The design of monitoring communication system Based on Power line carrier

The design of the power line carrier communication system was introduced in this paper,DSP was adopted as the hardware platform to complete the core task.DSP sending terminal delivered the collecting data to the DSP receiving terminal through the power line carrier, and the DSP receiving terminal send the data to PC through a serial port.The design improved the power line carrier communication system and the data transmission became faster and more reliable.The experiment results showed that the PER of the receiving data is less than 0.4%, which satisfied the power line carrier communication requirement Our design is feasible and effective.

Study of the EAST Fast Control Power Supply Based on Carrier Phase-Shift PWM

EAST （experimental advanced superconducting tokamak） fast control power supply is a high-capacity single-phase AC/DC/AC inverter power supply, which traces the displacement signal of plasma, and excites coils in a vacuum vessel to produce a magnetic field that realizes plasma stabilization. To meet the requirements of a large current and fast response, the multi- ple structure of the carrier phase-shift three-level inverter is presented, which realizes parallelled multi-inverters, raises the equivalent switching frequency of the inverters and improves the per- formance of output waves. In this work the design scheme is analyzed, and the output harmonic characteristic of parallel inverters is studied. The simulation and experimental results confirm that the scheme and control strategy is valid. The power supply system can supply a large current, and has a perfect performance on harmonic features as well as the ability of a fast response.

Bandwidth improvement of high power uni-traveling-carrier photodiodes by reducing the series resistance and capacitance

A backside illuminated mesa-structure In Ga As/In P modified uni-traveling-carrier photodiode（MUTC-PD） with wide bandwidth and high saturation power is fabricated and investigated. The device structure is optimized to reduce the capacitance and resistance. For the 22-μm-diameter device, the maximum responsivity at 1.55 μm is 0.5 A/W, and the 3-d B cutoff frequency reaches up to 28 GHz. The output photocurrent at the 1-d B compression point is measured to be 54 m A at 25 GHz, with a corresponding output radio frequency（RF） power of up to 15.5 d Bm. The saturation characteristics of the MUTC-PD are also verified by the electric field simulation, and electric field collapse is found to be the cause of the saturation phenomenon.

Degradation of effective carrier-power-to-noise densityratio based on code trackingspectral sensitivitycoefficient for GNSS radio frequencycompatibilityin C band

The frequency band between 5 010 MHz and 5 030 MHz allocated as C band has been used as a candidate in the global navigation satellite systems （GNSS） along with more and more naviga- tion services in L band. The potential benefits and technical requirements of C band for satellite navi- gation have been analyzed before. However the degradation of effective carrier-power-to-noise densi- ty ratio（ A （C/No ）eu） based on code tracking spectral sensitivity coefficient（ CT_SSC ） as a compati- bility assessment methodology for potential GNSS radio frequency compatibility in C-Band has not been discussed clearly. So the compatibility of the signals in the C band between BeiDou （BD） B1 C and GPS L1C, L1C/A, Galileo E1Os as the interoperability or classical signals in L band is analyzed. Simulation results reveal the interference degree between BD III B1C and GPS L1C/A, L1C, Galileo E1OS. The results can also reveal that the multiplexed binary offset carrier （MBOC） and binary phase shift keying （BPSK） modulation is not appropriate for C band.

面向电力线通信的基于Mitchell算法的OFDM同步检测方法

为了提高电力线通信系统中OFDM定时同步的准确度,文章基于低压电力线宽带载波通信互联互通技术规范下的物理层通信协议,提出了一种基于Mitchell算法的电力线载波通信符号定时算法。与理论本地互相关同步算法相比,文章的算法不需要进行乘法运算,易于硬件实现。与简化的单比特量化算法相比,该算法同步检测结果更加准确,峰值旁瓣更小,在低信噪比条件下符号定时更加准确。

Effect of Hot Carrier on Amplitude Modulation and Demodulation of Gaussian High Power Helicon Wave in Homogeneous Longitudinally Magnetized Strain Dependent Dielectric Material

