Charge Circuit Research Articles

An Area and Power-Efficient Analog Li-Ion Battery Charger Circuit

The demand for greater battery life in low-power consumer electronics and implantable medical devices presents a need for improved energy efficiency in the management of small rechargeable cells. This paper describes an ultra-compact analog lithium-ion (Li-ion) battery charger with high energy efficiency. The charger presented here utilizes the tanh basis function of a subthreshold operational transconductance amplifier to smoothly transition between constant-current and constant-voltage charging regimes without the need for additional area- and power-consuming control circuitry. Current-domain circuitry for end-of-charge detection negates the need for precision-sense resistors in either the charging path or control loop. We show theoretically and experimentally that the low-frequency pole-zero nature of most battery impedances leads to inherent stability of the analog control loop. The circuit was fabricated in an AMI 0.5-μm complementary metal-oxide semiconductor process, and achieves 89.7% average power efficiency and an end voltage accuracy of 99.9% relative to the desired target 4.2 V, while consuming 0.16 mm(2) of chip area. To date and to the best of our knowledge, this design represents the most area-efficient and most energy-efficient battery charger circuit reported in the literature.

Analysis and Implementation of Half-Bridge Series–Parallel Resonant Converter for Battery Chargers

This paper presents a novel application of half-bridge series-parallel resonant converter (HBSPRC) for dc source and secondary battery interface. The converter practically eliminates both low- and high-frequency current ripple on the battery, thus maximizing battery life without penalizing the volume of the charger circuit. Moreover, operation above resonance is preferred, because the power switches turn on at zero current and zero voltage; thus, the freewheeling diodes do not need to have very fast reverse-recovery characteristics. The proposed battery charger circuit has few components and low-energy conversion loss, which enhance the system's overall efficiency. Circuit operation modes are determined from the conduction profiles. Operating equations and an operating theory are also developed. Experimental results based on a 12-V 48-Ah battery charger are proposed to validate the analysis and to demonstrate the performance of the proposed approach. The maximum charging efficiency of the proposed topology during the overall charging period is 93.98%. Satisfactory performance is obtained from the measured results.

Study on the circuit producing high-speed pulse with high peak current

To achieve high peak current with narrow pulse width, the circuit model is analyzed based on a fast and high-power metallic oxide semiconductor field effecttransistor (MOSFET) as the high speed switch of the resistor-capacitor (RC) charge and discharge circuits. It is easy to obtain a narrow high-current pulse by adopting the narrow triggering pulse to control the on-off state of the MOSFET switch, and using the driving pulse to modulate the exponential decay pulse in the RC discharge loop. The procedure for the high speed MOSFET switch is then discussed. To make the speed of the MOSFET switch as quick as possible, the push-pull driving circuit for the grid of the MOSFET is brought forward and the circuit for producing the narrow trigger pulse is designed. The experimental result shows that the full width at half maximum (FWHM) of the trigger pulse is about 500 ps when the narrow trigger pulse is connected with the discharge return circuit. Measured results demonstrate that the RC discharge loop produces a narrow high-current pulse, with a peak current of up to 92.5 A and FWHM of 6.2 ns. After adjusting relevant parameters, the peak current could reach up to 115.9 A. However, the corresponding pulse width is broadened. Finally, influencing factors on the narrow pulse width for the discharge loop are briefly analyzed.

A Novel Synchronous Buck Topology for Battery Charger

This paper introduced a novel synchronous buck converter with soft-swithcing (ZCS and ZVS) for battery charger. The converter structure is simple and easy control.New converter combines synchronous retification and soft-swithing (ZCS and ZVS) to decrease circuit losses. Moreover, the circuit is designed to make current never pass through body diode of synchronous rectifier. Thus,the circuit avoids diode recovery effects which happened frequently in sycnchronous converter topologies. The operating modes of the converter and equivalent circuits are identified by analyzing the operating principles of the charger circuit. Simulation results reveal the theoretical effectiveness of novel battery charger with little voltage ripple and circuit losses, fast dynamic reponse and high efficiency.

Design, development and construction of a low cost automatic 2 kva inverter system.

