含SSSC输电系统的有功无功解耦算法

静止同步串联补偿器(SSSC)具有快速调节线路潮流的功能,对含SSSC电力系统的数学建模是深入研究SSSC的第一步.在两相同步旋转d-q坐标系下建立了装有SSSC双机系统的静态潮流方程并应用输入变换实现了有功和无功的解耦,同时给出了变换后等效的系统矩阵及所采用的输入变换矩阵.在MATLAB中对含有SSSC的双机电力系统进行了仿真,结果验证了该解耦策略的有效性.     

快速解耦牛顿法最优潮流

通过研究拉格朗日乘子的特点，结合电力系统支路参数特性，本文解决了牛顿法最优潮流算法海森矩阵元素合理常数化问题，在此基础上，提出了快速解耦牛顿法。该算法在选代过程中不必重新形成扩展海森矩阵的因子表，显著地缩短了每次选代时间。本文讨论了不同解耦方式对最优潮流的收敛性影响。计算实例表明，本文算法的收敛性好。     

基于快速解耦的电力系统连续潮流并行计算方法

为提高大型区域互联系统连续潮流的计算效率,提出一种改进的基于快速解耦电力系统连续潮流并行计算方法.通过在校正阶段采用快速解耦法求解潮流方程,根据系统的阻抗参数和功率增长方向构造修正方程组的系数矩阵,对潮流方程修正方程组进行预处理,并采用基于CPU-GPU混合架构加速的稳定双共轭梯度法进行求解.基于IEEE-118节点系统、Case13802等多个不同规模测试系统的算例分析表明,该改进算法有效提高了连续潮流的计算速度.     

基于内点法的快速解耦最优潮流算法

在电力市场环境下,最优潮流是计算实时电价的有力工具,因而就对最优潮流的计算速度提出了更高的要求。为适应一需求,本文在常规的内点法最优潮流的基础上提出了快速解耦内点法最优潮流,即把快速解耦的思想引入进来使其修正方程系数矩阵常数化,使每次迭代所需时间大大缩短,显著提高了计算速度。通过测试系统的计算表明该算法具有计算速度快,鲁棒性好的特点。     

基于坐标旋转变换的配电系统快速解耦潮流计算方法

配电系统中各支路的电阻与其电抗的比值较大,因此,经典的快速解耦潮流计算方法不适用于配电系统潮流计算。提出了一种坐标旋转变换方法,并将这种变换方法与经典的隐式Zbus高斯方法相结合,导出了配电系统的解耦潮流计算方法。以IEEE 33节点、IEEE 69节点和一个实际的145节点配电系统为例,对提出的解耦潮流算法进行了测试。结果表明,所提出的解耦方法不影响经典的隐式Zbus高斯方法的收敛性,因而是一种高效、实用的快速潮流计算方法。     

基于P-Q解耦的可用输电能力的计算分析

作为计算输电网可用输电能力的一种重要方法,连续潮流法一直受到电力工作者的关注.文章在分析基于P-Q解耦潮流的ATC模型基础上,给出了ATC计算中预测和校正的详细算法.这种算法在迭代过程中以不变的系数矩阵和代替变化的雅克比矩阵B′和B＂,可以节省存储空间、提高计算速度.以IEEE14节点系统为例,文章分别运用基于P-Q解耦和牛顿-拉夫逊法的连续潮流法进行ATC计算,进一步验证了基于P-Q解耦法ATC计算方法的有效性.     

解耦-补偿牛顿型三相潮流

首次将三相潮流计算中三相约束条件转化为单相正序红束条件，不仅简化了分析，而且为直接采用单相潮流算法铺平了道路。将性能良好的牛顿－拉夫逊法、Ｐ－Ｑ分解法与电力网元件的三相解耦或三相解耦－补偿模型结合，形成了性能优良的解耦－补偿牛顿型三相潮流算法－即解耦－补偿牛顿－拉夫逊法和解耦－补偿Ｐ－Ｑ分解法。提出的三相潮流算法不仅适合于不运行方式，如稳态单相继线或开路的分析。算例表明，两种方法具有良好的收敛特性     

含UPFC电力系统的潮流计算研究

提出一种含UPFC电力系统潮流计算的有效方法，该方法中的雅可比矩阵与传统的PQ分 解法中的对应矩阵完全相同，此外，还给出一种网络中任一支路潮流可控范围的快速估算方 法。     

