Broadband over Power Line (BPL): An Emerging Technology for Bangladesh

Broadband over Power Line (BPL) is an alternative means of providing high-speed Internet access, Voice over Internet Protocol (VoIP), and other broadband services to homes and businesses by using the existing medium voltage (MV) and low voltage (LV) power lines. This paper provides a comprehensive understanding about BPL with its implementation prospects. In this context, the existing power grid infrastructures are discussed elaborately. BPL system functionality with its components and its benefits over other access technologies is also pointed out. Implementation scenarios for various deployment options are illustrated here. The different implementation challenges for BPL system, such as the characteristics of power lines, attenuation problem, noise, potential interference with the other radio frequencies are also presented with their remedies. Comparative analysis between several broadband access technologies shows the feasibility of BPL deployments all over the world.

Cross-layer Resource Allocation on Broadband Power Line Based on Novel QoS-priority Scheduling Function in MAC Layer

Traditional resource allocation algorithms use the hierarchical system, which does not apply to the bad channel environment in broadband power line communication system. Introducing the idea of cross-layer can improve the utilization of resources and ensure the QoS of services. This paper proposes a cross-layer resource allocation on broadband power line based on QoS priority scheduling function on MAC layer. Firstly, the algorithm considers both of real-time users’ requirements for delay and non-real-time users’ requirements for queue length. And then user priority function is proposed. Then each user’s scheduled packets number is calculated according to its priority function. The scheduling sequences are based on the utility function. In physical layer, according to the scheduled packets, the algorithm allocates physical resources for packets. The simulation results show that the proposed algorithm give consideration to both latency and throughput of the system with improving users’ QoS.

A Power Line-delivered and Lamp-based Broadband Mobile Communication System

A new mobile communications network architecture is proposed to solve four existing bottlenecks that restrict the rapid development of mobile communications,as well as to meet the development demands of future broadband mobile communications. The architecture introduces the Information Lamp (IL),a novel device carrying out transceiver function,as the access point,besides providing light. It fulfills information interaction between the access points and radio access network through the power line (or fiber). The new system,supported by core technologies such as multi-antenna based distributed space-time signal processing and distributed radio resource management,integrates the wired and wireless networks to provide high-speed and high-quality mobile communication services.

A Miniaturized Broadband Wilkinson Power Divider Using Micro-Strip Branch Lines

A miniaturized broadband Wilkinson power divider is proposed. Micro-strip branch lines are introduced to replace multiple resistors used in multi-stage Wilkinson power dividers to increase the bandwidth of single-stage Wilkinson power dividers. To demonstrate its performance, an improved single-stage Wilkinson power divider with four micro-strip branch lines was designed. Simulated results show that the insert loss is better than 3.2 dB, the input return loss, output return loss, and isolation are better than 15 dB respectively, across a 76% bandwidth from 18 to 40 GHz. .

METHODS FOR IMPROVING EQUIDRIVING POWER-FREQUENCY CHARACTERISTICS OF BROADBAND HIGH POWER KLYSTRON

Two methods for improving the equidriving power-frequency characteristics of broad-band high power klystrons are presented. One is that a comb-line bandpass filter with someattenuation properties is inserted between the TWT driver and the klystron for compensatingthe gain-frequency characteristics of the klystron to get the required equidriving power-frequencycharacteristics. The other is that a reactive element is connected with the input cavity to changeits resonance frequencies f0 and QL, and thus to improve the power-frequency characteristics ofthe klystron.

基于BPLC的智能电网用电信息采集系统的应用研究

随着国家对智能电网的推进,用电信息采集系统作为用电自动化关键部分发展较快,由此,笔者介绍了国内智能电网用电信息采集系统的应用状况,并分析了该系统各种采集方式的优缺点,重点探讨了基于BPLC技术的用电信息采集系统的组网模式、技术特点,并以某小区为例给出了组网架构和方法以及运维效果。

基于自适应组播的BPLC网络高效组网协议

针对现有BPLC网络组网协议在回复关联确认消息的数量和时间上存在冗余的问题,对BPLC报文交互过程进行研究,提出一种基于自适应组播的高效组网协议。通过自适应地聚合关联确认消息并采用组播方式发送,在减少控制开销的同时加速发送部分关联确认消息。理论分析显示了该协议的有效性。仿真结果表明,与现有BPLC网络组网协议相比,该协议能够减少5.88%以上的控制开销并降低5.53%以上的入网时延。

