The growing penetration of renewable energy sources demands advanced control technologies to maintain grid stability and reliability, and grid-forming inverters (GFMs) have emerged as a promising solution to address this challenge. This paper presents a novel approach for managing power quality and energy storage in grid-connected systems through dual-purpose GFMs. In the proposed framework, one GFM connects a photovoltaic (PV) solar farm to the grid, while another GFM provides energy storage support and harmonic mitigation. The second GFM, referred to as the storage-GFM inverter, addresses challenges introduced by active loads, such as electric arc furnaces and pulse radars, which produce discontinuous high-magnitude harmonics. When the total harmonic distortion (THD) of the load current exceeds the predefined value, the storage GFM inverter switches to Shunt Active Filter (SAF) mode, ensuring compliance with IEEE 519-2022 harmonic limits. In the absence of active load, the storage GFM inverter functions as an inverter for the storage system, charging or discharging based on system demand. Both inverters operate in grid-following mode under normal grid conditions and can seamlessly transition to grid-forming mode during grid outages to maintain an islanded system. A key novelty of this work is the integration of a single inverter topology capable of performing multiple roles, including grid forming, harmonic filtering, and fault current limitation. The versatility of these inverters provides both stability through grid-forming capabilities and safety through effective harmonic elimination and fault current limitation.

Grid-forming (GFM) inverters enable inverter-based resources to act as voltage sources, providing support to power systems. They are anticipated to serve as a technology capable of replacing synchronous generators. However, during a fault, it is crucial to implement a function that limits their output current to prevent short circuit currents from exceeding their capacity. This raises concerns about the potential deterioration of transient stability in the power system. The influence of current limiting on transient stability depends on the current-limiting methodology. However, comprehensive theoretical evaluations are still lacking. This paper presents the theoretical evaluation of the influence of current limiting on transient stability for various current limitation algorithms. Accordingly, an equivalent virtual impedance (EVI) is proposed as a universal metric. EVI represents an impedance virtually assumed between the voltage source simulated in GFM control and the connection point of the inverter, and is computed so that the current through the EVI matches the limited output current. The transient stability is then assessed for various current-limiting algorithms based on the electric circuit characteristic of EVI. Finally, time-domain simulation is conducted to evaluate the consistency of the assessment.

This paper proposes a coordinated control strategy for grid-forming inverters (GFMs) to address two critical challenges in evolving power systems. These are the active harmonic mitigation under nonlinear loading conditions and dynamic overcurrent control during grid disturbances. The proposed framework integrates a shunt active filter (SAF) mechanism within the GFM control structure to achieve a real-time suppression of harmonic distortions from the inverter and grid currents. In parallel, a virtual impedance-based dynamic current limiting strategy is incorporated to constrain fault current magnitudes, ensuring the protection of power electronic components and maintaining system stability. The SAF operates in a current-injection mode aligned with harmonic components, derived via instantaneous reference frame transformations and selective harmonic extraction. The virtual impedance control (VIC) dynamically modulates the inverter’s output impedance profile based on grid conditions, enabling adaptive response during fault transients to limit overcurrent stress. A detailed analysis is performed for the coordinated control of the grid-forming inverter. Supported by simulations and analytical methods, the approach ensures system stability while addressing overcurrent limitations and active harmonic filtering under nonlinear load conditions. This establishes a viable solution for the next-generation inverter-dominated power systems where reliability, power quality, and fault resilience are paramount.

Grid-forming inverters (GFM) are a promising solution for increasing renewable energy penetration in power system networks. Adapting to dynamic changes in grid conditions, ensuring coordination with other inverters, and tuning and calibrating current-limiting parameters are crucial issues in GFM-based systems. GFM-based systems must ensure fault current contribution, current magnitude limitation, and fault recovery capability to support the grid and protect power semiconductor devices under strict disturbances. Various methods are described in the literature to limit the current, i.e., virtual impedance, current limiters, and voltage limiters. This paper suggests a virtual impedance-based approach that adjusts the internal induced voltage to maintain system synchronization and track system voltage changes. The technique inhibits phase angle change by regulating the current and avoids grid instabilities. The paper addresses challenges like temporary transient overcurrent and current saturation. Simulations are conducted to demonstrate performance. Results ensure the control scheme's robustness and reliability.

