reduction in CMV compared to continuous SVPWM and significantly lower THD compared to RSPWM. In contrast, NSPWM exhibits nearly double the THD compared to continuous SVPWM. [ABSTRACT FROM AUTHOR]

Improving photovoltaic systems to better withstand variations in temperature and irradiance, lessen steady-state ripples, maintain high efficiency, require less tracking time, and have minimal complexity is becoming increasingly important. The PV array's overall power output is negatively impacted by partial shading because the shaded cells produce less power and consume less power overall, which lowers efficiency and creates localized hotspots. Although bypass diodes may be used to counteract these impacts by rerouting current around cells that are shaded, they can result in several peaks, which complicates maximum power point tracking (MPPT). To manage several peaks and optimize power output, metaheuristic algorithms are compulsory. A recently developed game-based optimization methodology known as Golf Optimization Approach (GOA) is used in this study to find a way to MPPT in a grid-connected photovoltaic (PV) system under partial shading conditions (PSCs). Additionally, the same suggested approach is applied to get optimal parameters for the inverter with the goal of optimizing its voltage and current regulators. It aims to evaluate a plan to lower the output voltage and current's total harmonic distortion and DC voltage error. The proposed technique is contrasted to other tracking approaches such as the traditional Perturb & Observe (P&O), Gray Wolf Optimization (GWO), and Sea-gull Optimization Approach (SOA). Simulation is performed in MATLAB R2022b/SIMULINK environment. The obtained outcomes demonstrate the ability of the suggested technique to enhance the utility grid's power quality and improve the tracking system under various partial shading effects and temperature alterations. The proposed technique achieves a tracking efficiency of 99.8 %, surpassing the effectiveness of both of the previous methods which are at 97.2 % and 96.7 %. [ABSTRACT FROM AUTHOR]

The paper presents the results of research on the spatial distribution of the multi-phase, distributed windings in electric machines. The focus was on the analysis of the harmonics of the current linkage spatial distributions. To perform calculations for different windings patterns, taking into account the number of phases, pole pairs, and the number q of slots per pole and phase, the dedicated code was developed in the Matlab environment. Nine different multi-phase windings were studied, for which magnetomotive force (MMF) was determined to investigate the harmonic content and total harmonic distortion. The obtained results were compared with a reference three-phase symmetric system. Studies were also carried out on torque ripple and power density for different numbers of winding phases. [ABSTRACT FROM AUTHOR]

This paper aims to design a controller for a matrix converter fed induction motor drive providing less torque ripples and eliminating peak overshoots with good transient and steady state responses utilizing fuzzy and direct torque control. The proposed controller utilizes Direct Torque Control (DTC) strategy with space vector modulation for regulating stator flux and electromagnetic torque. Due to the superior control capabilities of the matrix converter such as bidirectional power flow, sinusoidal input/output waveforms, high power density and lesser volume, it has attracted significant research interest in the field of adjustable speed drive. Hence the proposed matrix converter based controller is developed in MATLAB/Simulink and tested in different input/output conditions. To validate simulation results, a laboratory prototype is built around the Altium Nano Board 3000 equipped with a Xilinx Spartan using Field Programmable Gate Array (FPGA) is employed. The proposed control scheme, validated through simulation and hardware testing, ensures stable, robust drive system with significant reductions in input side harmonics and enhances induction motor drive's performance.

In the inverter circuit, the speed at which the MOSFET is impacted by the presence of a parasitic inductor within the printed circuit board (PCB) leads to a delay in the switching process. Furthermore, the parasitic inductor within the circuit can easily form an LC oscillation with the parasitic capacitor of the MOSFET. These two issues result in an inconsistency between the actual output of the MOSFET and the driving signal waveform, leading to distortion in the sinusoidal pulse width modulation (SPWM) waveform and an increase in total harmonic distortion (THD). It is a common practice to mitigate gate oscillation by introducing a resistor at the gate of the MOSFET. However, elevating the resistance leads to deceleration in the charging process of the MOSFET's parasitic capacitor, consequently causing an increase in the switching delay, and thereby increasing THD. Therefore, an effective strategy to reduce THD is proposed in this paper, while augmenting the gate resistance, computing the MOSFET switching delay, and applying corrective compensation. In this way, the inherent issues of the switch are addressed, resulting in inverter output waveforms that closely resemble sine waves and reduced THD. Through a combination of simulation and empirical experimentation, the efficacy of the proposed approach in significantly reducing THD in the inverter's output waveform has been empirically substantiated. [ABSTRACT FROM AUTHOR]

