Constant Current Output Research Articles

A High-Efficiency Integrated LCC/S WPT System With Constant Current Output

A High-Efficiency Integrated LCC/S WPT System With Constant Current Output

A Hybrid-Frequency-Based Multi-Load Wireless Power Transfer System With Constant Current or Voltage Outputs

A Hybrid-Frequency-Based Multi-Load Wireless Power Transfer System With Constant Current or Voltage Outputs

Voltage Equalizing Strategy for Cascaded Constant Current Power Supply

In order to detect the underground medium with large depth, the transmitter of electromagnetic sounding instrument has higher and higher power and voltage. A novel voltage equalizing strategy for cascaded constant current power supply using in electromagnetic transmitter was proposed in this paper. The cascaded topology of the transmitter has two isolated full‐bridge AC/DC converters, which had same input source and were connected in series on the output side. The mathematical model based on state space average method was analyzed. After simplifying the circuit, the state space equation was used to describe the circuit model. The stability and frequency characteristics of the system were analyzed. Aiming at the constant current output and the output voltage balance of the two converters, the system coupling model was established. The constant current controller and voltage equalizing controller were designed with decoupling method. A 300 W prototype was built and the experimental results verified the performance of the proposed method. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

Research on Rectifier Fault Diagnosis and Self-Protecting for Inductive Power Transfer System with Constant-Current Output

Research on Rectifier Fault Diagnosis and Self-Protecting for Inductive Power Transfer System with Constant-Current Output

Characterizing an Autonomous WPT System with Either Constant Current or Constant Voltage Output Independency to Wide Multiple-Parameter Variations

Characterizing an Autonomous WPT System with Either Constant Current or Constant Voltage Output Independency to Wide Multiple-Parameter Variations

Analysis and Design of a Dual-Receiver WPT System with Constant Current and Constant Voltage Dual-Type Outputs

Analysis and Design of a Dual-Receiver WPT System with Constant Current and Constant Voltage Dual-Type Outputs

Research on Constant Current Output of Wireless Charging System for Unmanned Surface Vehicles

Research on Constant Current Output of Wireless Charging System for Unmanned Surface Vehicles

Design of Constant-Voltage and Constant-Current Output Modes of Double-Sided LCC Inductive Power Transfer System for Variable Coupling Conditions

Design of Constant-Voltage and Constant-Current Output Modes of Double-Sided LCC Inductive Power Transfer System for Variable Coupling Conditions

Deuterium Isotope Separation By Polymer Electrolyte Fuel Cell with Gas Circulation System

IntroductionHydrogen isotopes such as deuterium (D) and tritium (T) are in increasing demand in the fields of materials, energy, and medicine. A international fusion reactor in France will be equipped with water electrolysis for T separation. New methods are required, since the conventional processes perform low separation and consume large amount of energy. We have been studying D separation by polymer electrolyte fuel cell (PEFC) [1-3]. Here, the relationship between the gas consumption rate and separation efficiency is investigated. Therefore, the present PEFC can recirculate the unreacted hydrogen gas discharged from the anode, which proceeds high gas utilization. In our poster presentation, we will show the separation factor, D concentration and production volume depending on the gas circulation ratio.ExperimentalA JARI cell (electrode area: 25 cm2) was used for PEFC, and platinum was used as catalyst for both electrodes. For the anode, protium (H) concentration was set to 90 at% as a mixed gas. Oxygen gas was supplied to the cathode. Power generation was performed at room temperature, and a constant output current was obtained using a variable resistor. The H concentration in the anode gas was analyzed with a quadrupole mass spectrometer, and the gas volume discharged from the PEFC circulation system was calculated.Results and discussionThe ratio of the hydrogen gas circulation rate to the supply rate is defined as λ. The relationship with the H concentration is shown (Fig. 1). The H concentration was enriched during PEFC operation, while D was condensed in produced water. The gas circulation improved the separation efficiency because the outlet gas was repeatedly processed in PEFC. Figure 2 shows the relationship between λ and the volume rate of exhaust gas from anode. As λ increased, the gas rate decreased linearly from 8 mL min-1 to 2 mL min-1. That is, the circulation system let the gas residential time in PEFC be longer. When the gas was circulated more, the gas could react for long time. This was attributed to the high H concentration seen in Fig. 1. The present results demonstrated the importance of circulation parameter, λ, for the enrichment production.

