Dec07kodad

A new Recursive Power Flow (RPF) algorithm for balanced/unbalanced radial distribution systems is proposed in this paper. Four generalized constant matrixes, that are calculated based on the graph theory, are used to obtain the power flow solution. These matrixes completely describe topology of a distribution system and models of its elements. In this method, each branch of a distribution system is considered as a bipolar. The method is able to consider detailed model of the elements. Solvability and convergence properties of the method have been mathematically presented. The method has been studied on the standard 16, 33 and 69-bus balanced distribution systems. In addition, this method is tested on 4 and 13-bus unbalanced standard distribution systems. Also, the method is tested on a 1337-bus real distribution system in Lorestan Electrical Power Distribution Company, Iran. The simulation results demonstrate the accuracy, computational efficiency and robustness of the proposed method.

IEEE Transactions on Power Systems, 2019

Load flow methods for distribution networks such as Backward Forward Sweep (BFS) have a good computational performance and can find solutions with accuracy. However, some studies may demand the determination of low voltage solutions, and this poses a problem for these methods since they cannot find these solutions due to convergence issues. This paper presents a load flow method based on a novel complex-valued formulation developed for distribution networks, which works well on radial topologies by using an incidence matrix to avoid complicated series element models, allow high-performance and low-voltage solution capability. The formulation is solved by Newton's method via Wirtinger's calculus. To prove the lowvoltage solution capability, both sides of QV curves, i.e., unstable and stable regions were traced on balanced and unbalanced networks. Performance tests in the IEEE test feeders show that the runtime is less than or equal to the runtime of the BFS method. Furthermore, the line R/X ratio and the number of controlled voltage node or volt-var functions do not affect the computational performance, yielding advantages over the classic Newton and BFS methods.

International Journal of Electrical Power and …, 1995

The paper presents a simple and efficient method for solving radial distribution networks. The proposed method involves only the evaluation of a simple algebraic expression of voltage magnitudes and no trigonometric functions as opposed to the stan&~rd load flow case. Thus, computationally the proposed method is very effic&nt and it requires less computer memory. The proposed method can easily handle different types of load characteristics. Several Indian rural distribution networks have been successfully solved by using the proposed method.

Electric power systems research, 2005

This paper presents a simple and efficient method to solve the power flow problem in radial distribution systems. The proposed method takes into account voltage dependency of static loads, and line charging capacitance. The method is based on the forward and backward voltage updating by using polynomial voltage equation for each branch and backward ladder equation (Kirchoff's Laws). Convergence ability and reliability of the method is compared with the Ratio-Flow method, which is based on classical forward-backward ladder method, for different loading conditions, R/X ratios and different source voltage levels, under the wide range of exponents of loads. Results demonstrate that the proposed power flow algorithm has a robust convergence ability when compared with the improved version of the classical forward-backward ladder method, i.e., Ratio-Flow.

The objective of this work was to develop a formulation and an efficient solution algorithm for the distribution power flow problem which takes into account the detailed and extensive modeling necessary for use in the distribution automation environment of a real world electric power distribution system.

The objective of this work was to develop a formulation and an efficient solution algorithm for the distribution power flow problem which takes into account the detailed and extensive modeling necessary for use in the distribution automation environment of a real world electric power distribution system.

This paper presents a new load flow formulation to solve active and passive electric distribution networks. The fundamental idea discussed here is how to obtain the power flow solution by using the elements of a unique quasi-symmetric matrix called TRX in the iterative process. The method is formulated for singlephase balanced and three-phase unbalanced radially operated networks. It works with real variables as opposed to complex variables used in previous backward/forward sweep algorithms discussed in literature. The proposed TRX matrix constitutes a complete database by including information of network topology structure as well as branch impedances of the distribution feeder. Data arrangement is suitable to be exchanged under standard Common Information Model (CIM) under Distribution Management Systems (DMS) environment allowing an efficient computation of the state of the system for on-line and off-line study applications. The proposed methodology was applied on a group of IEEE test systems and a real distribution system of 49,000 nodes.

Power and Energy Systems, 2013

This paper presents a direct power flow method for radial distribution systems that include different system components. When step voltage regulators are installed on strategic buses along the distribution feeders, the system will have multi reference buses. Using graph theory, a modified branch path incident matrix of multi reference buses is built and used with the current injection technique to derive a direct mathematical expression. This expression can be used to solve the load flow problem for radial distribution system with multi reference buses. The test results of IEEE 13 and 34 bus unbalanced test feeders indicate that the proposed method is efficient, robust, and accurate.

This paper presents a simple three phase load flow method to solve three-phase unbalanced radial distribution system (RDS). It solves a simple algebraic recursive expression of voltage magnitude, and all the data are stored in vector form. The algorithm uses basic principles of circuit theory and can be easily understood. Mutual coupling between the phases has been included in the mathematical model. The proposed algorithm has been tested with several unbalanced distribution networks and the result of an unbalanced RDS is presented in the article. The application of the proposed method is also extended to find optimum location for reactive power compensation and network reconfiguration for planning and day-today operation of distribution networks.

This paper proposes a backward/forward sweep method to analyze the power flow in radial distribution systems. The distribution system has radial structure and high R/X ratios. So the newton-raphson and fast decoupled methods are failed with distribution system. The proposed method presents a load flow study using backward/forward sweep method, which is one of the most effective methods for the load-flow analysis of the radial distribution system. By using this method, power losses for each bus branch and voltage magnitudes for each bus node are determined. This method has been tested on IEEE 33-bus radial distribution system and effective results are obtained using MATLAB.