This article demonstrates the performance of back-to-back connected voltage source inverter (BTB-VSI)-based distribution static compensator (DSTATCOM). In the proposed system, a three-phase three wire electrical utility system (EUS) is integrated with distributed energy resources (DER) through BTB-VSI. It has drawn more attention due to enhanced active power filtering, simple design procedure and performs reliable operation. The objectives of the research work is to provide clean power for weak EUS with improved power quality (PQ) such as, better voltage regulation, improved power factor (P.F), reduced total harmonic distortion (THD), balanced voltage at point of common coupling (PCC) and better optimal active power flow control (OAPFC), and so on. An artificial neurocontrol technique Kernel Hebbian Least Mean Square (KHLMS) is chosen to determine the accurate reference source current for operation of voltage source inverter (VSI). The BTB-VSI performance is investigated on both shunt compensation and OAPFC. The proposed system is converted to a simulation model and hardware unit using MATLAB/Simulink software and SPARTAN−6 field programmable gate arrays (FPGA) controller. Finally, the Simulation and experimental results illustrate that the shunt compensating ability with OAPFC of BTB-VSI performs better over VSI as per IEEE Std 1159–2019 grid code. [ABSTRACT FROM AUTHOR]

In this paper, a second-order sinusoidal oscillator (SO) has been presented using current-feedback operational amplifiers (CFOAs) as the active element. The proposed oscillator uses five resistors and two grounded capacitors in its circuit design, making it simple and cost-effective to implement. Its design allows for greater control and flexibility in designing the oscillator circuit, making it an attractive option for a variety of applications. It also provides independent resistive tuning, allowing for greater control and flexibility in designing the oscillator circuit. Additionally, it offers low parameter sensitivity, makes it more stable and reliable. These features make it a valuable tool for engineers and designers in a variety of applications, including signal processing, communication systems, and control systems. The frequency tuning expression achieved has the ability to tune frequencies in a broad range of frequencies. PSPICE tool is used to simulate and analyze the behavior of the proposed circuit. The total harmonic distortion recorded was 5 %. [ABSTRACT FROM AUTHOR]

Fault diagnosis and detection in electrical power systems need a development of new and robust supervision structures. In the last years, different intelligent monitoring methods have been successfully proposed to deal with the problem of fault diagnosis in power transmission lines. In this work, a new hybrid strategy called FFT-FL combining Fuzzy Logic (FL) approach with Fast Fourier Transform (FFT) is proposed and applied to fault diagnosis in power line network. The elaborated fault detection structure consists of indicating whether the electrical transmission is working correctly or a fault has occurred with an effective isolation step to determine the faulty zone in the line. Whereas, an identification step consists of determining faulty phase thus fault classification in the studied line network. The novel proposed algorithm (FFT-FL) is used to improve the fault diagnosis response time and to decouple between faults and disturbances. In this paper, a comparative study is presented between the two intelligent methods for detection, isolation and identification of faults using only FL and the hybrid FFT-FL structure. The obtained simulation results verify the effectiveness and the correctness of the proposed fault method for all types of faults in the power line networks and in different zones. [ABSTRACT FROM AUTHOR]

Electrical transformers are generally designed to operate from sinusoidal sources. However, increased use of nonlinear loads, such as electric motor drives, lighting, fluorescent lamps, rectifiers, and computers, which generate high values of harmonics, makes this transformer operate in the nonlinear region. This paper discusses and focuses on the effect of the characteristics of a single-phase transformer when it is operated from a non-sinusoidal source with a non-linear load. An experimental 1 kVA single-phase transformer with a voltage of 220V and frequency of 50Hz with linear and nonlinear loads was considered. The results of this investigation show the losses increased by 25% when the transformer was fed from a sinusoidal power supply and the load was non-linear. In addition, the losses and THD for the current reached 40% and 12.4%, respectively, at nearfull load when the transformer was fed from a non-sinusoidal power supply and non-linear loads. The correlation between total harmonic distortion (THD) and these types of power supplies and loads was illustrated. The results showed that increasing the current harmonic distortion will lead to increased transformer losses and thus reduce their life expectancy. [ABSTRACT FROM AUTHOR]

In this article, the authors present a new competitive Packed-U-cell and neutral point clamped (PUC-NPC) 9-level converter that utilizes a small number of power switches and passive components. Only seven switches are added to a single DC source. However, the proposed converter takes benefits of the neutral point clamped (NPC) converter's capability to connect capacitors in series, all with a simple control that enables the algorithm associated to the proposed inverter operate correctly in an open loop operation. A technique of pulse width modulation (PWM) is employed to maintain capacitor voltage at desired values. The proposed inverter produces an almost sinusoidal waveform output voltage, as result, a perfectly sinusoidal charge current with minimal impact on the economy and energy consumption are optioned. The converter has been integrated with a photovoltaic system to minimize its impact on the electricity supply and enhance energy efficiency. In order to take a maximum power from the photovoltaic panel, authors employ a maximum power point tracking (MPPT) technique based on disturbance and observe (P and O). When combined with the proposed control technique, it offers a competitive system suitable for standalone use or as an energy source, eliminating the need for PI regulators or additional investments. The proposed 9-level converter has been validated through simulation, utilizing the MATLAB Simulink environment to model the proposed system. Dynamics of this later were verified by changing the load charge. [ABSTRACT FROM AUTHOR]

