Power Systems Analysis Illustrated with MATLAB® and ETAP®

Amicrogrid is a combination of clusters of distributed generators connected to fulfill the requirement of dedicated load. A microgrid can be operated with standalone or grid connected mode. A microgrid when operated in standalone mode with a limited voltage and power rating is more likely prone to a serious damage due to its unpredictable faults. Load flow, voltage stability & short circuit analysis of a micro-grid is essential for both design and performance monitoring and to ensure reliable microgrid operations. The faults with a continuously varying in nature affects the normal operation of buses and so to the peripherals associated to the micro-grid. The cause and severity of such faults plays a vital role while designing protection scheme in standalone micro-grid as standalone mode has confined generation. In this paper, electrical model of a 52.3 kW Photo-voltaic based micro-grid is developed on Electrical Transient Analysis Program (ETAP) and various transient conditions such as load flow, loss of DG & short circuit analyses are performed. A detailed short circuit analysis puts light on various short circuit conditions and provides useful analysis. ETAP is the most comprehensive analysis platform for the design, simulation, operation, and automation of generation, distribution, and industrial power systems. ETAP also provides the industry leading transient analysis of power system and micro-grid so chosen for this transient analysis study. A short circuit analysis is calculated based onIEC Std. 60909 using ETAP. This paper presents a simulated model of micro-grid with actual system oriented results and analyzes responses of system during fault conditions and various contingencies.

Power System study and analyses are important parts of power system engineering. This innovative concept deals with a 132 kV Grid simulation in Electrical Transient Analyzer Program (ETAP). Existing power distribution system in Pakistan consists of approximately 6000 11 kV feeders, which are mainly analyzed by software FDR-ANA (Feeder Analyses). This software does not have capability to provide comprehensive analyses for integrated power system which is essential. This research paper focused on the detailed analyses and monitoring by using the most modern software ETAP, which performs numerical calculations of large integrated power system with fabulous speed besides, generating output reports. In a developing country like Pakistan it is first time that Off-line monitoring is made which includes current flowing in every branch, power factor, active and reactive power flow, harmonic distortion etc. of large power system. Based upon the recorded data obtained from an actual 132 kV grid which has been implemented in ETAP for Off-line monitoring and analyses.

Significant equipment like electric arc furnaces (EAFs) and ladle refining furnaces (LRFs) are among the highly dynamic and nonlinear electrical loads found in steel production facilities like Surana Industry. Reactive power imbalance, harmonic distortion, and voltage instability are just a few of the significant power quality issues caused by these complex loads. Because of this, accurate modeling and thorough analysis of these complex power systems are essential to ensuring operational dependability and maintaining power quality. The current literature tends to emphasize mostly steady-state conditions that are frequently not verified empirically with respect to actual operating data, despite the fact that the Electrical Transient Analyzer Program (ETAP) is a common tool used for load flow analysis in industry applications. With an emphasis on accurately simulating the real system behavior under various operating regimes, this paper provides a thorough power flow analysis of the Surana Steel Industry using ETAP. Two 100 MVA, 220/110 kV transformers step down the 110 kV supply that powers the plant, which is drawn from the Chikkasagur substation. The primary loads—a 35-ton rolling mill, a 4 MW EAF, and an LRF are supplemented with a captive power generation system and a harmonic filter to improve power quality and reliability. Under five different operating conditions with different load levels and generator configurations, key performance metrics such as voltage regulation, reactive power flow, harmonic suppression, and generator dynamic response are thoroughly assessed. The power system of the Surana Steel Industry is accurately simulated by the analytical method employed here. Even though a real-time comparison with SCADA data was not attempted, the ETAP model was painstakingly built with detailed equipment specs, typical operating conditions, and performance patterns actually observed at the facility. Accurate simulation of industrial environments, including the complex, unbalanced, and nonlinear loads present in steel mills, was made possible by this all-encompassing approach. Thus, this study shows that when appropriately configured and backed by extensive empirical data, ETAP has a considerable ability to accurately model these difficult environments. These results offer practical information that can be used right away for large-scale industrial power system planning, assessment, and enhancement.