基于深度强化学习的Π型阻抗匹配网络多参数最优求解方法

针对电力线信道阻抗变化复杂、负载阻抗不匹配造成通信质量差等问题,提出一种基于深度强化学习的Π型阻抗匹配网络多参数最优求解方法,并验证分析了深度强化学习对于寻找最优匹配参数的可行性。首先,建立Π型网络结构,推导窄带匹配和宽带匹配场景下的最优匹配目标函数。其次,采用深度强化学习,利用智能体的移动模拟实际匹配网络的元件参数变化,设置含有理论值与最优匹配值参数的公式作为奖励,构建寻优匹配模型。然后,分别仿真验证了窄带匹配和宽带匹配两种应用场景并优化模型的网络参数。最后,仿真结果证明,经过训练后的最优模型运行时间较短且准确度较高,能够较好地自动匹配电力线载波通信负载阻抗变化,改善和提高电力线载波通信质量。

宽带电力线通信网络多层信道资源分配方法

为增加通信网络的吞吐量,研究宽带电力线通信网络多层信道资源分配方法。提取网络的多层信道特征,运用香农定理计算信道容量;提取载波特性,分析传输特性;建立抗干扰模型,通过控制器计算最优抗干扰策略。运用KM算法进行信道资源分配,转换为图着色冲突问题,优化颜色冲突以有效利用信道资源,实现更佳的资源分配效果。实验结果表明,实验组的总体吞吐量达到了10000bits/s,信道的整体占用率平均为79.03%,能够充分利用所有可用信道。

基于摩擦纳米发电机的输电线路振动能量收集装置

在电力物联网蓬勃发展的当下,如何持续且长时间地供能成为了数以万计的传感器所要面临的技术难题。摩擦纳米发电机(triboelectric nanogenerator,TENG)作为新崛起的高效供能技术,在传感器的自供电领域有着非常广阔的应用前景。文中基于摩擦电工作原理,利用多层弹性体结构的垂直接触分离TENG,设计出一种面向输电线路微风振动的多层弹性体TENG能量采集装置。通过振动能量采集器输出性能测试平台模拟输电线路微风振动状态,对不同频率和振幅下能量采集器的基本电气特性进行测试,结合电能管理策略,构建面向输电线路微风振动的振动能量采集自供电系统,实现宽频带振动能量的高效采集与转换,完成对商用传感器的供能。最后,通过输电线路振动缩比模型验证文中所设计振动能量采集装置的有效性与可行性。文中设计的振动能量采集自供电系统能够有效地将输电线路宽频振动能量转换为电能,具有结构简易、经济性好的特点,解决了电力物联网传感器不能持久绿色供电的问题。

基于平行双线结构的低频场发生器设计

针对电磁辐射抗扰度测试天线在低频时辐射效率低、体积大、难以生成高电场强度的问题,设计了一款平行双线传输线电场发生器。该场发生器输入端使用阻抗比为1∶4的传输线变压器巴伦,实现了输入端与负载的阻抗匹配,以及非平衡端转化为平衡端;为保证场发生器电气性能的稳定性和可靠性,平行双线传输线采用直径为100 mm的铜管,负载采用耐大功率的无感陶磁电阻,能够承受2 500 W的连续波输入功率。实验结果显示该场发生器在10 kHz~100 MHz的频率范围内电压驻波比均小于1.9,在距场发生器中心0.5 m远处可产生高达200 V/m的电场强度,在1 m远处可产生50~100 V/m的场强。该电场发生器可旋转改变电极化方向,具有覆盖范围广、场强分布均匀、场强幅度高的特点,广泛应用于低频辐射抗扰度测试。

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。

宽带同轴径向合成器的研制

基于同轴传输线的功率合成理论和波导同轴变换,研制了一款6路径向合成器,输入端采用N型连接器,输出端采用双脊波导形式。利用高频电磁场仿真软件CST对模型进行了优化仿真,并对加工完成的径向合成器实物进行了小信号测试和大功率试验。测试结果显示,在4 GHz~8 GHz频带范围内,合成损耗小于0.36 dB,回波损耗小于-10 dB,峰值功率耐受高于5 kW。该径向合成器具有宽带、低插损、幅相一致性高、高功率耐受的特点,在宽带大功率合成领域具有广阔的工程应用价值。

Broadband hybrid model for relay-aided cooperative MIMO power line communication systems

A hybrid model for broadband multiple-input multiple-output(MIMO) relay-aided indoor power line communications(PLC) system was proposed in this paper. The proposed model combines the top-down and bottom-up approaches and extends to a two-hop relay-aided cooperative system with variable gain relay in amplify-and-forward(AF) mode. Based on the proposed PLC model and generated channel, the channel statistical characteristics are further investigated in 2 MHz^100 MHz bandwidth. Simulated results show that the proposed model overcomes the difficulties that the existing models need a lot of topological information of the network or measurements information. It provides a practical simulation analysis method for cooperative relay MIMO-PLC system. The results also show that cooperative MIMO relaying communications can improve the indoor PLC performances and communication reliability.

