Switched-capacitor Converter Research Articles

Novel Topology for Modified Boost Series and Parallel Switching Capacitor DC-DC Converter

Theoretical and experimental work for a novel topology of DC-DC boost switching capacitor converter is introduced in this paper. This new design is an adjustment for boost series and parallel topology developed by Makowski. Thus, a comparison between the two designs presented in this paper aims to highlight the improvement in the conversion rate of the boost converter’s output voltage while using the same number and size of capacitors. Converter analyses for both with and without load are presented. Also, a boost converter with a nonlinear ferroelectric capacitor is presented to further increase the boost converter conversion rate using advantages of the ferroelectric capacitors, such as their big dielectric constant and polarization reversal.

Design Considerations for Power-Efficient Fully Integrated 3:1 Switched Capacitor DC-DC Converter for PV Modules

This article presents a power-efficient DC-DC converter based on a switched-capacitor (SC) cell in power management systems supplied for fully integrated photovoltaic (PV) modules. These modules shall provide high-performance point-of-load voltage regulation. The primary objective of this study is to better utilize capacitance and switches by selecting a proper SC topology in order to improve the power efficiency of SC converters. A general steady-state performance model is investigated to optimize and compare a variety of SC DC-DC topologies. The investigation method relies on a charge-multiplier approach and considers the impact of area constraint on capacitors. To identify the most suitable topology for a given conversion ratio, the performance-limit metrics of SC converters are calculated. The analysis provides framework to determine optimum switch size and switching frequency for a two-phase 3:1 series–parallel converter for a target load current of 10 mA implemented on a 22 nm process technology. The results shows that a minimum of 250 MHz switching frequency is desirable for achieving a target efficiency greater than 85% while maintaining the minimum output voltage of 0.34 V. The analysis results are verified through MATLAB and PSpice-based simulations.

A Fully Integrated Nine-Ratio Switched-Capacitor Converter With Overlapped-Conversion-Ratio Modulation for IoT Applications

A Fully Integrated Nine-Ratio Switched-Capacitor Converter With Overlapped-Conversion-Ratio Modulation for IoT Applications

Hybrid switched‐capacitor‐based boost DC–DC converter with reduced voltage stress

AbstractThis article presents the new hybrid switched‐capacitor (SC)‐based transformerless DC–DC converter with a high step‐up capability and common ground features. The proposed hybrid SC‐based converter provides low voltage stress across semiconductor devices to utilize MOSFETs with lower Rdson and low voltage ratings. In addition, the diodes in SC cells with low voltage stress can reduce the reverse recovery power loss of the converter. Thus, the overall efficiency of the proposed hybrid SC‐based converter can be increased. The converter circuit, operating principle, and design guidelines of the proposed hybrid SC‐based converter are discussed. To confirm the performance of the proposed hybrid SC‐based converter, a detailed comparison study with the conventional hybrid SC converter is also presented. Finally, a laboratory prototype with 200 W and 25 to 200 V is set up to verify the effectiveness of the proposed hybrid SC‐based converter.

Parallel Simulation for the Generalized Topology of Switched Capacitor Converter With Pillar-Connected-Double-Layer Structure

Parallel Simulation for the Generalized Topology of Switched Capacitor Converter With Pillar-Connected-Double-Layer Structure

Ladder-Type Resonant Switched-Capacitor Converter Achieving 99.1% Peak Efficiency and 4750 w/in3 Power Density for High-Current Application

Ladder-Type Resonant Switched-Capacitor Converter Achieving 99.1% Peak Efficiency and 4750 w/in³ Power Density for High-Current Application

A General Analysis of Resonant Switched-Capacitor Converters Using Peak Energy Storage and Switch Stress Including Ripple

This work presents a general analytical framework enabling large-signal characterization of resonant switched-capacitor (ReSC) power converters that accounts for passive component voltage and current ripple, for operation at and above resonance. From this, appropriate phase durations for minimized rms currents are derived, in addition to expressions for total passive component volume using an intuitive peak energy method. An example hardware prototype validates both the derived waveforms and timings—as well as total passive volume—through three comparable hardware configurations, one of which minimizes passive component volume. In addition, the proposed technique formulates analytical expressions for both rms currents and peak blocking voltages, facilitating refined loss estimation and component selection. Subsequent calculation of the large-signal Volt–Amp (VA) switch stress metric allows a more accurately quantified trade-off between active and passive components compared to prior work, which has not fully accounted for ripple. Four common ReSC topologies are exemplified throughout, with topology specific parameters documented for reference.