For short-circuit analysis in industrial and commercial power systems, a new approach of the ohmic method in such a form as to facilitate, as far as possible, its use and the realization of its evaluation is suggested. The 'characteristic' current method, by replacing the impedance of each equipment with the corresponding value of the 'characteristic' current, permits the application of the impedance properties to the inverse of the current values, either in meshed or nonmeshed networks. In order to achieve the correct design, rating and protection coordination of the whole power system, it is necessary to know and calculate step by step the values of short circuit current for each system component, from the utility or local generating connection point until the branch-circuits and the utilization equipments. The proposed approach assumes the above mentioned short-circuit current directly as calculation and comparison parameters. With the 'characteristic' currents as parameters the short-circuit analysis of substantial radial systems is made easier and a better matching of power system design requirements is permitted. >

Direct stability analysis using an energy function has recently been widely used for angular and voltage stability analysis in electric power systems. Considerable efforts have concentrated on seeking energy functions for lossy power systems, accomplished only for the simple two-bus system. A new approach is presented to derive an energy function by using the complex integral of bus current equations with respect to bus voltages. Under an assumption that all transmission lines have a uniform R/X ratio, it is shown that the energy function can be developed for multimachine power systems with losses. The proposed energy function is tested on sample systems by comparing the time simulation method, which shows the validity of the proposed method.

Guest Editorial: Situational awareness of integrated energy systems

To ensure stable operation of a power system, it is necessary to analyse the power system performance under various operating conditions. Analysis includes studies such as power flow and both steady-state and transient stability. To perform such studies requires knowledge about the models used to represent the various components that constitute an integrated power system. In situations where there is a risk of loss of stability, it is necessary to apply controls that can ensure stable and uninterrupted supply of electricity following a disturbance. The subject of stability thus encompasses modelling, computation of load flow in the transmission grid, stability analysis under both steady-state and disturbed conditions, and appropriate controls to enhance stability. All these topics are covered in this book, providing a comprehensive treatment of the overall subject of stability of power systems. Topics covered include modelling of the synchronous machine; the synchronous machine connected to power systems; modelling of transformers, transmission lines and loads; power flow analysis; optimal power flow; small signal stability; transient stability; transient energy function methods; artificial intelligent techniques; power system stabilizers; series compensation; shunt compensation; compensation devices; and recent technologies. The subject matter is covered at a level that is suitable for students, scientists and engineers involved in the study, design, analysis and control of power systems.

Nowadays, in power systems, we still lack the existence of standardized test systems that can be used to benchmark the performance and solution quality of proposed optimization techniques. Several authors report that the electric load pattern is very complex. It is therefore necessary to develop new methods for design of test cases for economic analysis in power systems. Therefore, we compared two methods to generate test systems: time series model and a method simulating stable random variables based on the use of Chambers-Mallows-Stuck. This paper describes a method for simulating stable random variables in the generation of test systems for economic analysis in power systems. A study focused on generating test electrical systems through stable distribution to model for unit commitment problem in electrical power systems. Usually, the instances of test systems in unit commitment are generated using normal distribution, but the behavior of electrical demand does not follow a normal distribution; in this work, simulation data are based on a new method. For empirical analysis, we used three original systems to obtain the demand behavior and thermal production costs. Numerical results illustrate the applicability of the proposed method by solving several unit commitment problems directly and through the Lagrangian relaxation of the original problem. All Rights Reserved © 2015 Universidad Nacional Autonoma de Mexico, Centro de Ciencias Aplicadas y Desarrollo Tecnologico. This is an open access item distributed under the Creative Commons CC License BY-NC-ND 4.0.

This paper presents the electric power system analysis and design of an expanding steel cogeneration plant. The power system configuration and the equipment parameters of the cogeneration plant are well designed according to the power flow, short circuit, voltage fluctuation, harmonic flow and transient stability analyses. According to the power flow analysis, the site and capacity of shunt capacitor banks as well as the tap position of transformers are determined to maintain all the buses voltage at acceptable range and to keep the power factor above 0.95. Also, to comply with the restriction of circuit breaker capacity, the high impedance transformers are designed even if they consumed more reactive power from the system. In addition, the voltage fluctuation resulted from the dramatic reactive power variation of hot strip rolling mill can be greatly reduced if proper static var compensator (SVC) is installed. The significant voltage sag due to the starting of induction motor can be effectively improved by applying wye-delta transformer starter. Furthermore, the total voltage harmonic distortion (THD <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</sub> ) and the total current demand distortion (TDD <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</sub> ) are both acceptable if the proper filters are installed. It is also found that the cogeneration system can keep stable operation in isochronous mode by applying the governor control action and the load shedding scheme after tie line tripping. It is concluded that the power system analyses is important for the steel plant with cogeneration unit to identify hidden problems and remedy strategy to ensure the system power quality and operation performance.

