This work introduces a six-level flying capacitor-based converter (6L-FCB) tailored for three-phase systems operating from a single DC source. The proposed structure overcomes key drawbacks of traditional multilevel designs, including dependence on multiple isolated sources, auxiliary voltage-balancing hardware, and excessive device counts. Each phase incorporates four flying capacitors, with voltage balance maintained through an optimized switching-state selection scheme that operates without additional circuitry. The control employs a level-shifted carrier PWM method combined with a priority index mechanism that exploits phase current polarity to regulate capacitor voltages. This strategy enables straightforward implementation while delivering high-quality output voltages with low harmonic distortion. Comparative analysis against existing six-level alternatives highlights the performance and hardware advantages of the proposed design. Simulation studies confirm the robustness of the modulation and balancing methods across various load and modulation index conditions.

Among multilevel topologies, flying capacitor (FC)-based converters stand out for their modularity, self-voltage balancing features, and fault-tolerant operation. However, conventional FC converters require multiple capacitors per phase, increasing hardware complexity and control effort. To address this, a four-level single flying capacitor (4L-SFC) converter is proposed in literature, which reduces the number of capacitors to one per phase without sacrificing output quality. The major challenge of this simplified topology lies in the absence of redundant switching states, which restricts voltage balancing flexibility. To overcome this, a Virtual Space Vector Modulation (V-SVM) technique is developed. By synthesizing virtual vectors through weighted combinations of space vectors, the method ensures zero-average capacitor current over each sampling period, enabling effective voltage balancing. The V-SVM algorithm divides each space vector sector into triangular regions and maps reference vectors to optimized switching sequences, ensuring stable flying capacitor voltages, improved switching loss distribution, and low voltage ripple.

This paper presents a three-phase seven-level nested switched-capacitor (7L-NSC) inverter that incorporates two symmetrical flying capacitors per phase, each rated at one-third of the DC-link voltage. To ensure reliable operation across all conditions, a finite control set model predictive control (FCS-MPC) strategy is employed. This control approach leverages redundant switching states to maintain accurate current tracking and ensure effective voltage balancing of the flying capacitors. A detailed mathematical analysis of the inverter, including capacitor voltage ripple behavior under both steady-state and transient conditions, confirms the robustness of the proposed control method. The performance of the control strategy is validated through comprehensive simulation studies in PSIM and verified by experimental testing using a laboratory-built prototype. Results from both simulations and hardware experiments demonstrate the method’s capability to maintain low THD and stable capacitor voltages, confirming its suitability for advanced multilevel inverter applications.

The global push for net zero emissions (NZE) by 2050 has accelerated the adoption of electric vehicles (EVs), supported by rapid advances in lithium ion battery (LiB) technologies, supportive policies and market incentives. Despite progress in addressing challenges such as high costs and range anxiety, the limited lifetime of LiBs remains a critical barrier to widespread EV adoption. This paper explores time-varying current (TVC) charging strategies, particularly pulse current charging (PCC), as promising alternatives or complements to the conventional constant current-constant voltage (CC-CV) method. It reviews recent trends in EV adoption, LiB chemistries, and state-of-health (SoH) estimation methods, including experimental, adaptive, and data-driven approaches. The analysis highlights the potential of PCC strategies to extend battery lifetime, enabling opportunities in vehicle-to-grid (V2G) services and shared mobility systems. By addressing current challenges and leveraging these opportunities, TVC charging methods offer promising solutions to extend the useful life of LiB and support a sustainable and decarbonized transportation ecosystem.

textit-The ability of Dual Active Bridge (DAB) converters to provide isolated, bidirectional power conversion offers distinct advantages over traditional converters, making them ideal for Vehicle-to-Grid (V2G) applications. Effective power regulation in such applications requires advanced modulation techniques. This paper proposes an innovative dual-phase shift strategy for DAB converters to enhance active power transfer and efficiency. Through analytical modeling and simulations, this approach demonstrates improved performance in managing bidirectional power flow. The results confirm its alignment with prior research, underscoring its potential for scalable and efficient energy systems. Specifically, the proposed Analytical Dual-Phase-Shift (ADPS) method derives closed-form expressions for optimal phase shift angles, minimizing reactive power and ensuring Zero-Voltage Switching (ZVS) across all bridge legs under light-load conditions. Compared to conventional single-phase and dual-phase shift methods, ADPS achieves a reduction of up to 12% in reactive power and an improved power factor without increasing control complexity. Simulation results validate the effectiveness of the approach, making it a promising solution for high-efficiency DAB control in modern DC-DC power conversion applications.

