This article introduces a new fully soft switched ultra-high step-up quadratic converter. The proposed converter benefits from several advanced features including high voltage gain at low duty cycle, low switch voltage stress, low sum of diodes voltage stress, switching at ZVS condition for switches, low ripple continuous input current, and common ground between the input and load. These advantages are achieved by integrating the quadratic structure with an auxiliary circuit consisting of coupled inductors, switched capacitors, and active clamp techniques. Furthermore, the presented converter mitigates the reverse recovery problem of all diodes especially the input side diodes which is a challenge in many quadratic base converters. These properties have contributed to providing an efficient converter with wide applicability. The converter is fully analyzed, its superiority to other structures is shown, and a 200 W laboratory prototype validates the theoretical analysis.

Luo converters represent the most extensive family of non-isolated DC-DC converters, yet achieving high voltage gain in these topologies often compromises simplicity. This study introduces a novel family of quadratic boost converters that address this challenge by combining six key features: 1) continuous input current, 2) reduced component count, 3) optimized voltage/current stress on semiconductors, 4) higher voltage gain than conventional designs, 5) high efficiency across a wide duty-cycle range, and 6) topological extensibility comparable to Luo converters. The proposed topologies are analyzed in both ideal and non-ideal operating modes, with derived expressions for voltage gain and efficiency sensitivity. Design requirements are detailed for continuous conduction mode (CCM), complemented by small-signal analysis and compensator design for the primary family members. Experimental results validate the theoretical models, demonstrating the converters’ performance and robustness. Additionally, voltage gain tests for extended topologies confirm their adherence to theoretical predictions. The proposed family offers a streamlined, high-performance alternative to existing Luo converters, with potential applications in high-gain, non-isolated power conversion systems.

Electric vehicles (EVs) offer a promising solution for mitigating greenhouse gas emissions and minimizing the transportation sector's dependency on non-renewable energy sources. However, efficient energy management poses a significant challenge for their broader adoption, particularly optimizing battery usage, maximizing driving range, and improving overall vehicle performance. This paper presents the state-of-the-art Artificial Intelligence (AI) techniques used in electric vehicle energy management systems (EV-EMS), discussing a variety of deep learning algorithms of AI methodologies, such as, neural networks, and fuzzy logic. Additionally, This paper discusses the role of auxiliary techniques like transfer learning, which enhances model adaptability and reduces training time in AI-driven EMS applications. Through a systematic analysis of each method, this review identifies key trends, highlights the challenges and limitations of each technique, and offers perspectives on potential solutions and future research directions. The paper aims to support researchers, industry professionals, and policymakers in developing advanced, sustainable, and adaptable EV-EMS solutions that maximize battery life, improve vehicle performance, and facilitate real-time adaptive control. Finally, this review highlights the importance of AI-driven strategies in making EV technology more efficient, reliable, and scalable.

In the contemporary landscape of trend industries including sustainable energy sources, high-voltage direct current, and electrified mobility, the need for power conversion units to bridge disparate sections is felt more than ever before. Among these conversion units, the step-up DC-DC converters occupy a pivotal role, elevating the DC voltage levels and facilitating interactions between converters and circuits. However, the multistage DC-DC converters, prevalent in large-scale industries, offer higher voltage gains and power density. This review paper has categorized the multistage DC-DC converters into isolated/non-isolated, voltage-fed/current-fed, unidirectional/bidirectional, hard-switched/soft-switched, and step-up/step-down configurations. It has been followed by a brief review of various voltage boosting techniques, containing an analysis of multi-staging voltage boosting methods and recent advances in converter structures. Then, the multistage DC-DC converters have been classified into several distinct categories: quadratic gain, cascaded, interleaved, modular, multilevel, and hybrid structures. Recent advancements and developments in each of these categories have been meticulously examined, with a focus on their fundamental concepts, advantages, and disadvantages. In particular, the voltage gains, voltage stresses, and current stresses associated with quadratic gain and cascaded DC-DC converters have been analyzed and compared in detail. Furthermore, an in-depth exploration of the structures and configurations of interleaved, modular, and multilevel DC-DC converters has been conducted. This includes a discussion on the combinations of modules, the benefits arising from these integrations, and insights for future developments. The applications of each category of multistage DC-DC converters across various industries—particularly in grid applications—have been thoroughly analyzed. Subsequently, these converters have been evaluated based on several criteria: reliability, component count, control complexity, voltage gain, power level, cost, and weight. The prioritization of these factors has also been systematically presented.

