An NMOS output-capacitorless low-dropout regulator with dynamic-strength event-driven charge pump

In this paper,an NMOS output-capacitorless low-dropout regulator(OCL-LDO)featuring dual-loop regulation has been proposed,achieving fast transient response with low power consumption.An event-driven charge pump(CP)loop with the dynamic strength control(DSC),is proposed in this paper,which overcomes trade-offs inherent in conventional structures.The presented design addresses and resolves the large signal stability issue,which has been previously overlooked in the event-driven charge pump structure.This breakthrough allows for the full exploitation of the charge-pump structure's poten-tial,particularly in enhancing transient recovery.Moreover,a dynamic error amplifier is utilized to attain precise regulation of the steady-state output voltage,leading to favorable static characteristics.A prototype chip has been fabricated in 65 nm CMOS technology.The measurement results show that the proposed OCL-LDO achieves a 410 nA low quiescent current(IQ)and can recover within 30 ns under 200 mA/10 ns loading change.

The Arc Regulation Characteristics of the High-Current Ion Source for the EAST Neutral Beam Injector

The arc regulation method is applied to the high-current ion source for high-power hydrogen ion beam extraction for the first time. The characteristics of the arc and beam, including the probe ion saturation current, the arc power and the beam current, are studied with feedback control. The results show that the arc regulation method can be successfully applied to ion beam extraction. This lays a sound foundation for the testing of a new ion source and the operation of a conditioned ion source for neutral beam injector devices.

Electrolytes additives for Zn metal anodes:regulation mechanism and current perspectives

With distinct advantages such as high gravimetric and volumetric capacity(5855 mAh·cm^(-3)and 820mAh·g^(-1)),low redox potential(-0.762 V vs.standard hydrogen electrode(SHE)),high abundance,low toxicity and intrinsic safety of Zn metal anode,Zn-ion batteries have become a potential alternative to Li-ion batteries.However,several challenges still need to be addressed prior to the practical applications of Zn-ion batteries,such as dendrite growth during Zn plating/stripping and interfacial side reactions on the Zn surface.Such issues can be addressed by introducing additives to regulate the components and structures of the electrolyte.In this review,we systematically discussed the core issues of metallic Zn anodes and comprehensively summarized a novel perspective of the regulation mechanism of inhibiting dendrite growth or interfacial side reactions in Zn anodes by introducing additives into aqueous electrolytes.Furthermore,some discussions and prospects for aqueous Zn ion batteries(AZIBs)are presented for future research.

Cystic fibrosis transmembrane conductance regulator functional evaluations in a G542X+/-IVS8Tn:T7/9 patient with acute recurrent pancreatitis

BACKGROUND Acute recurrent pancreatitis(ARP)is characterized by episodes of acute pancreatitis in an otherwise normal gland.When no cause of ARP is identifiable,the diagnosis of"idiopathic"ARP is given.Mutations in the cystic fibrosis transmembrane conductance regulator(CFTR)gene increase the risk of ARP by 3-to 4-times compared to the general population,while cystic fibrosis(CF)patients present with a 40-to 80-times higher risk of developing pancreatitis.CASE SUMMARY In non-classical CF or CFTR-related disorders,CFTR functional tests can help to ensure a proper diagnosis.We applied an individualized combination of standardized and new CFTR functional bioassays for a patient referred to the Verona CF Center for evaluation after several episodes of acute pancreatitis.The CFTR genotype was G542X+/-with IVS8Tn:T7/9 polymorphism.The sweat(Cl-)values were borderline.Intestinal current measurements were performed according to the European Cystic Fibrosis Society Standardized Operating Procedure.Recent nasal surgery for deviated septum did not allow for nasal potential difference measurements.Lung function and sputum cultures were normal;azoospermia was excluded.Pancreas divisum was excluded by imaging but hypoplasia of the left hepatic lobe was detected.Innovative tests applied in this case include sweat rate measurement by image analysis,CFTR function in monocytes evaluated using a membrane potential-sensitive fluorescent probe,and the intestinal organoids forskolin-induced swelling assay.CONCLUSION Combination of innovative CFTR functional assays might support a controversial diagnosis when CFTR-related disorders and/or non-classical CF are suspected.

An Ultra-Low Quiescent Current CMOS Low-Dropout Regulator with Small Output Voltage Variations

An ultra-low quiescent current low-dropout regulator with small output voltage variations and improved load regulation is presented in this paper. It makes use of dynamically-biased shunt feedback as the buffer stage and the LDO regulator can be stable for all load conditions. The proposed structure also employs a momentarily current-boosting circuit to reduce the output voltage to the normal value when output is switched from full load to no load. The whole circuit is designed in a 0.18 μm CMOS technology with a quiescent current of 550 nA. The maximum output voltage variation is less than 20 mV when used with 1 μF external capacitor.