This paper addresses the challenges and opportunities associated with integrating grid-forming inverters (GFMs) into modern power systems, particularly in the presence of nonlinear loads. Nonlinear loads introduce significant harmonic distortions in the source voltage and current, leading to reduced power factor, increased losses, and an overall reduction in system performance. To mitigate these adverse effects, active filters are employed. The objective of this study is to investigate a synergistic approach to modeling and control in integrated power systems with GFMs, focusing on enhancing power quality and grid stability by reducing harmonic distortions through the use of voltage-source active filters. This research contributes to sustainability by supporting the reliable and efficient integration of renewable energy sources, thereby reducing dependency on fossil fuels and minimizing greenhouse gas emissions. Additionally, improving power quality and system efficiency helps reduce energy waste, which is crucial for achieving sustainable energy goals. Simulations are conducted on a 1000 kW GFM connected to a grid with a nonlinear variable load, demonstrating the system’s effectiveness in adapting to dynamic conditions, reducing harmonics, and promoting a stable, resilient, and sustainable power grid.

Grid-forming inverters (GFMs) have emerged as crucial components in modern power systems, facilitating the integration of renewable energy sources and enhancing grid stability. The significance of GFMs lies in their ability to autonomously establish grid voltage and frequency, enabling grids to form and improve system flexibility. Discussing control methods for grid-forming inverters is paramount due to their crucial role in shaping grid dynamics and ensuring reliable power delivery. This paper explores the fundamental and advanced control methods employed by GFMs, explaining their operational principles and performance characteristics. Basic control methods typically involve droop control, voltage and frequency regulation, and power-balancing techniques to maintain grid stability under varying operating conditions. Advanced control strategies encompass predictive control, model predictive control (MPC), and adaptive control, which influence advanced algorithms and real-time data for enhanced system responsiveness and efficiency. A detailed analysis and performance comparison of different control methods for GFM is presented, highlighting their strengths, limitations, and suitability for diverse grid environments. Through comprehensive studies, this research interprets the ability of various control strategies to mitigate grid disturbances, optimize power flow, and enhance overall system stability.

The transport sector lies amidst major challenges like air pollution because of the emission of greenhouse gases (GHGs) and dependency on nonrenewable sources like fossil fuels. To alleviate those problems in the transport sector, the Electric vehicle (EV) has the potential to be the silver lining. EV is based on electric propulsion that requires the battery to power the engine and does not emit GHGs. Albeit of the advantages, running EV is not without its drawbacks. Electricity is needed to run EV, there are many places where either a charging station is not present or the grid itself is unavailable. To tackle the problem of EV charging and exploit the abundance of solar energy available, this research proposes a solution by integrating solar photovoltaic (PV) to EV battery charger charges directly and injecting excess energy of solar back to the grid. The battery charging process is controlled using DC-DC converter. Whereas, pure sinusoidal current has been injected in grid after reducing total harmonic distortion (THD) by passing through filter. And reactive power compensation has been applied to ensure only active power is being sent to the grid. The paper presents a mathematical analysis of the model as well as a simulation on the MATLAB/SIMULINKO package.

In this paper, a novel single-phase AC-AC boost converter has been discussed that comprises two side limb capacitors, two voltage lift networks, and one H-bridge module. The proposed converter provides a high boosted voltage at the output at different duty ratios. The converter poses features to control the output voltage frequency and its magnitude independently. Mainly reduced voltage spikes across the semiconductors, improved quality of input current, no shoot-through risk, etc. The proposed converter can be suitable for traction systems and adjustable speed drives. The simulation results verify the effectiveness of the proposed control and endorse the analytical study.

In Yemen, the lack of centralized power due to a collapsing power grid decimated by fighting, expensive commercial electricity, and skyrocketing diesel prices has forced a shift to solar power. As solar energy offers a cost-effective and environmentally friendly solution to the energy crisis, Stand-alone PV systems (SAPVs) are emerging as the primary energy source in Yemen. This paper presents the complete design of a SAPV system in different cases for a location in Ibb city, Yemen. The first case uses the lead-acid battery; the second uses the Lithium-ion battery to compare the economic feasibility. The system consists of multiple PV panels, inverters, batteries, and a charging controller. The “PVsyst” simulation software used analyzes the performance of the proposed SAPV system and anticipates the solar system's energy generation. As the performance of a photovoltaic (PV) system is affected by factors such as geographical location and the type of PV modules used, PVsyst also determines input data, losses considerations, system efficiency, and gross energy generation.