高斯-快速解耦潮流算法

高斯法潮流计算中,PV节点转化为PQ节点易造成计算收敛缓慢,对此文中提出了应用快速解耦法处理网络中PV节点的方法。该方法应用传统高斯法处理PQ节点,利用高斯消元法消去网络中的PQ部分,得到了一个由PV节点和平衡节点组成的网络,然后用快速解耦法求解这个网络,从而实现了算法的快速收敛。该方法有恒定的雅可比矩阵、且内存占用量小、收敛可靠、计算速度快。     

一种快速的定雅可比潮流算法

完美地组合了电流注入型潮流算法和保留二阶项的快速潮流算法的优点,弥补了二者的不足之处,提出了一种快速的定雅可比潮流算法.该算法修正方程式的雅可比矩阵是通过对电流注入型潮流算法PQ节点的雅可比矩阵进行改造而得来的,是一个对称的常数雅可比矩阵.修正方程式的常数项是在保留潮流方程式非线性项的基础上进行简化改进而获得的,是一个非常简单的修正公式,在迭代过程中完全不需要进行节点电压的修正和节点功率的计算.这些处理,既保证了算法的收敛性,又大大提高了计算速度.详细论述了该算法的原理及用法.最后将它与牛顿法、定雅可比牛顿算法、PQ分解法、快速解耦法(FDLF)等潮流算法在多个算例上进行了收敛性能和收敛速度的比较,结果证明该算法收敛速度远大于牛顿法和定雅可比牛顿算法,收敛能力与定雅可比牛顿算法相当,算法适用能力比PQ分解法和快速解耦法强.     

电力系统潮流算法的几点改进

对电力系统传统潮流算法进行了如下几点改进：①提出了基于诺顿等值的多平衡节点处理方法。该方法既能解算具有多个平衡平点的同一电网潮流问题。也能够同时解算相互解列的、各自内部具有多个平衡节点的不同子网潮流问题。②针对小阻抗和零阻抗网络参数易导致节点导纳矩阵病态并影响潮流收敛速度和精度的同时,提出了基于节点等效附加注入的小阻抗和零阻抗处理方法。该方法可使节点导纳矩阵良性化,从而保证算法快速、准确地收敛。③针对PQ分解法的收剑性敏感于R/X比的问题,提出了基于节点等效附加注入的改进PQ分解法,使适用于高压输电系统的PQ分解法能够成功地应用于具有大R/X比的低压配电网潮流解算中。     

一种求解环状配电网潮流的有效算法一两阶段法

本文提出了一种求解环状配电网潮流问题的有效新算法－两阶段法,首先,介绍了辐射状配电网的前代／回代潮流算法。然后,基于辐射状配电网的前代／回代潮流算法和多端口补偿理论,详细阐述了本文所提出的求解环状配电网潮流的两阶段法。在第一阶段中,通过解环,将环状配电网转化为辐射状配电网,并应用前代／回代潮流算法求出该辐射状配电网的潮流,从而得到断点电流。在第二阶段,断点的注入电流被更新,并重新应用前供／回代潮流算法来求解当前辐射状配电网的潮流,所得潮流即为原环状配电网的潮流。为了证明本文提出的方法的有效性,本文采用了两个不同规模的算例系统进行了验证,给出了效果,并与另外一种方法进行比较。     

An enhanced RCGA for a rapid and reliable load flow solution of electrical power systems

The paper presents a reliable and fast load flow solution by using a real-coded genetic algorithm (RCGA), bus reduction technique and sparsity technique. The proposed load flow solution firstly used reduction technique to eliminate the load buses. Then, the power flow problem is solved for the generator buses only using real-coded GA to calculate the phase angles. Thus, the load flow problem becomes a single objective function, where the voltage magnitudes are specified resulted in reduced computation time for the solution. Once the phase angle has been calculated, the system is restored by calculating the voltages of the load buses in terms of the calculated voltages of the generator buses. A sparsity technique is used to reduce the computation time further as well as the storage requirements. The proposed load flow solution also can efficiently solve the load flow problems for ill-conditioned power systems whereas the conventional RCGA alone fails to solve these systems. The proposed method was demonstrated on 14-bus IEEE, 30-bus IEEE and 300-bus IEEE, and a practical system 362-busbar Iraqi National Grid. The proposed solution has reliable convergence, a highly accurate solution and much less computing time for on-line applications. The method can conveniently be applied for on-line analysis and planning studies of large power systems.     