Modeling and Analysis of Switched-Capacitor Converters With Finite Terminal Capacitances

Modeling and Analysis of Switched-Capacitor Converters With Finite Terminal Capacitances

Self-Frequency Tracking for Fixed-Ratio Switch-Capacitors in Data Center Application without Extra Sensors

As research into data centers progresses, the importance of resonant switched-capacitor converters in power supply design becomes more evident. Practical applications reveal that the values of resonant capacitors and inductors may deviate from their nominal values due to various factors, leading to resonant frequency instability. This instability poses a challenge to power electronics technology, affecting system reliability and performance. This paper analyzes the effect of frequency deviation on system functionality, identifies the relationship between output voltage and switching frequency, and proposes a self-tracking frequency strategy to address this issue. Through experimental validation, this approach shows that it maintains synchronization between switching and resonant frequencies, reducing losses associated with frequency misalignment. Simulation and experimental results validate the converter’s stable operation and its ability to achieve zero-voltage and zero-current switching.

Performance Analysis of Positive Output (P/O) Push-Pull Switched Capacitor Converter for High Power Density Applications

The micro-power-consumption technique requires high power density DC/ DC converters and power supply sources. In this research, a PI and Fuzzy Logic Controllers for an elementary circuit of positive output (P/O) push-pull switched capacitor converter has developed for high power density applications with high sustainability under enormous line and load disturbances. The voltage lift technique is a popular application in electronic circuit design. The power converter performs DC-DC step-up voltage conversion with high efficiency, high power density and cheap topology in a simple structure. The proposed converter combines both switched-capacitor and voltage lift techniques. Referable to the time varying and switching nature of the power electronic converter their dynamic behavior becomes highly nonlinear. Conventional controllers are incapable of providing excellent dynamic performance and hence the fuzzy logic controller can be used as a feed forward controller for controlling power electronic converters. The control algorithm is developed to ensure tracking of the reference voltage and rejection of system disturbances by successive measurements of the converter output voltage at certain time instants within a conduction period. The simulation of PI and Fuzzy logic controls have been carried out using MATLAB/Simulink software to evaluate the controller’s performances. Keywords: Luo converter, DCDC converter, PI Controller, Fuzzy Controller.

A Family of Ladder Multi-Resonant Switched-Capacitor Converters With Extended Voltage Gain Range and Complete Soft Charging

A Family of Ladder Multi-Resonant Switched-Capacitor Converters With Extended Voltage Gain Range and Complete Soft Charging

A Step-Down Series-Parallel Dual-Resonant Switched-Capacitor Converter With Extended Voltage Gain Range and Complete Soft Charging

A Step-Down Series-Parallel Dual-Resonant Switched-Capacitor Converter With Extended Voltage Gain Range and Complete Soft Charging

Universal Modeling Method and Reactive Power Optimization for Phase-Shift-Modulated Resonant Switched-Capacitor Converters

Universal Modeling Method and Reactive Power Optimization for Phase-Shift-Modulated Resonant Switched-Capacitor Converters

A novel switched-capacitor based multilevel voltage boost inverter for EV interface

ABSTRACT Lithium cells are connected in parallel and series to meet the current and voltage requirements in Electric vehicles (EV). Voltage and charge equaliser techniques are employed to protect the lithium cells. These equalisation circuits introduce the loss to the circuit, and the battery pack gets disconnected if any cell is faulty. Switched-capacitor converters have become an alternative to meet the voltage requirement. This article presents a voltage boost multilevel inverter configuration for electric vehicle applications. The proposed MLI features an inherent capacitor self-balancing capability and generates an output with a nine-level range. Algorithms for capacitor voltage balancing or additional sensor circuits are not required because of intrinsic self-balancing. For generating output levels, capacitors with a voltage source with an appropriate charging/discharging pattern are used. The proposed inverter doubles the output voltage for nine levels. A comparison of components, such as the number of semiconductors, diodes, gate driver circuits, and capacitors; system parameters such as voltage gain, blocking voltage, and TSV, is presented to demonstrate the advantages of the proposed MLI over recently developed topologies.

