利用卫星时间作基准的电力系统同步相量测量

本文首先对同步相量测量的思想进行阐述，然后给出一种新的同步相量测量方案，该方案将基于ＧＰＳ时间信息的时钟同步技术与离散付氏变换算法相结合，能在统一参考基准下实时测量电力系统各节点的电压电流相量。文章对该方案涉及到的算法、同步采样技术、硬件构成以及可行性等进行了详细描述。     

同步相量测量及其在电力系统中的应用

利用全球定位系统(GPS)技术可方便地实现电力系统的同步相量测量。本文简要介绍了一种基于傅立叶级数的测量方案,并分析了同步相量测量技术在状态估计、失稳预测及控制、继电保护等方面的潜在应用。     

Interarea Model Estimation for Radial Power System Transfer Paths With Intermediate Voltage Control Using Synchronized Phasor Measurements

In this paper we develop measurement-based methods for estimating a two-machine reduced model to represent the interarea dynamics of a radial, two-area power system with intermediate dynamic voltage control. Two types of voltage control equipment are considered, namely, a static VAr compensator (SVC), and a synchronous condenser. The methods use synchronized bus voltage phasor data at several buses including the voltage control bus, and the line currents on the power transfer path.      

一种电力系统同步相量测量的新算法

鉴于传统的相量测量方法在精度和实时性方面不能很好地统一,提出了一种基于改进三点算法的相量测量方法,该算法采用多个采样点绝对值,选取合适的等间隔采样点,采取平均平滑补偿措施,有效地降低了随机噪声对测量结果的影响,计算精度较高,并对纹波有一定的抑制能力.通过MATLAB软件进行仿真验证,结果表明所提方法是正确可行的.     

应用广义状态估计简化模型进行电力系统可观测性分析

广义状态估计与传统状态估计不同,它应用系统的物理模型,加入了断路器的有功潮流和无功潮流作为状态变量来进行分析。根据SCADA系统所提供的断路器的状态,介绍了简化模型的方法,给出了广义状态估计可观测性检测算法,应用IEEE实验系统验证了这种方法的可行性、有效性和准确性。     

基于同步相量测量技术的配电网故障定位

配电网的故障定位是配电网自动化系统中的一项高级功能。为此,针对配电网的特点,结合同步相量测量技术对节点电压方程进行了处理,导出了一种新型的故障定位矩阵算法。该算法具有较强的通用性,求解过程简单快捷,故障定位快速,对于部分类型的故障还可以具体解出故障距离。最后结舍IEEE13节点系统和[EEE36节点系统,说明了该算法的定位方法并证实了其有效性。     

基于GPS的同步相量测量技术在电力系统中的应用

论述了基于GPS同步相量测量装置原理,并介绍相量测量装置在电力系统状态监测与控制、状态估计、非线性励磁控制、自适应保护、输电线路故障定位等方面的应用。     

Calculation of Transmission Line Parameters From Synchronized Measurements

Accurate knowledge of transmission system parameters, such as series impedance, optimizes distance relay settings and impedance-based fault location. A new method is developed to measure transmission line impedances and admittances from synchronized phasor measurements. Power system voltage and current phasors were recorded during commissioning tests of a 525 kV transmission system containing shunt and series compensation. Steady-state phase angles (delta) and magnitudes of line-side voltages and currents were measured relative to a satellite-based global time standard at two substations. Pairs of synchronized measurements were used to directly calculate real-time steadystate ABCD parameters. For comparison, two-port ABCD transmission system parameters were derived by classical methods and from an ElectroMagnetics Transients Program (EMTP) transmission system design model. To verify the accuracy of the measured parameters, a new method comparing field measured with calculated power flows was developed. Sending-end power flow was measured from accurate recordings and was compared with power flow calculated using the three estimates of ABCD parameters, sendingend voltages, and receiving-end voltages. Close agreement was found between field-measured power flows and calculations using the measured ABCD parameters.     

Power System Harmonic State Estimation and Observability Analysis via Sparsity Maximization

Harmonic state estimation (HSE) is used to locate harmonic sources and estimate harmonic distributions in power transmission networks. When only a limited number of harmonic meters are available, existing HSE methods have limited effectiveness due to observability problems. This paper describes a new system-wide harmonic state estimator that can reliably identify harmonic sources using fewer meters than unknown state variables. Note there are only a small number of simultaneous harmonic sources among the suspicious buses. Traditional observability analysis is extended to general underdetermined estimation when considering the sparsity of state variables. It is shown that the underdetermined HSE can become observable with proper measurement arrangements by applying the sparsity of state variables. The HSE is formulated as a constrained sparsity maximization problem based on L1-norm minimization. It can be solved efficiently by an equivalent linear programming. Numerical experiments are conducted in the IEEE 14-bus power system to test the proposed method. The underdetermined system contains nine meters and 13 suspicious buses. The results show that the proposed sparsity maximization approach can reliably identify harmonic sources in the presence of measurement noises, model parameter deviations, and small nonzero injections     

New Algorithms for Computer Based Power System Measurements for Relaying

Abstract

The paper presents two new algorithms for power system measurements for computer relaying. The algorithms involve the design of a discrete-time digital filter which interpolates the signal samples and generates Fourier Co-efficients either by using spectral observations or a functional expansion technique. Sample designs are presented for voltage and current phasor estimation during system transients. A method for including decaying dc and harmonic frequency components in the filter design is also described in the paper. Both computational and on-line test results using an LSI-11/23 microcomputer for power system phasor estimation are presented in the paper.     

