网络拓扑结构变化时配电网节点阻抗矩阵方程的统一算法

利用支路追加法生成节点阻抗矩阵的原理,根据配电网为少环状或弱环状的结构特点,归纳出单独形成配电网节点阻抗矩阵和计及配电网网络拓扑结构变化时配电网节点阻抗矩阵的统一算法。省去了节点编号优化、三角分解和连续回代等复数运算,具有计算速度快,物理概念清晰,易于编程实现等特点。     

基于节点阻抗矩阵的配电网故障测距算法

提出了一种基于节点阻抗矩阵的配电网故障测距改进算法,故障后,系统的网络拓扑结构及参数会随之改变,引起节点阻抗矩阵的变化,形成故障后的节点阻抗矩阵,其中含有未知量故障距离和过渡电阻,利用节点阻抗的物理意义建立测距表达式。该算法仅需要变电站出线电压、电流作为输入量,迭代计算故障区段上游母线的电压、电流,代入已建立的测距表达式求出故障距离和过渡电阻;为适应配网中负荷特性不统一、时变的特点,提出采用静态电压特性的负荷模型模拟负荷,采用此模型可以更加精确地计算故障后各负荷及分支的分流,使得故障测距结果更加准确;并提出结合配电系统的馈线自动化功能减少伪故障点个数实现故障点的定位;文章最后在PSCAD中搭建配电网IEEE 34节点模型,在 Matlab 中实现文中提出的故障测距算法,仿真测试表明该算法的有效性。     

基于回路阻抗法的配电网潮流计算

依据配电网潮流计算的回路阻抗法 ,结合配电网结线的特点 ,定义了反映支路电流流向与节点分布规律的关联矩阵 ,提出了形成阻抗矩阵和简单快速的节点、支路的编号方法 ;在此基础上 ,提出了一种配电网潮流计算的新方法。新算法具有编程简单易于实现 ,收敛速度快 ,计算精度高的特点     

基于回路阻抗法的配电网潮流计算

依据配电网潮流计算的回路阻抗法,结合配电网结线的特点,定义了反映支路电流流向与节点分布规律的关联矩阵,提出了形成阻抗矩阵和简单快速的节点、支路的编号方法;在此基础上,提出了一种配电网潮流计算的新方法.新算法具有编程简单易于实现,收敛速度快,计算精度高的特点.     

配电网短路故障的新算法

通过分析配电网的有向拓扑图,建立了配电网的数学模型－－节点线段关联矩阵,并在该数学模型的基础上,分析归纳出节点阻抗矩阵各元素的计算方法,结合配电风特点,提出了一种简单、准确的配电网短路计算机算法。     

一种形成节点阻抗矩阵的改进算法

文中根据节点注入电流与支路电流以及支路电流与节点电压之间的拓扑关系，分别定义了节点注入电流对支路电流矩阵MI，J，和支路电流对节点电压矩阵MI，V，并解释了其物理意义；借用稀疏矩阵求逆的前推回推算法，提出了一种能够快速形成大规模电网节点阻抗矩阵的改进新方法。该算法能统一处理互感和无互感线路、单连通树支集的特定网络以及树枝集中有分支的通用电网络。在考虑支路间存在任意互感的前提下，详细推导了2个过度矩阵以及节点阻抗矩阵的形成过程；2个构造矩阵能有效地反映电网支路发生短路故障或系统切除负荷的紧急事故前、后网络参量的变化。该算法具有占用内存少，计算速度快的特点。最后通过算例验证和比较了该方法的实用性和高效性。     

三相参数不对称的环状复杂配电网故障计算的新方法

根据少环配电网的结构特点，提出一种三相参数不对称的环状配电网故障计算新方法：将配电网分成不含环状结构的辐射状网络利不含辐射状结构的纯环状网络，从而通过回路阻抗矩阵来反映环网的影响，并利用叠加原理来进行整个配电网故障计算。该方法的主要特点在于：采用abc三相模型，克服了由于配电网三相参数不对称所造成的对称分量法无法应用的缺点；无需形成复杂的三相参数不对称的含环网的配电网三相节点复数导纳或阻抗参数矩阵；能够自动适心网络拓扑结构的变化；可方便地计及限流器的作用；计算速度快，效率高，方法简单。算例表明文中方法是三相参数不对称的含环形网络配电网故障计算的一种十分简单且有效的方法。     

CANONICAL METHOD FOR CALCULATING

文章以网络支路阻抗方程作为电网数学模型,系统地研究了配电网故障计算的通用方法。根据配电网少环的结构特点和固态限流器的工作原理,利用叠加原理、多端口戴维南定理和相序参数变换技术,提出了一种能自动适应网络操作、对故障类型没有限制、可计及固态限流器作用的配电网故障计算通用方法。这种方法具有无需形成配电网复数节点导纳参数矩阵或阻抗参数矩阵、极易在计算机上实现等特点。     