In the present communication, the hydrodynamic model is used to investigate the amplitude modulation as well as demodulation of an electromagnetic wave of high power helicon pump wave into another helicon wave in strain dependent dielectric material incorporating carrier heating (CH) effects. The consideration of CH in modulation and demodulation is prime importance for the adding of new dimension in analysis of amplification of acoustic helicon wave. By using the dispersion relation, threshold pump electric filed and growth rate of unstable mode from the modulation and demodulation of the high power helicon wave well above from the threshold value will be discussed in the present analysis. The numerical analysis is applied to a strain dependent dielectric material, BaTiO3 at room temperature and irradiated with high power helicon wave of frequency 1.78 × 1014 Hz. This material is very sensitive to the pump intensities, therefore during studies, Gaussian shape of the helicon pump wave is considered during the propagation in stain dependent dielectric material and opto-acoustic wave in the form of Gaussian profile (ω0,κ0) is induced longitudinally along the crystallographic plane of BaTiO3. Its variation is caused by the available magnetic field (ωc), interaction length (z) and pulsed duration of interaction (τ). From the analysis of numerical results, the incorporation of CH effect can effectively modify the magnitude of modulation or demodulation of the amplitude of high power helicon laser wave through diffusion process. Not only the amplitude modulation and demodulation of the wave, the diffusion of the CH effectively modifies the growth rate of unstable mode of frequency in BaTiO3. The propagation of the threshold electric field shows the sinusoidal or complete Gaussian profile, whereas this profile is found to be completely lost in growth of unstable mode. It has also been seen that the growth rate is observed to be of the order of 108 - 1010 s-1 but from diffusion of carrier heating, and that its order is enhanced from 1010 - 1012 s-1 with the variation of the magnetized frequency from 1 to 2.5 × 1014 Hz.

基于窄带频谱分析的电力线载波通信干扰过滤技术

电力线路载波通信受到背景噪声、脉冲噪声等方面干扰因素影响,导致通信信号质量下降,为此提出一种基于窄带频谱分析的通信干扰过滤技术。首先构建近似模型分析通信信号特征,利用马尔可夫链模拟信道上脉冲噪声状态。然后基于窄带频谱分析算法,在信号频谱周期图下,利用正交数据窗分离直接频谱,筛选估计方差以避免频谱泄漏事件的发生。利用傅里叶变换计算特征频谱,估计信号能量的集中特性,分析通信信号,平衡信号振幅和干扰抑制。最后通过时频峰值实施干扰滤波,有效保证电力线载波通信信号质量。经过实验数据分析证明,所提技术的载波干扰幅值最小值为1.1 dB,载波通信信号误码率平均值为1.9%,方法耗时平均值为3.8 s。

串联补偿无线电能传输变换器载波通信研究

无线电能传输(WPT)负载电压、电流等状态信息需送到原边进行闭环控制和监控处理,副边到原边的通信至关重要。首先介绍了电容调制的WPT系统拓扑和工作原理,电容调制与否使得系统拓扑发生变化,未调制时原、副边拓扑为串/串(S/S)结构;调制时原、副边拓扑为串/串并(S/SP)结构。调制电容的投切形成两种状态来传递通信信息,且该状态变化可以反映到原边电流上。其次采用幅移键控(ASK)解调电路对原边电流处理即可还原通信信号,为提高解调精度和抗干扰能力,对ASK解调电路进行改进。最后通过仿真和实验验证了方案的有效性,实验结果表明,该系统在100 W的运行功率、2~5 kHz的通信频率下,可以精准完成副边到原边的通信。

室内VLC-WiFi异构网络中多色载波资源分配

可见光通信接入点(VLC AP)在室内密集部署的方式在扩大VLC-WiFi系统容量的同时,增加了覆盖的小区间干扰。为了降低小区间干扰,提高系统的吞吐量和平均用户满意度,本文设计了多色载波分配与功率控制(MCAPC)的资源分配方法。该方法依据VLC AP的部署位置和信道特性,采用软频率复用方法确定各VLC AP的无干扰的主载波和多色副载波,并设计基于匹配博弈的载波和子频带分配算法为用户分配异构网络的频带资源;最后,设计基于功率控制效用值的干扰抑制的载波功率控制算法进一步抑制小区间干扰。研究结果表明,所提MCAPC方法能够提高室内多色VLC-WiFi异构网的系统吞吐量和用户的平均满意度。