基于新型耦合线隔离网络的紧凑型宽带滤波功分器设计

基于耦合双线与三线结构,文章提出一种紧凑型宽带滤波功分器的设计方法。通过延长耦合三线结构中两输出边线为终端短路枝节,实现通带两侧带有传输零点的滤波响应。同时,文章利用延长的短路枝节,构造带通耦合线结构,用于新型隔离网络的设计,实现输出端口间良好的宽带隔离。为指导设计,文章根据奇偶模等效电路,对三端口滤波功分器的理论滤波响应进行了预测,分析实现良好端口隔离的阻抗条件,从而确定滤波功分器的初始尺寸和隔离电阻初始值。作为验证,利用多层平面印刷电路,设计、加工了一款中心频率位于1.93 GHz、3 dB相对带宽为60.5%的滤波功分器原型,并进行了测试。结果表明,该滤波功分器在0~2.26 GHz内实现了15 dB的端口隔离,实际电路的尺寸仅有0.35λg×0.17λg。

Analysis of electromagnetic field emitted from home plug power line used for indoor high-speed broadband communication

High-speed broadband power line communication(BPL)is a novel and practicable technique for NetatHome or home area local area networking(LAN).Because of the characteristics of BPL,the electromagnetic wave emitted from the BPL transmission media will influence the indoor electromagnetic environment,which would also affect the performance of other wireless communications.Based on the analysis of the communication channel characteristic,network impedance and attenuation characteristic of the BPL,this paper proposes a novel model for calculating the BPL radiation and the computer simulation model,which are proved by the coherence of the simulation and the test data.The interferences from the high-speed BPL to indoor wireless communications are analyzed to stipulate the standards of high-speed BPL in the future.

电力线载波技术的现状及发展

对电力线载波技术的现状及发展作了综述，介绍了数字电力线载波的几种主要技术及宽带电力线载波技术的应用。为了适应整个通信网发展数字化综合化的大趋势，电力线载波也应逐步实现通信业务的综合化、传输能力的宽带化和网络管理的智能化，并实现和远程网的无缝连接，才能充分发挥无所不在的电力线网络的通信潜能。

宽带MIMO-PLC随机参数信道建模与特性

为研究宽带多输入多输出(multi-input multi-output,MIMO)电力线通信(power line communications,PLC)信道的随机特性,提出了一种基于多导体的MIMO-PLC随机参数信道模型。在建模过程中利用统计分布来表征信道的物理参数,比较分析了参数随机且分支不同的MIMO-PLC宽带信道特征。结果表明,平均信道增益(average channel gain,ACG)服从正态分布,均方根时延扩展(root mean square delay spread,RMS-DS)服从对数正态分布,相干带宽(coherent bandwidth,CB)和均方根时延扩展成反比;分支数越多信道频率选择性衰落和RMS-DS越大,ACG、CB和信道容量越小;与单输入单输出(single-input single-output,SISO)PLC信道相比,MIMO信道的信道容量有较大提升。提出的随机参数模型为MIMO-PLC提供了一种具有实用价值的建模方法,该模型对在复杂环境下MIMO-PLC系统的研究、设计以及工程应用具有重要的指导意义。

中压宽带电力线通信接入及信道特性测试与分析

针对国内中压电网的结构和特性进行了分析,给出了国内中压线路的宽带电力线通信(PLC)接入方式及其接入原理,对中压线路的接入设备、接入接口进行了归纳,在此基础上完成了国内第1条实际的中压PLC信道的测试,给出了反映信道特性的测试结果并进行了分析与研究。所完成的中压PLC信号的传输实验和测试研究,为宽带PLC进一步向中压电力线发展提供了设计依据和技术储备,为未来中压线路全程长距离接入提供了参考数据和资料。

网络参数对低压宽带电力线信道的影响

在电力线载波信道的研究中，目前有关电网结构对电力线载波性能的影响研究较少，多径效应和频率选择性衰落现象难以从现有模型得到合理解释，也对电力线节点间的通信性能和路径拓扑中继理论支持不足，制约了宽带电力线载波通信性能的提升。针对此，通过使用基于传输线理论的方法对低压电力线通信信道仿真建模，分析了不同网络拓扑结构对频率为2～30MHz的低压宽带电力线信道特性的影响。仿真得到不同电力线长度、分支长度、单节点分支数、分布式分支数和负载阻抗的低压宽带电力线信道频率响应，并通过反傅里叶变换得到对应的信道时域冲激响应。结果表明，电力线信道频率响应中的峰值点和陷波频点的位置和衰减会受到上述网络参数的影响，时域冲激响应也会因此而衰减和失真。本文的研究对于宽带电力线通信技术在能源互联网中的有效应用具有重要意义。