共查询到19条相似文献,搜索用时 171 毫秒
1.
为了减小电压源型逆变器死区时间引起的输出电压畸变,对死区产生的原因进行分析,总结出三点原因,列出误差电压计算公式,最后运用到感应电机矢量控制中,对ua、ub、uc三项输入到逆变器中的电压进行补偿。该补偿策略首先计算控制周期内的误差时间,算出误差时间与电流的对应关系,最后将算出的周期TS内误差电压补偿到逆变器输入端上。通过补偿误差电压,降低了电流谐波对控制系统的影响,同时电网侧的能量利用率得到了提高。实验结果表明,该策略对电流波形起到了改善作用。 相似文献
2.
电能监测系统采用意法(ST)半导体公司STM32F103ZDT6的ARM芯片为核心,以ATT7022C电表芯片对电能参数进行取样,实现电网电压和电流、功率的因数、有功、无功和视在功率等诸多参数的检测,通过W5200A硬件TCP/IP通信芯片进行数据传输,借助乐为物联公司物联网平台,通过网页、博客等方式进行数据发布和管理,参数测量与传输误差在许可范围内,能够投入实际使用;该系统为能耗监测与管理提供了底层硬件平台,提供了数据可靠传输方式,提供了方便、直观的上层管理平台,综合了电能计量与测控、嵌入式系统、物联网、WebServer等多项技术,具有一定的创新性。 相似文献
3.
电网波动对上海光源加速器的正常运行有较大影响。针对该问题,展开了系统的分析和研究工作。首先介绍了电网波动的成因以及电网波动对上海光源的影响情况。通过对具体事例进行分析,优化了上海光源加速器受电网波动影响后的基本恢复流程。分析了各硬件系统在发生电网波动时的不同表现,并依此探讨了如何优化此类故障的处理流程,建立完善的机器恢复程序。针对外电网波动提出若干建议,并提出了面对电网波动时需要采取的措施,尽可能降低电网波动对如低温压缩机、超导高频腔等关键设备的影响。以期缩短实际故障时间,加快机器恢复速度,保障上海光源稳定运行。以近10年运行数据为基础,研究发现电网波动对上海光源的影响存在若干重要阈值,这些阈值对机器恢复具有指标性作用。对因电压暂降产生的二次故障进行分析讨论,并提出若干建议。 相似文献
4.
随着智能电网和绿色能源技术的快速发展,双向充放电机也越来越受到关注;文章主要研究双向充放电机充电过程中电压的稳定性和放电过程中并网电流波形的畸变率;提出了一种基于RTW的matlab/simulink控制方法,在simulink环境下搭建仿真模型和控制模型,然后将达到预期效果的仿真模型所对应的控制模型编译为代码并烧写到DSP中;此种方法在能够保证在恒流源和恒压源两种充电模式中电流和电压的稳定性,在放电过程中并网谐波电流总畸变率小于5%,功率因数基本为1;仿真结果和基于DSP2812的硬件平台实验都证明了这种方法的有效性。 相似文献
5.
6.
在大视场光电测量系统中一般会采用广角镜头,这会导致获得的测量图像存在严重的畸变问题。为了对这一类大畸变相机进行精确标定,可以通过径向畸变除式模型以及角点亚像素坐标提取方法,首先求解出图像畸变中心坐标及畸变参数,然后利用二维平面棋盘格标志点与图像点的对应关系求解出单应性矩阵,再根据单应性矩阵进一步求解出相机内外参数。求解出相关参数后,对求解出的参数利用Levenberg-Marquardt法进行迭代优化,再在迭代优化的基础上根据3σ法则对重投影误差数据进行坏点剔除,然后对剔除坏点之后的坐标数据重新进行标定,直至所有数据都符合要求,最终可以实现大视场畸变图像的高精度校正。为了验证所提方法的有效性,进行了仿真图像及实际图像的标定实验,结果显示,本方法能适当提高标定精度,在实际实验中均方重投影误差平均值减小了0.0103个像素点,相当于提升了0.7%的校正误差精度。 相似文献
7.
8.
9.
