Combination Of Induction Research Articles

Hierarchical equalization scheme for retired lithium-ion battery packs based on inductor-flyback transformer

Some lithium-ion batteries can be reused after sorting and recombination. Equalization of these batteries during the process of step utilization is an effective way to improve the inconsistency of battery packs and extend their lifespan. This paper proposes a hierarchical equalization topology based on a combination of inductor and transformer, which is divided into intra-group and inter-group battery equalization. The intra-group equalization circuit achieves energy transfer between non-adjacent individual batteries through an improved Buck-Boost circuit. The inter-group equilibrium circuit exchanges energy between any battery subpackages and the entire battery pack using a flyback transformer. An LCD (Inductance-Capacitor-Diode) lossless absorption network is added to the transformer to absorb voltage spikes caused by leakage inductance while achieving soft switch to reduce switch losses. Considering that retired lithium-ion batteries can affect battery capacity and State of Charge (SOC) estimation accuracy due to aging issues, a modified Extended Kalman Filter (EKF) algorithm is proposed to improve battery SOC estimation accuracy. A fuzzy logic controller is introduced into the SOC-based control strategy to improve the equalization efficiency of the battery pack. Finally, to validate the effectiveness of the proposed equalization scheme, a model is built and simulated using MATLAB/Simulink software. The experimental results show that compared with the traditional double-layer inductor equalization scheme using the most value equalization algorithm and fuzzy logic control algorithm respectively, this equalization scheme has a faster equalization speed and higher equalization efficiency.

Minimization of Low Frequency Current Oscillation in Resonant Link of a Solid State Transformer by Passive Filters

Solid State Transformer (SST) is expected to be a key component in future smart grid systems, which integrates MVAC grid with LV DC/AC grid. For a three stage SST, resonant converter is a potential candidate as the DC-DC stage due to its high conversion efficiency. However, it exhibits an oscillation of 100 Hz (double line frequency) in the high frequency (HF) link current, which increases device current stress and conduction loss. This paper proposes an analytical model which determines the magnitude of this oscillation at different power factor operations. The obvious solution to minimize this oscillation is to keep a high value of capacitor at each MVDC bus, but it reduces the power density of the system. Therefore, this paper proposes an improved solution with a combination of inductor and capacitor at the LVDC bus. The proposed filter reduces the RMS value of the HF link current by 29% at unity power factor operation. The dynamics of the proposed filter is also included in the control system design by deriving a dynamic equivalent circuit in this paper. The design is verified in a laboratory prototype of 8 kVA, 1.65 kV/300 V solid state transformer.

Parametric Uncertainty Compensation and Ripple Mitigation Control for Family of Z-Converters

Unlike VSIs, the single-stage inverters (SSIs) from the family of Z-converters are capable of boosting input dc to a desired ac voltage. The Z-network of these converters consists of a symmetric X-shaped network or a combination of inductors and capacitors. The basic Z-source converter (ZSC), connected in X-shaped fashion is modeled as a fourth-order system. This can be further modeled as a second-order system to reduce the sensor count but this may lead to an unstable system if there is an asymmetry in network parameters. Also, the source current of SSIs contains second-order ripple current (SRC) component, which oscillates at twice the supply frequency and has detrimental effects on sources. To alleviate the above problems, a parametric uncertainty compensation and ripple mitigation (PUCRM) control methodology is proposed. PUCRM control can be used to maintain stability and achieve desired performance during parametric uncertainties in the dc–dc stage and to reduce SRC propagating to the sources while feeding ac loads. PUCRM consists of a nominal dual-loop PI controller, which regulates the SSIs to achieve desired performance and a nonlinear integral sliding mode component that mitigates the uncertainties and ripple component. The proposed method is verified using simulation and experimentation.

A Novel Dual-Mode Dual-Band Bandpass Filter Based on a Single Ring Resonator

In this paper, a dual-mode bandpass filter that operates in two different bands is proposed. A circular patch with a small circular hole is set as the basic resonator, and, as the circular hole moves, the linewidth of the ring resonator becomes non-uniform. Consequently, the ring resonator is structurally asymmetric and exhibits a dual-mode characteristic. A gap is formed in the middle of the resonator, a pair of inductors and capacitors is applied to the gap, and the proposed dual-mode structure operates as a dual-band filter. The first resonant frequency <i>f</i><sub>1</sub> is determined by the inductor and capacitor values, and the second resonant frequency <i>f</i><sub>2</sub> is determined by the capacitor values. In addition, the frequency ratio (<i>f</i><sub>2</sub>/<i>f</i><sub>1</sub>) can be adjusted by an appropriate combination of inductor and capacitor values.