This paper presents the analyses a real-time 10.765-MVA distribution network in Kayathar in Tuticorin district in the state of Tamilnadu, India. Recently the wind energy is the fastest increasing and most gifted renewable energy sources, among them because it is voluminous, cheap, inexhaustible, widely distributed, clean and climate benign. Renewable energy sources like wind and solar power to make a Distributed Generation (DG). The major problem nowadays in Power sector is losses within the distribution network. The Load Flow Analysis (LFA) and Short Circuit Analysis (SCA) is that the more efficient tool to see the performance of electric power network. Simulations are performed with Static Var Compensator (SVC) FACTS device to calculate the 3 cases to study the impact of wind in three totally different eventualities of macro level by exploitation of an Electrical Transient Analysis Program (ETAP) software.

Foreword . Preface . Acknowledgements . 1 Energy and Electricity . 1.1 The World Energy Scene. 1.2 The Environmental Impact of Energy Use. 1.3 Generating Electricity. 1.4 The Electrical Power System. References. 2 Features of Conventional and Renewable Generation . 2.1 Introduction. 2.2 Conventional Sources: Coal, Gas and Nuclear. 2.3 Hydroelectric Power. 2.4 Wind Power. 2.5 PV and Solar Thermal Electricity. 2.6 Tidal Power. 2.7 Wave Power. 2.8 Biomass. 2.9 Summary of Power Generation Characteristics. 2.10 Combining Sources. References. 3 Power Balance/ Frequency Control . 3.1 Introduction. 3.2 Electricity Demand. 3.3 Power Governing. 3.4 Dynamic Frequency Control of Large Systems. 3.5 Impact of Renewable Generation on Frequency Control and Reliability. 3.6 Frequency Response Services from Renewables. 3.7 Frequency Control Modelling. 3.8 Energy Storage. References. Other Useful Reading. 4 Electrical Power Generation and Conditioning . 4.1 The Conversion of Renewable Energy into Electrical Form. 4.2 The Synchronous Generator. 4.3 The Transformer. 4.4 The Asynchronous Generator. 4.5 Power Electronics. 4.6 Applications to Renewable Energy Generators. References. 5 Power System Analysis . 5.1 Introduction. 5.2 The Transmission System. 5.3 Voltage Control. 5.4 Power Flow in an Individual Section of Line. 5.5 Reactive Power Management. 5.6 Load Flow and Power System Simulation. 5.7 Faults and Protection. 5.8 Time Varying and Dynamic Simulations. 5.9 Reliability Analysis. References. 6 Renewable Energy Generation in Power Systems . 6.1 Distributed Generation. 6.2 Voltage Effects. 6.3 Thermal Limits. 6.4 Other Embedded Generation Issues. 6.5 Islanding. 6.6 Fault Ride-through. 6.7 Generator and Converter Characteristics. References. 7 Power System Economics and the Electricity Market . 7.1 Introduction. 7.2 The Costs of Electricity Generation. 7.3 Economic Optimization in Power Systems. 7.4 External Costs. 7.5 Effects of Embedded Generation. 7.6 Support Mechanisms for Renewable Energy. 7.7 Electricity Trading. References. 8 The Future - Towards a Sustainable Electricity Supply System . 8.1 Introduction. 8.2 The Future of Wind Power. 8.3 The Future of Solar Power. 8.4 The Future of Biofuels. 8.5 The Future of Hydro and Marine Power. 8.6 Distributed Generation and the Shape of Future Networks. 8.7 Conclusions. References. Appendix: Basic Electric Power Engineering Concepts . A.1 Introduction. A.2 Generators and Consumers of Energy. A.3 Why AC?. A.4 AC Waveforms. A.5 Response of Circuit Components to AC. A.6 Phasors. A.7 Phasor Addition. A.8 Rectangular Notation. A.9 Reactance and Impedance. A.10 Power in AC Circuits. A.11 Reactive Power. A.12 Complex Power. A.13 Conservation of Active and Reactive Power. A.14 Effects of Reactive Power Flow - Power Factor Correction. A.15 Three-phase AC. A.16 The Thevenin Equivalent Circuit. Reference. Index.

