One-line Diagram Research Articles

Intelligent Digitization of Substation One-Line Diagrams Based on Computer Vision

Intelligent Digitization of Substation One-Line Diagrams Based on Computer Vision

Evaluation of Electric Power Quality in the Ship-Integrated Electrical Power System with a Main DC Bus and Power Semiconductor Electric Drives as Part of the Electric Propulsion Complex

The relevance of the work is connected to the energy efficiency of specialized vessels of the technical fleet. The purpose of the study was to determine and evaluate the power quality indicators associated with the non-sinusoidal shape of the voltage and current curves in the electrical power system of the marine platform support vessel, which contains powerful semiconductor propulsion electric drives, taking into account the inherent and parasitic parameters of the power three-phase cable lines. A simplified one-line diagram of an electric power system with a DC main bus was the object of the study, which was compiled as a result of the analysis of analog systems typical for the indicated type of vessels. The phenomenon of voltage and current distortion caused by the presence of higher harmonics generated by power semiconductor converters in a three-phase ship network was the subject of the research. For the experimental study of the quality of electric power according to the simplified one-line scheme of the electric power system in MATLAB Simulink, its model was created. Based on the proven methods of calculating the ship’s electrical equipment, a methodology was developed for the reliable determination of model parameters. According to the results of the experiment in MATLAB Simulink, qualitative and quantitative indicators were obtained regarding the non-sinusoidality of the linear voltage and current of the three-phase network (curve shapes, amplitude spectra, distortion coefficients), and their comparative analysis with the current norms and standards was performed. In contrast to the previous ones, the methodology for assessing the quality of electricity in the studied electric power system takes into account its circuit, mode features, and the presence of a parasitic capacitance “phase to ground” of a three-phase network, and it can be used in solving similar non-trivial tasks for various similar structurally modified systems.

Detection of High-Resistance Connections in Industrial Power Systems During Induction Motor Start-up

We propose a methodology for detecting and isolating high-resistance connections (HRC) in industrial power systems during induction motor (IM) start-up. Negative sequence components are analyzed during the IM start-up transient in different points of the electric system of an industrial plant. The effects of HRC are evaluated using an analytical model of an industrial power system in steady state and validated with numerical simulations obtained of a transient model. These results show not only the possibility to detect HRC but also its isolation from unbalance voltage conditions of the grid. In addition, an approximation of the total power of motors affected by the HRC is calculated with our proposal. This power and the electric one-line diagram of the industrial plant allow us to determine the location of HRC. Finally, the proposal is validated by using experimental results obtained in a meat processing industry.

Algorithm for visualizing substation areas in electric power systems

Electric power distribution systems can be represented with mathematical graphs in which the hub nodes are substations receiving electric power from the transmission system and delivering it to the consumers via feeders consisting of transformers, junctions, cables and power lines. High-quality diagrams depicting these systems are key elements of efficient monitoring and control. Existing automatic diagram generation solutions are usually limited to drawing single feeders or contain significant simplifications of the underlying distribution system e.g., visualize multiple feeders with their interconnections removed. The goal of this research was to develop an algorithm capable of generating visually-pleasing diagrams of substation areas consisting of a single hub node and a complex network of thousands of interconnected elements. The resulting algorithm was defined as a sequence of transformations which takes a mathematical graph as input and generates a one-line diagram as output. Multiple novel approaches are incorporated to optimize the algorithm thereby allowing it to run efficiently on regular desktop computers. Also, a novel diagram quality evaluation procedure was developed to automatically measure and compare the usability of each generated diagram. The algorithm was tested on 2510 different substation areas of various complexity extracted from the network models of real-life, European distribution systems. The quality of the generated diagrams was measured with the novel evaluation procedure and verified with a human domain experts on a subset of the resulting diagrams. Based on these analyses, it was concluded that the generated diagrams are usable in newly built supervisory and control systems with minimum human intervention.

Coordination of Overcurrent Relay In Distribution System

The overcurrent phenomena are a dangerous condition that can be occurred in the electrical system and equipment. The condition of the overcurrent will cause the short-circuited current flows through the system and affect the other distribution line. The purpose of this study is to investigate the coordination of the overcurrent relay in different types of the distribution network which are radial distribution system, ring distribution system, and interconnected distribution system during line to ground fault occur at the bus. The generation of the overcurrent and directional overcurrent flow in the distribution network will damage the nearest equipment and reduce the power stability. The installation of the IDMT overcurrent relay in the distribution system will clear the faulty section from affecting the other distribution line. This protective device also operates to detect the abnormal condition with proper time current characteristic condition that involves the optimum time speed, accurate coordination, and sensitivity. The simulation of the IDMT overcurrent relay in the one-line diagram of the distribution network is executed by using ETAP software meanwhile the IDMT relay setting is calculated via MATLAB.

