OFDMA系统中下行资源分配方案设计

针对OFDMA通信系统多小区间的同频干扰问题．提出了一种用于OFDMA系统下行链路的基于干扰的动态子载波分配方案。该方案与接入控制和功率控制相结合,通过最大化同频子载波用户之间的距离,降低同频用户的发射功率,减小同频信道的干扰,保证每个用户的QoS要求,提高无线资源利用率。仿真结果表明,与已有方案相比,该方案既可以很好地保证用户的QoS要求,又能充分利用频谱资源以保障系统吞吐量。     

下行链路基站协同蜂窝系统中不完全同步下的干扰消除方法

多蜂窝联合处理可以消除蜂窝间干扰,提高蜂窝系统的频谱效率.但是,对多蜂窝联合处理的研究还多局限在假设多个协同基站的信号同步到达接收端的场景.针对一个下行链路基站协同不完全同步的蜂窝系统,提出了一种使用1 bit反馈预编码和信道衰落补偿功率分配的内部联合分布式空时编码基站协同方案,用以消除蜂窝边缘用户遭受到的蜂窝间干扰以及协同基站不同步引起的码间干扰.仿真结果表明,该方法可以明显的消除蜂窝边缘用户所遭受到的蜂窝间干扰和码间干扰,明显提高系统的误码率性能;与基站间不协同传输、即基站间以时分多址的方式传输信号时相比,可以提高系统的分集增益和频谱效率,同时保持一个相对低的结构和计算复杂度.     

输电线路检修计划的优化算法综述

目前人工编制检修计划的方法,无法综合考虑输电线路检修的可靠性和经济性,而优化算法可以实现两者的平衡。该文综述了国内外输电线路检修计划优化算法的研究现状,介绍了该算法的两种类型即输电与发电联合和输电线路单独编制检修计划的优化算法。前者重点介绍了基于Benders分解的算法和灵敏度分析法,后者主要有基于Benders分解和基于可靠性评估的两种算法。对四种算法分析比较后,提出今后的研究方向应为从实用化的角度改进算法的计算效率和收敛性。     

Traffic scheduling in distributed networked control systems with packet losses and delays for power systems voltage stabilization

In this paper, medium access control (MAC) sublayer data traffic scheduling in distributed networked control systems (DNCSs) with networked induced packet losses and delays is investigated for stabilization and control of system dynamics. An effective‐information‐directed distributed sensor selection algorithm is proposed to select sensors to participate in delay‐tolerant information filtering for state estimation. The distributed scheduling algorithm is based on the total amount of effective information for all measurements stored in the sensors. We consider packet loss in wireless networks as a special type of delay, so the impact of packet losses on effective information amount can also be studied for the formulation of distributed scheduling strategy in the presence of packet losses. The distributed data traffic scheduling considering packet losses and delays is carried out in a networked system with data packet dropout governed by a Markov process for voltage regulation and stabilization with distributed energy resources (DERs). Experimental results demonstrate that the scheduling algorithm with awareness of the system dynamic state can well control the power system dynamics. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Daily generation scheduling optimization with transmissionconstraints: a new class of algorithms

The authors describe a novel class of algorithm dealing with the daily generation scheduling (DGS) problem. These algorithms have been designed by adding artificial constraints to the original optimization problem; handling these artificial constraints by using a dual approach; using an augmented Lagrangian technique rather than a standard Lagrangian relaxation technique; and applying the auxiliary problem principle which can cope with the nonseparable terms introduced by the augmented Lagrangian. To deal with the DGS optimization problem these algorithms are shown to be more effective than classical ones. They are well suited to solve this DGS problem taking into account transmission constraints     

空间频率分集MIMO-OFDM系统的译码算法

本文主要目的是研究空间频率分集MIMO-OFDM系统的各类译码算法的优劣和使用场合.提出了一种能充分利用空间分集、空间复用、频率复用增益,且能对抗时间选择性和频率选择性衰落的空时频率分集MIMO-OFDM系统,完整介绍了应用于该系统的三类算法:线性检测算法、非线性检测算法以及准最大似然检测算法.其中线性检测算法每一类算法均作了较详细的定义、原理介绍以及算法复杂度、性能的分析,并给出了算法的建议应用场合.最后系统仿真证实了上述分析和结论.     