The self-regulation process and its mechanism of channels' bed changes in the Changjiang(Yangtze) Estuary in China

Recent bathymetric changes in the Changjiang Estuary under the influence of artificial regulation engineerings and basin reservoirs have been analyzed based on the maritime charts since 1997 and recent fieldworks. The results indicate a slight erosion of the channels in the upper and middle estuary, continuing deposition and seaward move of the mouth bar crest and intensifying erosion at the nearshore seabed. It is noteworthy that the morphological evolution caused by intensive human activities dominates over the changes from nature process. First, the riverbes are eroded overall in the South Branch （SB）, the South Channel （SC） and the upper and middle reaches of the North Channel （NC）. The nearshore seabed outside the river mouth is being eroded slightly, which is attributed to the declining sediment supply from the Changjiang Basin due to the construction of the Three Gorges Dam upstream. The sediment above the seabed is very active and coarsened, meanwhile, sand waves are becoming more distinct. Second, a deposition occurs in the North Brach （NB）, the mouth of the NC, the mouth bars of the North Passage （NP） and the South Passage （SP） and especially the main channel of the NP, where it shows a massive siltation after the deep waterway project. The reasons for the recent changes are not only the dynamic structure in estuarine mouth bars, but also the supply of sediment resuspension in a local and offshore area. Meanwhile, the severe erosion and siltation in some reaches is related to the construction of estuarine engineerings. It is indicated that the Changjiang Estuary is gradually self-adjusted and adapting to the varying natural factors and intensive human activities. The study on the mechanism of self-regulation of the recent bathymetric changes in the Changjiang Estuary has important and practical significance.

STUDY OF HIGH-STABILITY CURRENT REGULATORS FOR CURRENT FROM 0.1A TO 8A

Improving the temperature stability and widening the constant current range are two important problems to be solved in the application of the current regulators. This paper introduces a modular approach for the design of the current regulator with a very wide current range. The test results show that their output current ranges from 0.1A to 8A, with its current temperature coefficient as low as 10-4/℃ to 10-5/℃ and limiting voltage lower than 0.4V.

Predicting Individual Phase Current in Couple Inductor Based Voltage Regulators (VRs)

Coupled inductor is one appealing technology to improve transient response and reduce output decoupling significantly in interleaved multi-phase voltage regulators (VRs). One known problem is that there is no mature solution yet to sense the individual phase current accurately in a lossless way for couple inductor based VRs design. This will impact VR some normal function in one phase mode. This paper proposes a new solution to this problem and simulation is conducted to verify effectiveness of the proposal.

A Model-Based Unmatched Disturbance Rejection Control Approach for Speed Regulation of a Converter-Driven DC Motor Using Output-Feedback

The speed regulation problem with only speed measurement is investigated in this paper for a permanent magnet direct current(DC)motor driven by a buck converter.By lumping all unknown matched/unmatched disturbances and uncertainties together,the traditional active disturbance rejection control(ADRC)approach provides an intuitive solution for the problem under consideration.However,for such a higher-order disturbed system,the increase of poles for the extended state observer(ESO)therein will lead to drastically growth of observer gains,which causes severe noise amplification.This paper aims to propose a new model-based disturbance rejection controller for the converter-driven DC motor system using output-feedback.Instead of estimating lumped disturbances directly,a new observer is constructed to estimate the desired steady state of control signal as well as errors between the real states and their desired steady-state responses.Thereafter,a controller with only speed measurement is proposed by utilizing the estimates.The performance of the proposed method is tested through experiments on dSPACE.It is further shown via numerical calculations and experimental results that the poles of the observer within the proposed control approach can be largely increased without significantly increasing magnitude of the observer gains.

