Contribution for Efficient Planning of Millimeter Wave Frequencies: Case of the 80 GHz E-Band for High-Speed Broadband Transmissions

Due to the very high demand for Internet data capacity from mobile and fixed customers as well as the saturation of conventional frequency bands by numerous services, many countries have opened the E band, for broadcasting services. E-band involves the creation of a significant number of links in a given area. The present work addressed the problem that arises in the context of transmission is that of assigning the frequencies of this band to these multiple transmission links. The aim of this work is to study and plan the radio links of the 80 GHz frequency and to implement them in a tool in order to define an optimal distribution on the telecommunications network by guaranteeing maximum flow of data traffic while minimizing the interference. The contribution of this work is part of its unique subject: the planning of E-band frequencies for improving the quality of service of transmission in the network of telecommunications operators. Also, it intends to contribute to the resolution of unsatisfied situations of poor planning of E-band radio frequencies in telecommunications networks. With the aim of opening several opportunities for alternative high-speed data transport solutions, our work has helped prove that E-band transmission links are very efficient with capacities in the gigabyte range.

Generation-expansion planning with linearized primary frequency response constraints

As renewable energy resources increasingly penetrate the electric grid,the inertia capability of power systems has become a developmental bottleneck.Nevertheless,the importance of primary frequency response(PFR)when making generation-expansion plans has been largely ignored.In this paper,we propose an optimal generation-expansion planning framework for wind and thermal power plants that takes PFR into account.The model is based on the frequency equivalent model.It includes investment,startup/shutdown,and typical operating costs for both thermal and renewable generators.The linearization constraints of PFR are derived theoretically.Case studies based on the modified IEEE 39-bus system demonstrate the efficiency and effectiveness of the proposed method.Compared with methods that ignore PFR,the method proposed in this paper can effectively reduce the cost of the entire planning and operation cycle,improving the accommodation rate of renewable energy.

Trajectory Planning for OTFS-Based UAV Communications

Unmanned aerial vehicles(UAVs)have attracted growing research interests in recent years,which can be used as cost-effective aerial platforms to transmit collected data packets to ground access points(APs).Thus,it is crucial to investigate robust airto-ground(A2G)wireless links for high-speed UAVs.However,the A2G wireless link is unstable as it suffers from large path-loss and severe Doppler effect due to the high mobility of UAVs.In order to meet these challenges,we propose an orthogonal time frequency space(OTFS)-based UAV communication system to relief the Doppler effect.Besides,considering that the energy of UAV is limited,we optimize the trajectory planning of UAV to minimize the energy consumption under the constraints of bit error rate(BER)and transmission rate,where the Doppler compensation is taken into account.Simulation results show that the performance of OTFS-based UAV system is superior to orthogonal frequency division multiplexing(OFDM)-based UAV systems,which can accomplish transmission tasks over shorter distances with lower energy consumption.

质心动态路径规划的变转速齿轮箱时频脊线索引算法

针对强噪声下难以估计信号瞬时频率的问题,提出了基于质心动态路径规划(DPPB)的变转速齿轮箱时频脊线索引算法。该算法在剖析多路径匹配追踪(MMP)脊线索引算法及其在强噪声下失效原因的基础上,通过对MMP算法得到的脊线集加窗求质心,构建信号的脊线质心稀疏矩阵,并针对质心稀疏矩阵设计动态路径规划函数索引脊线上的质心点,根据脊线代价函数值计算最优时频脊线。将相似度系数Ra和置信度σRa作为脊线提取效果的衡量指标,通过仿真和试验验证了DPPB算法可有效提取强噪声信号的时频脊线,且不同程度噪声下的可靠性和鲁棒性均优于峰值索引算法和MMP脊线索引算法。

新型电力系统下构网需求储能的双层优化选址方法研究

提出了一种新型电力系统下构网需求储能的双层优化选址方法,该方法考虑了储能在电力系统中对调峰调频的响应,建立了多目标双层优化模型。其中,运行层将弃风弃光量和网损计入经济惩罚中,以系统的年运行成本最优为目标,计及调峰、调频收益;规划层评估系统的安全性,并以系统的年综合运行成本最优为目标进行建模。利用改进的帝国竞争算法进行仿真分析,通过多场景比较说明调峰调频经济性和最优场景下的储能选址。最后,采用IEEE-33节点进行仿真,验证所提模型的有效性,并选取不确定性因素指标对总成本进行敏感性分析,确定影响经济成本更需关注的指标。

基于充放电裕度的电动汽车集群一次调频控制策略

针对未来电网一次调频资源不足的问题,文中提出一种基于充放电裕度的电动汽车集群虚拟储能参与电网一次调频的自适应控制策略。首先,分析电动汽车的调控运行范围。其次,研究电动汽车集群参与电网一次调频方法。考虑电动汽车充放电时间和电池荷电状态(state of charge,SOC)裕度,设计电动汽车充放电裕度指标。接着,提出基于充放电裕度的自适应一次调频控制策略,优化电动汽车参与一次调频的下垂功率,从而兼顾电网一次调频和电动汽车充放电需求。然后,通过定时更新方式评估电动汽车集群虚拟储能的一次调频能力,并提出一次调频效果评价指标。最后,通过区域电网仿真案例分析,验证所提策略减少系统频率偏差和优化电动汽车一次调频出力的有效性。

PLANET在GSM移动通信网频率优化中的应用

介绍了北电网络系统中通常使用的软件规划工具PLANET在GSM移动通信网频率规划中的操作特点.在网络规划后期的优化阶段,对典型的三扇区基站标频的分配工作中,利用剩余频点的优先级排序法,可有效地抑制同、邻频干扰的发生.

