Accurate steady-state modeling is essential for power converter design. A growing class of converters uses all active switching (no diodes), including the dual active bridge, resonant DAB, and wireless power transfer (WPT) systems. The use of all active devices presents an opportunity for rapid frequency domain analysis. The conventional first harmonic approximation (FHA) methods lack accuracy, even in some resonant converters, while time-domain models are computationally intensive and topology-specific. This paper presents a fast Fourier transform (FFT)-based steady-state simulation method that enables fast and accurate prediction of steady-state waveforms, output power, and zero-voltage switching (ZVS) conditions for various topologies. Validation against Simulink, PLECS, and experimental results show that the proposed method achieves over 100× faster computation while maintaining high prediction accuracy.

This work presents a dynamic phase control method for a multiphase modular buck converter aimed at applications aiming for zero downtime, such as data centers. A key feature of the work is that the converter design has a switchable modular power stage that can be installed or removed while the converter is still operating. This allows converters to stay online while a sub-module can be repaired or upgraded to higher power. To achieve this, a control strategy has been developed that allows for an arbitrary number of converter phases that dynamically adapt to different numbers of phases.

An isolated flying-capacitor (FC) based, quasi-resonant (QR), hybrid step-up converter topology capable of producing voltage conversion ratios exceeding 50x, while maintaining relatively high-power processing efficiency at sub-1W power levels, and a complementary mixed-signal controller are presented. By resonantly charging and discharging a small flying capacitor on the secondary side, through a specific control scheme: (a) load-independent soft-switching is achieved on all the switches on the secondary side, (b) volage stress across the primary switch has been reduced to just the input voltage, (c) operation independent of input-to-output voltage conversion ratio. With significant reduction in switching losses, and isolation, the converter is well suited for low-power applications, where switching losses would otherwise be dominant. The operation of the converter is experimentally verified using a discrete prototype with input voltages 3 V to 3.6 V, output voltages up to 300 V, and output power as low as 50 mW.

This paper presents a novel control technique, Integral Cycle Mode (ICM), for RF inverters used in plasma generation applications. Conventional control methods such as phase-shift, DC voltage, and frequency control, face trade-offs between dynamic response, soft-switching range, and system complexity. The proposed ICM method achieves fast dynamic performance comparable to phase-shift control while ensuring soft-switching across a wide load range through maintaining inductive load operation and frequency tracking. This approach eliminates the need for additional hardware or complex interleaving schemes. The effectiveness of ICM is validated through both simulation and experimental results, demonstrating its potential for semiconductor process.

Series-input, parallel-output power converters are an effective solution for applications requiring high energy density and large conversion ratios. Hybrid switched-capacitor topologies are a compelling alternative to the traditional magnetics-based topologies commonly used in stacked converters. One required feature of these series-input, parallel-output converters is the ability to achieve electrical isolation between the input and output grounds. Capacitor-based isolation enables low passive volume, indicating the potential for use in weight- and volume-constrained application spaces. This digest presents a capacitively-isolated variant of the series-parallel hybrid switched-capacitor converter capable of at- and above-resonance operation. Generalized equations for the mid-range voltages of the flying capacitors and phase duration equations are provided. Experimental results of a prototype of the 4:1 capacitively-isolated series-parallel converter validate the analysis.

This digest presents a novel full-state feedback (FSF) controller for compensating changing coupling variations in dynamic capacitive wireless power transfer (WPT) systems utilizing an active variable reactance (AVR) rectifier. The AVR rectifier enables continuous compensation, allowing the WPT system to maintain high-efficiency power transfer at a fixed frequency by appropriately distributing power between its two branches. Conventional PID control approaches are suboptimal for the AVR rectifier due to the higher-order system dynamics, nonlinearities, and cross-coupling between control loops. In contrast, the FSF control strategy presents an optimal and robust way to control higher order multi-input multi-output systems like the AVR rectifier. A state-space model is developed for the AVR rectifier, and the FSF controller is designed based on this model. To validate the proposed approach, a 13.56 MHz 100-W capacitive WPT system with an AVR rectifier is built and tested. The controller’s effectiveness is demonstrated through both simulations and experiments on the hardware prototype.

All magnetic components have parasitic capacitance that limits performance. This work derives closed-form mathematical expressions to model parasitic capacitance and applies them in a multi-objective optimization method to assess design trade-offs in toroidal inductors with single-layer windings. The model is validated through Finite Element Analysis (FEA), showing good agreement.