Two-stage resilience-constrained planning of coupled multi-energy microgrids in the presence of battery energy storages

In recent years, severe weather-related catastrophes have caused irreparable damages to the body of power systems, which has attracted the attention of planners to increase the resilience of power systems. In line with the goals of this issue, this paper introduces a two-stage programming on the basis of resilience oriented model to design solar panels, micro-turbines, and mobile batteries within the multi energy carrier microgrid to increase the resilience of the system against high-impact events. The propounded framework is formulated as mixed-integer quadratic programming that takes investment decisions at the first stage while optimizing operation variables at the second stage in order to reinforce the resilience of the system. An integrated power and gas model is used to increase the perception of readers about the mutual interactions between electricity and heat energy. Therefore, the availability of fuel and the price of the micro turbine are explicitly formulated and evaluated. One-line diagram of 14-bus coupled micro energy grids is used to investigate the efficiency and proficiency of the proposed model. Comparative studies numerically show that the suggested method helps the microgrid operator in identifying optimal solutions to reinforce the resilience of power system against severe events.

Comparison of Radial and Zonal DC Distribution System for Hybrid-Powered Trimaran Vessels Power Flow Analysis

Two types of power grid structures have been applied to the shipboard, namely the radial and the zonal networks. These two distribution systems have different power characteristics transmitted to the bus panel. The power characteristics affect the power density of each bus at each level. This paper explores the power characteristics of the radial type and the zonal type power grid structures in a DC distribution system. The power flow of both distribution system types has been determined by the Adaptive Newton-Raphson method and simulated based on ship operation conditions using Electrical Power System Analysis Software (ETAP). In determining the power flow for the DC distribution system, one-line diagram modelling is developed in radial type and zonal type. The simulation parameters are adjusted to the operating conditions of the ship, namely sailing, manoeuvring, loading-unloading, and at the port. After that, a power flow simulation has been carried out using ETAP and has showed what had successfully implemented the power flow in the DC distribution system for radial and zonal types. The capacity of Power generation is adequate all through a ship operation. The characteristics of the transmitted power show that the zonal type has a higher efficiency rate than the radial type. The zonal type has a backup bus so that the electrical system's reliability is higher than the radial type. However, the power distributed to the equipment bus from the load bus, both the radial type and the zone type, has the exact power requirements.

Load Flow Simulation of Radial Shipboard Network Structure with Direct Current Distribution Systems

The aim of this research is to investigate load flow of direct current distribution system on trimaran ferry ship. Radial Shipboard Network Structure with Direct Current Distribution Systems has been proposed in this research. Load flow simulation has been done by calculating electrical load calculation based on ship operation. Then, the one-line diagram of direct current distribution system is developed on electric power software. Simulation results show that direct current distribution system has been successfully implemented on hybrid powered trimaran Ship. In sailing conditions, the overall real power requirement is 20,201 MW and the reactive power is 7,757 Mvar. While the power distributed is 20,493 MW of real power and 7.816 Mvar of reactive power. In manoeuvring conditions, the actual power requirements are 21,251 MW and the reactive power is 8,16 Mvar and for power distributed is 21,573 MW of real power and 8,224 Mvar of reactive power. In loading and unloading conditions, the actual power requirements in this operating condition are 0.616 MW and the reactive power is 0.292 Mvar and for power distributed is 0,635 MW of real power and 0,296 Mvar of reactive power. In the condition of entering the port, the required power is 12.906 MW for real power and 4.969 MW for reactive power and for power distributed is 13,027 MW of real power and 4,994 Mvar of reactive power. The result showed that the concept direct current distribution system has been successfully developed in this research to combine diesel generators with marine renewable energy to make sure that the distributed power stay adequate all through operation.

Power Flow Study on Container Crane with Simulation-Based Renewable Energy Supply

Container port’s loading-unloading process is still using heavy equipment with less eco-friendly fuel. However, currently, several container ports are implementing an eco-friendly port (green port) concept. Renewable natural resources, such as the sun’s heat energy, are used as an alternative to supports the green port concept. Container cranes, the main heavy equipment in the loading and unloading processes, are generally supplied with electricity from PLN and diesel generators. In this research, it was tried by modeling container crane’s one-line diagram into ETAP, but by adding renewable energy resources simulation, such as solar panels. Solar panel’s characteristics, such as voltage and output frequency are different from PLN and diesel generators. Then, the difference results will be analyzed. After the simulation, results in comparison, known that solar panels can be used for container crane’s electrical system supply. In this study, the PV’s inverter output voltage is 0.38 kilo-volt. The PV supply simulation results in lower power efficiency and higher voltage drop than the PLN and diesel generator’s supply. As for each PV supply scenario, power efficiency and drop voltages are still within the IEC and IEEE standard limits. For example, in the gantry scenario, the power efficiency is 94.44%, and the drop voltage is 0.274% .