节点导纳矩阵和阻抗矩阵的互感支路组整体追加方法

在以支路追加法形成节点导纳矩阵和节点阻抗矩阵的过程中,互感支路的追加远比非互感支路复杂,因此提出以支路组为单位的节点导纳矩阵及节点阻抗矩阵支路组追加法。该方法将相互之间有互感耦合的支路分为一组,应用所推导的追加公式以整组互感支路为单位直接追加到节点导纳矩阵和节点阻抗矩阵中,使得计算方法简单统一,可显著减少计算量,提高计算效率。最后通过算例验证和比较了所提方法的实用性和有效性。     

一种含分布式发电系统的三相配电网潮流直接算法

提出一种基于道路矩阵的三相不平衡配电网潮流直接算法,该算法充分利用配电网络的结构特点,建立了节点电压与注入电流的关系矩阵,实现了潮流的直接计算。基于PV节点的特性,推导了PV节点网络的有功电流和无功电流关系,并提出了一种新的处理PV类型分布式发电的方法。将该方法引入到三相系统潮流计算中,保证了PV节点幅值为预设定值（假定无功功率没有越界）。6母线和69母线系统算例验证了该方法简单实用,潮流计算时间短和迭代次数少,具有很好的通用性。     

A DIAKOPTICAL TECHNIQUE FOR SHORT CIRCUIT STUDIES OF LARGE SIZE POWER SYSTEM NETWORKS

ABSTRACT

The paper presents a diakoptical technique for deriving the impedance matrices required for short circuit studies of large size power system networks by tearing the system into smaller subsystems by cutting appropriate tie lines. The bus admittance matrix is formed for the sequence networks of each subsystem and then modified later by means of diakoptics. The simulation of mutual couplings is taken into account in the zero sequence networks. Only columns of the impedance matrices corresponding to the faulted buses are computed in the proposed technique which is based on factorized bus admittance matrices and full exploitation of sparsity. The proposed technique can either be used in a single–processor computer for sequential solution of torn subsystems or in a multicomputer configuration for a faster solution by parallel processing of torn subsystems. Both symmetrical and unsymmetrical faults are studied by using the proposed technique which produces exact results as the untorn system. No iterative calculations are required as short circuit analysis is basically a linear problem. Included in this paper is a numerical example of a sample test system.     

输电开放下基于交叉影响矩阵的损耗分摊方案研究

在输电开放的电力市场中，双边交易已成为电力市场中的重要行为。然而计算双边交易所引起的损耗，目前提出的方法均忽略了交易之间的相互影响。针对这一点，该文提出了一种基于交叉影响矩阵的损耗分摊方案。在该方案中提出了交叉影响矩阵，根据矩阵中的元素可以定量地分析交易之间的相互影响；通过交叉影响矩阵定性地分析了逆向流性质，提出了显逆向流、准逆向流和隐逆向流的概念并给出判据；在该文提出的损耗分摊方案中由于将交叉影响矩阵中的元素作为损耗分摊系数，因此其分摊结果可反映交易间的相互影响。通过IEEE-57母线标准测试系统演示了所提方案的计算过程。     

Transmission loss allocation using combined game theory and artificial neural network

An artificial neural network based method is suggested for allocation of transmission loss in a deregulated power system involving bilateral contract based power transactions between power suppliers and the distribution companies. The proposed method allocates transmission losses to operating transactions on the basis of Shapley value game theoretic approach. For this, bilateral transactions for power system are simulated and corresponding losses are obtained through load flow analysis. Shapley value approach is used to calculate the loss allocations. A large number of such simulation cases are generated and a large data pool stores these possible bilateral transactions and the corresponding loss allocations following Shapley value approach. For allocating losses to the transactions of an operating system environment the required neural network is developed online. A simple filtering technique is used to extract the suitable training data that are close enough to the actual operating condition from the generated data pool and neural network is trained online. The performance of such a network when tested on standard power networks has been found to be very encouraging.     

基于独立性网损微增率和环境成本的发电调度

网损微增率的计算是电力系统有功优化的重要组成部分.基于经典电路理论对独立性网损微增率进行了推导,在推导中仅用到了系统所有节点的节点注入电流和节点阻抗矩阵,不涉及平衡节点的选取问题.基于该独立性网损微增率,在传统的发电成本中计入环境成本,建立了发电成本最小包含风力发电的发电调度模型,并用有功优化经典算法进行求解.IEEE...     