Dynamic capacitive wireless charging enables electric vehicles (EVs) to charge in motion, eliminating range limitations, charging time, and reducing EV costs with smaller batteries. This digest explores cost, weight, and size reductions in capacitive charging pads to enhance adoption. First, alternative coupling plate materials and thicknesses are examined to lower cost and weight. Additionally, optimizing the dielectric layer with strategic cutouts further reduces these factors. The proposed design achieves a 41% cost reduction, 76% weight decrease, and 37% height reduction while maintaining performance. Finally, two 6.78-MHz 12-cm air-gap 1-kW prototypes validate the effectiveness of these optimizations.

This paper presents a mathematical formulation of the Photovoltaic Exponential Model (PVEM), which describes the electrical characteristics of photovoltaic (PV) modules. In the paper, the PVEM is derived from fundamental physical principles and known boundary conditions while balancing mathematical rigor and clarity. The study demonstrates the PVEM's practical utility by deriving through the model an analytical solution for the maximum power point (MPP) using the Lambert W function, a significant departure from traditional numerical methods. This work also provides an analysis of the elusive characteristic constant 'b', clarifying its existence and impact on the MPP by demonstrating plots with differing values of 'b'.

This digest discusses the reverse power flow issue in wireless battery charging for drone applications. The charger, which incorporates an active rectifier at the receiver end, is susceptible to reverse power flow during the constant voltage charging mode. To resolve this, a cascaded Constant Current (CC)-Constant Voltage (CV) control approach is employed. The charger is designed for a 6S LiPo battery pack, consisting of six series-connected cells, with no cell voltage balancing circuits. The proposed control scheme monitors the voltage of each cell and ensures that the appropriate charging mode is selected to avoid overcharging any single cell. The sensing, monitoring, and control mechanisms are detailed with relevant simulation and experimental results for a 200 W wireless charger

This digest presents the design and implementation of a closed-loop control to synchronize the switching actions of an active rectifier (AR) on-board the receiver of a wireless drone charger with the offboard transmitter induced magnetic field. A discrete time model of the wireless drone charger is used to model the synchronization dynamics. A compensator is designed to achieve stable performance over the full load range. The synchronization controller is designed to achieve a stable transition from passive to active rectification, and to reduce susceptibility to noise. To validate the control design, a GaN-based prototype is constructed and stable startup and low-noise synchronization experimentally demonstrated.

The integration of energy storage into renewable energy systems helps address the growing demand for electricity and the intermittency of power generation. Incorporating batteries into photovoltaic microinverters improves grid power stability but increases system complexity, requiring a bidirectional DC-DC converter for efficient battery management. This study compares the strategies between switching frequency control and charge control for bidirectional CLLC resonant converters to enable rapid battery charging/discharging transitions.

This paper proposes a specialized design for inductively-coupled-plasma generator without matching-network. Plasma’s nature, negative-differential-resistance, and soft-switching of DC-AC converters are considered with extensive comparisons of circuit topologies. Voltage-driven series-resonance frequency-tracking scheme showed great suitability.

This paper introduces a novel curvature-based ripple correlation control (RCC) technique for maximum power point tracking (MPPT) in photovoltaic (PV) systems. RCC has become a prominent MPPT method due to its straightforward implementation, high accuracy, and quick asymptotic convergence. It effectively tracks the maximum power point (MPP) of PV systems amidst swift changes in solar irradiance and temperature. The curvature of the power-voltage curve provides essential insights into the power output behavior of PV panels in response to voltage fluctuations. Specifically, the curvature offers a critical indication of the system's proximity to the MPP. This information is crucial for optimizing the control gain of the RCC to enhance both dynamic and steady-state performance. Simulation and experimental results corroborate the theory proposed in this paper and validate its contributions.

Classic control system approaches sometimes lack a transparent and convenient process. The designer needs to simultaneously observe multiple criteria including stability, stability margins, transient response indices, and steady-state errors. The approaches based on state-space models, on the other hand, suffer from lack of a systematic procedure to choose closed-loop poles, or to choose optimal control weight matrices. This paper presents a control structure and a design procedure to address these issues. The proposed approach is applicable to both single-input single-output (SISO) and multi-input multi-output (MIMO) control systems. It system enjoys systematic design and robust performances with controlled transient responses.