基于联合功率量/载波调制的DC-DC变换器功率/数据复合传输方法

DC-DC变换器可以同时进行功率变换和数据传输。针对较低通信速率限制功率/数据复合传输(power/data multiplexing transmission,PDMT)应用的难题,提出一种联合功率量/载波调制(joint power/carrier modulation,JPCM)的新方案。与传统二进制PDMT方案不同,JPCM同时对功率量/载波进行2FSK调制,实现两种数据并行传输,可以看作一种四进制FSK,有效提高通信速率。相较于传统四进制PDMT方案,JPCM方案解调环节所需带通滤波器数目可减少一半,且软件开销更低。首先,证明PDMT在理论上的可行性;然后,根据4种不同电压纹波频率配置不同码元,并设计了包含高低数据位调制的JPCM和基于滑动傅里叶变换的数据解调方案;此外,重点分析输出参考电压突变对通信的影响,动态调整阈值可有效抑制误码;最后,搭建一个由2个Buck变换器并联的实验装置,实验结果表明在稳态、负载突变和输出参考电压突变的工况下,JPCM方案均能实现20 kb/s的通信速率,验证了该方案的有效性。

基于功率控制环扰动的DC-DC变换器能量信息一体化研究

针对实现DC-DC变换器之间的信息交互较为复杂的问题,提出了一种基于功率控制环扰动实现其能量信息一体化的方法。通过在DC-DC变换器的传统功率控制环中叠加二进制频移键控(binary frequency shift keying,2FSK)信号作为扰动,将数据信息叠加到传统脉冲宽度调制(pulse-width modulation,PWM)信号中,使得该PWM信号同时包含数据信息,实现能量信息一体化。首先,给出基于2FSK的功率/数据双载波调制以及实时的滑动离散傅里叶变换(sliding discrete Fourier transform,SDFT)解调方案。然后,通过对Buck变换器的能量信息一体化模型进行小信号建模与分析可知,降低输入阻抗可提升通信的信噪比。最后搭建一个由两个Buck变换器并联的实验装置进行验证。实验结果表明在稳态和负载突变的工况下均可实现3 kb/s的稳定通信,验证了所提方法的可行性。该方法使得DC-DC变换器能同时进行功率变换和数据传输,提升数字化和智能化水平。

一种X波段机载MPM设计与工程实现

微波功率模块(MPM)是高集成度的一种微波发射机,它是真空放大器件应用的重大变革,涉及微波、真空电子、集成电源、微系统集成等多技术领域,具备单机功率大、频带宽、效率高、功率密度高、可靠性高等优点,可用于无人机电子对抗系统、有源相控阵、拖曳式高功率电子干扰诱饵、气象雷达等许多领域。文中介绍了一种X波段中功率机载MPM的设计方法,详细阐述了励磁电感、谐振电感、谐振电容三元素串联谐振全桥拓扑高压电源、载频脉冲调制器、模块结构与热设计及其关键技术,并给出了实测数据,以期给相关从业人员带来一些启发和帮助。该项目研制的MPM已在外场成功完成空空、空地试验应用,性能非常好,可推广使用。

加权K-Means与DRSS定位结合的GNSS干扰源定位方法

针对基于载噪比(carrier to noise ratio,CNR)的GNSS干扰源定位,在存在多个干扰源、多径传输且接收机间距较远时定位难度大、精度低的问题,提出了一种加权K均值(K-Means)聚类算法与基于差分接收信号强度(differential received signal strength,DRSS)的方程解算定位相结合的多干扰源定位方法.在假设干扰源个数确定以及单个接收机只受到一个干扰源影响的前提下,设计了改进的加权K-Means聚类算法实现对多个干扰源位置的初步估计.为了进一步降低在观测接收机相距较远时加权K-Means方法的定位误差,在聚类后选取各簇内受干扰影响显著的接收CNR构建基于DRSS的定位方程组,通过方程解算得到更加精细的定位结果.仿真结果表明,所提出的定位方案可以实现对多干扰源的定位,结合DRSS参数定位后,单干扰源场景下定位误差可降低19%以上,存在两个单音干扰源的场景下定位误差可降低38%以上.