Frequency Regulation of Alternating Current Microgrid Based on Hierarchical Control Using Fuzzy Logic

An alternating current(AC)microgrid is a system that integrates renewable power,power converters,controllers and loads.Hierarchical control can manage the frequency of the microgrid to prevent imbalance and collapse of the system.The existing frequency control methods use traditional proportion integration(PI)controllers,which cannot adjust PI parameters in real-time to respond to the status changes of the system.Hierarchical control driven by fuzzy logic allows real-time adjustment of the PI parameters and the method used a two-layer control structure.The primary control used droop control to adjust power distribution,and fuzzy logic was used in the voltage loop of the primary control.The secondary control was added to make up for frequency deviation caused by droop control,and fuzzy logic was used in the secondary frequency control to deal with the dynamic change of frequency caused by the disturbances of loads.The proposed method was simulated in Matlab/Simulink.In the primary control,the proposed method reduced the total harmonic distortion(THD)of two cycles of the output voltage from 4.19%to 3.89%;in the secondary control,the proposed method reduced the frequency fluctuation of the system by about 0.03 Hz and 0.04 Hz when the load was increased and decreased,respectively.The results show that the proposed methods have a better effect on frequency maintenance and voltage control of the AC microgrid.

超级电容技术支持下电力储能功率调节系统仿真

储能过程中,相电压、相电流的频繁变化是导致电力功率无法保持稳定状态的主要原因,为解决上述问题,针对超级电容技术支持下电力储能功率调节系统进行仿真设计。在主电路传输回路中,设置有源滤波器与并网逆变器,实现对储能功率的调节,完成电力储能功率调节系统硬件单元的仿真设计。定义超级电容模型,并将其串联在电力回路中,从而在控制电力脉冲功率的同时,实施对电功率的等效调试,完成对电力系统储能功率的全面调节。

无线电能传输系统恒流输出控制方法研究

此处提出了一种发射端控制的无线电能传输(WPT)系统输出恒流调节方法。该方法无需在接收端增加传感器和无线通信装置,即可实现对系统输出电流的调节,因此,能够减小接收端体积和重量。首先,建立WPT系统等效电路模型,考虑整流电路等效输入阻抗的电阻和电感分量,推导得到发射端电压/电流与负载电流之间的量化关系;然后,采集发射端并联电容电压有效值和输入直流电流值,并通过逆变器移相控制,实现系统恒流输出;最后,搭建WPT实验台架,实验结果表明:在变负载工况下,恒流控制精度在3%以内,动态调节时间小于200ms,从而实现了负载电流快速、精准的调节。

独立充放时序SIDO开关变换器电流型变频控制技术

单电感双输出(single-inductor dual-output,SIDO)开关变换器工作在共享充放时序下存在电感电流纹波大、输出支路间交叉影响严重以及电路参数宽范围变化下控制电路不能正常工作等问题.为此,提出一种独立充放时序电流型变频控制(current-mode variable frequency control,C-VF)技术.首先,具体描述变换器在连续导电模式(continuous conduction mode,CCM)下的工作原理,并推导主电路开环传递函数;进一步构建闭环小信号模型,推导闭环交叉阻抗,详细分析不同输出电压及负载电流下变换器的交叉影响特性;最后,通过仿真和实验进行验证.研究表明:相较于共享充放时序,独立充放时序C-VF CCM SIDO buck变换器减小了交叉影响,改善了负载瞬态响应性能;当两支路负载电压不等时,减轻某一支路负载可以降低该支路的交叉影响;当两支路输出电压相同但负载不同时,重载支路对轻载支路的交叉影响更小.

‘唐半夏’无菌繁殖体系建立

以‘唐半夏’块茎为试材,采用组织培养的方法,研究了不同种类及浓度的植物生长调节剂对不定芽诱导、增殖、生根的影响以及电流刺激对不定芽增殖的影响,以期为‘唐半夏’无性快速繁殖体系的建立提供参考依据。结果表明:最适不定芽诱导培养基为MS+1.5 mg·^(L-1)6-BA+0.1 mg·L^(-1)NAA,平均每个外植体诱导的不定芽数最多(9.38个)且诱导率为93.75%;采用电流刺激不仅提高不定芽的增殖倍数,且对‘唐半夏’植株的生长产生明显的促进作用。特别是20 mA、5 min处理下,不定芽增殖倍数最大(13.31倍),组培苗生长健壮且出现生根的现象。最适生根诱导培养基为1/2 MS+0.2 mg·L^(-1)NAA,生根率为100%,生根数为23.75条。

复矢量电流调节器抑制高速永磁电机高次谐波

永磁电机高速运行时,定子电流高次谐波的含量和幅值快速增加,增加涡流损耗、发热和转矩脉动,研究基于电压补偿改进算法抑制定子电流高次谐波。针对高速永磁同步电机运行过程中存在的交直轴电流分量强耦合以及电机参数非线性变化的问题,设计了复矢量电流调节器来提高解耦性能和动态响应以改进传统电压补偿的电流谐波抑制算法。首先,搭建了集成高速永磁同步电机模型、高速电机弱磁控制和谐波抑制算法的联合仿真模型。在此基础上,运用软件在环仿真方法,验证了复矢量电流调节器相比于传统的电压补偿算法的重大优越性。仿真结果表明,复矢量电流调节器大大降低了定子电流的高次谐波含量、总THD和转矩脉动。以上的研究可以为高速永磁电机高次谐波的抑制和仿真分析提供重要的理论和方法论指导。