Abstract The multiphase matrix converter outperforms the conventional three‐phase system with higher fault tolerance capability and higher power control competency. This paper discusses the direct control based on different possible switching combinations of a three‐phase to five‐phase matrix converter (MC). The proposed control topology significantly reduces the switching commutations in a switching cycle when compared with its counterpart. The control is based on the modified space vector pulse width modulation (SVPWM) strategy. The proposed space vector scheme intelligently selects the voltage vectors to get the desired output characteristics with the least possible switching transitions in a switching cycle. Three possible cases exist in controlling space vectors based on their magnitude, the number of active switching vectors, and their commutations. The results for three different cases of SVPWM have been presented and compared. The total harmonic distortion (THD) obtained in the output is lower in case 2; however, it suffers from a higher common‐mode voltage (CMV). The scheme has been successfully implemented and verified in hardware.

This paper presents the field-oriented control (FOC) of a five-phase induction motor (FPIM) fed from a three-to-five phase direct matrix converter (DMC). The article focuses on the modulation and control of the three-to-five phase DMC, which discusses minimizing the problems associated with switching vector selection, sector identification, switching sequence selection, and dwell-time calculations. The DMC is controlled from the space vector pulse width modulation (SVPWM) technique, eliminating the x-y components of space vectors. Moreover, the matrix converter can perform unity power factor control at the input side. The FPIM is sourced from a DMC, and the FOC technique is applied to control the drive. The dynamic characteristics of the drive are succeeded for different loading conditions. The proposed work is simulated in Simulink/Matlab environment and further verified through practical experimentation. The control signals of the IGBTs are generated through FPGA embedded in dSPACE 1006. The experimental and the simulation results prove the practicability of the FOC to FPIM fed from a DMC.

Solid-state transformers (SSTs) have emerged as a superior alternative to conventional transformers and are regarded as the building block of the future smart grid. They incorporate power electronics circuitry and high-frequency operation, which allows high controllability and enables bi-directional power flow, overcoming the limitations of conventional transformers. This paper presents a detailed analysis of the solid-state transformer, expounding the fundamentals, converter topologies, applications, and future challenges of the SST in a systematic manner. The paper discusses the necessity of improved replacement of the low-frequency transformers (LFTs) and presents the configuration of SST. It presents SST fundamentals in individual stages and explores its origin and evolution. The basic topologies, their specifications, and control strategies are also described. The applications of SST as a replacement of LFTs are discussed along with recent applications. The future challenges for real-time implementation of SSTs are explored, and research directions are proposed.

Wireless power transfer (WPT) has already been the subject of intense research in an effort to promote the incorporation of electric product lines into our everyday lives. WPT’s extensive use and rising demand arise from its innate ease and the potential of continuous functioning without any recharging downtime, which are two of the main issues that arise with conventional wired charging stations. The power pad coil configuration is one of the most significant aspects of electric vehicles’ wireless charging station implementations. The appropriate architecture of a power pad is the essential factor in designing an efficacious and sustainable wireless power transfer framework. Every coil architecture available offers its own merits for special application domains. This chapter presents a comprehensive analysis and comparative study of DD, DDQ, and rectangular. The comparability research focused on the simulation results, a magnetic flux pattern, and statistics abstracted from the result obtained. Dimensional structure with maximized connection coefficient and current directions optimized to the less possible area, finite Element Analysis (FEA) obtained using Ansys Maxwell audits with the least interruption between corresponding coils.

The feasibility of power transfer enhancement, through simultaneous AC–DC power transmission in a two-terminal transmission network, has been proposed earlier by the authors, and the concept is well established. To meet the increase in demand for electricity, a new technique is proposed in this article to increase the use of existing transmission lines in addition to independent control of AC and DC power flow. This paper extends the concept to a three-terminal transmission network by considering a power tapping from the middle of the line. DC is also superimposed in the already existing three-terminal AC transmission system. In the proposed topology, a multi-terminal simultaneous AC–DC system is used, which is integrated with a zig-zag transformer and more than two voltage source converter (VSC) stations. Each terminal may represent an area of the power system. Anyone/two-terminal(s) may act as sending end, whereas the remaining two/one terminal(s) may act as receiving end. Power can flow in either direction through each segment of the transmission system. At sending end, VSC converts a part of AC to DC and injects it into the neutral of the zig-zag transformer. On receiving terminal, DC power is tapped from neutral of zig-zag transformer and fed to VSC for conversion back to AC. The concept is verified in the digital simulation software PSCAD/EMTDC.