This paper introduces a novel single-loop control scheme for voltage regulation in islanded inverters, using a proportional-integral-lead (PI-Lead) controller designed within the synchronous reference frame (SRF) through a loop-shaping approach. Commonly, dual-loop controllers have been employed for this purpose owing to several limitations, such as insufficient stability with a narrow gain margin, a trade-off between stability and bandwidth, and constrained bandwidth due to the need for a significantly lower outer voltage loop bandwidth compared to the inner current one. The proposed method overcomes these challenges by integrating a Lead compensator, which enhances voltage regulation by eliminating steady-state error, improving stability margins, and providing a fast transient response while maintaining robustness against model parameter variations. Additionally, the control strategy reduces dependence on current measurements, except when dealing with inductive loads where virtual resistor-based active damping is necessary. Despite the challenges posed by multi-resonance phenomena and coupling effects inherent in single-loop SRF-based modeling, a comprehensive frequency-domain analysis is performed, with systematic controller parameter design guidelines to mitigate multi-gain crossover issues. Rigorous experimental results validate the theoretical findings and simulations, demonstrating the superior performance and practical effectiveness of the proposed control strategy compared to existing methods.

This article presents a dual-side capacitor tuning and cooperative control strategy for wireless electric vehicle (EV) charging. To improve the efficiency of wireless EV charging across broad output voltages and wide-range load variations, this article introduces a reconfigurable WPT system by incorporating two switch-controlled-capacitors (SCCs) into the double-sided LCC (DLCC) compensation network. Based on the analytical model of the system, optimal capacitor tuning factors are derived to reduce the rms values of the inductor currents and to minimize the turn-off currents across the semiconductors. Furthermore, a dual-side cooperative control strategy is proposed. Through the collaborative control of the inverter, rectifier, and SCCs, the proposed method achieves dual-side optimal zero-voltage-switching (ZVS), wide power regulation, and maximum efficiency tracking simultaneously. Compared with the existing triple-phase-shift (TPS) method, the proposed approach improves the system efficiency across a wide range of dc output voltages and power levels. Experimental results demonstrate that the proposed method achieves a maximum efficiency improvement of up to 1.8% in the boost mode and 1.9% in the buck mode.

This article presents a new transformerless switched-capacitor (SC) based five-level grid-connected inverter with inherent voltage-boosting capability. The proposed topology achieves a voltage gain factor of two without requiring an additional dc–dc boost converter or transformer, resulting in a more compact, cost-effective, and efficient design. A single SC cell is utilized to perform bidirectional capacitor charging during both positive and negative grid half cycles, thereby improving energy transfer efficiency and significantly reducing capacitor size and volume compared with the conventional topologies. The inverter employs a minimal number of components—only nine switches and one flying capacitor—while maintaining high performance. Only five switches operate at high frequency, which reduces switching losses, gate driver complexity, and electromagnetic interference. A straightforward control strategy ensures that the inverter delivers a high-quality sinusoidal current waveform to the grid and supports both active and reactive-power flow under various power factor conditions. The reliability of the proposed inverter is analyzed, and its performance is validated through detailed simulations and experimental results. A comparative study with the existing solutions highlights the advantages of the proposed topology in terms of efficiency, voltage gain, component count, and waveform quality.

This paper introduces a soft-switched high step-up converter applicable to photovoltaic systems. In the proposed topology, to further improve the voltage gain and reduce the components voltage stress, coupled inductors and voltage multiplier cell (VMC) techniques are integrated with the conventional boost converter. Hence, it addresses challenges in traditional boost converter when operating at near unity duty cycle and enables it to utilize high-quality components that lead to decreased conduction losses in high-output voltage applications. Furthermore, the converter achieves soft switching operation by incorporating a lossless snubber cell, which consists of just two diodes and requires no additional switches and magnetic cores. These features contribute to enhancing the converter efficiency. Notably, the energy stored in the snubber circuit is effectively recovered to the output without any circulating current, making it a beneficial characteristic among the lossless snubber structures. The proposed topology also offers a common ground between the input and output terminals, as well as the switch which simplifies the converter control circuit. Additionally, it maintains continuous input current, which makes the proposed converter more suitable for photovoltaic system applications. To validate the converter benefits, a 150 W laboratory prototype converter is implemented.

