Low Output Current Ripple Research Articles

High-Efficiency Multiphase Stacked Interleaved DC-DC Buck Converter with Very Low Output Current Ripple and Low Current–Voltage Stress

High-Efficiency Multiphase Stacked Interleaved DC-DC Buck Converter with Very Low Output Current Ripple and Low Current–Voltage Stress

Low Output Current Ripple Ultra High Step-Down Two-Phase Buck Converter With Low Switching Losses

Low Output Current Ripple Ultra High Step-Down Two-Phase Buck Converter With Low Switching Losses

Analysis and Design Considerations of Input Parallel Output Series-Phase Shifted Full Bridge Converter for a High-Voltage Capacitor Charging Power Supply System

Capacitor charging power supply (CCPS) is used for impulse-power applications such as electromagnetic rail guns, flash lamps, medical sterilization, and rock crushing, among many other application fields. This paper describes the design and analysis of an Input Parallel Output Series-Phase Shifted Full Bridge converter for CCPS. The proposed system has a low output current ripple to improve the lifetime of the high-voltage pulsed capacitor. Design considerations of topology's electrical parameters such as HF transformer's leakage inductor and output inductor for the CCPS application are presented. The intermediate DC-link capacitance is provided as an energy storage element to minimize the disturbances (power variation) on the source for the CCPS application. Analysis and sizing of the capacitance for two different charging methods are analyzed and compared. A controller design procedure for the Active Front End Converter (AFEC) is also included to ensure near-constant power drawn, rejecting the load disturbances. Finally, a complete design procedure for the whole CCPS system is presented. Design and simulation results are presented for a rated system, followed by experimental results from a scaled-down hardware prototype to validate the design.

A ZVS Three-Level Synchronous Buck Converter With Simple LC Circuit

This brief presented a new soft-switching auxiliary circuit for the three-level buck converter with synchronous rectification (TLBC-SR). The new zero voltage switching (ZVS) auxiliary circuit only employs one inductor and one capacitor, and has the features as full soft-switching conditions, high efficiency, low output current ripples, and simple modulation control method. The detailed operation principle and soft-switching design method are also given. Finally, an experimental prototype is built to verify the proposed ZVS TLBC-SR. The experimental results show that all switches operate under zero voltage switching (ZVS) conditions, and the peak efficiency of the prototype is up to 96.85%@100kHz.

Impact of Parameter Mismatch on Three-Phase Dual-Active-Bridge Converters

Three-phase dual active bridge converters (DAB3) are a widely used topology in battery charging applications thanks to their numerous advantages, such as bidirectional power flow, galvanic isolation, low output current ripple, and inherent soft-switching. In such applications, three single-phase transformers are commonly employed as the AC-link to simplify manufacturing and reduce costs. These transformers’ leakage inductance can be utilized instead of the external leakage inductance to achieve high power density. However, the assumption of uniformity in these inductances is not always accurate as they can vary significantly during fabrication. This study presents a comprehensive analysis of the impact of transformer leakage inductance variation, which can deviate by up to 24% from the desired value. The effects of this variation are investigated from different perspectives, including power transfer, soft-switching range, root-mean-square (RMS) current, and the temperature rise of the transformer winding. Although the power transfer and total copper loss of transformers are changed insignificantly even under highly mismatched leakage inductance, the currents and thermal distribution among phases are considerably impacted. Based on statistical probability, a maximum leakage inductance variation threshold of 10–15% compared to the desired value is recommended to ensure the maximum acceptable temperature rise among phases. Experimental results are presented to validate the analysis.

A Single-Switch Soft-Switched High Step-Down Zeta Converter With Low Output Current Ripple

This article proposes a new nonisolated high step-down converter that is derived from Zeta converter. By employing coupled-inductor technique, zero-current switching is achieved for the switch at turn <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> and turn <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> . Also, introduced converter incorporates a current ripple cancellation cell, which provides dc output current for full load as well as light load. Another main feature of the proposed converter is using a single switch and a magnetic core. Therefore, high efficiency and high power density are attained. For further efficiency improvement, a synchronous rectifier is employed, which results in efficiency greater than 96% for the entire load range. A 100-W prototype of the proposed converter is designed and implemented to verify the theoretical analysis and confirm its efficiency improvement and advantages.