An operations-oriented formulation and solution to the load flow problem

This paper presents an operations-oriented formulation and solution to the load flow problem. In this approach all the unit real power outputs are assumed specified and the objective is to calculate the bus loads. This fundamental change is useful in some power system problems and is also closer to the actual problem facing a load flow user.Different solution approaches, including a decoupled method, are proposed to solve the above problem. The numerical and analytical properties of this new decoupled load flow approach are similar to those of the conventional decoupled method. The main advantages of this proposed approach are: all the bus generations can be specified, a slack or swing bus need not be defined, and losses are independent of a choice of reference bus.This fundamental change in the load flow formulation has various applications. These include transmission loss evaluation, loss penalty factor calculation, and study applications in energy management systems.     

基于交流电路的临界电压崩溃特性分析

针对电力系统电压崩溃问题,在简单电路的基础上,用更直观的方法对电压稳定性问题加以分析。分析交流电路的临界电压崩溃运行点,在求解交流电路的方程组过程中,采用了几何分析方法。分析得出在不同运行点情况下临界电压崩溃潮流的电流电压特性。通过分析不计电阻的交流电路临界电压崩溃时的负荷特性、电压特性,指出交流电路的工作域和崩溃域。同时分析指出,在电力系统的工作域中,交流电路的功率输送特性必须与负荷的功率特性相容。     

用常规潮流程序直接计算含统一潮流控制顺的电力网络潮流

文章介绍了一种用常规潮流计算程序直接含多个统一潮流控制顺（ＵＰＦＣ）的电力网络潮流的方法。     

Load flow solution of distribution systems with voltage dependent load models

The classical constant-power load model is usually used to solve the load flow problem of a transmission or distribution system. However, the actual load of a system is not independent of voltage magnitude. Incorporation of voltage dependent load models in the load flow algorithm is essential to get better and accurate results. This paper compares the load flow results of a distribution system for various voltage dependent load models. The load flow problem of a distribution system is also formulated in terms of three sets of recursive equations so that very sophisticated voltage dependent load models can easily be incorporated in these equations. A 12.66 kV, 33-bus distribution system was used to observe the effects of load models on the load flow results. The convergence patterns of the load flow method for various load models were also compared.     

Application of quasi-Newton method to load flow studies and solution of load flow during three-phase fault

Newton's method, because of its quadratic convergence, is mathematically the most preferable of the several known methods for the solution of load flow problems. However, this method is not absolutely convergent for ill-conditioned problems. This paper presents a modification to Newton's method designed to reduce the number of function evaluations required in the solution of the load flow problem. It is a variation of Newton's method, in which the partial derivatives are replaced by difference equations, which is capable of giving significant improvement for routine load flow studies.In addition, an algorithm using the Freudenstein-Roth technique is incorporated in the program. This technique, which is essentially a parameter perturbation procedure, together with the quasi-Newton method, envisages a fast and accurate solution for load flow during a solid three-phase short-circuit.     

小阻抗支路对牛顿法潮流的影响及其处理方法

在分析小阻抗支路对牛顿法潮流影响的基础上,结合电力系统的网络的特点,提出了一种选取牛顿法潮流电压初值的新方法－－小阻抗支路零功率法。分析与计算结果表明,中所提方法能够较好地解决牛顿法在计算含有小阻抗支路系统的潮流收敛性问题。     

Fast service restoration for large-scale distribution systems withpriority customers and constraints

A fast, effective service restoration method is designed for large-scale distribution systems with priority customers. The service restoration problem is formulated as a constrained multi-objective optimization problem. A ranking-based search method employing analytical information obtained from three-phase power flow simulations is designed to restore service to as many priority customers as possible while maximizing the amount of total load restored and minimizing the number of required switch operations. The proposed method is designed with consideration to networks which have predominantly manual switches. Comprehensive simulation results of the search method, including priority customers, single and multiple faults and multiple out-of-service areas are presented for a 416 bus distribution network