Over frequency control of photovoltaic inverters in an island microgrid

This paper discusses the power variation of photovoltaic power plant (PVPP) impact on the frequency response of an isolated island microgrid. An island microgrid with PVPPs and diesel generators is selected for study. The power system network, diesel generation units, load and PVPP data are collected in detail. And the one-line diagram of the study system with regarding peak and off-peak loading is set up in the simulation software for the steady state load flow analysis. After that, the transient stability analysis is executed with considering the tripping and power variation of various PVPP ramp rates with and without considering the over frequency compensation of photovoltaic (PV) inverters. The dynamic response of diesel generators and system frequency are examined carefully. It is found that the over frequency phenomenon can be controlled effectively by the regulation of PV inverters to achieve better reliability of the microgrid.

Techniques for Drawing Geographic One-Line Diagrams: Substation Spacing and Line Routing

Visualization of electric power transmission systems centers on the one-line diagram, which is a simplified logical depiction of the circuit's connections and elements. Such a graph drawing is useful for supporting the study, analysis, and presentation of power system data. This paper proposes an automated way to generate one-line diagrams, given substation identifiers with geographic tags and the system bus-branch model. Two approaches to drawing the substations are given: a force-directed approach and a greedy approach, which in different ways modify the position and size of substations as drawn. For transmission line routing between substations, a Delaunay-based method is employed, which segments the transmission line drawings to avoid overlapping with substations and other lines. These methods show good visual properties in spacing, geographic context, relatively straight lines, and computational speed. The result is that large power systems, real and synthetic, can be easily and quickly visualized with a diagram that merges geographic context with logical clarity.

Expansion of the effective action around non-Gaussian theories

This paper derives the Feynman rules for the diagrammatic perturbation expansion of the effective action around an arbitrary solvable problem. The perturbation expansion around a Gaussian theory is well-known and composed of one-line irreducible diagrams only. For the expansions around an arbitrary, non-Gaussian problem, we show that a more general class of irreducible diagrams remains in addition to a second set of diagrams that has no analogue in the Gaussian case. The effective action is central to field theory, in particular to the study of phase transitions, symmetry breaking, effective equations of motion, and renormalization. We exemplify the method on the Ising model, where the effective action amounts to the Gibbs free energy, recovering the Thouless–Anderson–Palmer mean-field theory in a fully diagrammatic derivation. Higher order corrections follow with only minimal effort compared to existing techniques. Our results show further that the Plefka expansion and the high-temperature expansion are special cases of the general formalism presented here.

Analysis of Stability Improvements by Using Capacitors

The demand for electricity has increased substantially while the expansion of electricity generation, power transmission is very limited, due to environmental restrictions, consequently some transmission lines, limiting power factor. Power flow in the generation system, covering the area of North Sumatra and Aceh which is managed by PT. PLN (Persero), ETAP 4.0 (Electrical Transient Analizer Program) is a program that can display GUI (Graphical User Interface) with unlimited bus number, ETAP 4.0 is useful for Power flow study. The data required by ETAP 4.0 on a generation system is a one-line diagram, nominal kV, and generator, bus, transformer, transmission, and safety rating. The power flow approach method used is the Newton-Raphson method with maximum iteration of 99 and the accuracy of 0.000001. The problem of power flows under consideration is the normal state system, one transmission is disconnected, one of the plants is not operating. The results of the power flow study for each problem obtained the lowest bus voltage, the highest losses in the transmis. The largest power distributed in power plants, new in high voltage transmission, increases the power of power from power to load, changes in voltage problems and improves system stability. This paper aims to verify the capacitor's ability to improve voltage regulation (voltage stability) in electric power transmission systems, from this capacitor simulated using ETAP 4.0 included in Newton-Raphson model.

Development of an Interactive Program to Study of the Continuation Power Flow

The purpose of this paper is develop an interactive program to study of the continuation power flow. Both, the graphical user interface and the power flow program have been developed in the Matlab environment and it allows the direct change of information between both. Besides, it provides not only a good computational performance, but also an users-friendly teaching software. With the use of this interactive program the user is liberated to edit the input and output data files of the selected systems and can visualize and analyze the results of the program directly in the computer screen. Directly from the system one-line diagram, the graphical interface allows the user change the parameters of the system (bus and lines system data); remove the transmission line clicking directly on it; view the buses voltage profile, and the real and reactive power flows. In addition, the user can obtain all the P-V curves of pre and post-contingency loading margin. All these characteristics make the developed program recommended for educational purpose.

