Calculation Of Distribution Network Research Articles

A Graph Partition-Based Large-Scale Distribution Network Reconfiguration Method.

This article focuses on the analysis of large-scale distribution network reconstruction fused with graph theory and graph partitioning algorithms. Graph theory and graph segmentation algorithms have been rushed by many researchers in the fields of medicine, drone, and neural network. It is a newcomer in the field of computer vision, which can not only realize the division in color but also divide it by image data. The distribution network is also indispensable for new energy, electric machines, but the traditional distribution network has many problems, such as not suitable for distributed power access and excessive network loss. To improve the performance of distribution networks and reduce network losses, this paper A multi-division model for distribution network construction and reconstruction is established, and a graph theory-based division algorithm method is proposed to effectively solve the problem of feeder-to-feeder reconstruction during large-scale distribution in distribution networks. Through its superconductivity phenomenon and the characteristics of clustering algorithm division, this paper uses formulas to show its division principle and gives examples of various distribution network reconstruction algorithms to explore which method of improvement can improve the performance of the distribution network and reduce network losses. The number of iterations is also strictly considered, and the value is taken after multiple iterations to reduce the error. Through the distribution network calculation example, the network loss reduction value is obtained, and the distribution network fault repair model is exemplified. The picture is used to briefly describe the process of distribution network reconstruction and find that the faults of the distribution network can be quickly located and isolated through the FTU, and quickly repaired. Finally, in order to reduce the network loss, reduce the load of power flow calculation, and solve the problem of local optimization, a JA-BE-JA optimization algorithm based on large-scale distribution network reconfiguration is proposed. The mixed sampling method is preferred to test the number of divisions in the four states, and the parameters are selected to test the performance of the improved annealing simulation algorithm, and the conclusion is drawn as follows: the improved graph segmentation algorithm has strong robustness, can avoid local optimization of graph data, and can reduce network loss. Compared with traditional distribution network reconstruction methods, the network loss can be reduced to 454.3 KW, which can be optimized by 10.68% compared with the initial network loss.

Problems of energy supply of the main consumers of distribu-tive networks of Iraq

The main purpose in this paper to study the main features of the distribution network for Iraq, which showed that the distribution network is physically and morally obsolete. Analyzing of electrical distribution networks is considered of highest priority at the present time in Iraq. This paper presents efficient practical methods for calculating the main parameters of the distribution network based on scientific and practical fundamentals. In this work the analysis is based on the advanced RasterWin3 software as a tool for the calculation of a basic parameters for distribution network performing the required analysis. RasterWin3 software is practical and efficient analysis software used by many electrical companies worldwide. The distribution network calculation was implemented (11/33) kV. The calculation results showed that the voltage deviation exceeds the maximum permissible value and is 12% in normal mode and 40% in emergency mode. Power losses in the branches of the power system of Iraq reach 20% of the consumed electricity. This is justified by the low quality of electricity and overload of the power supply system.

Short-Circuit Calculation in Distribution Networks with Distributed Induction Generators

This paper presents an improved current source equivalent model method to determine the short-circuit current of a distribution system with multiple fixed-speed and variable-speed induction generators (IGs). The correlation coefficients of flux components between stator and rotor under the unsymmetrical fault are analyzed using the positive and negative sequence steady-state equivalent circuits of an IG. The terminal voltage and current responses of fixed-speed and variable-speed IGs with and without the rotor slip changes under different penetration levels are compared to investigate the coupling relation between the short-circuit currents of IGs and the nodal voltages in the distribution network. Then the transient equivalent potential of an IG at the grid fault instant is derived. Sequence components of the short-circuit current in the network can be determined using the proposed technique. The correctness of the proposed method is verified using dynamic simulation.

A Novel Policy for LMP Calculation in Distribution Networks Based on Loss and Emission Reduction Allocation Using Nucleolus Theory

This paper proposes a new policy to calculate the locational marginal price (LMP) in the distribution networks containing distributed generation (DG). The proposed policy is based on remunerating the DG units to reduce the loss and emission of the network. LMP at each DG bus is calculated according to the contribution of the DG to the reduced amount of loss and emission. An iterative algorithm which is based on the nucleolus theory is proposed to allocate the loss and emission reduction. The proposed algorithm will provide a robust state estimation tool for distribution companies (DISCOs) in the next step of operation. The state estimation tool provides the decision maker with the ability to exert its control over private DG units when the loss and emission are minimized. Also, the proposed pricing policy requires decision maker to simply apply its best response strategy to the LMP based on the priority of loss, emission and DISCO's extra benefit. The proposed methodology is applied to two realistic distribution networks, and efficiency and accuracy of the method are verified.