Accurate loss data is necessary for effective magnetic component design and evaluation – both of complete components and of core materials. While automated systems are available for core loss characterization at sub-MHz frequencies, existing resonance-based measuring methods for higher frequency characterization are labor intensive, typically relying on Fast Fourier Transform (FFT) and requiring human supervision to locate resonant points. In this paper, an integrated automated measurement system is proposed to eliminate dependence on FFT computations and manual adjustments to evaluate core losses in high-frequency magnetic components within seconds. The system uses high-frequency conditioning circuits to extract the magnitude and phase information of signals of interest. An embedded microcontroller in the system executes real-time algorithms to reach resonant points and collect core-loss-related data. The automatic test results on MHz magnetic materials align with datasheets, thus verifying the effectiveness of the proposed system.

Accurate magnetic modeling at high frequencies is critical for designing compact, high-efficiency power electronic converters. Previous work developed a physics-based core loss model using the Landau-Lifshitz-Gilbert (LLG) equation to analyze nonlinear magnetic properties, including core loss and permeability variations. In this study, the hethe spherical form of the LLG equation is employed, significantly reducing computational effort compared to the cartesian formulation. Furthermore, precessional motion is eliminated by simplifying the full LLG equation to a reduced LLG equation, where only the dθ/dt term is retained, and dφ/dt=0 is enforced. As a result, the model in this paperThis resulting model focuses solely on magnetization switching, which governs hysteresis behavior. The findings in this work are based on a single-domain model, demonstrating the effectiveness of the simplified LLG equation in preserving magnetization reversal behavior. Future work will aim to extend this approach to macroscale core loss modeling.

Hysteretic current control (HCC) of the inductor current in switched-mode power converters enables fast and direct control and requires high bandwidth isolated current sensing. However, analog-isolated Hall or TMR sensors consume a high power (typ.: 15 mW at 1.5 MHz). This work presents a digitally isolated HCC circuit using a shunt resistor, differential amplifier and two comparators with selectable reference values. A 1.2 MHz bandwidth HCC circuit was built and applied to a half-bridge converter, consuming only 2.3 mW during operation (from which 1 mW are from an isolated 5 V power supply).

This paper presents an analysis of phase current ripple and output voltage ripple in a multiphase full-bridge inverter employing air-core magnetics. Various phase winding configurations with different extents of coupling and parallel interleaving are investigated. We demonstrate the potential for significant phase current ripple reduction by optimal selection of both the coupling coefficient and the relative phase shifts between phase windings. The proposed approach is experimentally validated on a four-phase, 2 MHz hardware prototype.

This digest presents the design of a Class-E power amplifier invariant to load changes for inductively heating a fluidized graphite bed. Experimental power output of an initial Class-E design was limited to 25 W by high conduction losses due to high input currents from driving a resistive load less than 5 Ω. A new design developed according to the temporal load impedance profile uses load transformation to both minimize input current and compress output network reactance. Thus, this digest presents simulation results of a 60 V 13.56 MHz amplifier with a maximum power of 125 W delivered to the load.

The development of future electric vehicles depends on high-performance power electronics. Aircraft require lightweight hardware with extreme efficiency, while volumetric density is important in traction applications. This work presents the design process of a flying capacitor multilevel inverter intended for lightweight, low-inductance electric machines. A detailed loss model is developed which includes the impact of flying capacitor voltage ripple. Along with a volume estimation framework, this enables multi-objective optimization to assess the impact of various design parameters. Key findings from the optimization are summarized. To validate this analysis, a 10-level FCML GaN-based hardware prototype is designed and fabricated, which is optimized for maximum power density. An innovative 3D-stacked layout is utilized, which makes efficient use of volume. This inverter achieves an unprecedented 800 kW/L volumetric power density and 250 kW/kg gravimetric power density, along with a peak efficiency of 97.34 % and THD < 5 %.

Dual Path (DP) DC-DC converters use a parallel switched-capacitor (SC) branch to reduce DC current in the inductor. Past work has motivated the approach based on a stated advantage of being able to reduce overall loss while using relatively low quality (high resistance) inductors. This work explores a range of operating scenarios under which such claims are valid. We develop a unified model for all four 2:1 SC-based DP converters that factors in SC charge sharing loss, voltage and current ripple, and fixed-volume inductor scaling. We develop a set of constraints and criterion to compare the 2:1-based DP topologies to the conventional 3-level buck (3LB) converter to establish regimes where the DP value proposition is justified.