应力调控下基于Skyrmion的晶体管特性

研究了不同应力、磁各向异性常数对电流驱动Skyrmion的动力学特性影响。随着施加应力增大,能够产生稳定Skyrmion的各向异性常数取值范围的上下限增大,即外加应力影响电流驱动时Skyrmion运行的稳定性。设计了一种宽-窄-宽型Skyrmion基晶体管,通过调控应力和各向异性常数来调控晶体管的开关特性。仿真结果表明,当极化电流密度、各向异性常数变化时,晶体管导通状态对应的应力范围也随之变化。研究结果为设计Skyrmion基晶体管及相关逻辑功能器件提供了新思路。

一种高PSR低静态电流LDO设计

设计了一种基于0.18μm BCD工艺的高电源抑制(PSR)低静态电流低压差线性稳压器(LDO)。详细分析了多条电源噪声传递路径对系统PSR的影响。为优化系统中低频段PSR,设计了一种双轨供电的三级误差放大器。此外还引入了预稳压单元,降低了电压基准模块对系统低频段PSR的影响。为降低系统的静态电流,设计了一种基于耗尽管的超低静态电流电压基准。仿真结果表明,该LDO在不同输出电压下静态电流仅5μA,并且在250 mA负载电流内PSR<-110 dB@1 kHz, PSR<-55 dB@1 MHz。

乙二胺作为电解锰新型pH调节剂

锰电解过程在(NH_(4))_(2)SO_(4)-MnSO_(4)体系进行时,需维持电解液pH值稳定在7.0~7.2。但阳极析氧反应使得长期电解条件下电解液pH值不断下降。生产上均使用氨水调节电解液pH值。但氨水易挥发,导致整个生产车间氨气味道刺鼻,影响身体健康。此外,持续加入氨水造成电解液中的氨不断累积膨胀,最终产生大量氨氮废水和氨氮锰渣。鉴于乙二胺与氨水的化学性质相似性,且具备更强的碱性及更低的挥发性,探索以乙二胺取代氨水作为pH值调节剂,以减少氨源的使用量、改善作业环境,探究乙二胺新体系电解锰的可行性。

混合式潮流控制器关键参数设计与控制策略研究

随着分布式光伏等新能源接入电网的规模快速增长,给新能源电力汇聚、疏散、消纳和电网潮流优化控制带来严峻挑战。基于电力电子技术的柔性交流输电系统装置可有效提升输电网络的传输容量,由大容量Sen变压器(sen transformer,ST)和小容量统一潮流控制器(unified power flow controller,UPFC)组成的混合式潮流控制器(hybrid unified power flow controller,HPFC)在实现潮流连续调节的基础上,能够有效提升装置的经济性,具有很好的应用前景。为了确保HPFC调节潮流的准确性和可靠性,给出了HPFC容量分配的一般性方法及其主电路参数确定方法;为解决ST机械有载分接开关和UPFC电力电子开关二者响应速度的协调问题,提出了一种基于预测电流控制的潮流控制策略,并在Simulink中搭建220 kV双回线路及三机九节点系统进行仿真。仿真结果验证了HPFC容量分配方法正确有效,且预测电流控制策略能够合理计算抽头位置,减缓过渡电流对HPFC控制系统的冲击,使系统功率快速调节至目标值。

一种高电源抑制比低温度系数的带隙基准电路

采用两种方式提高了带隙基准电路的电源抑制比。首先,采用峰值电流源结构将三极管自身的增益引入反馈环路,从而提高了环路增益和带隙基准核心的电源抑制比。其次,运用预调制电路进一步提高了电源抑制比。此外,还提出了一种仅需源极负反馈非对称电流镜的曲率补偿电路,该电路具有跨工艺的通用性。所提出的电路采用0.18μm BCD工艺进行了验证,并应用在一款降压DC-DC变换器中。结果表明,所提出的电路在2.4 V、3.3 V和5 V供电下,低频分别具有127 dB、134 dB和136 dB的高电源抑制比,同时实现了3.74×10^(-6)/℃的低温度系数,总电流消耗仅为6.3μA~14.5μA。