The four-level single flying capacitor converter (4L-SFC) is an efficient topology for medium-voltage applications, offering a reduced component count over traditional four-level flying capacitor converters. However, maintaining balanced capacitor voltages is a key challenge in this topology, which is critical for stable and reliable operation. In this paper, an active voltage balancing method for 4L-SFC converters is presented, using a straightforward algorithm to adjust voltage levels in response to real-time measurements of capacitor voltages and phase currents. As a result of the proposed method, capacitor voltages remain balanced across a wide range of modulation indexes and operating conditions without significantly increasing switching frequency. Simulation results have demonstrated the effectiveness of the proposed approach, demonstrating that it is capable of maintaining stable capacitor voltages.

Renewable energy sources (RES) such as solar photovoltaic (PV) are employed in electric vehicle (EV) charging stations to promote sustainable transportation and reduce the load on the AC grid. This paper introduces a modular power converter topology that interfaces with solar PV, EV batteries, and the AC grid. The proposed topology supports EV battery charging in two modes: DC/DC (from PV modules) and AC/DC (from the AC grid). Additionally, during peak hours, EV batteries can function as energy storage units (ESUs) in vehicle-to-grid (V2G) mode. A central element of the proposed topology is the submodule (SM), which is implemented as a single-stage isolated bidirectional Cuk-based converter. This converter is chosen for its exceptional features, including high efficiency and inherent power factor correction (PFC) due to continuous input and output currents. The paper first details the operating modes of the Cuk-based SM. To improve performance, an extra switching state is added in the AC/DC (rectifier) mode, enabling the second-order harmonic from the AC grid to be stored within the Cuk SM instead of being passed to the battery. Additionally, power losses at the SM level are examined, and the effectiveness of the proposed topology is demonstrated through experimental results.

One of the main challenges of the NPC topology in high-power applications is to balance the power losses of the switching devices. This paper proposes a modulation method for loss balancing among main switching devices of the NPC converter. The concept of the proposed modulation scheme is based on reconstructing the middle voltage level of each phase by a linear combination of other voltage levels. By applying the proposed modulation scheme, the power losses of switching devices are balanced. However, an added feature of the reconstructed voltage levels is that its implementation results in lower neutral point current over one sampling period. The proposed scheme retains the merits of NPC topology such as the dv/dt of output voltage and dynamic voltage sharing of the switches. In addition, due to reduced rms current of the dc capacitors in the proposed scheme, the use of bulky and large capacitors is avoided. Simulations and experiments are presented to demonstrate the effectiveness of the proposed modulation method.

This paper investigates the control of the Modular Multilevel Converter (MMC), a versatile converter topology. The MMC offers advantages such as modularity, scalability, and fault- tolerance capabilities. To address the challenges of controlling the MMC, various methods including Model Predictive Control (MPC) have been proposed. This paper focuses on online weighting factor selection for MPC in Direct MPC and Indirect MPC and emulating these control techniques with neural network controllers. Dynamic equations of the MMC considering a novel method for including the discrete-time common model voltage are derived, and direct MPC (DMPC) and indirect MPC (IMPC) with online weighting factor selection are implemented. Auto-tuned DMPC and IMPC are used to extract data for training neural networks, which emulate the auto-tuned MPC controllers.The optimal neural network structure is selected and trained. Comparisons of steady-state and transient performance among auto-tuned DMPC, IMPC, and neural network-based controllers reveal that neural network-based controllers perform similarly to conventional auto-tuned MPC controllers, but with reduced computational burden. These controllers exhibit improved robustness to parameter mismatches and unpredictable converter performance, indicating their potential as viable replacements for conventional auto-tuned MPC controllers in MMC control, offering enhanced efficiency and reduced calculation burden.