This article implements a real-time digital twin (RTDT) of a 10 kW Dual Active Bridge (DAB)-electrolyzer system. The electrical model of a 10 kW alkaline electrolyzer is presented to understand its I–V characteristics. A sensitivity analysis is performed to assess the impact of various parameters on the electrolyzer’s electrical characteristics. The series inductance, crucial for power transfer within a DAB converter, is examined using PLECS software to study the impact of the electrolyzer load on the peak and RMS currents. Based on this, the value of series inductance is optimized, resulting in a minimum overall RMS current throughout the operating power range. RTDT of the DAB electrolyzer system is developed using an OP4610XG real-time simulator to validate the presented model and simulation parameters. A comparison with the PLECS simulation results shows that the developed RTDT accurately operates within the 10 kW alkaline electrolyzer’s electrical characteristics. Thus, this setup exhibits the potential to evaluate power electronics converter designs without a physical electrolyzer system.

A novel single-stage LED driver for street lighting application is proposed in this article which combines a totem-pole boost PFC and a non-isolated LCCL resonant network. The converter offers several benefits, including: appropriate total harmonic distortion (THD) level and high power factor (PF) of the input current; reduced conduction losses and suppressed electromagnetic interference (EMI) thanks to its bridgeless structure; zero-voltage switching (ZVS) for the main switches and zero-current switching (ZCS) for rectifier diodes across the entire input voltage range and load conditions; a constant output current to an LED string load due to the LCCL network characteristic at the resonant frequency; and fixed-frequency operation via the main switches duty cycle for regulating the output current. The paper provides a detailed explanation of the proposed driver operating modes and theoretical analysis, as well as a comprehensive analysis of the impact of parameters on DC-link voltage level and main switches voltage stress. A design procedure is also presented. Experimental verification is demonstrated through a 100W prototype circuit operating at 200 kHz.

Switched capacitor multilevel inverter topologies are attractive among industrial power electronics researchers due to their applicability in sustainable energy systems such as renewable energy source (RES) applications. In this paper, a new switched capacitor (SC)-based grid-tied seven-level inverter is proposed for renewable energy sources (RES) applications. The proposed inverter can generate a seven-level output voltage waveform with voltage boosting ability and a gain factor of 3. Also, the proposed topology can provide the self voltage balancing for capacitors. The most important challenge of the SC-based topologies, i.e., the capacitor charging spike current, is solved by applying a soft charging circuit in the charging loop of the capacitors. The soft charging circuit consists of an inductor and a power diode in the capacitor charging path. Using a small size inductor in the soft charging circuit, the proposed inverter can limit the input current spikes. Comprehensive experiment results and comparisons are presented to verify the accurate performance of the proposed inverter.

Quasi-Z source (qZS) multilevel inverters have become popular in sustainable energy systems, particularly in photovoltaic (PV) systems. This study proposes a qZS five-level nested neutral point clamped (5L-NNPC) inverter, benefiting from continuous input current, high voltage gain, and insignificant voltage stress across semiconductors. The proposed topology provides a common ground between the input sources and the inverter's DC link, thus entirely eliminating leakage current, making it a suitable candidate for PV applications. Moreover, model predictive control (MPC) is employed to regulate the voltages of flying capacitors and the output current of the 5L-NNPC inverter. The study also includes analyses of steady-state performance, circuit design, efficiency, and control considerations. Finally, experimental results are presented to validate the converter's performance.

This paper presents an innovative control strategy to enhance the stability of interconnected Microgrids (MGs) with low inertia and high penetration levels of Renewable Energies (REs). The proposed control strategy encompasses a new virtual droop control mechanism that emulates the primary control of synchronous generators for enhanced system stability. Additionally, a weighted Proportional-Integral (PI) controller is used to mitigate the adverse effects of measurement delays caused by Phase-Locked Loop (PLL) dynamics. Furthermore, a feedback integral loop is introduced to improve the efficiency and lifespan of Vanadium Redox Flow Batteries (VRFBs) enabling swift and precise power delivery while reducing steady-state errors. Finally, a new fractional-order virtual inertia control (VIC) is introduced to leverage the fractional derivatives and enhance the system's frequency response. The presented simulation results demonstrate the effectiveness of the proposed control approach in improving the frequency response and power exchange dynamics across interconnected MGs under various operating scenarios.