Research on DC Power Supply for Electrolytic Water to Hydrogen Based on Renewable Energy

Hydrogen production from electrolytic water based on Renewable Energy has been found as a vital method for the local consumption of new energy and the utilization of hydrogen energy. In this paper, the hydrogen production power supply matching the working characteristics of electrolytic water production was investigated. Through the analysis of the correlation between the electrolysis current and temperature of the proton exchange membrane electrolyzer and the electrolyzer port voltage, energy efficiency, and hydrogen production speed, it was concluded that the hydrogen production power supply should be characterized by low output current ripple, high output current, and wide range voltage output. To meet the requirements of the system of hydrogen production from electrolytic water based on new energy, a hydrogen production power supply scheme was proposed based on Y which is the type three, is the phase staggered parallel LLC topology. In the proposed scheme, the cavity with three is the phase staggered parallel output is resonated to meet the operating characteristics (high current and low ripple) of the electrolyzer, and pulse frequency control is adopted to achieve resonant soft in the switching operation and increase conversion efficiency. Lastly, a simulation model and a 6kW experimental prototype were built to verify the rationality and feasibility of the proposed scheme.

An Improved Zero-Voltage and Zero-Current- Switching Phase-Shift Full-Bridge PWM Converter With Low Output Current Ripple

In order to improve the performance of traditional phase-shifted full-bridge converters and reduce the output current ripple, an improved zero voltage and zero current switching phase-shifted full-bridge PWM converter is proposed in this article. By adding a simple auxiliary circuit, the leading-leg switches realize zero voltage switching and the lagging-leg switches realize zero current switching. The primary current is reset during the freewheeling period, so the efficiency of the converter is improved. What is more, the improved converter can effectively reduce the output current ripple. The added auxiliary circuit does not include any lossy components or saturable reactors. The improved phase-shifted full-bridge converter has many advantages, including simple circuit topology, easy implementation of soft switching, high efficiency, and low output current ripple. The operational principle and analysis of the proposed converter are presented in this article. An 800 W experimental prototype is built for experimental verification.

Development and Analysis of a Novel High-Gain CUK Converter Using Voltage-Multiplier Units

High conversion gain is often required for the grid integration of renewable energy resources such as PV, fuel cells, and wind. It is desired that the stress across switches is lower when higher voltage gain is attained. Similarly, it is also preferred that the converter can achieve high voltage gain without operating at higher duty cycle values. This article presents a novel high-gain CUK converter (HGCC) that uses voltage-multiplier units. The HGCC is a combination of a modified CUK converter and voltage-multiplier units (VMUs). The converter utilizes a boost converter as an input to the modified CUK converter, resulting in an increase in the gain value. The voltage gain of HGCC is increased further by placing VMUs. Based on its overall design, the HGCC inherits various advantages of the CUK converter, such as continuous input and output current, resulting in low input and output current ripples. A mathematical model is developed for the HGCC, which helps calculate its voltage gain at different stages. The model is developed considering ideal elements without conduction and switching losses. Generalized equations for output voltage and gain are derived for n level converter. A simulation study was performed in MATLAB/Simulink that further highlights the advantages of the HGCC. Voltage stresses across different components and the switching of MOSFET and diodes are studied in simulations. An experimental setup is established for hardware prototyping of the converter and validation with the simulation and Mathematical models.

Hybrid Active Power Filter for Power Quality Improvement

A Deadbeat current controller for an LC-coupling hybrid active power filter is proposed, which can track with the reference compensation current with low steady- state error and fast dynamic response. Moreover, it can lead Hybrid Active power Filter to be operating at a fixed switching frequency with low output current ripples, thus reducing the size of the filtering circuit. The stability issue and parameter design of the proposed deadbeat current controller are analyzed and discussed. Finally, the compensating performance of the deadbeat current controller for the Hybrid Active Power Filter (LC-HAPF) is verified by simulation compared with the conventional hysteresis bandwidth modulation control, the proportional-integral (PI) control, and the proportional multi-resonant control for the LC-HAPF, which shows its effectiveness and superior compensating performances.

Output Current Ripple and Efficiency Optimal Control Method for Multi-Phase Interleaved LLC Resonant Converter

The interleaving technique is required for LLC resonant converters to achieve high power levels, handle higher input/output currents, and reduce output current ripple. However, the high system efficiency and the low output current ripple for the multi-phase LLC resonant converter cannot be achieved at the same time at low and medium power levels. Most methods try to keep the multi-phase LLC resonant converter in load-sharing mode regardless of the power level, which will result in low system efficiency at low and medium power levels. In this paper, an output current ripple and efficiency optimal control method with finite load distribution schemes is proposed for the multi-phase LLC resonant converter to balance the efficiency and output current ripple. The optimal control method improves the efficiency as much as possible while keeping output current ripple low. According to the calculation of output current ripple and efficiency, the optimal load distribution scheme is selected. The pulse-frequency modulation (PFM) and phase-shift modulation (PSM) hybrid control is applied to regulate the load of each phase. An analysis is provided, and a 540-W three-phase interleaved LLC resonant converter is built to verify the superiority.

