Three-dimensionalization via control of laser-structuring parameters for high energy and high power lithium-ion battery under various operating con ditions

Laser-structuring is an effective method to promote ion diffusion and improve the performance of lithium-ion battery(LIB)electrodes.In this work,the effects of laser structuring parameters(groove pitch and depth)on the fundamental characteristics of LIB electrode,such as interfacial area,internal resistances,material loss and electrochemical performance,are investigated,LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) cathodes were structured by a femtosecond laser by varying groove depth and pitch,which resulted in a material loss of 5%-14%and an increase of 140%-260%in the in terfacial area between electrode surface and electrolyte.It is shown that the importance of groove depth and pitch on the electrochemical performance(specific capacity and areal discharge capacity)of laser-structured electrode varies with current rates.Groove pitch is more im porta nt at low current rate but groove depth is at high curre nt rate.From the mapping of lithium concentration within the electrodes of varying groove depth and pitch by laser-induced breakdown spectroscopy,it is verified that the groove functions as a diffusion path for lithium ions.The ionic,electronic,and charge transfer resistances measured with symmetric and half cells showed that these internal resistances are differently affected by laser structuring parameters and the changes in porosity,ionic diffusion and electronic pathways.It is demonstrated that the laser structuring parameters for maximum electrode performance and minimum capacity loss should be determined in consideration of the main operating conditions of LIBs.

A Home Appliance Recognition System Using the Approach of Measuring Power Consumption and Power Factor on the Electrical Panel, Based on Energy Meter ICs

Currently a large effort is being done with the intention to educate people about how much energy each electrical appliance uses in their houses, since this knowledge is the fundamental basis of energy efficiency programs that can be managed by the household owners. This paper presents a simple yet functional non-intrusive method for electric power measurement that can be applied in energy efficiency programs, in order to provide a better knowledge of the energy consumption of the appliances in a home.

Energy band adjustment of 808 nm GaAs laser power converters via gradient doping

The gradient doping regions were employed in the emitter layer and the base layer of GaAs based laser power converters(LPCs).Silvaco TCAD was used to numerically simulate the linear gradient doping and exponential gradient doping structure,and analyze the transport process of photogenerated carriers.Energy band adjustment via gradient doping improved the separation and transport efficiency of photogenerated carriers and reduced the total recombination rate of GaAs LPCs.Compared with traditional structure of LPCs,the photoelectric conversion efficiency of LPCs with linear and exponential gradient doping structure were improved from 52.7%to 57.2%and 57.7%,respectively,under 808 nm laser light at the power density of 1 W/cm^(2).

A new method of electric energy metering considering harmonic responsibility

Aiming at the shortcomings of the existing electric energy metering method,combining with the harmonic responsibility analysis model based on the reference impedance method and the idea of apparent power decomposition in IEEE Std 1459-2010 standard,two new metering indicators—billing active power and billing power factor are defined.A new electric energy metering method is proposed and its specific implementation steps are given.The simulation model is built in Matlab/Simulink,and three different examples are set up.Using the simulation data,the various metering indicators need to be examined by the existing electric energy metering method and the new electric energy metering method are calculated.The calculation results show that the new electric energy metering method not only overcomes the shortcomings of the existing electric energy metering method,but also is very easy to be popularized and applied.

定向能武器在电磁空间的运用

为探讨以激光武器和高功率微波武器为代表的定向能武器在电磁空间中的作战应用,采用演绎和类比的研究方法,从电磁频谱的物理原理和战争基本规律出发,论述电磁空间的基本性质、电磁火力的基本特点、电磁精确战的基本原理,以及定向能武器的基本定位、优势劣势、软硬杀伤。分析定向能武器在电磁空间的信息破坏力与信息创造力,梳理总结定向能武器的主要作战场景及运用方式,最后就加快定向能武器走向实战提出建议。

分布式储能在成都科幻馆的应用

通过电化学储能在2023年第81届世界科幻大会主场馆——成都科幻馆项目的示范应用,重点从应用场景、并网接入电压、接入系统方案、运行策略等方面分析用户侧分布式储能在民用建筑的应用要点。

面向新型电力系统的电能计量技术

简述了新型电力系统呈现的新特性,分析了电能准确计量面临的突出问题。针对新型电力系统中对电能计量的新需求,提出了电能计量技术的创新发展方向,给出了一种多源互补场景的电能计量应用架构。

大功率高能脉冲激光电源设计

根据YAG激光器对大功率高能量脉冲电源的应用需求,设计了一种大功率脉冲激光电源,可实现高脉冲能量重复频率输出及充电电压灵活调控。前级充电网络采用串联LC谐振变换器,后级脉冲形成网络选择晶闸管触发LC放电电路。最终,研制了1台7 kW实验样机,最大重复频率10 Hz,最高充电电压2.2 kV,可实现单脉冲最高700 J电能输出,满足大功率高能脉冲输出的应用需求,实验测试结果验证了设计的可行性。