Load independence ensures stable output voltage or current and efficient power transfer across varying load conditions. Resonant converters leverage resonance to achieve this, making them ideal for such applications. This work presents general mathematical models for an n-mesh voltage-fed $T$ network, describing the transadmittance between any self-mesh current and input voltage. We derive general and particular solutions for even- and odd-numbered mesh networks, demonstrating that both can exhibit current- or voltage-source characteristics under suitable conditions. This systematic approach enables the design of resonant converters with tailored output characteristics. The results are validated through a 4-mesh voltage-fed DS-LCC wireless power systems.

Electrical converters are becoming increasingly important. Especially if galvanic isolation is required, resonant converters are among the most often used converters. Many models are obtained using Fundamental Harmonic Approximation, Generalized Averaging Method and Extended Describing Function methods. It is in the nature of these techniques that, with increasing accuracy requirements, the model’s order increases and thus becomes more complex. To remedy this shortcoming, the following contribution presents a second order, discrete time, control oriented model for CL(L)LC Series Resonant Converters. Due to the model’s simple structure and its applicability below as well as above resonance frequency it can be used in a wide range of applications.

This digest presents the design of an isolated full bridge DC--DC converter for converting a battery input (< 20 V) up to an output of 25 kV DC. The converter features a parallel voltage multiplier designed using custom high-voltage capacitors. A prototype (weight: 6.75 oz., volume: 7.5 in.^3) is presented along with experimental results under open-circuit conditions. This supply functions as a subcomponent of a larger DC supply (for future publication) which combines four parallel-driven 25 kV supplies, connecting their outputs in series to achieve a 100 kV DC output enabling the design of compact, lightweight neutron generators.

This work proposes and analyzes a capacitively-isolated resonant dc/dc converter employing a flying capacitor multilevel (FCML) bridge leg to achieve a high step-down ratio. Limits on the maximum permissible isolation capacitance are identified through analysis of the constraint of touch current. Additionally, the FCML bridge leg is operated under zero-voltage switching, allowing operation at switching frequencies up to 1.3MHz. A 380V to 47V hardware prototype utilizing class Y2 safety capacitors is constructed and tested to a maximum output power of 680W.

This paper presents a multiloop predictive control strategy for the Dual Active Bridge (DAB) converter, designed to achieve a fast dynamic response for both inductor current and output voltage. The proposed controller consists of an inner predictive current loop based on enhanced single-phase shift (ESPS) modulation using peak current sampling and an outer voltage loop that generates a reference for the current loop. A voltage disturbance observer is employed to estimate and compensate for the lumped disturbance, eliminating the need for a load current sensor. The performance of the proposed controller is validated through experimental results.

This paper introduces an efficient algorithm that enables designers to quickly generate capacitor configurations and switch control signals for multi-phase Fibonacci converters. The algorithm provides a systematic approach, bridging the gap in existing methods and facilitating the practical implementation of high conversion-ratio SC converters. Measurement results of various experimental converters with two to six phases and up to five flying capacitors confirm the algorithm’s validity and practical applicability.

This paper proposes a model reference correction method for discontinuous current mode (DCM) grid-tied inverters to improve average current regulation and zero-voltage switching (ZVS) accuracy. The method addresses errors due to deviations in the inductor value in the control system and their impact on the grid-side current. By integrating grid-side current data with a DSP-based valley sensing module, these errors are detected, enabling model reference correction. This approach reduces the need for precise circuit parameter knowledge, simplifying the design while maintaining high performance.

This paper proposes a passivity-based control method for an IPM motor drive system to ensure stability. The proposed method is based on the design of an additional feedforward (FF) compensation loop, which makes the frequency characteristics of the DC input impedances resistive or passive. The method utilizes an extended small-signal IPM model and analytical expressions considering FF compensation. Frequency characteristics of the proposed method by the impedance method are investigated and assured to be passive. The system stability is validated analytically and experimentally.

Miniaturization and performance enhancement of single-phase ac/dc power electronic converters is challenging owing to commonly employed multi-stage conversion and dc regulating buffer capacitors. The recently proposed harmonically partitioned power converter (HPPC) enables minimum energy storage sizing of the buffer capacitor, unity power factor operation, galvanic isolation, and dc output voltage regulation within a single conversion stage by leveraging bidirectional switches (BDS) and transferring power through a high frequency ac tank rather than a dc link. This work presents an analytical power loss model for the bidirectional switches employed in a single-branch HPPC which considers the time-varying phase shift between currents carried and voltages blocked by the BDSs.