The power quality problem refers to the issues caused by the sudden rise of nonstandard voltage, current, or frequency. The problems that emerge from poor power quality due to non-linear loads are voltage sag, swell, interruptions, harmonics, and transients in distribution systems. Various compensation devices are used nowadays to improve power quality. The advances in power electronic technologies improve the reliability and functionality of power electronic based controllers, resulting in increased applications of FACTS devices like DSTATCOM and Dynamic Voltage Restorer (DVR) which are fast, flexible, and efficient solutions to the power quality problems. These devices are used to restore the source, load voltage, and current disturbances caused by different loads and faults. These devices were tested in a standard IEEE 14-bus system for Total Harmonic Distortion (THD) minimization while utilizing PI-based Artificial Neural Networks (ANNs) and Linear Regression (LR). The results were analyzed and compared. [ABSTRACT FROM AUTHOR]

In this paper, a Dual Second Order Generalized Integrator_Phase Locked Loop (DSOGI_PLL) technique applied to the Photovoltaic (PV) system supplying a Z-Source five-level Inverter (ZSI) is presented. The ZSI assures the increasing voltage of the PV system and provides the desired output DC at the input of the five-level Neutral Point Clamped Inverter (5L_NPCI), without any control which reduces the complexity of the overall system, this is due to the impedance network in its structure. We use Z-Source in order to eliminate the controlled DC bus as well as the use of the DC-DC Boost converter as an intermediary. A DSOGI technique is employed to control and optimize the energy quality, especially in distorted grid conditions and allows one to obtain a very low value of Total Harmonic Distortion (THD) which means lower peak currents, and higher efficiency. Low THD is an essential feature in power systems that international standards such as IEC 61000-3-2, and IEEE-519 set limits on the harmonic currents of various classes of power equipment connected to a distorted three-phase grid. Compared to the classic structure of inverters, the NPC five-level inverter presents a very high performance. [ABSTRACT FROM AUTHOR]

The research objective is to enhance the power quality performance of a single-phase unified power quality conditioner (UPQC) system supplied by a combination of photovoltaic (PV) array and battery energy storage (BES) using fuzzy logic control (FLC) connected to a 220 V-50 Hz distribution system. The PV array consists of several PV panels with a maximum power of 12 kW. Solar PV is highly dependent on external environmental factors i.e. sunlight, temperature, radiation, weather and seasons where levels can change at any time. BES functions to store PV power and both provide a more stable load power supply to the load when an interruption/disconnection occurs on the source (off-grid mode). The proposed system is also more efficient because it does not require a DC-link capacitor. The FLC method with the Mamdani fuzzy inference system (FIS) is proposed to overcome the weaknesses of proportional and integral (PI) control in determining proportional constants and integral constants. The faults were selected in a total of six case studies (CS) based on the fault categories and single-phase UPQC configuration i.e. CS 1 (sinusoidal/S-Sag-non-linear load/NL-PV), CS 2 (S-Swell-NL-PV), CS 3 (S-interruption/Inter-NL-PV), CS 4 (SSag- NL-PV-BES), CS 5 (S-Swell-NL-PV-BES), and CS 6 (S-Inter-NL-PV-BES). In single-phase UPQC systems from CS 1 to CS 6, FLC is able to produce lower total harmonic distortion (THD) of load voltage and source current, as well as higher source power factor (PFS) compared to proportional-integral (PI) control. The system using singlephase UPQC on CS 1 to CS 6 with PI/FLC control is capable of producing load voltage THD and source current THD below IEEE 519 limits. The system with a single-phase UPQC configuration with PI/FLC control shows that CS 4 to CS 6 is capable produces a change in load voltage disturbance that is slightly greater than CS 1 to CS 3. The system uses single-phase UPQC with PI/FLC control on CS 3 and CS 6 is able to deliver load active power with values close to CS 1 and CS 4. [ABSTRACT FROM AUTHOR]