In this work, detailed techniques for the design and construction of a low cost automatic inverter system capable of converting 24Vdc to 220Vac 60Hz with a power handling capacity of 2 kVA have been presented with emphasis on the step-up transformer specification. The major modules of the inverter system consist of a driver and switching circuit; an automatic battery charger circuit; a battery voltage level indicator circuit; and a capacitive– inductive filter. Both solid-state and electromechanical relays were employed to provide automatic fast switching capabilities both in the presence or absence of public power supply (PPS) without voltage fluctuations supplied to the loads during the power switching process. Several experiments have been conducted with the automatic inverter system using different equipment with different power requirements. Analysis and results show that the designed and constructed inverter system has negligible output resistance with low power consumption and it is highly suitable for use in experimental and research laboratories as well as in domestic and industrial applications. KEYWORDS: Design and construction; automatic inverter system; automatic battery charger; battery voltage level indicator; driver and switching circuit.

The Realization of 16-Bit PWM for Lithium-Ion Battery Pack Charging by Using C8051F020 MCU

In the lithium-ion battery charging circuits, needs to solve the PWM signal and systems synthesis control item. Therefore, converting voltage feedback signal by C8051F020 MCU ADC0, the result which ADC0 converts delivers the Programmable Counter Array PCA0 module to realize 16-bit PWM trigger signal to control the charging circuit output. At the same time in producing the PWM signal, Use the ADC0 window detector to realize entering value surpassing range alarm and protection, Also, because 12-bit ADC0 is, therefore, Have carried out a recondition on the PCA0 value in program, have realized PWM control signal output, it's frequency is to set up, cause it's application to further nimble, control accuracy more highly.

Charge Strategy in Boost Motor Driver With EDLCs

The boost motor driver with electric double layer capacitors (EDLCs) was proposed. This driver was proved to be able to stably boost the dc-link voltage and reduce peak input power without degrading the motor-drive performance. In this paper, an EDLC charge strategy to operate the charge circuit implemented in the driver is presented. The strategy has three modes of operation: the initial charge mode, the driving charge mode, and the regenerative charge mode. In the initial charge mode, the charge circuit operates in order to charge the EDLCs before a motor drive. In contrast, the driving charge mode is operated in order to charge the EDLCs while a motor is driven. The charge circuit in the regenerative charge mode suppresses the increase in the dc-link voltage in regenerative braking. The experimental results confirm that the charge circuit can well perform in accordance with this charge strategy. Moreover, the comparison with the results of a conventional driver proves that the drive performance of the proposed driver does not degrade during the charge operation. Finally, the proposed driver is confirmed to be able to perform well without decreasing the EDLC voltage in extended duration drive.

Charge Characteristics by Exciting-Axis Voltage Vibration Method in Boost Driver With EDLCs

Charge-pumping boost driver (CPBD) with electric double-layer capacitors (EDLCs) was proposed by the author. CPBD has advantages over conventional drivers. However, CPBD comprises a charge circuit, including an inductor to charge the EDLCs, which increases size and cost of CPBD. This problem led to the proposal of noncharge-circuit charge-pumping boost driver (NCPBD) with EDLCs. NCPBD can be realized in a smaller and more reasonable configuration than CPBD because NCPBD does not comprise the charge circuit. In this paper, an EDLCs charge method, exciting-axis voltage vibration method (EVVM), is proposed for NCPBD. EVVM enables NCPBD eliminating the charge circuit to charge the EDLCs. Additionally, EVVM can work even in a motor standstill and in a constant speed drive. The charge performance by EVVM is experimentally confirmed to be sufficiently well. Additionally, the drive performance during the charge operation is proved not to degrade. From the experimental results, the charge characteristics of EVVM are reported. Then, these charge characteristics introduce a charge strategy. Finally, the charge experiment adopting the strategy confirms that EVVM enables NCPBD to drive the motor without decreasing the EDLCs voltage in an acceleration and deceleration drive.

A Compact Repetitive Unipolar Nanosecond-Pulse Generator for Dielectric Barrier Discharge Application

Dielectric barrier discharge excitated by pulsed power is a promising approach for producing nonthermal plasma at atmospheric pressure, but pulsed power generators vary widely in performance and should be chosen according to application requirements. In this paper, a repetitive unipolar nanosecond-pulse generator is constructed using resonant charging and one-stage magnetic compression circuits, where IGBT and magnetic switches are the key units, respectively. The generator is capable of providing repetitive pulses with a voltage of up to 30 kV and duration of 70 ns at a 300 resistive load. Output pulse voltage can be adjusted by varying ac input voltage or trigger pulse-width. This compact and convenient generator has been used successfully to produce stable dielectric barrier discharge.