基于电力线载波通信的光伏汇流箱监测单元设计

该文介绍了一种光伏汇流箱智能监测设备,其采用模块化设计,支持多种通信方式;可将通信数据通过已有光伏电缆传输,不需要额外布通信线;支持标准MODBUS-RTU协议,可在线进行程序升级,方便配合各类监控后台系统监测数据;测试数据精度满足测量标准,能够实现电流测量、模拟量测量及报警功能。

基于Mask R-CNN的电力关键设备载波运行状态检测

为解决因载波信号大幅波动造成的电力设备运行状态检测失准问题,提出基于Mask R-CNN的电力关键设备载波运行状态检测方法。在Mask R-CNN网络模型中,通过定义小波基向量的方法确定电力载波暂态系数的计算结果。联合电量阻抗特征,求解连续阈值区间表达式,将获取到的电力载波信号放置在已定义阈值区间内。计算奇异值检测系数的取值条件,完成电力关键设备载波运行状态检测。对比实验结果表明,所提方法可以将电力载波信号波动幅值控制在±17 dB之间,对载波信号波动行为起到了明显的抑制作用,能够提升电网主机对电力设备运行状态检测的准确性。

基于多参数识别的电力载波通信信号监测系统设计

电力载波通信信号在传输过程中存在衰减,为降低电力载波通信传输误码率,实时监测信号传输行为,设计了基于多参数识别的电力载波通信信号监测系统。根据动态遗忘因子取值范围,建立多参数识别机制,再联合相关载波通信数据,求解信号衰减参数,完成对电力载波通信的可行性分析。按照载波通信体系整体架构的布局形式,确定滤波器、耦合器元件所属连接位置,完成电力载波通信信号监测系统设计。对比实验结果表明,在多参数识别机制作用下,电力载波通信传输误码率最大值仅为23.5%,在实时监测信号传输行为方面具有突出应用价值。

双用户分组上行多载波非正交多址接入的能耗最小化

为实现边境地区无线传感网长期工作,采用无人机与非正交多址(Non-Orthogonal Multiple Access,NOMA)技术结合的网络对分布在狭长边境线的传感器进行数据采集,以有效降低无线传感网(Wireless Sensor Networks,WSNs)的能耗。传感器用户组以多载波NOMA方式上传数据至无人机,在最大发射功率、用户服务质量(Quality of Service,QoS)及无人机移动性的约束下,通过优化传感器用户调度和分组、发射功率及无人机轨迹最小化所有传感器总能耗。该优化问题为混合整数非线性优化问题,将其分解为3个子问题求解。利用穷举搜索、拉格朗日对偶分解和逐次凸逼近(Successive Convex Approximation,SCA)依次求解各子问题并迭代优化,得到能耗最小值。仿真结果表明,所提方案可以有效降低无线传感网总能耗。

电力物联网载波通信节点数据聚合隐私保护算法

电力物联网对通信数据的处理必须遵循隐私连接协议,为保障电力载波通信效果,维护数据的隐私性,提出电力物联网载波通信节点数据聚合隐私保护算法。在电力物联网载波通信平台中,定义完整的聚合映射表达式,完成对载波通信节点数据的聚合处理。按照隐私加密协议,求解多维聚合向量与审计参数,保证电力物联网主机能对通信数据进行编码处理,实现电力物联网载波通信节点数据聚合隐私保护算法的设计。实验结果表明,在所提算法作用下,数据链路聚合长度最大值达到了9.4×10^(8)bit,且物联网主机对于通信数据的处理完全遵循隐私连接协议,能够实现高水平的电力载波通信。

基于“边端协同”架构的台区短路故障定位技术

针对新型电力系统低压台区故障准确定位要求,开发了一种基于“边端协同”架构的低压台区短路故障定位技术。提出多层级短路故障定位的台区物联网架构体系,研究采用二阶最小二乘拟合算法的台区各层级物联终端短路故障检测方法;设计基于高速电力线宽带载波通信的故障定位通信协议,面向智能配变终端,提出基于台区拓扑结构的短路故障定位策略,并开展边缘计算及其硬件化技术实现。在此基础上,通过真型低压交流系统短路故障测试实验,验证了“边端协同”物联台区短路故障定位技术的有效性。