Behavioral and Cognitive Reactions of Rats with Experimental Chronic Obstructive Lung Diseases of Different Degree

The study presents the results of behavioral phenotyping of rats with experimental chronic obstructive pulmonary disease (eCOPD) of different severity modeled by using a combination of inductors (purified papain and bacterial LPS) in increasing concentrations. Locomotor and exploratory activity, spatial memory, and anxiety were evaluated. In mild eCOPD, locomotor and exploratory activity increased, while other parameters did not differ from the control values. Rats with moderate eCOPD demonstrated moderately restricted locomotor function and increased anxiety. Severe eCOPD was associated with pronounced changes in all analyzed parameters. Correlation analysis revealed relationships between some behavioral parameters and blood oxygen saturation, inspiratory lung volume, and respiration rate. This indicates the role of respiratory failure in the pathogenesis of cognitive disorders.

수동형 필터 적용시 무효전력의 변화에 관한 연구

Generally, the low-voltage customer has been used with a linear load and nonlinear load in the 3-phase 4-wire distribution system. Linear load has usually configured the resistance and inductance, current phase is slower than the voltage phase, so power factor is low. It is required for the power factor correction device prior to the phase of the current than the voltage. The capacitor is connected in parallel to the load in order to ensure a low power factor. Power converter such as an inverter is a typical non-linear load. Non-linear load generates harmonic currents in the energy conversion process. Many electrical equipment may be adversely affected by the harmonic current. There, passive or active filter have been used to reduce these harmonics current. Passive filter consisting of inductor and capacitor generates a reactive power. According to the combination of filter inductor and capacitor, reactive power can be adjusted. In this paper, we analyzed how the combination of inductor and capacitor affects the overall power factor by simulation and measurement.

A NOVEL HIGH EFFICIENCY CONVERTER FOR RENEWABLE ENERGY GENERATION APPLICATIONS

Resonant converters are those, which has the L and C components that would provide a sinusoidal voltage or current wave during any sub interval in the switching interval. These wave form help in obtaining the Zero Voltage and Zero Current Switching to occur in the converters. The topology of the resonant converters uses the different combination of inductor and capacitors to obtain this property. The combination of this inductor and the capacitor is called the resonant tank. This project is to develop such a resonant converter, which utilizes the LLC resonant tank. This is a full bridge topology, which is a isolated topology in DC-DC converter topology. The isolation is happening because of the high frequency transformer placed between the inverter in the sourceside and the converter in the load side. The high frequency is obtained by switches of inverter in HF mode to supply to the source of the HF transformer. The multiphase converters are the main source that is used in the high performance point of load converters. This project uses the two-phase converter, which would split the current path into two in the source side. As the two currents join in the output capacitor the ripple at the output is reduced to half the value as the frequency of the ripple is doubled.The simulation work was carried out for both high efficiency LLC converter and full bridge converter of 14V input. Here, the efficiency of both the converters are calculated and was proved that efficiency of proposed system is higher than that of resonant converter of full bridge.

Coupled line based unequal dual band power divider

ABSTRACTThis article presents theoretical design of dual band unequal power divider based on coupled line structure. The structure consists of two coupled line segments along with five transmission line segments used to satisfy unequal matching characteristic. The isolation is achieved using a circuit, which is a combination of inductor, capacitor, and resistor. Design equations of proposed power divider and the circuit providing isolation are based on circuit representation of ideal transmission lines. Simulation and measured results are given to verify the theoretical design equations. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:953–956, 2016

Electrophysiological characteristics of cardiomyocyte-like cells from rat bone marrow derived mesenchymal stem cells by four inductors

Background Bone marrow derived mesenchymal stem cells (BMdMSCs) can differentiate into cardiomyocyte-like cells induced by different inductors individually or collectively. In this study, by inducing BMdMSCs with p53 inhibitor (p-fifty three inhibitor-alpha, PFT-α), 5-azacytidine (5-AZA), angiotensin-II (Ang-II) and bone morphogenic protein-2 (BMP-2) we compared the influences of four inductors on the differentiation of rat BMdMSCs into caridomyocyte like-cells. Methods BMdMSCs were collected from the bone marrow of Sprague Dawley rats and after the fourth generation, the purified cells were divided into five groups: 5-AZA (10 μmol/L), Ang-II (0.1 μmol/L), PFT-α (20 μmol/L), BMP-2 (10 μg/L) and control. The purity of the BMdMSCs and the cardiac differentiation rates were obtained by flow cytometry. The expressions of cTnT in the BMdMSCs after four weeks of induction were detected by immunofluorescence and the expressions of cTnI and Cx43 detected by Western blotting. The green fluorescent levels reflecting intracellular calcium transient function were determined by laser scanning confocal microscopy. The total potassium current levels of cells were measured on patch clamp. Results All inductors affected to a different degree the differentiation of BMdMSCs into cardiomyocyte-like cells and the expressions of cTnT, cTnI and Cx43 suggesting that the combination of inductors could be an improved method for cardiac regenerative medicine. In addition, the total potassium current level and calcium transient in PFT-α cardiomyocyte-like cells were higher than other groups. Conclusions The cardiac differentiation of BMdMSCs induced by PFT-α, 5-AZA, Ang-II and BMP-2 has been improved at different levels. PFT-α has an advantage of differentiation rate and electrophysiological function over other inductors.