多能互补提供频率支撑的储能容量分布鲁棒规划方法

随着具有不确定性的新能源大规模并网,电力系统的频率安全面临严峻挑战,而合理规划储能是维持电力系统稳定运行和应对可再生能源不确定性的重要手段。为此,针对高可再生能源渗透率系统的储能容量规划问题,提出了一种考虑多能互补提供频率支撑的储能容量分布鲁棒规划方法。首先,建立了多能互补提供频率支撑的频率安全模型,并将其线性化后嵌入到典型日运行中,以维护电力系统频率的稳定性。其次,采用基于生成对抗网络的分布鲁棒优化,实现在新能源出力最劣概率分布下的储能容量规划,以应对新能源出力的不确定性。最后,基于IEEE 39节点系统进行算例分析,验证了所提方法可在保证电力系统频率安全的同时,具有较好的经济性和鲁棒性。

某平台凝析油外输泵改造方案研究

凝析油外输泵作为天然气处理平台中的关键设备,对气田群正常生产起着至关重要的作用。为了优选凝气田降压后凝析油外输泵改造方案,以具有代表性的南海某中心平台作为研究对象,在原改造方案的基础上进一步提出了三种改造选型和配置方案,并针对不同方案的凝析油外输泵各模式运行工况,评估了凝析油外输泵在工艺、仪表、电气等方面的改造措施,同时利用价值工程原理最终确定了老泵废弃单泵直接增压、回流控制、60 Hz变频泵为最佳改造方案,为天然气降压开采中凝析油外输泵的改造应用提供了解决方案。运行结果表明,所选用的改造方案较原设计方案减少60%能耗,每年将减少燃气消耗221.2×10^(4) m^(3),节能减排2570 tce。

Frequency-constrained Co-planning of Generation and Energy Storage with High-penetration Renewable Energy

Large-scale renewable energy integration decreases the system inertia and restricts frequency regulation. To maintain the frequency stability, allocating adequate frequency-support sources poses a critical challenge to planners. In this context, we propose a frequency-constrained coordination planning model of thermal units, wind farms, and battery energy storage systems (BESSs) to provide satisfactory frequency supports. Firstly, a modified multi-machine system frequency response (MSFR) model that accounts for the dynamic responses from both synchronous generators and grid-connected inverters is constructed with preset power-headroom. Secondly, the rate-of-change-of-frequency (ROCOF) and frequency response power are deduced to construct frequency constraints. A data-driven piecewise linearization (DDPWL) method based on hyperplane fitting and data classification is applied to linearize the highly nonlinear frequency response power. Thirdly, frequency constraints are inserted into our planning model, while the unit commitment based on the coordinated operation of the thermal-hydro-wind-BESS hybrid system is implemented. At last, the proposed model is applied to the IEEE RTS-79 test system. The results demonstrate the effectiveness of our co-planning model to keep the frequency stability.

Planet系统中MRP的实现

GSM网络建设中,如何提高频率利用率对网络建设具有重要的意义。MRP是提高频率利用率的有效方法之一。本文介绍了如何在Planet规划系统中实现MRP规划。

Frequency Trajectory Planning-based Frequency Regulation Strategy for Wind Turbines Equipped with Energy Storage System

The increase in wind power penetration has weakened the equivalent inertia of the power system,posing a significant challenge to frequency stability.In this paper,a frequency trajectory planning(FTP)-based frequency regulation(FR)strategy is proposed for permanent magnet synchronous generator-based wind turbines equipped with an energy storage system(ESS)on the DC link.The core idea is that the frequency index provided by the grid code is used to plan a safe frequency trajectory when the system frequency fluctuates.The FR power provided by the ESS is controlled by tracking the planned frequency trajectory to compensate for the unbalanced power in the system,provide inertia support,and ensure the frequency stability of the power grid.The proposed strategy can suppress the frequency fluctuation and optimize the FR power of the ESS.It also effectively circumvents the complex parameter design process of virtual inertia control.The simulation model is established in Matlab/Simulink to verify the effectiveness of the control strategy.

