This essential resource contains the information needed to design electric distribution systems that meet the requirements of specific loads, cities, and zones. The authors also show how to recognize and quickly respond to problems that may occur during system operations, as well as revealing how to improve the performance of electric distribution systems with effective system automation and monitoring. This updated edition:
Written for engineers in electric utilities, regulators, and consultants working with electric distribution systems planning and projects, the second edition of Electric Distribution Systems offers an updated text to both the theoretical underpinnings and practical applications of electrical distribution systems.
The electric power distribution system is characterized by heavy loading conditions at some buses and a high R/X ratio, unbalanced load and mostly radial topology. Many power flow methods have been designed and proved to work efficiently for transmission systems [9,10,11]. However, the design assumptions considered for power flow methods in transmission networks are not suitable for power flow analysis in radial distribution networks due to their convergence, memory requirements and computational efficiency.
In this work, simulations were conducted in three parts. In the first part, the simulation was conducted using IEEE standard buses to test the accuracy of the proposed algorithm by comparing it with other studied algorithms. In the second part, simulations were conducted in a meshed IEEE 15 bus to test the capability of the proposed algorithm in handling network reconfiguration cases. The third part is the simulation of the application of the proposed algorithm in a practical electrical secondary distribution network. All simulations were carried out using MATLAB 2017b on 3.80 GHz 4 Cores core i7 computer with 16GB RAM.
The proposed algorithms have been compared with popular load flow methods such as CIM, BFS and DLF. The results show that the proposed method has obtained similar power flow solutions as BFS and DLF, which proves its efficiency in solving power flow problems. Also, the proposed algorithm has shown its efficacy in handling network configuration problems without node renumbering. The proposed algorithm has efficiently performed when tested using data from a practical Tanzania electric power system with arbitrary numbering. Therefore, we propose using the proposed load flow method for medium- and low-voltage radial distribution systems.
Because of the strict requirement of power quality at the input AC mains, various harmonic standards and engineering recommendations such as IEC 1000-3-2, IEEE 519 (USA), AS 2279, D.A.CH.CZ, EN 61000-3-2/EN 61000-3-12, and ER G5/4 (UK) are employed to limit the level of distortion at the PCC. To comply with these harmonic standards, installations utilizing power electronic and nonlinear loads often use one of the growing numbers of harmonic mitigation techniques . Because of the number and variety of available methods, the selection of the best-suited technique for a particular application is not always an easy or straightforward process. Many options are available, including active and passive methods. Some of the most technically advanced solutions offer guaranteed results and have little or no adverse effect on the isolated power system, while the performance of other simple methods may be largely dependent on system conditions. This paper presents a comprehensive survey on harmonic mitigation techniques in which a large number of technical publications have been reviewed and used to classify harmonic mitigation techniques into three categories: passive techniques, active techniques, and hybrid harmonic reduction techniques using a combination of active and passive methods. A brief description of the electrical characteristics of each method is presented with the aim of providing the designer and site engineer with a more informed choice regarding their available options when dealing with the effects and consequences of the presence of these harmonics in the distribution network.
Electrical system reliability and normal operation of electrical equipment rely heavily upon a clean distortion free power supply. Designers and engineers wishing to reduce the level of harmonic pollution on a power distribution network where nonlinear harmonic generating loads are connected have several harmonic mitigation techniques available. Because of the number and variety of available methods, selection of the best-suited technique for a particular application is not always an easy or straightforward process. A broad categorization of different harmonic mitigation techniques (passive, active, and hybrid) has been carried out to give a general viewpoint on this wide-ranging and rapidly developing topic. PHF is traditionally used to absorb harmonic currents because of low cost and simple robust structure. However, they provide fixed compensation and create system resonance. AHF provides multiple functions such as harmonic reduction, isolation, damping and termination, load balancing, PF correction, and voltage regulation. The HHF is more attractive in harmonic filtering than the pure filters from both viability and economical points of view, particularly for high-power applications. It is hoped that the discussion and classification of harmonic mitigation techniques presented in this paper will provide some useful information to help make the selection of an appropriate harmonic reduction method for a given application on an easier task.
Solar energy resource assessment is critical for accurate evaluation of the quantity of incoming solar radiation available to develop, install, and operationalize highly efficient solar power technologies1,2. The task primarily involves development of a comprehensive climatological solar radiation and related parameters database at short-time intervals, an in-depth grasp of the spatiotemporal distribution and correlations, and accurate forecasts to ascertain precisely the performance of solar power systems and the technical effect of solar radiation variability on national electric grids. However, due to sparse or non-existent solar radiation measurement stations in many parts of the world, the gap between installation and performance modeling widens3,4,5,6. 2b1af7f3a8