Power system state scheduling with the two-stage problem

Traditional statements of optimization problems in power system state scheduling lead to complexities at the on-line correction of variables. This paper considers a stochastic optimization problem with corrective functions of the given analytical type. The problem solution gives scheduled values of the state variables and the adjustment coefficients for corrective functions. The corrective functions represent a response of the control system to the unforeseen deviations in operation conditions. The preliminarily obtained coefficients of corrective functions allow a very easy and quick organization of the on-line optimal state correction. Dual variables of the optimization task can be corrected as well for fast spot price adjustment. A case study demonstrating the efficiency of state control using the suggested approach is considered     

Development of a high-speed switching system for distributionnetworks

This paper describes a high-speed switching system for distribution networks which has been developed with the aim of improving power supply reliability (reducing the number of supply interruptions) of distribution systems. When a fault occurs in conventional distribution systems, the fault section is isolated using a sequential time-out control scheme which requires the reclosing and re-reclosing of the entire system. A major drawback of such systems is that normal sections are also subjected to unnecessary power supply interruptions. In order to resolve this problem, the authors have developed a high-speed switching system which isolates only the fault section without interrupting the power supply to normal sections. This new system can fully restore power to the normal sections and completely isolate the fault section within 500 ms in the case of a ground fault     

行波故障测距系统中高速数据采集卡的开发与应用

在行波故障测距中,传统的数据采集系统无法适应采集高速变化的暂态电压、电流行波的要求,难以实现故障的精确定位。介绍了一种基于PCI总线的高速数据采集卡的软硬件。硬件以现场可编程门阵列FPGA(FieldProgrammableGateArray)为核心,由高速A/D转换、高速SDRAM缓存、PCI接口等一系列外围电路组成,采用Pass-Thru工作方式实现PCI总线接口和用户外部互联设备或存储设备间高性能突发式数据传输。软件分为数据采集、启动、选相定位、远程通信等几部分。该系统采样率达60MHz,能够很好地进行输电线路暂态行波的采集,在故障定位及微机保护中都可广泛应用。     

超宽带定位应用系统及算法改进

UWB(超宽带)技术由于具有低功耗,大带宽等特点非常适合于无线测距定位应用.针对智能交通系统中的车辆定位特点提出了一种理想应用环境中只需两个参考节点的二维车辆定位系统,并针对该系统在非理想情况下精度较低的问题提出了3种分别基于方程解平均,多次测距平均,及AOA测距平面修正的定位精度改进方案.通过理论分析及仿真结果证明,提出的车辆定位系统可以有效实施车辆定位,在3种改进算法的辅助下能够达到较高的定位精度.三种改进算法中,基于方程解平均及AOA测距平面修正以增加成本为代价,多次测距平均以增加时间开销为代价,因此在实际车辆定位系统设计中,可根据应用环境及精度要求灵活使用.     

Undergraduate teaching of real-time scheduling algorithms by developed software tool

Theoretical foundations of scheduling in the course Real-Time Systems of the undergraduate studies program are extended by the usage of the developed visual software tool. The tool enables teaching of simulated fixed-priority scheduling algorithms. The user simply sets the simulation and algorithm properties and loads the prepared input task sets from the database. Results are obtained within the program or from external applications. The paper deals with the problem of scheduling the mixture of periodic and aperiodic tasks in a uniprocessor system. Results are displayed in the form of a flow report, table report, and diagrams of dependencies of evaluation parameters on the change of periodic and aperiodic workload. The flow report explains the algorithm behavior and the table form and dependency diagrams enable a more precise scheduling analysis and mutual comparison, respectively. Some of the evaluation parameters are the following: aperiodic response time, number of tasks with missed deadlines, utilization of resource and server tasks, resource-breakdown utilization. The software tool improves teaching of the course and the final success of students regarding relevant exam exercises.     