Solar energy is widely used among the various renewable energy sources since it is conveniently accessible. Various Non-Isolated DC-DC converter configurations, such as Boost, Buck-Boost, and CUK, associated with Maximum Power Point Tracking (MPPT) controller i.e., Perturb-observation (P&O) and Incremental Conductance (INC) to bring out MPP from Solar Photovoltaic (PV) System, discussed in this article. Controlling the switching operations of the converters by providing the appropriate switching pulse to the DC-DC converter through the MPPT controller allows the desired output voltage of 220V DC to be maintained across the load. This article tries to analyze and examine the characteristics of the various converters to find out more optimum converter for different operating situations. The performance parameters, taken as output voltage, ripple in output voltage and current, output power, efficiency, and required size of passive elements are needed. The desired responses of mathematical modelling are verified through the simulation, which is executed in MATLAB/Simulink.

Low terminal voltage at the output of a solar photovoltaic needs efficient boost converters for establishing a proper communication and energy transfer to the DC microgrids. In order to serve this purpose, the traditional boost converter is required to operate at some large duty ratio which is perilous to the converter performance and would create undesirable effects such as more losses, spikes of voltages and poor transient response. A boost converter with significantly high gain at low duty ratio has been presented in this paper. The proposed converter is well suited for integration of a solar PV with the DC bus of higher voltage levels in a DC microgrid. This particular converter is simple in structure and easily controlled with a single train of pulses. The advantages of switched inductor circuit embedded with the capacitor is availed in an intelligent way to uplift the voltage gain significantly. The converter behavior and suitability for high voltage is analyzed in continuous conduction mode, and later, the performances are verified through simulation results at a frequency of 10 kHz.

In this paper, a single phase five level cascaded H bridge multilevel inverter followed by unipolar control schemes have been analyzed for full range of linear modulation indices. Pulse width modulation (PWM)—based modulation scheme is used for the switching of power electronic switches. Inverter performance has been analyzed and discussed by taking performance parameters as output voltage transferred to load, harmonics in output voltage, switching stress across the switches, power loss, and efficiency of inverter. The proposed topology is simulated in MATLAB/Simulink.

Multilevel inverters are getting preference over conventional inverter in different applications due to inherent advantages offered by it, for example reduced harmonic distortion, higher number of voltage levels, lower switching losses, high power quality, etc. The two important conventional topologies for structure multilevel inverters are the clamped diode and the cascaded H-bridge inverter. There are two control techniques, unipolar and bipolar. In this paper bipolar control technique is opted to control the cascaded H-bridge five level inverter. The single-phase full bridge cascaded H-bridge inverter controlled by bipolar technique is presented. Cascading connections of two full bridge inverter helps to get five levels of the output voltage. A detailed analysis of the controlled technique and the performance of the inverter is represented in this paper. The controlled operation is performed at wide range of switching frequencies. The theoretical analysis is verified by simulation performed in Matlab/Simulink platform. The results are compared with unipolar control scheme of the inverter.

This paper presents a novel, scalable, and modular multiport power electronic topology for the integration of multiple resources. This converter is not only scalable in terms of the integration of multiple renewable energy resources (RES) and storage devices (SDs) but is also scalable in terms of output ports. Multiple dc outputs of a converter are designed to serve as input to the stacking modules (SMs) of the modular multilevel converter (MMC). The proposed multiport converter is bidirectional in nature and superior in terms of functionality in a way that a modular universal converter is responsible for the integration of multiple RES/SDs and regulates multiple dc output ports for SMs of MMC. All input ports can be easily integrated (and controlled), and output ports also can be controlled independently in response to any load variations. An isolated active half-bridge converter with multiple secondaries acts as a central hub for power processing with multiple renewable energy resources that are integrated at the primary side. To verify the proposed converter, a detailed design of the converter-based system is presented along with the proposed control algorithm for managing power on the individual component level. Additionally, different modes of power management (emulating the availability/variability of renewable energy sources (RES)) are exhibited and analyzed here. Finally, detailed simulation results are presented in detail for the validation of the proposed concepts and design process.