共查询到20条相似文献,搜索用时 921 毫秒
1.
常规变电站数字化改造工作在全国各地开展,改造过程中有不少亟待解决的问题。以110kV李堡变电站数字化改造工程为实例,按IEC61850通信标准实现全站信号采集、传输、处理、控制的标准化,采用电子式互感器实现数字化采样,过程层智能单元实现开关信号采集和控制数字化,应用GOOSE通信方案构建全站网络,实现信号采集数字化、传输网络化、通信标准化等目标,在全站不停电的情况下顺利完成数字化改造,为常规变电站改造为数字化变电站提供了运行、改造经验。 相似文献
2.
本文设计了一种基于任意信号注入法的永磁同步电机无位置传感器FPGA实现。任意信号注入法的原理是利用电流信号的过采样,获取一个开关周期内有效电压矢量作用时的平均电流斜率,通过电流斜率的变化率来估计转子位置。本文利用FPGA的快速采样能力和并行运算特点,对任意信号注入法进行数字化实现。通过电流过采样技术可以提高电流采样精度,改进转子位置估计精度。利用一台3kW永磁同步电机对算法进行了实验验证。 相似文献
3.
通过常规变电站与数字化变电站二次信号传输原理和方式的对比.以110kV变电站数字化改造工程为例,分析数字化变电站的特点及对采样系统提出的要求,提出在发展数字化变电站中采样技术应注意的问题。 相似文献
4.
宋利军 《国外电子测量技术》2012,31(10):10-14
随着广播事业的发展,传统的模拟接收机已经无法满足应用需求,尤其是对广播信号的多信道信号同步解调,模拟接收机无法实现。如果将模拟射频信号采用全数字化后,通过数字处理,就可以实现多信道信号同步解调,以及信号的存储。本文阐述了数字化信道接收机的设计过程,如何将模拟射频信号通过采样原理实现数字化,应用数字处理FFT技术及解调算法完成基带信号的解调。 相似文献
5.
为满足在高速率卫星通信中全数字化中频解调的要求,对全数字化载波同步算法进行了深入研究,根据奈奎斯特采样定理以及中频采样定理,分析了利用高速中频调制BPSK/QPSK信号恢复本地同步相干解调载波算法的可行性。同时给出了全数字锁相环算法及720MHz中频调制信号下全数字载波同步算法的设计与实现,对其关键组成模块:鉴相器、数控振荡器和环路滤波器等给出了详细的设计方法,并最终使用MATLAB对算法进行了功能仿真,仿真结果表明该算法能够很好地实现数字解调端的载波同步功能,能够完成1MHz以内频偏锁相的功能,相位误差较小,达到了卫星通信系统接收端载波同步的性能要求。 相似文献
6.
介绍了采用数字化技术对传统电压互感器进行改造的原理,给出了实际挂网运行结果.通过对传统互感器的二次信号数字化,可消除信号传输过程中的压降,并为目前电网中大量传统变电站的数字化改造,探索可行的技术方案. 相似文献
7.
8.
9.
针对电力谐波的准同步加窗分析法存在所用信号周期多、计算复杂和谐波泄漏分布不均匀等问题,基于准均匀采样提出了一种仅需1个信号周期特别适于单片机快速、准确实现的电力谐波分析方法。准均匀采样的时间离散误差不随连续采样而积累,在1个信号周期内取2的整数次幂个同步采样点,直接采用FFT算法即可实现谐波分析。基于信号的基波近似,并假设信号采样时的时间离散误差和幅值量化误差均服从均匀分布,对采用准均匀采样的电力谐波估计误差进行了分析。给出了基于准均匀采样电力谐波分析的算法和具体实现流程,流程中通过长整型变量对采样时间进行精确控制,算法简单高效。最后对准均匀采样谐波分析算法进行了仿真,结果表明基于通用单片机即可实现电力谐波的快速、准确分析。 相似文献
10.
11.
12.
数字仿真技术在继电保护中的应用及其展望 总被引:1,自引:1,他引:1
叙述用于测试继电保护装置的SJ和DSF双侧电源数字静模仿真器,分析仿 真的电力系统模型、算法和软硬件的实现,展望数字仿真技术应用前景。 相似文献
13.
14.
15.
16.
17.
J. Milias-Argitis Th. Zacharias 《International Journal of Circuit Theory and Applications》1990,18(1):33-51
In this paper, a general and systematic method for the analysis of varying topology power semiconductor circuits is presented. the changes of the conduction state of the semiconductor switching devices are handled by successive modifications of the tree of the circuit graph. These tree modifications are systematically reflected on a square transformation tensor. On the basis of well known network topological concepts, this generalized transformation tensor can be constructed in a relatively simple way. This tensor constitutes a flexible and powerful tool to assemble automatically the necessary on-switch current and off-switch voltage equations required for any conduction pattern. These manipulations are accomplished with a step-by-step modification procedure of the equations describing the circuit in the most previous conduction state. the basic steps of an algorithm suitable for the practical implementation of the analysis of any power switching network on a digital computer are described, and an example is used to demonstrate the effectiveness of the proposed method. 相似文献
18.
Soo-Hwan Cho Gilsoo Jang Sae-Hyuk Kwon Jung-Wook Park 《Electrical Engineering (Archiv fur Elektrotechnik)》2009,91(3):125-131
A standard of International Electrotechnical Commission (IEC) has defined the flicker measuring specification in an analog manner. But the analog specs are inefficient when implementing a flickermeter in the real world according to the standard. Therefore, it is necessary to convert its original analog filters to the corresponding digital forms as well as applying other digital processing techniques such as data sampling, bit resolution, and filtering theory. Even though a digital flickermeter may meet the requirements of the IEC standard, its outputs will vary according to the analog-to-digital filtering conversion methods used such as bilinear transformation, impulse invariance transformation, and covariance invariant transformation. This paper presents the characteristics of various filter conversion methods and the influences on the digital implementation of a flickermeter, which are simulated by using MATLAB®. Finally, this paper concludes with which methods are the most adequate to implement an IEC digital flickermeter, helping ultimately to avoid ambiguities from analog prototypes described in original standard. 相似文献
19.
20.
Omar Ramadan 《Electrical Engineering (Archiv fur Elektrotechnik)》2006,88(5):327-335
A generalized method for implementing the diagonal anisotropic perfectly matched layer (APML) in the finite difference time domain (FDTD) algorithm is presented for truncating three-dimensional (3-D) open region domains. The method is based on incorporating the digital signal processing algorithms developed for digital filters into the APML formulations. In this method, the permittivity and the permeability tensors of the APML are modelled as a set of infinite impulse response digital filters by using the Bilinear transformation technique. The proposed method has the advantage of the simplicity as it allows direct FDTD implementation of Maxwells equations in the APML region and also can be used for modelling general FDTD domains such as lossy, dispersive, anisotropic, or nonlinear without any modifications. The new formulations are validated by analyzing 3-D radiation and guided-wave problems. 相似文献