机载130 mJ激光照射器的脉冲驱动电源设计

针对机载130 mJ激光照射器对脉冲驱动电源的实际使用需求,设计了一款高可靠性、宽温度范围、小型化的脉冲驱动电源。采用了基于超低ESR储能单元的前级低功率充电、后级高功率脉冲放电的技术方案。详细设计中,防反及缓启电路采用双PMOS管的方式;BOOST升压式充电电路选用具有开关频率可调、逐周期电流限制的控制芯片CYT5022JVS;储能单元由多只超低ESR的高分子固态铝电解电容器并联构成;放电电路开关管选用两只2.3 mΩ导通内阻的IRF150P220并联来降低发热功率。为保证宽温工作范围,采用电压补偿的方式来解决高、低温下储能单元容值变化的问题。测试表明,驱动电源能够输出峰值160 A、脉宽230μs、频率25 Hz的脉冲电流,激光照射器在照射模式下单脉冲平均能量大于130 mJ,满足系统要求。

量子功率标准综述:原理、现状及展望

随着国际单位制(International System of Units,SI)量子化变革的稳步推进和广域落地实施,以更加准确、稳定的量子计量标准替代实物计量标准,已成为计量学领域的重点攻关任务之一。量子功率标准对电能的精准计量将发挥关键作用,可有力保障电能贸易结算、电碳交易的公平和公正。首先,该文从交流功率标准和直流功率标准两方面,对当前国内外功率标准研究现状进行了综述。对于交流功率标准,分别阐述了工频交流功率标准和宽频交流功率标准的基本架构、测量原理,指出基于热电变换器的交流功率标准可实现工频和宽频(百kHz)交流功率的高准确度溯源,而国内外已有交流量子功率标准的工作频带一般不超过400Hz,需开展宽频交流量子功率标准研究;对于直流功率标准,国内外还处于初步研究阶段,由于当前尚缺乏对直流电压、电流信号的标准化定义,导致应以何种形式的直流功率信号作为标准被测对象尚不明确,无法为构建直流量子功率标准提供方向性指导。随后,该文对比分析了不同的功率标准,给出了对当前构建功率标准所存在问题的思考,并试对交、直流功率标准的未来发展做出展望:随着宽频量子电压标准技术的发展与进步,有望实现宽频量子功率标准;同时,开展宽频、宽量限电压、电流放大器和比例技术的研究,是实现高准确度交、直流量子功率标准的重要前提。

无线激光功率计数据采集传输模块设计

为实现远程激光功率的测量并保证数据传输的安全性,设计了一种非联网的无线激光功率计数据采集传输模块。该模块由三个部分组成:STM32数据采集模块、无线RS485透传模块和Qt上位机软件。其中STM32数据采集模块将探测器采集的电压模拟信号转换为数字信号,无线RS485透传模块负责STM32数据采集模块与PC端的数据通信,Qt上位机程序处理接收的数据并显示实时激光功率曲线。验证实验结果表明,在1 km传输距离下,该模块成功采集到完整的激光功率曲线,数据传输出错率为0。该模块实现了远距离、高速率的功率数据采集和传输功能,为后期无线激光功率计的研制工作奠定了基础。

基于微通道散热的板条激光放大器热仿真分析

众所周知,热效应是限制大功率高能量激光器发展的一大瓶颈,在高能激光产生的过程中伴随着大量的废热产生,影响高能量激光器的光束质量甚至会影响其正常工作。为了保证高能量激光器的稳定运作并研究其工作物质的散热过程中的热分布状态,本文建立了一种用于高能Zig Zag板条激光放大器的双端入水微通道散热模型,利用CFD模拟仿真软件在额定工况下对微通道与空腔热沉进行散热对比,还研究了模型的可变参量:通道高度、翅片厚度,以及水流量对于散热性能的影响。模拟研究发现本文提出的微通道热沉冷却效果优于全腔水冷效果,微通道热沉将晶体表面最高温差控制在4℃以内,表面温度也降低了32;同时在压降允许范围内优化通道参数能再将冷却效果提升10,实现增益介质分布式高效散热。

基于电能计量的中央空调冷量分摊方法

在国家“双碳”重大战略驱动下,中央空调系统逐渐成为助力国家节能减排的重要担当。为充分调动中央空调用户的节能积极性,提高中央空调分户计费精确性,该文在分析风机盘管供冷量与耗电量关系的基础上,提出了一种基于电能计量的中央空调分户冷量分摊方法。通过仿真比较得出,该方法在低投资情况下有效地提高了中央空调分户计量冷量分摊的精度,保证了空调分户计费的公平性,更好地促进国家中央空调分户计量任务的推广。

Remote electric powering by germanium photovoltaic conversion of an Erbium-fiber laser beam

The commercially available 4000-Watt continuous-wave(CW)Erbium-doped-fiber laser,emitting at the 1567-nm wavelength where the atmosphere has high transmission,provides an opportunity for harvesting electric power at remote“off the grid”locations using a multi-module photovoltaic(PV)“receiver”panel.This paper proposes a 32-element monocrystalline thick-layer Germanium PV panel for efficient harvesting of a collimated 1.13-m-diam beam.The 0.78-m^(2) PV panel is constructed from commercial Ge wafers.For incident CW laser-beam power in the 4000 to 10,000 W range,our thermal,electrical,and infrared simulations predict 660 to 1510 Watts of electrical output at the panel temperatures of 350 to 423 K.