In this work, a novel SRF-PLL and DSOGI-PLL with the JAYA based optimization approach is presented herein for the control of a unified power quality conditioner (UPQC) system. The proposed UPQC system is linked to a three-phase distribution system that has nonlinear loads. Increased use of non-linear loads has contributed to harmonic effluence in power distribution systems and thus power quality issues have been elevated which is essential to be efficiently addressed. Since, the UPQC consists of a shunt and a series filters therefore, it is a most promising custom power device to mitigate power quality issues of instance voltage swell, sag, phase unbalance, current and voltage harmonics, DC-link voltage regulation, reactive power compensation etc. SRF-PLL and DSOGI-PLL perform grid synchronization and reference signal generation simultaneously in a single platform. Additionally, JAYA based optimization has been employed for determination of PI controller gains of both the controller. To validate the performance of UPQC and its controller, the complete UPQC system has been developed and fabricated in MATLAB/ Simulink as well as in hardware platform. The accuracy of simulation as well as hardware outcomes and their comparative power quality investigation is found to be satisfactory. [ABSTRACT FROM AUTHOR]

This paper aims to introduce a new multilevel inverter topology less number of switches and gate drivers with a hybrid control method. In the proposed topology three kinds of voltage sources are utilized in the topology. A combination of these voltage sources, switches, and two H-bridges derived a new topology. Moreover, combining the nearest level and pulse width modulation created an efficient way to control the proposed topology which is described in this paper. Equations to determine the number of components and total standing voltage of the proposed multilevel is presented. A comprehensive comparison between the proposed topology and other best topologies is made. Additionally, the simulation results which are obtained by PSCAD/EMTDC and experimental results are in accordance with the theory. The proposed multilevel inverter with a hybrid control method has less number of switches, gate drivers, and low THD. [ABSTRACT FROM AUTHOR]

The rising popularity of grid-connected multilevel inverters with photovoltaic panels underscores the importance of effective modulation and control strategies for ensuring optimal power quality. The performance of these inverters hinges significantly on modulation and control approaches, specifically addressing issues like common mode voltage, harmonics, switching loss, and dynamic response. This study introduces a novel approach to mitigate current harmonics in these inverters by employing sliding mode control. Notably, this technique achieves harmonic reduction without necessitating an increase in the switching count. The presented technique eliminates phase-locked loop, current controllers, and carrier waves, thereby easing hardware computation. Beyond computational efficiency, this approach contributes to enhanced power quality and dynamic response within the inverter system. Simulation results affirm the efficacy of the proposed method when compared to the use of the phase opposite disposition modulation combined with the current controllers. In the nominal operational mode, the proposed method reduces the current Total Harmonic Distortion (THD), the highest magnitude of individual harmonics, and the switching count by 43.6%, 73.5%, and 19.6% respectively, compared with those of the method using the phase opposite disposition modulation combined with current controllers. [ABSTRACT FROM AUTHOR]

This paper provides a comparative analysis of bipolar versus unipolar Sinusoidal Pulse Width Modulation (SPWM) in DC-AC inverters, focusing on Total Harmonic Distortion (THD) across modulation indices and the latter's effects on the R-L loads. Using the PIC18F2431 microcontroller for its efficiency, a single-phase inverter accomplished to deliver a high-fidelity sine wave. This study discovered that while both SPWM methods reduce harmonics, the unipolar approach yields more uniform THD reduction and superior performance, particularly noticeable in RL load conditions, where minimal harmonic distortion is crucial. The bipolar inverter, despite a higher initial THD, shows a considerable improvement at higher indices, significantly enhanced by an LC low-pass filter. This filter is a key component in achieving sub-1% THD levels at full modulation, ensuring optimal sine wave quality. The findings highlight the operational differences between the SPWM techniques and the importance of the LC filters in ameliorating the inverter output for various power applications. [ABSTRACT FROM AUTHOR]

This work introduces an improved control technique for a dual-stage grid-connected proton exchange membrane fuel cell (PEMFC) power system, using model predictive current control. The first step (Boost Converter) is subjected to the use of a maximum power point tracking (MPPT) technique known as fuzzy logic. Moreover, the use of a twolevel inverter serves as an intermediary component for injecting the electricity obtained from the Proton Exchange Membrane Fuel Cell (PEMFC) into the utility grid. A model predictive current control strategy has been developed with the objective of regulating the grid current and achieving synchronization between the grid voltage and current, with the ultimate goal of achieving a power factor of unity. The results obtained from numerical simulations conducted inside the Matlab/SimulinkTM environment demonstrate that the proposed Maximum Power Point Tracking (MPPT) approach effectively achieves precise tracking of the Maximum Power Point (MPP) while minimizing power oscillation in a stable state, even in the presence of temperature variations. Additionally, the MPCC ensured the integration of the extracted power into the network while maintaining a low level of total harmonic distortion (THD %) in the grid currents. [ABSTRACT FROM AUTHOR]