An anti-offset wireless power trasfer system with constant current/constant voltage output

This article proposes a wireless power transfer (WPT) system based on LCC-LCC and LC-LC series hybrid compensation topology with offset resistance and constant current/voltage output performance. The system uses LCC-LCC and LC-LC networks for input and output series and adopts a four-direction decoupled magnetic coupling structure. On this basis, by designing appropriate parameters, a constant current output independent of the load was achieved, and the performance of resisting coil offsets in the four directions of x, y, xy, and -xy can be achieved. Furthermore, a T-network facilitates the mode conversion for achieving constant current/constant voltage output. Subsequently, an experimental simulation platform was built to verify the feasibility of the theory presented in this paper.

Implementation of the irregular pulse density modulation‐controlled wireless power transfer system for constant current and constant voltage output

SummaryIn this paper, irregular 32 pulse density modulation (PDM)‐controlled wireless power transfer (WPT) system is proposed for constant current (CC) and constant voltage (CV) outputs. The proposed WPT system has a load independent ZPA frequency characteristic with CC and CV outputs. Thus, soft switching conditions are achieved for both CC and CV outputs. An experimental prototype was prepared to validate the effectiveness of the proposed irregular 32 PDM‐controlled WPT system. WPT coil design parameters are presented and analyzed with lateral and rotational misalignment conditions in ANSYS. The experiments were determined as 3 A for CC output and 200 V for CV output. The maximum efficiency of the proposed system is measured (95.34%) at aligned coils with 100 mm air gap. In addition, the efficiency results are presented and evaluated by performing experimental studies under both lateral and rotational misalignment conditions.

Closed Loop Control of DSMST Converter for Ev Applications

Transformerless step-down and step-up DC-DC topologies are currently extensively employed in a variety of applications. A positive output voltage SEPIC-type DC-DC converter without a transformer is proposed in this article. This configuration has the benefit of input continuous current over the traditional buck-boost converter, making it better suited for use with electric vehicles. Moreover, it has an increase in gain that is quadratic of the voltage gain of a standard topology. Also, the suggested converter has a constant current output, which decreases the output voltage ripple and reduces the current stress on the converter's output capacitor. As a result, this converter can generate an extensive range of voltages with less input and output ripples. In addition, closed loop control of DSMST converter is presented in the paper using PI control Ziegler- Nichols method. In the end, simulation findings are shown to support the converter's closed loop study.

Ternary Electrification for Efficient Charge Accumulation and Synergetic Charge Collection

AbstractA direct current triboelectric nanogenerator (DC‐TENG) based on corona discharge has a high efficiency in collecting electrification charges. However, enhancing the constant current output with an ultra‐low crest factor and average power density of DC‐TENG through a rational structure design is still a great challenge. Herein, a novel ternary dielectric electrification TENG (TDE‐TENG) is proposed with Kapton/electrode/Polytetrafluoroetylene (PTFE) on the slider and Polyurethane (PU) modified by PTFE powder on the stator. The PTFE powder is coated on PU film to regulate its triboelectricity and realize its electropositivity/electronegativity under friction with PTFE/Kaption, which is an important discovery for tribomaterials. The collecting electrode on the slider can synergistically capture charges generated from its adjacent two tribo‐materials. This structure of TDE‐TENG can further realize multiple unit integration to fully capture the tribo‐charges. TDE‐TENG achieves a charge density of 5.5 mC m−2 and a constant current output with an ultra‐low crest factor of 1.02 at 30 rpm. Moreover, the sliding TDE‐TENG has an average power density of 12.4 W m−2, which breaks the record for all sliding DC‐TENGs. The direct connection of the 4‐unit TDE‐TENG with the PMC generates an output charge of 1.17 mC s−1. This work provides a novel strategy for enhancing DC‐TENG output performance.