Modular Multilevel Converters (MMC) have gained popularity for high power integration. In the same domain of applications, energy storage (ES) integrated MMC system is used to provide grid ancillary services involving voltage and frequency regulation. Offshore wind power has made a major contribution to the grid renewable power generation. The grid integration of offshore wind energy poses two major challenges. One of them is the requirement of voltage-frequency regulation at point of common coupling (PCC) and secondly, harvesting active power to compensate for fluctuations in wind power. The ES-STATCOM based MMC system caters to these challenges and enhances grid reliability by enabling active power compensation for peak loads. This paper defines the stable operating region of ES-STATCOM and based on that proposes grid forming control to integrate offshore wind power. The proposed control architecture is validated in a test system environment through a Real-Time Digital Simulator (RTDS) and Virtex 7-based FPGA controller in a Control Hardware-in-Loop (C-HIL) environment.

Oceans can provide great potential for the American energy dominance. There is significant potential to utilize marine energy resources. In the United States, the total amount of marine energy available is equivalent to about 57% of the country's total power generation in 2019. Even if a fraction of this technical potential is harnessed, marine energy technologies could play a crucial role in fulfilling the nation's energy requirements. Marine energy resources are spread out geographically, and because more than 50% of the United States' population resides within 50 miles of the coastline, they are well-positioned to power local communities. These resources are also very dependable, making them a viable option for contributing to a consistent, trustworthy energy grid. Due to their predictable

With the growing number of retired electric vehicle batteries, the second-life battery energy storage system (2-BESS) has attracted significant research attention due to its cost-effectiveness and environmental benefits. This paper proposes a battery-integrated cascaded H-bridge (BI-CHB) 2-BESS architecture equipped by a hierarchical partial power processing (HiPPP) network, effectively addressing the challenges posed by second-life battery (SLB) heterogeneity. The proposed HiPPP network is designed based on a novel statistical framework integrating multivariate distribution flattening and mixed-integer linear programming (MILP). The study reveals a new trade-off frontier among active power capability, reactive power capability, and energy utilization. Importantly, the HiPPP network significantly improves the power-energy trade-off and demonstrates robust reactive power injection capabilities, essential for voltage support in grids with high renewable penetration. Moreover, the HiPPP network effectively mitigates the adverse effects of SLB heterogeneity, enhancing reliability and reducing uncertainty in the output power of 2-BESSs.

This research focuses on the development of an ultra-compact and high-efficiency Quad-Active-bridge (QAB) DC-DC multiport converter, which can be used to interconnect PV panels, battery energy storage (BES), and electric vehicles (EVs) with a DC distribution grid. The emerging Gallium Nitride (GaN) switching devices are utilized to achieve high switching frequency, higher efficiency, and high power density. Additionally, a multi-winding planar transformer is employed in the QAB converter to provide galvanic isolation and couple different power ports for flexible power management. Single-phase shift (SPS), Extended-phase shift (EPS), and Dual-phase shift (DPS) modulation strategies are investigated and compared to regulate the power flow in various operating modes. Electro-thermal modeling and simulation of the QAB converter are conducted, and a 15kW GaN-based QAB converter prototype is developed for experimental validation.

Realizing modular multilevel versions of single-stage converters for single-phase AC to DC applications is particularly challenging due to the need to manage twice the line-frequency power. This power must be buffered by internal energy storage elements, which can lead to significant energy storage requirements being imposed on the converter. An additional challenge is ensuring smooth transitions when the grid voltage polarity reverses every half cycle. In this digest, a novel self-balancing single-stage modular multilevel converter is proposed that can scale based on the voltage and therefore is suitable for distribution-level applications. This structure leverages submodules that feature two half-bridges connected in an anti-series arrangement. The converter is operated such that the submodule dc-link voltages naturally follow the grid voltage. The topology shares a similar energy transfer mechanism as the dual active bridge converter for DC-DC applications. This digest introduces the topology, discusses key operating principles and provides transient simulation results for a representative application. The full paper will provide experimental results using a laboratory-scale prototype.

In this article, the design and characterization of a 1200 V, 200 A rated printed circuit board (PCB) embedded silicon carbide (SiC) MOSFET half-bridge are being presented. The layout of the power module has been optimized to reduce the power loop inductance, achieving a 2.1 nH of power loop inductance. The dimensions of the fabricated module are 48 mm x 32 mm (L x B), with thickness being 0.35 mm, leading to a reduction of 57% in footprint and a reduction of 95% in volume compared to commercially available half-bridge SiC MOSFET power modules of 1200 V, 200 A with GM4 package.