A 0.8–4.2 GHz monolithic all-digital PLL based frequency synthesizer for wireless communications

A 0.8–4.2 GHz monolithic all-digital PLL based frequency synthesizer for wireless communications is successfully realized by the 130 nm CMOS process. A series of novel methods are proposed in this paper.Two band DCOs with high frequency resolution are utilized to cover the frequency band of interest, which is as wide as 2.5 to 5 GHz. An overflow counter is proposed to prevent the ＂pulse-swallowing＂ phenomenon so as to significantly reduce the locking time. A NTW-clamp digital module is also proposed to prevent the overflow of the loop control word. A modified programmable divider is presented to prevent the failure operation at the boundary.The measurement results show that the output frequency range of this frequency synthesizer is 0.8–4.2 GHz. The locking time achieves a reduction of 84% at 2.68 GHz. The best in-band and out-band phase noise performances have reached –100 d Bc/Hz, and –125 d Bc/Hz respectively. The lowest reference spur is –58 d Bc.

城市轨道交通跨线列车开行方案优化研究

在城市轨道交通线网规模迅速扩张和客流需求快速增长的背景下,针对现有的单线运营模式导致的乘客换乘次数多、系统资源共享程度不高等问题,研究跨线列车开行方案优化以弥补上述不足。根据设施设备跨线运营基本条件、列车跨线次数和跨线客流需求生成跨线交路备选集,以备选跨线交路和本线交路的发车频率为决策变量,考虑线路通过能力、列车满载率和区间交路数量上限约束,以乘客换乘次数最少和出行时间最短为原则,对各OD乘客组进行客流分配,建立线网层面的跨线列车开行方案优化模型,最小化列车运行成本和乘客出行成本。应用模拟退火算法求解模型。南宁地铁线网的案例分析结果表明,相比于单线运营模式,跨线运营模式可使总成本降低6.18%,其中乘客时间成本降低7.33%,乘客换乘次数减少13.79%,可实现成本节约,提升线网服务质量和乘客出行效率的目标。

基于CiteSpace的《林业调查规划》期刊2018—2022年刊载文献的可视化研究

以中国知网(CNKI)收录的《林业调查规划》期刊2018—2022年刊发的1165篇文献为研究数据,运用CiteSpace 6.1.R6可视化分析软件对《林业调查规划》期刊近5年刊载文献的作者、发文机构、高频关键词、基金论文占比等进行分析研究。结果表明,《林业调查规划》期刊已形成了由郑进烜、郭晋平、华朝朗等一大批专家学者组成的核心作者群体,形成了由云南省林业调查规划院、西南大学、河南农业大学、山西农业大学、广东林业调查规划院等数十家林业科研院所、高等院校组成的高质量稿件来源基地。期刊发文关键词以植物配置、景观设计、生态旅游等出现的频率最高,在5年刊载的文献中有502篇文献得到各类基金项目的支持,基金论文比超过43%,且呈不断增长趋势。《林业调查规划》期刊已成为展示我国林业调查规划研究成果的重要平台,积极引导研究者加强交流合作,不断拓宽稿源,适时开展国际合作,将有助于期刊影响力的提升。

适应风电接入的异步联网高压直流输电系统自适应调频控制策略

大规模风电接入高压直流送端系统将导致系统惯量降低,送端系统调频能力不足.为充分挖掘直流和风电协同调频的潜力,提高含风电高压直流送端系统的调频性能,提出一种基于频率轨迹规划的异步联网高压直流输电系统自适应调频控制策略.分析了含风电高压直流送端系统的频率控制特性;综合考虑风电主动频率支撑和直流辅助频率控制,以频率偏差和频率变化率为量化指标,生成参考频率轨迹;在此基础上,对频率轨迹进行区域划分,以参考频率轨迹为基准,实现高压直流输电对送端系统频率的自适应调节.基于MATLAB/Simulink平台搭建改进的两区域4机模型进行仿真分析,验证了所提策略的有效性和优越性.

柔性分频输电系统的构建规划及关键设备技术综述

传统工频交流输电方式受长距离海缆充电无功功率的限制,直流输电方式又受到海上换流站建设与维护成本的制约。柔性分频输电系统通过降低输电频率,极大提升了传输容量与输电距离,在海上风电高效输送领域具有竞争力。文中首先全面论述了柔性分频输电系统的优势。其次,详细阐述了以频率优选为决策变量的构建规划技术以及具有异频交互特性的稳定性分析方法。然后,分析了频率变化对关键分频设备特性的影响,并重点对比了铁磁型交交变频装置和电力电子型变频器。最后,就柔性分频输电系统需要进一步突破的静动态特性和电磁暂态特性分析、样机研制与系统验证等技术难题进行了展望。

考虑用户充电计划的电动汽车辅助调频控制策略

电动汽车(electric vehicle,EV)可作为储能装置参与电网调频,但车网互动(vehicle-to-grid,V2G)过程的低惯性、低阻尼会影响电网稳定性,且目前的EV辅助调频策略无法保证按时完成用户的充电计划。因此,文中将虚拟同步机技术应用于EV的充放电控制中,使充电机具有与同步发电机类似的惯性、阻尼特性。然后,基于T-S模糊控制器,提出一种考虑用户充电计划的EV辅助调频控制算法,EV的充/放电功率由其充电状态和电网频率共同决定。仿真结果表明,所提控制策略能够在不同的充电计划、EV荷电状态和电网频率条件下,智能调节电网与EV之间的功率流动。在满足用户充电需求的同时,该策略能有效提高电网的频率稳定性,规避电池过充、过放风险。