内蒙古电力系统同步时钟解决方案

介绍了内蒙古电力系统专网通信网的系统构成,分析了内蒙古电力通信网的现状以及建立通信网同步系统需考虑的定时分配、性能要求、传输链路状况等因素,并针对实际情况,提出了通信网同步系统的建设方案。     

基于GPS的同步相量测量技术在电力系统中的应用

论述了基于GPS同步相量测量装置原理,并介绍相量测量装置在电力系统状态监测与控制、状态估计、非线性励磁控制、自适应保护、输电线路故障定位等方面的应用.     

A Distributed State Estimator Utilizing Synchronized Phasor Measurements

With the creation of balancing authorities by the North American Reliability Council that span large portions of the North American interconnection, and stringent requirements for real time monitoring of power system evolution, faster and more accurate state estimation algorithms that can efficiently handle systems of very large sizes are needed in the present environment. This paper presents a distributed state estimation algorithm suitable for large-scale power systems. Synchronized phasor measurements are applied to aggregate the voltage phase angles of each decomposed subsystem in the distributed state estimation solution. The aggregated state estimation solution is obtained from the distributed solution using a sensitivity analysis based update at chosen boundary buses. Placement of synchronized phasor measurements in the decomposed subsystems is also investigated in this paper. Test results on the IEEE 118-bus test bed are provided     

基于免疫BPSO算法与拓扑可观性的PMU最优配置

以电力系统状态完全可观测和相量测量单元PMU配置数目最小为优化目标,基于PMU的功能特点和电力网络的拓扑结构信息,形成快速且通用的电网拓扑可观测性判别方法,并设计了一种结合免疫系统信息处理机制的二进制粒子群优化算法对目标函数进行求解,该算法综合了粒子群优化算法简单快速和免疫系统种群多样性的优点,明显改善了进化后期算法的收敛性能和全局寻优能力.最后通过对IEEE14和新英格兰39母线系统进行PMU优化配置仿真及量测冗余性分析,验证了本文方法的有效性和优越性.     

GPS同步时钟用于电力系统暂态稳定控制的初步研究

本文提出了一种新的全局性的暂态稳定控制方法，它利用基于ＧＰＳ同步时钟的相量测量单元来测量各发电机的转子角度，并用它们来预测系统未来的摇摆情况，当预测出系统将失去稳定时进行切机控制以保持暂态稳定性。     

交直流系统可观测性分析

基于潮流定解条件对交直流系统可观测性进行了分析。该方法将直流系统中的每个换流站视为独立的单元,在直流系统整体不可观测的情况下,仍能合理利用其中换流站的量测,以尽可能扩大交直流系统的可观测范围。文中对交直流系统中交流部分和直流部分的相互影响进行了详细讨论,并归纳出用于交直流系统可观测性判断的规则。指出交直流系统边界节点上的交流电压幅值和注入量测是交流部分和直流部分的耦合变量,应用直流相关系数的概念和交替迭代的思想,提出了有效的交直流系统可观测性判断方法。在算例分析中,指出了直流线路的可观测性对状态估计程序收敛的影响,并验证了文中所述算法的效果。     

基于时频原子变换的电力系统同步相量测量方法

时频原子变换具有理想的复带通滤波特性,对基频带滤波能够获取同步复相量并同时阻隔其他频带分量的干扰.滤波频域带宽和计算数据窗长度均实现与带通中心的频率解耦.通过尺度参数灵活控制滤波的时域和频域特性.时频原子滤波函数的实部和虚部具有一致的幅频特性,对系统频率变化有较好的适应能力.提出基于时频原子变换的同步相量测量方法,通过...     

电力系统PMU最优配置数字规划算法

随着相量量测装置(PMU)硬件技术的逐渐成熟和高速通信网络的发展,PMU在电力系统中的状态估计、动态监测和稳定控制等方面得到了广泛应用.为达到系统完全可观,在所有的节点上均装设PMU既不可能也没有必要.文中提出一种基于系统拓扑可观性理论的数字规划算法,利用PMU和系统提供的状态信息,最大限度地对网络拓扑约束方程式进行了简化,以配置PMU数目最小为目标,形成了PMU最优配置问题,并采用禁忌搜索算法求解该问题.其突出优点是利用了系统混合测量集数据,即不仅考虑了PMU实测数据,同时计及了可用的潮流数据.在IEEE14节点和IEEE 118节点系统的仿真结果表明,与常规的PMU最优配置算法相比,所提出的数字规划算法可以实现安装较少数量的PMU而整个系统可观的目标.     

多机电力系统低频振荡模式可控性可观性研究

应用现代控制理论及大系统固定模的概念，研究了多机电力系统低频振荡模式可控性和可观性，并以新英格兰10机系统为算例进行了计算，所得结论对电力系统低频振荡抑制具有重要的参考价值。     

Fault-location Observability Analysis on Power Distribution Systems

Most of the fault-location methods developed in the past employed measurements obtained from a limited number of meters installed in a power system. Optimal meter placement in power systems is to make the best use of a limited number of meters available to keep the entire network observable. This article presents the fault-location observability analysis for distribution systems and proposes a novel optimal meter placement algorithm to keep the system observable in terms of fault-location determination. First, the observability of fault location in power systems is defined. Then analysis of the whole system is performed to determine the fewest number of meters needed and the best locations to place those meters to achieve fault-location observability. Case studies based on a 16-bus distribution system have been carried out to illustrate the proposed algorithms.