An analytical model of the bidirectional AC-AC Dual Active Bridge (DAB) converter is developed. Since the AC-AC DAB converter has grid, switching, and side-band harmonics, it cannot be modeled using the traditional Generalized Average Method (GAM), which deals only with one frequency and its harmonics. A proposed sixteenth order continuous-time EGAM model that considers the aforementioned harmonics is derived. Validation again PLECS has been provided to highlight model accuracy.

A DC transformer (DCX) is a DC–DC converter that operates at a fixed voltage conversion ratio, enabling optimized design. The Series Resonance Converter (SRC) operating in Discontinuous Conduction Mode (DCM) is commonly used as uncontrolled DCX. However, it cannot support bidirectional power flow and suffers from high losses under light-load conditions. This digest explores the use of a Dual Active Bridge–SRC (DAB-SRC) topology, where both bridges are active and switch symmetrically and at near series resonance frequency to achieve ideal bidirectional DCX operation. It is observed that the topology inherently compensates for any resonance mis-tuning arising from practical non-idealities - through counterbalancing effects during the dead time. This work investigates and models this physical phenomenon in detail, and predicts the minimum dead time required for stable operation as a function of resonance mis-tuning. These developed models would be useful for designing an SRC to operate as a bidirectional, uncontrolled DCX that is tolerant to resonance mistuning.

The increased popularity of the flying capacitor multilevel (FCML) converter, as well as the use of wide-bandgap devices in this topology has opened up a number of questions around conducted electromagnetic interference (EMI). Common- mode EMI is generated by parasitic capacitances throughout the circuit and the currents arising through them as a result of large dv/dt switching events. The mechanisms by which the FCML converter generates conducted common-mode EMI is an under- explored area of research, despite the critical nature of EMI. This paper proposes modeling a lumped parasitic capacitance for each switch to understand how common-mode currents are generated in multilevel operation. Common-mode EMI scaling behavior from first principles for an FCML converter are derived, and hardware validation with a 6-level converter prototype provides concrete evidence in both the time and frequency domains that the level of modeled detail is sufficient to capture power-stage CM behavior for this converter topology.

Power converters in automotive applications generate high-frequency switching voltages and currents that act as primary noise sources, producing electric and magnetic dipoles, responsible for radiated emissions. Identifying these sources in the near-field region remains challenging. This digest models the critical near-field magnetic and electric emissions caused by the switching transients of a SiC MOSFET in a DC-DC half-bridge converter. Experimental validation is performed by measuring near-field emissions from the converter, providing insights into the dominant radiated noise sources and their type of emission(s). The full paper will extend the modeling and near-field measurement to single and three-phase power converters.

Serial-connected photovoltaic (PV) power systems are commonly used for renewable energy generation. However, partial shading on PV panels can cause significant power losses. To address this issue, differential power processing (DPP) structures can be implemented to improve the overall efficiency of the PV system. The topology used in this work is a split-inductor boost converter used to control three series-connected PV submodules. In this work, we propose a discontinuous conduction mode (DCM) switching scheme for this DPP converter architecture that allows for the current through each inductor to be different. Simulation results demonstrate that the proposed switching scheme enables the PV system to operate close to its theoretical MPP, similar to existing DPP converter architectures but with fewer components.

This paper proposes a cost-effective wave energy harvesting system for grid-forming applications using a permanent magnet synchronous machine and a Lyapunov-based controller for torque and speed regulation. A battery-capacitor dc bus enhances reliability under low wave conditions by supporting load power delivery. On the consumer side, a similar control architecture ensures low total harmonic distortion in output voltage under unbalanced or nonlinear loading. The overall system is designed to maintain operational efficiency and reliability across varying wave conditions. System performance is validated through simulations in MATLAB/Simulink and PLECS, with additional experimental and real-time case studies reserved for the final version.

In power converters, active device losses are distributed between switching and conduction loss, which scale in opposite directions with transistor gate width. Focusing on GaN devices, this work describes the relationship between device losses, parasitic, and size, and a simple analytical size optimization is performed to minimize the overall losses. Additionally, the results of this optimization are related to common transistor figures of merit, and an approach to discrete device selection is provided. Simulation and experimental results are presented for GaN-based 50 W buck and hybrid switched capacitor converters.