含抽水蓄能电站的可再生能源电网优化调度策略

由于可再生能源电网发电功率的不确定性十分突出,以功率平衡为首要任务的电网调度控制必须采取有针对性的应对措施。在电网储纳运行机制的基础上,建立含抽水蓄能电站的日前调度及实时调度的数学模型。将电网备用分为波动性备用(即调峰备用)和不确定性备用:平衡波动性功率的备用容量主要由常规电源承担,平衡预测误差的不确定性备用主要由抽水蓄能电站承担,2类电源分工互济实现电网功率平衡。提出一个风电上网功率稳定性评价指标,用于衡量不同调度策略补偿失衡功率的优劣。算例分析验证了所提调度策略是可行的。     

用于高速网络分析仪校准的自动测试系统设计

高速网络分析仪是射频生产测试中非常重要的仪器,对网络分析仪的定期校准用于检查其性能是否满足使用要求。本文提出了一种用于高速网络分析仪校准的自动测试系统的实现方案。该系统以计算机为控制核心,通过GPIB总线将各仪表进行互连,并且使用VC作为校准应用程序的开发工具。通过程序控制总线上的仪表作业,按要求进行测试和数据处理工作,最终生成校准证书,实现了网络分析仪的自动校准。该系统节省了人力和时间,显著地提高了工作效率。     

基于FPGA的高速动态测量数据采集系统

针对长距离多轴激光干涉测长同步动态数据采集问题,研制基于FPGA的高速动态测量数据采集系统及上位机动态测量软件。采用FPGA挂载DDR3的硬件系统方案,提出基于边沿检测捕捉外触发同步信号、构造读写FIFO结合MIG IP核实现读写逻辑的方法设计离线系统,满足降低测量软件的实时性要求。硬件与上位机建立串口通信,实现温度、大气压强、湿度等多参数多路环境传感器的实时采样及激光波长对空气折射率的实时修正。在触发脉冲重复间隔TPRI≤20 μs的条件下,与商品干涉仪进行动态测量比对,实现差值小于8 nm。实验结果表明该系统在50 kHz采样率下实现了纳米级高精度测量,且无数据缺失、误码现象,可广泛应用于高速、高精度的动态测量数据采集。     

Industrial power system analysis with database access

This paper presents a useful software tool to analyze an industrial power system. The program has two main functions. One is to let the personnel of the industrial plant graphically set up and access the electrical database, such as filtering or searching information. The database can be included in the company documentation. Based on the database, the other is to graphically perform a load-flow analysis and short-circuit current calculation on a PC. Considering the structure and connection of transformers, a system analysis is performed with appropriate phase shifts. In addition, the unbalanced fault current calculation is generalized with all types of faults happening in a power system such as single-phase fault or multiphase fault, with or without faulted impedance, and bus faults or cable faults. Using the results of load-flow analysis as the prefault condition instead of preset voltage, one can obtain more accurate and practical results. Therefore, this program is very useful for industrial companies to analyze their electrical power system and train their electrical personnel     

脉冲功率高速数据采集系统实现

探讨用于脉冲功率装置运行状态监测的高速数据采集方法与相应的实现技术,可为脉冲功率装置设备故障的诊断提供一种新的手段.利用数字信号微处理器TMS320F206和高速A/D转换器MAX120,研究并实现了可进行4路同步采集且每路采样速率高达200 KSPS的多路同步波形采集系统.该数据采集系统采用了光纤通信和外积分方式 Rogowski 线圈测量电路等抗干扰措施,成功地解决了在脉冲放电电流产生强大电磁干扰条件下的高速数据采集问题.讨论了数据采集系统的信号测量、数据采集及其监控的硬件和软件的设计和实现.实验结果表明,所实现多路高速数据采集系统具有很好的测量精度,各测量脉冲峰值电流的测量相对误差不大于0.7%,各测量主脉冲宽度相对误差不大于2.4%.     

高速列车涡流制动试验台研制

总结了高速列车涡流制动技术的实验和应用 ,分析了存在的问题 ,介绍了高速列车涡流制动试验台的结构和工作原理 ,提供了试验结果和分析 ,试验表明涡流制动用于高速列车效果非常明显。控制系统的核心采用MC68HC908MR32单片机 ,其PWM控制器功能完善     

基于PSO-GA算法的电力系统机组组合研究

机组组合优化问题是一个大规模、多约束、非线性的混合整数规划问题,因此求解非常困难.粒子群优化(PSO)算法是一类随机全局优化技术,它通过粒子间的相互作用发现复杂搜索空间中的最优区域.PSO算法的优势在于操作简单,可调参数少易于实现而又功能强大.该文采用二进制粒子群优化方法解决机组状态组合问题,用遗传算法结合启发式技术解决经济分配问题,并对最小开停机时间及启停费用进行了处理,使得运算速度大大加快.方法的可行性在10台机组系统中检验.模拟结果表明文章所提出的算法具有收敛速度快及解的质量高等优点.