Theoretical Line Loss Calculation of Distribution Network Considering Wind Turbine Power Constraint

This paper presents a theoretical line loss calculation of distribution network containing an uncertainty power of wind turbine. First, this paper establishes the theoretical line loss mathematical model considering wind turbine power constraint within the sampling period. Then this paper gets multi group wind turbine output data satisfied the power constraints through Monte Carlo simulation. By combining with the first power coefficient method and Monte Carlo simulation technique, this paper also generates multi groups load pseudo measurement test of non real time. By combining the real-time measurement of power flow calculation, a group of simulated data with minimum error between the power flow results and the real time measurement are selected. Finally based on the selected pseudo measurement, the theoretical line loss within the given time period based on periodic accumulative calculation of real-time measurement are calculated. 14 nodes example is given to verify the accuracy and practicality of the algorithm.

Probabilistic Harmonic Calculation in Distribution Networks with Electric Vehicle Charging Stations

Integrating EV charging station into power grid will bring impacts on power system, among which the most significant one is the harmonic pollution on distribution networks. Due to the uncertainty of the EV charging process, the harmonic currents brought by EV charging stations have a random nature. This paper proposed a mathematical simulation method for studying the working status of charging stations, which considers influencing factors including random leaving factor, electricity price, and waiting time. Based on the proposed simulation method, the probability distribution of the harmonic currents of EV charging stations is obtained and used in the calculation of the probability harmonic power flow. Then the impacts of EVs and EV charging stations on distribution networks can be analyzed. In the case study, the proposed simulation and analysis method is implemented on the IEEE-34 distribution network. The influences of EV arrival rates, the penetration rate, and the accessing location of EV charging station are also investigated. Results show that this research has good potential in guiding the planning and construction of charging station.

Power Flow Calculation of Distribution Network with DG Based on Advanced Forward and Backward Substitution Algorithm

Compared with the traditional power system, there are some differences in the aspect of distribution network structure, line parameters and load parameters in the power system with distributed generations. Therefore, the conventional power flow algorithm can not be applied to this kind of networks. Considering that the distributed generations have special influence on the operation of distributed network, a novel power flow calculation method for this kind of distribution network is studied in this paper. Several equivalent circuit models of distributed generations and the corresponding approaches have been researched. The feasibility of this proposed power flow algorithms can be verified through the program designed in Matlab software.

Design and Application of Decision Support System for Power Loss Reduction of Rural Power Network

Theoretical line loss calculation is the basis of line loss analysis and decision-making in loss reduction. Due to technical constraints in the past, traditional theoretical line loss calculation method uses a large number of simplified calculations. This paper proposes a new online method of line loss calculation in distribution networks which is based on PQU (active power, reactive power and voltage) load curves. The proposed method has a large amount of data operation and thus can accurately reflect the load variation with time. Based on a new kind of metrical equipment and the proposed method, the assistant decision system for comprehensive power loss reduction of rural power network has been developed and has been tested on several rural power networks. The results show its convenience, accurate calculation and high efficiency.

Customer Classification and Load Profiling Method for Distribution Systems

In Finland, customer class load profiles are used extensively in distribution network calculation. State estimation systems, for example, use the load profiles to estimate the state of the network. Load profiles are also needed to predict future loads in distribution network planning. In general, customer class load profiles are obtained through sampling in load research projects. Currently, in Finland, customer classification is based on the uncertain customer information found in the customer information system. Customer information, such as customer type, heating solution, and tariff, is used to connect the customers with corresponding customer class load profiles. Now that the automatic meter-reading systems are becoming more common, customer classification and load profiling could be done according to actual consumption data. This paper proposes the use of the ISODATA algorithm for customer classification. The proposed customer classification and load profiling method also includes temperature dependency correction and outlier filtering. The method is demonstrated in this paper by studying a set of 660 hourly metered customers.