In this paper, a new approach is presented to derive the equivalent average circuit for modeling the power stage of a pulse-width-modulated switching converter operating in continuous conduction mode. First, the power stage line transfer function is derived using the basic state-space averaging model. Subsequently, this line transfer function is transformed into an equivalent average circuit using the time- and transfer-constant-based circuit synthesis technique.

The precision of the proposed method is verified by SIMPLIS simulation results for the traditional buck, boost, and buck-boost topologies, as well as modern hybrid topologies. In addition, the proposed methodology for deriving the equivalent average circuit is shown to be compatible with both conventional inductive-type and modern high-order hybrid-type DC–DC converters.

Efficient modulation of radio-frequency (RF) power can be challenging in applications with varying load impedance. Conventional solutions often use multi-stage systems to achieve the required wide power range and load range. However, these approaches can be complex, costly, and inefficient. This digest presents an approach for designing a wide-range current-mode Class-D (CMCD) inverter as a single-circuit alternative to these multi-stage systems. The proposed topology has a simpler architecture and achieves a comparable power and load range while potentially improving overall efficiency. Key design trade-offs and considerations are also discussed.

This paper proposed a new grid-forming control scheme for operating grid-interfaced PV inverters as black-start resources. Compared with the generic PV control proposed by the Western Electricity Coordinating Council (WECC) and the traditional voltage regulation control, the proposed control shows eminent advantages: i) it is applicable to handle large black-start transients, such as transmission line energizations and load pick-ups; ii)it can be simulated with great fidelity of inverter dynamic behaviors; iii)it features grid-side frequency and voltage regulation functionalities, which enhance the system stability in the power restoration process. Simulation results based on a 5-bus PV-interfaced black-start testbed are provided for verification purposes

This paper presents a novel two-stage optimization strategy to improve efficiency in active cell balancing for high-voltage lithium-ion battery packs. The proposed method utilizes a linear programming formulation, the Transportation Problem, to optimize charge redistribution, thereby minimizing conduction losses and balancing duration. Additionally, principles from Graph Theory, particularly Eulerian Paths, are used to reduce switching losses. In contrast to conventional rule-based controllers, the proposed algorithm achieves faster balancing, fewer switching events, and improved efficiency. The results demonstrate considerable improvements in balancing performance, reducing inefficiencies typically associated with high-voltage battery packs.

Stealth cyber intrusions in networked DC microgrid (DCMG) clusters employing primary droop control can severely impact system stability while remaining undetected. While significant efforts focus on strengthening cybersecurity, understanding the direct effects of such intrusions on microgrid dynamics is equally critical. This paper analyzes the stability of parallel-connected DCMG clusters under stealth cyber intrusions of varying intensities. The intrusion is modeled as a non-linear and discontinuous input, capturing the strategic disruption of the behavior of the system by the adversary. A small-signal model of the affected DCMG cluster is developed, and stability is assessed using the quasi-linearization method. The analysis reveals that even with droop-controlled power sharing, stealth cyber intrusions can introduce instability, leading to performance degradation and potential system-wide failures. The simulation results are presented to validate the theoretical findings, highlighting the vulnerability of DCMG clusters to covert cyber threats.

This paper describes a three-phase soft-switching traction motor drive with a sinusoidal output voltage. A variable-frequency control algorithm is developed to achieve soft-switching at all operating points. This is done using current ripple generated in both the leakage and magnetizing inductances. The coupled inductor allows soft-switching, high frequency operation. The sinusoidal inverter output is filtered and has a stable common mode. It is shown that the stored energy in the coupled inductor approaches half that of interleaved inductors, and reduces further with level count. The inverter is compared to interleaved soft-switching inverter topologies. The motor drive function is verified in simulation.

This paper proposes an optimized design for complete zero voltage switching (ZVS) operation of the phase-shift full-bridge DC-DC Converter with series-connected transformers. This topology extends the ZVS range at light load, compared with the standard phase-shift full-bridge Buck topology, by exploiting the energy stored in the transformer’s magnetizing inductances. However, at full load, ZVS condition still requires a suitable leakage inductance, which reduces the effective duty-cycle. A design procedure is proposed that allows a complete ZVS operation without relying on the transformer’s leakage inductance, that can be minimized. Experimental results will follow, highlighting the effectiveness of the proposed design.