On the radiofrequency system of ground plane booster antenna technology

Recent trends in handset antenna design are oriented to maximise the contribution of the ground plane to the radiation process. The challenge of these techniques mainly relies on the complexity of the radiofrequency system (combination of inductors, capacitors, and transmission lines) required to satisfy bandwidth and efficiency specifications. With the aim of simplifying the said radiofrequency system, proposed is a new solution capable of minimising the number of reactive components in a ground plane booster-based antenna technology. The results demonstrate that the number of reactive elements can be reduced by a factor around 3 with respect to previous solutions while improving the electromagnetic performance. The benefits of such reduction not only rely on a significant decrement of power losses but also on an enhancement of the performance and the integration capabilities. Based on the proposed architecture, hepta-band operation at GSM850/GSM900/DCS/PCS/UMTS/LTE2300/LTE2500 is achieved by means of two ground plane boosters of 5×5×5 mm and a radiofrequency system composed of only five reactive components.

A mixed-mode PWM controller

In this article, a mixed-mode (MM) PWM controller for dc–dc power converter topologies is presented and analysed. Compared to the conventional peak current-mode (PCM) controller, the proposed controller exhibits better results in terms of robustness towards load and reference voltage variations while maintaining better dynamic response. In the PCM controller, the control signal is a combination of inductor or, most often, switch current and a suitable compensation ramp which in the most common applications is constant. In the proposed controller, the constant compensation ramp has been replaced by a ramp voltage which is proportional to the output voltage taking into consideration the output voltage variations during load and reference transients. Consequently, the proposed controller, which exhibits the same advantages as with the PCM controller, additionally exhibits better load and reference performance for constant output voltage and output tracking applications without increasing the cost and the complexity of the control circuit. Finally, in order to verify the theoretical analysis and conclusions, both control schemes (i.e. PCM and MM) have been simulated and experimentally tested using a 75 W buck converter unit.

Development of LC resonator for label-free biomolecule detection

In this research, LC resonator was designed and tested for biomolecule detection. As the first step, 15 nH spiral inductor at 2 GHz and 15 pF inter-digital capacitor at 2 GHz were designed. And the measured each inductance and capacitance were 15.3 nH and 0.41 pF at 2 GHz. From both the data, LC resonator was designed by the combination of inductor and capacitor. The difference of return loss between bare device after fabrication and biotin binding was 1.87 dB, and biotin–avidin binding was 0.53 dB at 2.2 GHz, respectively. The impedances for bare device, biotin and avidin steps were Zo*(0.718-j0.002), Zo*(0.761-j0.003) and Zo*(0.803-j0.002) in the Smith chart, respectively. From the mentioned data, we can conclude that the return loss variation at resonance point is large distinctly. From the smith chart analysis, we can confirm that the biomolecule acts as a resistance and the increased resistance of the resonator leads to the impedance matching change.

A low-phase-noise and low-power multiband CMOS voltage-controlled oscillator

A low voltage multiband all-pMOS VCO was fabricated in a 0.18-/spl mu/m CMOS process. By using a combination of inductor and capacitor switching, four band (2.4, 2.5, 4.7, and 5 GHz) operation was realized using a single VCO. The VCO with an 1-V power supply has phase noises at 1-MHz offset from a 4.7-GHz carrier of -126 dBc/Hz and -134 dBc/Hz from a 2.4-GHz carrier. The VCO consumes 4.6 mW at 2.4 and 2.5 GHz, and 6 mW at 4.7 and 5 GHz, respectively. At 4.7 GHz, the VCO also achieves -80 dBc/Hz phase noise at 10-kHz offset with 2 mW power consumption.

Rod melting of intermetallic compounds by rf heating

With the help of a special combination of inductor and water-cooled copper boat it is possible to obtain compact rods of V3Si of up to 10 cm length with only 10 kW oscillator power.