A Bidirectional Direct AC-AC Resonant SCC

A direct ac-ac resonant switched-capacitor converter (SCC) for both noninverting and inverting output voltages is proposed here, which is suitable for bidirectional power transmission including different applications such as dynamic voltage restorer (DVR), constant voltage regulator (CVR), and constant current regulator (CCR). Zero voltage switching (ZVS) and zero current switching (ZCS) operation conditions are easily realized for its power switches, which effectively reduce the switching losses, as well as the electromagnetic interference (EMI) noise. Consequently, high-frequency operation is possible, which improves the converter power density, in practice. Continuous voltage-gain, transformerless connection of the converter output port to the gird, no commutation problems without using extra components, and improving the electrical specifications are some other advantages of the given resonant SCC. The converter operation principles, its key waveforms and different operational states, its mathematical analysis and normalized state-plane trajectories, simulation results, as well as its design procedure, are also given here, in detail. To verify the given theoretical analyses and simulation results, a 500 W prototype converter for a 2 kW DVR with 220 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> nominal output voltage has been implemented successfully, which realizes 96.55% efficiency at its rating power value.

A Semi‐Passive Smart Contact Lens with on‐Lens Power Storage Element

This paper presents a semi‐passive smart contact lens platform for sensor and actuator applications. It focuses on design improvements made prior to human clinical trials involving basic considerations on comfort and safety, which are verified through animal studies. Observations of tissue temperature variation and post‐trial surgery examinations confirm that the 50 μW on‐lens wireless power delivery reduces the impact on tissue of previously reported SCL. Migration of wirelessly powered radio frequency identification (RFID)‐based passive SCL to semi‐passive systems is enabled with the proposed on‐lens power storage element. Furthermore, a switched capacitor converter extends the active time of the storage element and reduces electromagnetic influence. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Composite Converter Combined APFC with Switched-capacitor Converter

Composite Converter Combined APFC with Switched-capacitor Converter

Investigation of the Use of Switched Capacitor Converters as LED Drivers

Investigation of the Use of Switched Capacitor Converters as LED Drivers

Performance Limits of Resonant Switched-Capacitor Converter with Voltage Regulation

Performance Limits of Resonant Switched-Capacitor Converter with Voltage Regulation

Comparison and Optimization of Non-isolated DC-DC Converters for Electric Vehicle Applications

This paper discusses the importance of electric vehicles in solving the problem of environmental pollution. In electric vehicles, DC/DC converter is a vital part to connect many electrical units with high voltage bus, so it plays a vital and indispensable role in electric vehicles. The paper analyzes the disadvantages of isolated DC/DC converter, and concludes that non-isolated DC/DC converter is a more suitable technical solution for electric vehicles. The research paper introduces a number of fundamental non-isolated DC/DC converter topologies before analyzing the technical optimization strategies of a number of DC/DC converters in general. which are Half-bridge converters, Cascaded Half-bridge converter (CHB), multi-phase interleaved parallel converter, tri-level converter, soft-switching converter, and switched-capacitor converter (SC converter). The benefits and drawbacks of these DC/DC converter optimization measures are compared, the findings can serve as a technical framework for guiding the application of DC/DC converter technology in the context of electric vehicles. Finally, this paper analyzes and looks forward to the development prospect of flying switched-capacitor DC/DC converters (FCDCs) technology, puts forward the existing technical problems, and gives suggestions for the solution of these problems, which is conducive to the wider application of this technical solution in electric vehicles.