This digest compares the 2N+1 and N+1 operating modes of the single-phase AC-AC MMC. Unlike conventional DC-AC energy conversion, the AC-AC MMC offers versatile operating combinations based on the number of levels in the common-mode voltage vpwm and the differential-mode output voltage vo. By applying the multilevel modulation strategies such as PS-PWM and Staircase, these voltages improve power quality at the converter's input and reduce the output voltage. The 2N+1 operating mode results in a lower voltage level across the input inductor of the AC-AC MMC converter when using the same number of cells in each arm, compared to the N+1 operating mode. Simulation results demonstrate the AC-AC MMC operating under medium-voltage and medium-power conditions, emphasizing the key differences between the two operating modes.

Grid-forming (GFM) controllers in photovoltaic (PV) systems encounter distinct challenges since ac power demand may exceed PV generation capacity. In this digest, we propose a multi-mode control architecture for two-stage grid-tied PV systems by introducing a limited grid-forming mode to sustain operation during capacity-limiting disturbances. The framework combines three operational modes, namely a pre-synchronization mode for startup, a mode with prototypical GFM dynamics, and the proposed limited GFM mode when power constraints are reached. The ability to ride through large disturbances requires only dc-dc controller adaptation while the dc-ac converter contiguously retains one control law. Accordingly, this approach minimizes implementation complexity. Finally, simulations validate seamless ride through during large disturbances.

Isolated converters are essential in Electric Vehicle (EV) systems for their versatility. This work presents an isolated on-board converter for EV charging, based on an interleaved Forward topology with a coupled inductor, doubling the switching frequency in passive elements. Operating in Continuous Conduction Mode (CCM) with Zero Voltage Switching (ZVS), it enhances efficiency. A State-Space Averaging (SSA) model was developed, and a robust control strategy was designed. A prototype was tested under load step conditions, demonstrating stable operation. The model accurately represents the converter's behavior in the frequency domain.

Electrocaloric heat pump systems provide a sustainable cooling and heating solution, but require highly efficient power electronics for cyclic charging and discharging of electrocaloric capacitors. This was achieved using multilevel converters for ideal capacitive loads. However, multilevel operating without balancing for real electrocaloric capacitors leads to drifting inner buffer voltages and eventually to inefficient 2-level operation. This work proposes a purely software-based balancing technique. A 4-level GaN-based converter is built. Compared to unbalanced operation, balancing reduced the measured power loss by 24.1%, which will increase the coefficient of performance (COP) of future electrocaloric heat pump systems. The balancing operation experimentally achieves the stabilization of the internal buffer voltages and thereby enables a steady-state multilevel operation.

Ripple-based control strategies offer superior transient performance compared to traditional current-mode and voltage-mode control schemes, making them well-suited for applications requiring fast response to large load variations. This digest presents the modeling and design of a 2MHz GaN-based constant-on-time (COT) virtual-ripple-controlled (VRC) buck converter, designed to convert a 5–12V input to a 1.2V output for high-performance computing (HPC) applications. Simulation results demonstrate that the converter supports up to 20A load current and effectively manages load transients from 1A to 20A with a 5A/µs slew rate. GaN FETs are employed for their high figure-of-merit (FoM) and compact size, contributing to improved efficiency and power density.

The Robicon-type drive has remained a popular medium-voltage drive option since its conception. It is often found as a part of complex multi-converter configurations. Considering this, there is a surprising lack of literature on the average modeling of topology itself. This paper presents a first-hand effort at attempting to model the average nature of a five-level Robicon-type drive. The topology is modeled as a cascade connection combining three individual stages. The developed average-value model (AVM) is validated using simulation tools against a corresponding switching. The results corroborate the validity of the developed AVM.

Abstract: A multiloop deadbeat control for voltage source converters (VSCs) with LC filters was introduced in [1]. However, we found that the inner current loop model in [1] does not fully capture the significant transient dynamics of the inductor current. We have proposed a revised model that more accurately reflects these dynamics. Based on the proposed inner loop model, an improved outer deadbeat voltage control has been developed.

The dual comparison one cycle control (DC-OCC) proposed in this paper regulates both the peak and valley of the current, unlike conventional one cycle control (C-OCC), which controls only the peak. This dual control approach effectively eliminates the steady-state DC offset, current distortion, and localized sub-harmonic instability issues observed in C-OCC. The DC-OCC structure is further extended to support bidirectional power flow, adjustable power factor operation, and STATCOM functionality. These enhancements are achieved with relatively simple modifications compared to existing methods in the literature. An average model of the DC-OCC is developed to analyze instability when the converter draws or injects lagging current into the grid. The controller's effectiveness is validated through detailed simulation and experimental studies.