High-Efficiency ZCS Buck Converter for Rechargeable Batteries

To obtain zero-current-switching (ZCS) operation, this paper develops a novel soft-switching approach for rechargeable batteries. By inserting an auxiliary switch in series with a resonant capacitor, the proposed topology can obtain a novel ZCS buck dc-dc battery charger and significantly decrease the switching losses in active power switches. The proposed ZCS dc-dc battery charger has a straightforward structure, low cost, easy control, and high efficiency. The operating principles and design procedure of the proposed charger are thoroughly analyzed. The optimal values of the resonant components are computed by applying the characteristic curve and electric functions derived from the circuit configuration. Finally, a prototype charger circuit designed for a 12-V 48-Ah lead acid battery is constructed and tested to confirm the theoretical predictions. The maximum charging efficiency of the proposed topology during the overall charging period is 90.3%. Satisfactory performance is obtained from the experimental results.

Double Protection Charger for Li-Ion Battery

A low cost battery charger is introduced in this paper. The charging feature meets the requirement of a Li-Ion rechargeable cell designed for electric vehicles and manufactured by E company. The charger is capable of constant current/constant voltage charging strategy, double over current/voltage protection and automatically offloaded with a sound alarm when the charging current is smaller than about 40mA. A detail circuit diagram and its operation principle are proposed and some experimental results are also given. All devices used in the charger circuit are very common and easily purchased. Because of its simple structure only a few modifications are needed to make one’s own specific charger.

A proposal of a power distortion compensator using a matrix converter

AbstractRecently, renewable resource supplies, such as fuel cells, photovoltaic cells, wind power, and engine generators for distributed power systems have been studied intensely. Conventional compensators with switching devices are constructed based on a voltage source inverter using six arms. Therefore, conventional power quality compensators require a large electrolytic capacitor in the DC link part of the equipment. The use of a large capacitor hinders downsizing efforts and the lowering of equipment costs.Direct converters, which do not have a large electrolytic capacitor and an initial charge circuit, can be used to realize downsizing and lowering of equipment costs, when compared with conventional converters.This paper proposes a new application of a matrix converter to a PM generator for power quality compensation, such as reactive power compensation, harmonic current, and power interruption. The novel point of this work is that the matrix converter provides reactive power with harmonic current. Simulated and experimental results confirm that the matrix converter can maintain high performance the same as a conventional active filter and an uninterruptible power supply (UPS). © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(4): 37–44, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20972

A Li-Ion Battery Charger With Smooth Control Circuit and Built-In Resistance Compensator for Achieving Stable and Fast Charging

A built-in resistance compensator (BRC) technique is presented to speed up the charging time of a lithium-ion battery. A smooth control circuit (SCC) is proposed to ensure the stable transition from the constant-current (CC) to the constant-voltage (CV) stage. Due to the external parasitic resistance of the Li-ion battery-pack system, the charger circuit switches from the CC to the CV stage without fully charging the cell. The BRC technique dynamically estimates the external resistance to extend the CC stage. The experimental results show that the period of the CC stage can be extended to 40% of that of the original design. The charging time is effectively reduced.

Investigation of changes in properties of activated carbon cloth upon polarization and of electrosorption of the dye basic blue-7

The changes taking place in surface and electrochemical properties of activated carbon cloth (ACC) upon polarization have been investigated. The ACC was polarized at +1.0, +2.0 and −2.0 mA for a period of 90 min. The surface properties such as specific surface area, pore volumes, pore size distribution, pH at the point of zero charge and the electrochemical properties such as specific capacitance, potential of zero charge and open circuit potentials of polarization-treated ACCs were determined. They were compared with the corresponding properties of pristine ACC. In the second part of the work electrosorptive removal of a polycyclic dye, basic blue-7 (BB-7), from its solutions in water, in 0.01 M Na 2SO 4 and in a buffer at pH 6.4 was studied. The adsorption/electrosorption data in the three media were treated according to pseudo-first-order kinetics. Good fits were obtained with the experimental and simulated data. Adsorption/electrosorption behavior of BB-7 in different media were discussed in terms of interactions between the ACC surface and the adsorbate with some proposed mechanisms.