A Misalignment-Tolerant Hybrid Coupler for Electric Vehicle IPT Charging Systems

To solve the problems of output voltage and system efficiency sharply decreasing in the case of misalignment for the electric vehicle inductive power transfer (IPT) charging system, a universal hybrid coupler with high misalignment tolerance is proposed. The hybrid coupler consists of a four-coil bipolar (BP) coupler, the T-type network and a compensation capacitor, which effectively achieves high anti-misalignment for any compensation networks. The introduction of the T-type network makes the two overlapping coils in the same side of the BP coupler transmitter decouple effectively and simplifies the design. Although the two overlapping coils in the receiver side are still coupled with each other, the parameter design only needs to consider the cross-coupling to be small enough, which significantly reduces the design difficulty of the coupler without iteration and repetition. Finally, a 2-kW misalignment-tolerance hybrid IPT system is constructed based on the proposed hybrid IPT coupler. A configurable series-series (SS) and series/inductor-capacitor- capacitor(S/LCC) compensation topologies are used to implement constant current (CC) and constant voltage (CV) load-independent outputs in the face of conditions where the coupling coefficient and load change simultaneously. The experimental results validate the correctness of the theoretical analysis.

Design and Implementation of High-Misalignment Tolerance WPT System for Underwater Vehicles Based on a Variable Inductor

Wireless charging for autonomous underwater vehicles (AUVs) has been widely explored recently by the merit of safety and convenience. However, due to the misalignment between charging coils in the horizontal and vertical directions, the system may not maintain constant current (CC) or constant voltage (CV) output. Therefore, this article proposes a mistuned IPT system structure and corresponding design methods to improve misalignment tolerance. The proposed IPT system adopts series-series compensation and includes a variable inductor (VI) on the secondary side. A general design method based on the established mathematical model is proposed. The worst scenarios (i.e., the maximum value of misalignment) are used for the optimization of the system parameters. The control strategy for VI without any communication link to the primary side is established. Finally, a 1 kW IPT system for tolerance of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> of 0.15-0.5 and output voltage of 74-150 V variation is set up. The experimental results show that the horizontal and vertical direction misalignment ranges reach ±47% and +140%, respectively, and the maximum system efficiency exceeds 96% for full power output. The proposed system improves the freedom and stability of charging in the harsh underwater environment.

Analysis of output characteristics of wireless power transfer system based on LCC/S-S hybrid compensation structure

PurposeTo simplify the circuit design and control complexity of the magnetic coupling resonant wireless charging system, the radio energy transmission constant current and constant voltage charging is realized.Design/methodology/approachThe purpose of this study is to simplify the circuit design and control complexity of the magnetic coupling resonance wireless charging system, in order to achieve constant current and constant voltage charging for wireless energy transmission. First, the principle of LCC/S-S compensation structure is analyzed, and the equivalent mathematical model is established; then, the system characteristics under constant current and constant voltage mode are analyzed, and the design method of system parameters is given; finally, a simulation and experimental system is built to verify the correctness and feasibility of the theoretical analysis.FindingsThe results show that the proposed hybrid topology can achieve a constant current output of 2 A and a constant voltage output of 30 V under variable load conditions, and effectively suppress the current distortion problem under light load conditions. The waveform distortion rate of the inverter current is reduced from 33.97% to 10.45%.Originality/valueBy changing the high-order impedance characteristics of the compensation structure, the distortion of the current waveform under light load is suppressed, and the overall stability and efficiency of the system are improved.