This article presents a detailed procedure for deriving the generalized average model (GAM) of a dual active bridge converter. The proposed model incorporates higher orders of harmonic components to increase accuracy. Moreover, the turn ratio of the high-frequency transformer (N_t) is considered for realistic modeling, which removes the conventional assumption of unity turn ratio. A detailed model of the DAB will ensure an accurate control design. Required mathematical expressions are derived and explained thoroughly, with an example showcasing a GAM model of the DAB converter up to the ninth harmonics. Several GAM models using different harmonic orders (first, third, fifth, seventh, and ninth harmonics) are derived and compared to the PLECS simulation model and a real-time simulation of the DAB converter on the PLECS RT-Box-2. Results show that including up to the ninth harmonics in the proposed model of the DAB converter leads to achieving accurate voltage and current amplitudes that are almost identical to the simulation outputs and even better than the experimental results.

This article presents a new high step-up quasi-Z-source-based dc-dc converter with switched boost techniques and voltage multiplier cells. Compared with the conventional Z-source-based converters, this converter not only can achieve high voltage gain but also has good efficiency at high output voltage and higher output power conditions. Most of the Z-source-based converters suffer from high current stress across the power mosfets and the operation in lower power. However, the other important advantages include very low input current ripple, low voltage and current stress across the power switches, no duty ratio limitation, and leakage current elimination by providing the common grounded feature. So, in this topology, the null of the output is connected to the negative terminal of the input dc source directly. Therefore, the leakage current can be eliminated completely. As a result, the proposed converter is suitable for renewable energy sources (RESs)' applications, such as photovoltaic (PV) systems. The mathematical analysis, operating principle for the proposed converter, and comparison with other converters are evaluated. Finally, in order to verify the accurate performance of the proposed converter and confirm the mentioned features of the proposed converter, a 1-kW laboratory prototype is built and tested.

This paper proposes a novel sensorless phase-shift modulation-based voltage balancing technique for a 5-level Packed U-Cell (PUC5) inverter. Two phase-shifted triangular carriers are used to modulate the reference signal and generate the appropriate gate pulses. The switching pulse generation is specifically designed to charge and discharge the capacitor at the speed of switching frequency, resulting in a fast voltage balancing of the auxiliary capacitor. Compared with the reported level-shifted modulation method, the proposed technique simplifies comparators and logic gates while keeping the benefit of fast sensorless voltage balancing and, consequently, the capacitor size reduction. In other words, it modifies the reference signal to achieve the fast voltage balancing of the auxiliary capacitor in PUC5. Simulation results are shown to investigate the effectiveness of the proposed technique.

In this paper, a Reinforcement Learning controller (RLC) is designed and implemented on a 5-level Packed U-Cell (PUC5) grid-connected inverter to control the injected current flowing into the electric network.The RL agent is trained using a Proportional-Integral (PI) reward function to optimize its control strategy. Moreover, the voltage balancing of the auxiliary capacitor in PUC5 is separated from the RL controller and integrated into the switching algorithm to reduce the training burden. This modification reduces the observation inputs required for RL training, significantly shorten the training time. Simulation studies conducted in Matlab/Simulink evaluate the performance of the proposed RL controller, demonstrating robust dynamic response and accurate tracking of reference signals across different operational conditions.

Power electronics converters (PEC) play a crucial role in interfacing renewable energy systems and electrolyzers to ensure a high production yield of green hydrogen. The design of such PEC is not straightforward due to the safety hazards of using multiple electrolyzer stacks and converter modules at industrial levels. Therefore, real-time simulations should be conducted to ensure the converter design satisfies all the requirements before deploying it on-site. This paper presents a real-time digital twin (RTDT) of a 10 kW dual-active bridge converter interfaced with an electrolyzer. OPAL-RT simulator (eHS toolbox) is used for RTDT. Finally, the voltage across the series inductance and current flowing through it are presented for the open-loop operation of DAB.

Electrolysis requires a high DC current at low voltage to produce hydrogen from water. Designing power converters for such a load requirement could be challenging while fulfilling the galvanic isolation needs. Therefore, prior knowledge of the electrolyzer's impact on the converter operation should be needed. In this context, this paper investigates the behavior of the Dual Active Bridge (DAB) converter when utilized for electrolysis. A MATLAB simulation of DAB with a 10 kW alkaline electrolyzer is developed. Several converter parameters, such as the phase shift angle, series inductance, peak and RMS currents, and voltage gain, are analyzed during electrolysis. Distinct operating behavior is observed from the analysis.