Connection Algorithm Proposal of Real Time Digital Simulator with Miniaturized HTS SMES

Superconducting Magnetic Energy Storage (SMES) system is one of the key technologies to overcome the voltage sag, swell, interruption and frequency fluctuation by fast response speed of current charge and discharge. In order to evaluate the characteristics of over mega joule class grid connected High Temperature Superconducting (HTS) SMES system, the authors proposed an algorithm by which the SMES coil could be connected to the Real Time Digital Simulator (RTDS). Using the proposed algorithm, users can perform the simulation of voltage sag and frequency stabilization with a real SMES coil in real time and easily change the capacity of SMES system as much as they need. To demonstrate the algorithm, real charge and discharge circuit and active load were manufactured and experimented. The results show that the current from real system was well amplified and applied to the current source of simulation circuit in real time.

Proposal of optimal process parameters for polymethylmethacryl plastic adhesion using a pulsed Nd:YAG laser

In this study, we propose a pulsed Nd:YAG laser system that uses a sequential charge and discharge circuit to adhere polymethylmethacryl (PMMA) plastics. Two PMMA plastics adhere to each other when the red one transmits the laser beam and the black one absorbs it. The optimal adhesion depends on several process parameters, such as the charging voltage of the capacitor, the pulse rate [in pulses per second (pps)], the velocity of the target, and the laser beam diameter. We try to optimize the adhesion process parameters from trial-and-error experiments. It has proposed that the optimal adhesion process parameters are a charging voltage of 650 V, a pulse rate of 11 pps, a target velocity of 4.20 mm/s, and a laser beam diameter of 4.00 mm in this pulsed Nd:YAG laser system. In addition, we generalize the optimal conditions for plastic adhesion, such as energy per pulse, peak power, and the velocity of the target.

P‐91: Power Reduction Using Adiabatic Charge Method for PDP Driver Circuit

AbstractPlasma display is using an energy recovery circuit and can be reduced its circuit power consumption. However, further power reduction is necessary for large‐Size high resolution picture of in such as Super HDTV. Our theoretical relative power consumption in ideal adiabatic charge circuit is 0.81, and produced 2 steps adiabatic charge circuit is 0.93 of the conventional energy recovery circuit.

Low-Complexity MPPT Technique Exploiting the PV Module MPP Locus Characterization

This paper proposes a method for tracking the maximum power point (MPP) of a photovoltaic (PV) module that exploits the relation existing between the values of module voltage and current at the MPP (MPP locus). Experimental evidence shows that this relation tends to be linear in conditions of high solar irradiation. The analysis of the PV module electrical model allows one to justify this result and to derive a linear approximation of the MPP locus. Based on that, an MPP tracking strategy is devised which presents high effectiveness, low complexity, and the inherent possibility to compensate for temperature variations by periodically sensing the module open circuit voltage. The proposed method is particularly suitable for low-cost PV systems and has been successfully tested in a solar-powered 55-W battery charger circuit.

Safety in new onboard networks

Vehicle electrification largely depends upon the performance and reliability of the electrical energy storage system. This guideline is intended to focus primarily on safety requirements, and more specifically on those above the typical operating parameters, such as peak short circuit currents up to 4000 Amps as in the case of a severe malfunction. Tremendous arc energies have to be handled safely by the main contactors. In this presentation, the interaction of melt fuses on these contactors/relays as well as the necessity of pre charge circuits used for protection, will be further explored.

Dynamically Programmable Electronic Pill Dispenser System

Compliance in medicine dispensation has proven critical for dosage control, diagnosis, and treatment. We have designed, manufactured, and characterized a novel dynamically programmable e-pill dispensing system. Our system is initially programmed remotely through a cell phone. After programming, the system may be reconfigured in order to adapt pill dispensation to new conditions. In this paper we describe the mechanics, electronics, control, and communication protocols implemented. Our dyn-e-pill devices can be actuated for over 350 h with two pill retrievals per hour. We challenged the charging circuit and demonstrated that the system has a lifetime longer than 6 h with a 30 min charging cycle, while it lasts for 14 h of uninterrupted use with a full charge.