Calculation of Short Circuit Current Based on Equipment Graphics Database

According to the structural characteristics of the electrical one-line diagram at substation, Its proposed that designing the database which stores electrical properties and graphics properties of the equipment in the paper. And an intelligent graphical modeling and automatic implement of main electrical connections are achieved based on the database. By means of the graph database integrated platform, a topology analyzing method based on bus for main electrical connections is presented, which is capable of not only computer graphics processing easily, but also describing accurately and reliably the topological structure of the main electrical connections. Finally the node admittance matrix is generated and the calculation of short circuit current is completed automatically.

Development of Fault Management Dispatcher Training Simulator for TDAS in Korea

A fault management dispatcher training simulator for large-scale Distribution Automation System (TDAS) is developed to train operators in distribution control center. This simulator is composed of independent simulation server and operator consoles and can be used for network analysis, network operation, fault management and evaluation. TDAS DB is duplicated online to the simulation server keeping the data security. The system can model distribution network penetrated with distributed generations (DG) using the real data from the TDAS DB. Network fault scenarios are automatically generated by calculating fault current and generating fault indicators. Also, manual entry of cry wolf alarm is available. Moreover, operation solution for scenario of fault isolation and service restoration is generated automatically so that trainee can check their operation result. Operator actions during training session are saved and can be played back as well as displayed on one-line diagram pictures.

Disturbance Analysis for Power Systems [Book Reviews

The book has three introductory chapters about the need for tools, techniques, and issues involved in disturbance analysis ranging from the functioning of digital fault recorders to symmetrical components and COMTRADE. The chapters contain more than 80 larger case studies based on the author?s 40 years of experience organized by disturbances involving generators, transformers, overhead transmission lines, cables, and breaker failure protection. Each case has substantial evidence of the event itself with one-line diagrams and DFR records. A typical case study is presented in four to ten pages with numerous fi gures along with a careful analysis of the event, suggested corrective action, and issues raised by the event.It is a tour de force in the true sense of the word. It is not clear there are very many others who could have written the book. Mr. Ibrahim is uniquely qualified to write such a book and has obviously gone to great lengths to produce this encyclopedic book. The book should be on the shelves of those in the industry that carry on the task of analyzing such disturbances.

Drawing Meshed One-Line Diagrams of Electric Power Systems using a Modified Controlled Spring Embedder Algorithm Enhanced with Geospatial Data

Problem statement: One-line diagrams are widely used in electrical power systems to provide a graphical view of state of the system and to assess its performance. Several methodologies and algorithms have been proposed to automatically draw the power system’s one-line diagram and provide satisfactory results for radial or small-size meshed networks. Nevertheless, actual power systems models are generally associated to strongly meshed networks and in this case, the usage of the mentioned methodologies can yield unsatisfactory solutions, with a great number of line crossings. Approach: This study proposes a method that generates bus/branch one-line diagrams of meshed power systems, based on a modified version of the Controlled Spring Embedder algorithm enhanced by the usage of physical laws and geospatial data. Results: The methodology was tested using a portion of the Brazilian interconnected power system that corresponds to a meshed bus/branch model with 58 nodes and 64 branches. The graphical portrayal was obtained from the branches list of the network, firstly without the presence of geographical information and then considering it. Conclusion: The proposed algorithm was able to evolve a graphical portrayal of the bus/branch electric model of a power system, yielding satisfactory results. In special, geospatial data have proved to be fundamental information, allowing the elimination of branch crossings and providing consistent representations for a specific electrical network in 95% of the simulated cases.

An Object-Oriented Graphical Modelling for Power System Analysis

Object-oriented programming is a major trend in computer software because it increases flexibility of large-scale software systems. This paper presents an intuitive visual framework for power system analysis. The following features achieve the flexibility of the frame-work: a graphical editor used to visually edit power system one-line diagrams, communication interface that reuses existing application, results processing and exporting, and graphic presentations. The embedded application modules in the framework include the power flow, the continuation power flow, the available transfer capability, and sensitivity analysis. Design and implementation details of the framework, as well as applications implemented on top of the framework, together with power system application components, are presented in this paper.

An Open Source Power System Analysis Toolbox

This paper describes the Power System Analysis Toolbox (PSAT), an open source Matlab and GNU/Octave-based software package for analysis and design of small to medium size electric power systems. PSAT includes power flow, continuation power flow, optimal power flow, small-signal stability analysis, and time-domain simulation, as well as several static and dynamic models, including nonconventional loads, synchronous and asynchronous machines, regulators, and FACTS. PSAT is also provided with a complete set of user-friendly graphical interfaces and a Simulink-based editor of one-line network diagrams. Basic features, algorithms, and a variety of case studies are presented in this paper to illustrate the capabilities of the presented tool and its suitability for educational and research purposes.