A reconstructed LCC‐LCC compensated inductive power transfer system with inherent constant current to constant voltage transition capability

SummaryDue to the merits of convenience and flexibility, inductive power transfer (IPT) systems have become popular for energy storage devices, such as lithium‐ion batteries, which require constant current (CC) and constant voltage (CV) outputs. The conventional LCC‐LCC topology with high design freedom is widely used for battery charging. The conventional LCC‐LCC topology achieves the initial CC output and the subsequent CV output by reconfiguring its topology or hopping its operating frequency, which increases the control complexity. This paper proposes a reconstructed LCC‐LCC compensated IPT system, which can achieve the inherent CC‐to‐CV transition without extra components and control methods. Compared with the conventional LCC‐LCC topology having CC and CV outputs, the operating frequency and topology of the proposed IPT system are fixed. Besides, the battery state of charge (SOC) detection and wireless communication are not required. The analysis and parameters design of the proposed IPT system is performed. Finally, an experimental prototype of the proposed IPT system with 48 V input and 72 V/2 A output is built to validate the proposal.

UAV-WPT System Based on Novel Magnetic Structure and Model Predictive Control.

In this paper, a UAV-WPT based on a new orthogonal coupling structure is first designed. An offset weight method is proposed to optimize the design of the system resonance parameters to improve the power transmission efficiency in the offset state. The coupling mechanism's coupling ability and anti-offset performance are experimented with using Ansys software simulation. The system adopts LCC-S topology and proposes a secondary side constant current control strategy based on the model prediction control to ensure constant current output in the case of coupling coefficient deviation. Finally, an experimental platform is designed for experiments. The results show that the system can quickly realize 3A constant current output under the change of load and coupling coefficient, and at the same time, improve the working efficiency of the system.

A Double-Receiver Compact SCC-WPT System With CV/CC Output for Mobile Devices Charging/Supply

The single capacitance coupled wireless power transfer (SCC-WPT) technology facilitates improving the spatial freedom of the system to offer charging/supply services in two-dimensional planar. This paper proposes a double-receiver SCC-WPT system with three-plate compact coupler to achieve free-position charging and superior system performance. The system consists of two independent receivers: one receiver adopts the LCLC-S topology to achieve constant-voltage (CV) output, while the other adopts the LCLC-M topology to achieve constant-current (CC) output and did not affect each other. By circuit analysis, a simplified equivalent circuit of the three-plate coupler is established and, on this basis, the CV and CC characteristics are theoretically analyzed. The effectiveness of the proposed system is verified by building a prototype system, where the coupler and parameters are designed and optimized. The experimental results show that the two receivers can realize CV output and CC output, respectively. The output characteristic of each receiver is almost unchanged when another receiver is removed or moved in. The receiver can obtain stable output power at any position within the transmitting plate.

A Control-Free Series Resonant Converter for Battery Charging With Automatic CC-to-CV Profile and Whole-Process High Efficiency

Constant current (CC) and constant voltage (CV) outputs are required by electric vehicle chargers to comply with the battery profile, which are challenges to the wide operating range, accurate current and voltage control, and high efficiency of the battery chargers. This paper proposes a control-free battery charger based on a series resonant converter (SRC) that features an inherent automatic CC-to-CV profile and whole-process high efficiency. Both the CC and CV modes enjoy identical switching sequences and operating waveforms, and the transition of CC-to-CV depends on the load condition. Automatic and smooth CC-CV transition can also be obtained after the CC charging process, thus avoiding the overvoltage charging risk. Detection of battery state and active control for the charging profile can therefore be eliminated, making the proposed battery charger rugged and reliable. The CC and CV outputs are flexibly configurable by setting the operating frequency and designing the turn ratio of the transformer respectively. Moreover, with an assistive circuit, soft switching can be realized for all switches regardless of the operating conditions to achieve a high efficiency throughout the whole charging process. Finally, a 1 kVA prototype is presented to validate the control-free and automatic CC-to-CV profile. High efficiency up to 98.4% is measured during the whole CC and CV charging periods.