A methodology for probabilistic simultaneous transfer capabilityanalysis

This paper presents a methodology for simultaneous transfer capability analysis based on a probabilistic approach. All areas in a large scale power system are divided into three groups: (a) study area, (b) transfer participating areas, and (c) external areas which have no direct transactions or they have fixed transactions with the study area. A performance index based contingency selection procedure is applied within the study and transfer participating areas to rank those contingencies which will affect simultaneous transfer capability. The contingency ranking order is utilized by a variation of the Wind Chime diagram to selected contingencies which are then evaluated by an optimal power flow algorithm. Subsequently, the probability distribution of simultaneous transfer capability is computed based on the electric load, circuit and unit outage Markov models. The 24×3 bus IEEE RTS is utilized to evaluate the proposed method. The performance of the proposed method is also demonstrated on an actual large scale system (2182 bus, 8 area system)     

A simple approach to voltage stability assessment in radialnetworks

Analytical approach to voltage collapse proximity determination is proposed for radial networks. Under corresponding assumptions, a radial network with arbitrary bus loads is transformed into a two bus equivalent. The voltage phasors at the generator bus and at the last load bus of the radial network are transformed to form the voltage phasors of the two bus equivalent. The latter are further used for assessment of voltage collapse proximity. Exact stability limit relations for a two bus system derived from Jacobian matrix can be exploited. Moreover, an analytical expression is derived for calculation of active and reactive power reserve margins for a radial network equivalent. The proposed procedure has been tested for practical examples of radial networks with inductive and capacitive loads     

基于Shapley值的网损分摊新方法

介绍了目前网损分摊方法的研究现状，提出了一种基于Shapley值的网损分摊新方法，这种方法根据每个交易加入交易联盟后给交易联盟带来的边际网损大小来分摊网损，该网损分摊方法平等地对待所有可能的交易加入次序，并且考虑了所有可能存在的包含该交易在内的交易联盟，因此能够被各市场成员视为公平，另外，这种网损分摊方法能保证收支完全平衡，并且能够向各交易提供适当的经济激励信号，促进电力负荷的合理分布，从而降低系统的总网损，数值算例结果表明，基于Shapley值的网损分摊方法是公平，有效的。     

Optimal placement and sizing of distributed generators and shunt capacitors for power loss minimization in radial distribution networks using hybrid heuristic search optimization technique

This paper attempts to minimize power losses in radial distribution networks and facilitates an enhancement in bus voltage profile by determining optimal locations, optimally sized distributed generators and shunt capacitors by hybrid Harmony Search Algorithm approach. To overcome the drawback of premature and slow convergence of Harmony Search Algorithm (HSA) over multi model fitness landscape, the Particle Artificial Bee Colony algorithm (PABC) is utilized to enhance the harmony memory vector. In the first approach, the formulation echoes the determination of loss sensitivity factor to decide the sensitive nodes and thereafter decides on the optimal rating through the use of hybrid Algorithm. The second approach encircles the role of hybrid Algorithm to search for both the optimal candidate nodes and sizing of compensating devices by significant increase in loss reduction with the former approach. The procedure travels to examine the robustness of the proposed hybrid approach on 33 and 119 node test systems and the result outcomes are compared with the other techniques existing in the literature. The simulation results reveal the efficiency of the proposed hybrid algorithm in obtaining optimal solution for simultaneous placement of distributed generators and shunt capacitors in distribution networks.     

Z-bus loss allocation

This paper presents a new procedure for allocating transmission losses to generators and loads in the context of pools operated under a single marginal price derived from a merit-order approach. The procedure is based on the network Z-bus matrix, although all required computations exploit the sparse Y-bus matrix. One innovative feature and advantage of this method is that, unlike other proposed approaches, it exploits the full set of network equations and does not require any simplifying assumptions. The method is based on a solved load flow and is easily understood and implemented. The loss allocation process emphasizes current rather than power injections, an approach that is intuitively reasonable and leads to a natural separation of system losses among the network buses. Results illustrate the consistency of the new allocation process with expected results and with the performance of other methods     

地下隧道中电力电缆的线路阻抗矩阵相序阻抗矩阵和参数的分析

在研究电力电缆发生短路对周围通讯系统的危险影响时,短路电流的分布和入地电流系数的计算是至关重要的,这必然涉及线路阻抗,相序相抗和自互阻抗等参数,文章给出了电缆线芯不换位,金属护套交叉互联两端接地系统的线路阻抗矩阵,相序阻抗矩阵的直观表达式,分析了它们的一些性质,介绍了隧道中电缆参数的一种分析方法,即虚拟媒质法,应用该法可以方便地处理道空气区对其自互阻抗的影响,由于该法是数值方法,隧道横截面形状可以