针对变电站各类高压容性设备在线监测装置的现场校验,提出一种新的容性设备在线监测装置校验方法并研制出相应的校验系统,校验项目涉及:全电流,阻性电流,容性电流,介损因数。该校验系统由信号采集无线发送装置和检定装置组成,信号采集无线发送装置将现场变压器二次侧电压作为参考电压通过无线传输方式传入检定装置,检定装置内的控制模块根据预设指令及参考电压信号控制内部数控交流电流源生成一路与电网电压频率同步,幅值和相位可调的电流信号。将该电流信号耦合到容性设备在线监测装置电流传感器,通过比较耦合前后装置相应监测量变化值与校验系统设定值的误差,达到校验容性设备在线监测装置有效性的目的。实验证明,该校验系统输出电流指标满足现场校验的要求。 相似文献
10.
11.
为提高电源在电网非理想输入情况下工作的适应性,采用解耦双同步坐标系下的三相锁相环,能够获取电网电压的相位与频率信息,并通过FIR滤波环节提取输入线电压的基波幅值,及时准确地为电源提供控制参数。建立了Matlab/Simulink仿真模型,在三相输入不平衡、频率变化、电压畸变等情况下进行仿真,并基于DSP2812芯片编写了控制程序进行测试。仿真与实验结果表明:在各种电网输入情况下,该方法都能够准确提取输入线电压的幅度、相位以及频率信息,为电源的良好运行提供保障。 相似文献
12.
13.
Fangfang Zhang 《中国物理 B》2023,32(1):10502-010502
With the development of smart grid, operation and control of a power system can be realized through the power communication network, especially the power production and enterprise management business involve a large amount of sensitive information, and the requirements for data security and real-time transmission are gradually improved. In this paper, a new 9-dimensional (9D) complex chaotic system with quaternion is proposed for the encryption of smart grid data. Firstly, we present the mathematical model of the system, and analyze its attractors, bifurcation diagram, complexity, and 0-1 test. Secondly, the pseudo-random sequences are generated by the new chaotic system to encrypt power data. Finally, the proposed encryption algorithm is verified with power data and images in the smart grid, which can ensure the encryption security and real time. The verification results show that the proposed encryption scheme is technically feasible and available for power data and image encryption in smart grid. 相似文献
14.
地磁暴是全球范围内地球磁场的剧烈扰动现象, 在电网中产生地磁感应电流(GIC)。电力变压器在GIC的作用下进入半波饱和状态, 其产生的谐波和增加的无功损耗影响电网电压稳定, 造成系统中继电保护装置误动, 随着电网电压等级的提高和电网规模的扩大, 地磁暴可能严重威胁电网安全运行。分析了变压器对GIC入侵后的响应, 以及次生灾害在电力系统中的传播过程, 阐明了磁暴对电力系统的影响机理, 分析了GIC对变压器、无功补偿设备和继电保护装置等设备的影响, 建立了GIC对系统电压稳定性影响的分析框架及基本方法, 最后提出了一种GIC优化治理策略, 与传统治理方法相比具有明显的优越性。 相似文献
15.
In the Internet of Things (IoT) ecosystem, devices will predominate, using it in a manner similar to how people used it. Devices will cooperating in a multicast network to collect, share, and forward information way while interacting with one another autonomously and without centralised supervision. The building of an intelligent environment the capability of real-time collection of data, which is crucial for maximising the value of the IoT, will make this possible. A typical electric grid is made up of many power plants that use various power generating units, such as coal-based units, gas-based units, hydro units, etc. The majority of the infrastructure and wires that make up the conventional electricity grid have been in existence for a long time, it should be mentioned. They require significant investments, so providing them could take years. As a result, many grid components are outmoded and must be maintained and monitored on a regular basis to keep power flowing. A sophisticated technology is the smart grid (SG) system that makes it easier to integrate green technology and environmental considerations. The SG cyber–physical system was implemented thanks to the advancement and use of communication technologies in the conventional power system. The Internet of Things (IoT) and essential devices are both present in the complicated architecture of the SG systems. The traditional electric grids are been transformed into smart and efficient grid known as “Smart grid”. The Internet of Things’ smart grid allows for two-way communications among connected devices and technology that can recognise and respond to human needs. The cost and reliability of a smart grid are superior to that of conventional power infrastructure. Through use and data maintenance, smart grid technology will assist in reducing energy use and costs. One of the primary contributions made to grids is the integration of IoT with producing facilities using sustainable energy at various levels. To enhance the smart grid for bidirectional information exchange, improve power quality, and increase reliability Internet of Things (IOT) devices are becoming an important part of smart electric grid. IOT Infrastructure (IOTI) provide a flexible, efficient and secure platform providing strategic management for monitoring and controlling of different operations under different working conditions. This paper discusses cyber security on IOT based infrastructure for electric power systems. A comprehensive study is highlighted which includes type of IOTs, architecture used for smart grid, and future challenges. 相似文献
16.