Design a H-bridge low ripple and high bandwidth air core magnet corrector power supply in NSRRC

This paper is the study of a low-current-ripple and high-bandwidth corrector power supply. The main circuit of this power supply is using a full bridge (H-bridge) structure, and the output current through the high-precision direct current current transducers (DCCT) to transfer the reference voltage to the controller. Previous TPS corrector power supply had a 4.7 kHz current bandwidth, and its output current ripple was 100 μA. Such current ripple and bandwidth do not satisfy the requirements of a rapidly orbiting feedback system of air core loading. Therefore, our research team designed a novel prototype power supply with a high bandwidth (more than 10 kHz) and low output current ripple (less than 10 μA) which was developed via a novel topology circuit. The operation frequency of the main power switch's n-type metal-oxide-semiconductor logic of this novel circuit is increased to 245 kHz. Moreover, the output results of the filter inductor and filter capacitor are modified to 80 μH and 2.46 μF, respectively. The prototype power supply bandwidth reached 10.546 kHz and increase of 124% and its output current ripple was lowered below than 5 μA. The properties of this corrector power supply are very important for the beam correction in storage rings. Finally, A circuit with an input voltage of 48 V, a maximum output current of 10 A, and an output power of 400 W is tested in a laboratory to verify the performance of the developed corrector for the National Synchrotron Radiation Research Center.

Power Factor Preregulation in Interleaved Luo Converter-Fed Electric Vehicle Battery Charger

This work deals with the design and implementation of a new interleaved Luo power factor preregulator (PFP)-based electric vehicle (EV) battery charger, which is suitable for low-cost and improved power quality (PQ)-based EV charging. By interleaving two Luo converter cells, the input current is divided between them, which provides reliable and efficient charging of the battery at high-power discontinuous conduction mode (DCM) operation. This reduces the switch conduction loss due to reduced device current stress and thus, the charger efficiency is improved. The interleaved Luo converter incorporates low input and output current ripple due to ripple cancellation. This charger operates in constant current mode up to certain battery state of charge (SOC). However, for higher SOC range, it maintains constant voltage charging using a flyback converter at the next stage. Two converters are designed in DCM to provide inbuilt zero current switching and circuit diodes show good reverse recovery. An inherent PF preregulation is obtained at input mains over a wide range of supply voltages as well as dc-link voltage. The total harmonic distortion of input current is obtained as per PQ regulations. Its prototype is built and tested to validate its improved performance over two-stage solutions.

Novel Cuk-Based Bridgeless Rectifier of Wireless Power Transfer System With Wide Power Modulation Range and Low Current Ripple

A novel Cuk-based bridgeless rectifier is proposed for receiving side of wireless power transfer (WPT) system. The proposed converter can not only help improve overall efficiency but also is with features of wide power modulation range and very low output current ripple. In terms of the output current source characteristics of series-series-compensated WPT system, a bridgeless rectifier and a Cuk converter are combined and an input inductor of Cuk converter is cut down to form the proposed single-stage converter. Besides, a synchronization operation method is derived for the proposed converter to realize the optimal working point of transmission power and efficiency. Operation principles of the converter and its impact on performance of WPT system are analyzed. Also, design methods for system parameters are given. A prototype is built up to verify the feasibility of the proposed topology and the operation method. It is noted that the proposed converter can well adjust the output power of WPT system to realize the desired working point via adjusting the duty cycle at different transfer distances and loads.

Implementation and design of an interleaved Cuk converter with selective input current ripple elimination capability

SummaryNowadays, buck–boost DC–DC converters are widely used in numerous power devices. However, to have a suitable buck–boost DC–DC converter, reducing the input current ripple seems to be necessary. Also, having a lower current ripple at the converter output allows using low‐cost, long‐life ceramic capacitors instead of electrolytic capacitors. The presented buck–boost converter is made by interleaving two Cuk converters with positive and negative output voltage polarity, which provides the chance to eliminate the input current ripple at the selective duty cycle. The selective duty ratio can be determined by designing the inductors amounts at the input side of both converters. Though a new combination for the buck–boost converter is presented, which has zero input current ripple and low output current ripple which is obtained by output inductors. The converter maximum voltage gain is 2D/1‐D and has easy control. In conclusion, a prototype model with 100‐W output power is implemented, and the theoretical analysis and laboratory results are compared and validated.