High-energy and high-peak-power GHz burst-mode all-fiber laser with a uniform envelope and tunable intra-burst pulses

We report a Yb-doped all-fiber laser system generating burst-mode pulses with high energy and high peak power at a GHz intra-burst repetition rate.To acquire the uniform burst envelope,a double-pre-compensation structure with an arbitrary waveform laser diode driver and an acoustic optical modulator is utilized for the first time.The synchronous pumping is utilized for the system to reduce the burst repetition rate to 100 Hz and suppress the amplified spontaneous emission effect.By adjusting the gain of every stage,uniform envelopes with different output energies can be easily obtained.The intra-burst repetition rate can be tuned from 0.5 to 10 GHz actively modulated by an electro-optic modulator.Optimized by timing control of eight channels of analog signal and amplified by seven stages of Yb-doped fiber amplifier,the pulse energy achieves 13.3 mJ at 0.5 ns intra-burst pulse duration,and the maximum peak power reaches approximately3.6 MW at 48 ps intra-burst pulse duration.To the best of our knowledge,for reported burst-mode all-fiber lasers,this is a record for output energy and peak power with nanosecond-level burst duration,and the widest tuning range of the intra-burst repetition rate.In particular,this flexibly tunable burst-mode laser system can be directly applied to generate high-power frequency-tunable microwaves.

电能计量自动化系统在电力营销中的应用探讨

现阶段,计量自动化系统逐渐成为电力发展一大趋势,将该系统用于电力营销中,不仅可以提高电网自动化水平,还能够达到节电保电的目的。计量自动化系统是集各级计量点与采集终点为一体的现代化应用平台,随着电力系统的日益发展,电能计量自动化系统在电力营销中的关键性作用凸显,因此,电力企业要根据自身发展需要及发展状况合理应用电能计量自动化系统,重视其在电力营销中的应用程度,在提供用电数据的基础上,提高电力企业经济利润。

一种不须停电且无电量损失的电能表更换方法

现有电能表更换技术普遍存在若干问题,实用性较差。为此,文章提出一种实用性很强的电能表更换方法,该方法基本步骤是通过换表线先行并入新表,然后拆离旧表,最后装上新表。该方法具有不须用户停电、不存在电量损失、电量交接简单、绝缘防护完善等优点。

计及电力数据安全的智能合约上链方法及防篡改技术研究

随着“大云物移智链”等数字化技术在能源电力领域迅猛发展,大量新兴技术快速地在电网业务系统中进行创新应用,导致用电信息采集系统中数据交互更加频繁,从而出现数据经过流转后发生缺失、损坏等问题,进而导致业务数据公信力下降,且流转过程不清晰不透明,难以进行数据追溯溯源。针对用电信息采集系统数据可信度低、溯源难等问题,分析了区块链技术在用电信息采集系统应用情况,设计了区块链-用电信息采集系统三元结构模型,提出了一种采用区块链-用电信息采集系统三元结构的基于改进模型的实用型哈希算法的结构防篡改加密算法。仿真结果表明,区块链-用电信息采集系统三元结构的防篡改加密算法可提升数据质量进而提升业务数据公信力,同时通过该结构增强了数据的溯源能力,极大提升了用电信息采集系统数据在交互和使用过程的安全性。

谐波条件下感应式电能表误差校验方法研究

在谐波存在的情况下,电流、电压工作磁通会随着谐波频率的增大而减小,驱动力矩也随之减小,使得电能表转速减慢,计量失准。为提升电能计量系统的准确性和可靠性,研究了谐波条件下感应式电能表误差校验方法。通过计算感应式电能表实际电能消耗,可以定量评估谐波对电能表计量误差的影响程度,由此得到谐波误差。结合谐波误差,在Budeanu功率定义的基础上,引入谐波特性系数,构建感应式电能表计量误差的校验模型,并采用基于功能驱动原理的赋权法确定电能表对各次谐波的重要计量特性系数,实现谐波条件下感应式电能表误差校验。实验结果表明,该方法校验后的电能读数实际电能值偏差均在0.02 kW·h以下,并且受温度的影响较小,在稳定性、变差和反应时间三个关键性能指标上均表现最佳。

智能物联电能表扩展功能模组设计

在能源转型和数字化革命的大背景之下,仅具备传统计量、收费、通信功能的智能电能表,已经无法支撑能源互联网快速发展带来的迫切需求。文中设计了一款具备硬件扩展功能的智能物联电能表,通过采用多芯、模组化的理念,设计各类模组的标准化接口,为扩展功能模组提供电源、通信接口以及原始采样数据,可满足电力用户多样化的应用需求。以需要开展电能质量分析的应用场景为例,设计了智能物联电能表用电能质量监测模组,并通过试验验证了扩展功能模组的功能及数据监测的准确性。