根据数值计算的抽样原则,对激光大气传输数值模拟中如何准确地选取计算参数作了比较全面的分析,导出计算参数选取所应遵循的判据。结合高斯光束及平台光束准直传输热畸变后的相位分布,得到了网格间距与Bradley-Hermann热畸变参数的关系。在算出此热畸变参数后,便可选定合适的网格间距,由数值结果便能准确评价实际激光大气传输的效果。数值结果表明,相同网格数、不同网格间距下数值结果的差别相对较大,若网格间距选取不当,将给数值结果带来较大误差。 相似文献
17.
用于高功率激光脉冲整形的可编程任意波形电脉冲发生器 总被引:2,自引:2,他引:0
研制了一种基于GaAs场效应管与超快脉冲信号微带传输的可编程任意波形发生器.它由计算机控制的多路高准确度偏置电压,多个级联的GaAs场效应管基元电路,以及微带脉冲传输线组成.输出电脉冲波形导入LiNbO3集成光波导调制器,经过电光调制获得相应的激光脉冲波形.通过计算机设置各基d元电路中GaAs场效应管栅极偏压,进而控制整形电脉冲的形状,使高功率激光装置前端时域脉冲整形实现远程控制. 相似文献
18.
利用MATLAB对中国聚变工程实验堆(CFETR)低混杂波高压电源系统的调节模块进行仿真,分析了静态电网波动、负载变化、滤波参数等对输出电压的影响。利用补偿网络可以大大减少纹波,增加输出电压的稳定性。该系统的稳定时间在几个毫秒之内,纹波系数<1%。通过仿真决定对该高压电源系统调节模块采用比例积分微分(PID)控制与超前-滞后补偿策略。 相似文献
19.
S. Auer K. Kleis P. Schultz J. Kurths F. Hellmann 《The European physical journal. Special topics》2016,225(3):609-625
Extreme events are a challenge to natural as well as man-made systems. For critical infrastructure like power grids, we need to understand their resilience against large disturbances. Recently, new measures of the resilience of dynamical systems have been developed in the complex system literature. Basin stability and survivability respectively assess the asymptotic and transient behavior of a system when subjected to arbitrary, localized but large perturbations in frequency and phase. To employ these methods that assess power grid resilience, we need to choose a certain model detail of the power grid. For the grid topology we considered the Scandinavian grid and an ensemble of power grids generated with a random growth model. So far the most popular model that has been studied is the classical swing equation model for the frequency response of generators and motors. In this paper we study a more sophisticated model of synchronous machines that also takes voltage dynamics into account, and compare it to the previously studied model. This model has been found to give an accurate picture of the long term evolution of synchronous machines in the engineering literature for post fault studies. We find evidence that some stable fix points of the swing equation become unstable when we add voltage dynamics. If this occurs the asymptotic behavior of the system can be dramatically altered, and basin stability estimates obtained with the swing equation can be dramatically wrong. We also find that the survivability does not change significantly when taking the voltage dynamics into account. Further, the limit cycle type asymptotic behaviour is strongly correlated with transient voltages that violate typical operational voltage bounds. Thus, transient voltage bounds are dominated by transient frequency bounds and play no large role for realistic parameters. 相似文献