Flicker-Free Resonant LED Driver With High Power Factor and Passive Current Balancing

A flicker-free resonant LED driver with high power factor (PF) and passive current balancing is proposed and analysed in this paper. The proposed LED driver are composed a buck power factor correction (PFC) unit and a resonant dc-dc unit by sharing an active switch. Based on this topology, the low output current ripple can be achieved via small voltage ripple on bulk capacitor and fast voltage-mode control loop. By the charge balance for resonant capacitor, the output current of each LED string can be balanced. In a half line cycle, owing to the small voltage ripple on bulk capacitor of pre-stage output, the duty cycle of active switch is almost constant. Therefore, when the inductor current of buck PFC unit operates in discontinuous conduction mode, high PF can be realized. Moreover, as the resonance is existed between resonant capacitor and leakage inductor of transformer, the diodes in resonant dc-dc unit can achieve zero-current turn-off. Thus, the efficiency can be improved. Finally, an 82W LED driver prototype with three-output is built to verify the studied results.

Active-Clamp Resonant Power Factor Correction Converter With Output Ripple Suppression

An active-clamp resonant power factor correction converter with output ripple suppression is proposed and analyzed. It combines a buck power factor correction (PFC) unit and a resonant dc-dc unit by sharing one active switch. With another active-clamp switch, a recycling path is built to recover the leakage inductance energy of transformer, which improves the efficiency and the voltage stress of active switch. The effect of voltage ripple of dc link on output can be suppressed by fast voltage mode control loop. Therefore, low output current or voltage ripple can be achieved. With small voltage ripple across output of buck unit, the turn on time of active switch is almost constant in a half line cycle. Therefore, power factor correction can be achieved with inductor current of buck unit operating in discontinuous conduction mode (DCM). Finally, a 65W high power factor (PF) converter prototype for LED driver application with 91.08% peak efficiency and low output current ripple is built to verify the analytical results.

Stacked Buck Converter: Current Ripple Elimination Effect and Transient Response

To balance the cost and volume when applying a low output current ripple, the power supply design should be able to eliminate the current ripple under any duty cycle in medium and high switching frequencies, and considerably reduce filter volume to improve power density. A stacked buck converter was eventually selected after reviewing the existing solutions and discussing their advantages and disadvantages. A stacked buck converter is used as a basis to propose the transient response and output current ripple elimination effect, boundary limit control method, and low output ripple dead time modulation method to make individual improvements. The principle, mathematical derivation, small-signal model, and compensator design method of the improvement method are presented in detail. Moreover, simulation results are used to mutually verify the correctness and effectiveness of the improvement method. A stacked buck converter with 330-V input, 50-V output, and 1-kW output power was implemented to verify the effect of the low output current ripple dead time modulation. Experimental results showed that the peak-to-peak value of the output current ripple was reduced from 2.09 A to 559 mA, and the RMS value was reduced from 551 mA to 91 mA, thereby effectively improving the output current ripple.

A Nonisolated Soft Switching Interleaved Converter With Extended Duty Cycle and Low Output Current Ripple

In this article, a new nonisolated interleaved dc–dc converter with extremely extended duty cycle and low current ripple is presented. The applied interleaved architecture along with complementary operation of the switches provide zero voltage switching condition for all switches and reduce the output current ripple. Both of diodes turn ON and turn OFF under zero current switching condition, and thus the reverse recovery losses associated with the diodes are eliminated. In the proposed converter, energy-transferring capacitors are used as voltage sources to reduce the input voltage and the switches voltage stress. Also, the coupled inductors are applied to extend the duty cycle while the leakage energy is absorbed without imposing extra voltage stress across the switches. As a result, extremely high step down voltage conversion ratio is achieved and the overall efficiency is improved. In this architecture, the input shares the ground with the output and any auxiliary circuit is not required. The operating modes of the proposed converter are analyzed and the presented experimental results confirm the theoretical analysis.

Interleaved Ultrahigh Step-Down Converter With Low Component Count

An ultrahigh step-down converter with a low number of semiconductor devices is presented in this article. Important features of this converter are simple structure with low size and cost, low voltage and current stress on components, low output current ripple, and low conduction and switching losses. In this converter, the power switches are turned on under zero current switching (ZCS) condition, whereas the output diodes commutate under ZCS condition without any auxiliary circuit. Thereby, in addition to the converter efficiency improvement, the diodes reverse recovery problem is alleviated. The proposed topology has employed a two-phase interleaved structure to reduce current stress, three windings coupled inductors to further decrease the voltage gain, and two series capacitors to diminish the voltage stress on the semiconductors elements and recover the leakage inductances energy. The experimental results of an implemented prototype are provided to evaluate the effectiveness of the proposed topology at 100 kHz and 200 W, which converts a 400-V input voltage into a 12-V output voltage.