The modern world is increasingly reliant on technology and consequently the systems which power it. Portable power systems are used in a wide variety of applications to varying degrees of success. Within the power range of 10 – 5000W the current power systems are not adequately ‘portable’. Thus the aim of this thesis is to recommend chosen portable power systems which are best suited to certain portable power applications.A comprehensive, critical analysis of relevant portable power systems; micro combustion engines, fuel cells and batteries has led to accurate recommendations being made on the benefits of each in various portable power applications of unmanned aerial vehicles, military services, personal electronics and portable generators.An extensive literature review has been undertaken and research compiled on the previously stated portable power applications and portable power systems. From this research, a relevant assessment framework was created to perform a comparative analysis of each power system. Using a multi-criteria decision making analytical hierarchy process, a matrix of criteria necessary for portable power applications was made presenting weightings for each criteria, quantifying their importance. A ranking system was defined to enable each power systems features in relation to each stated criteria to be ranked. Multiplying the weightings and rankings together resulted in weighted rankings for each power system in relation to each portable power application.Analysing the results obtained from the assessment framework indicated that micro combustion engines were best suited to all portable power applications. Batteries were a close second in all applications and fuel cells ranked significantly lower than both of these systems in all applications. Whilst micro combustion engines are not currently commercially available, they have incredible potential in the portable power market, and if research and improvements continue they will be a preferred choice to a battery in future. Currently batteries are still the best product on the market for portable power applications due to their maturity and commercial success.It is recommended that in future the further criteria be established and a wider range of rankings used to improve the accuracy of results. It is also recommended that in future the data the rankings are based off be updated, as fuel cells and micro combustion engines are a quickly improving technology whose features will change in future.

Voltage instability and voltage collapse have been considered as a major threat to present power system networks due to their stressed operation. It is very important to do the power system analysis with respect to voltage stability. Flexible AC Transmission System (FACTS) is an alternating current transmission system incorporating power electronic-based and other static controllers to enhance controllability and increase power transfer capability. A FACTS device in a power system improves the voltage stability, reduces the power loss and also improves the load ability of the system. FACTS have made the power systems operation more flexible and secure. Amongst the several FACTS controllers, the Unified Power Flow Controller (UPFC) is most effective to improve the enhancement of voltage stability and reduces the power loss. This study investigates the application of Particle Swarm Optimization (PSO) to find sizing of Unified Power Flow Controller (UPFC) device to minimize the voltage stability index, total power loss, load voltage deviation, and cost of FACTS devices to improve voltage stability in the power system. A new model is proposed in this thesis to improve existing power-based model by using the Norton Equivalent Theorem. The proposed model can be integrated with the Equivalent Current Injection (ECI) power flow model easily. By ECI algorithm, it is much quickly and precisely to implement power flow calculations. Finally It is observed from the results that the voltage stability margin is improved, the voltage profile of the power system is increased and real power losses also reduced by optimally sizing UPFC device in the power system. Index Terms: Voltage stability, Unified Power Flow Controller (UPFC), Equivalent -Current Injection (ECI), Modified particle swarm optimization (MPSO)

This paper explores the feasibility of rapid a- stability analysis of electric power systems containing as many as 60 generators by using Liapunov functions. Many Liapunov functions, approximate integrals, and critical value equations are presented, some for the first time. The results of applying these functions with the aid of a CDC 6600 digital computer to electric ric power systems whose number of generators is 4, 10, 20, or 60 are given for both the computation time and result accuracy. Recommendations are made for additional research on the development of more accurate ate functions for el'ectric power system analysis.

This work deals with assessing the reliability of wind energy sources incorporated into a microgrid system to increase grid stability. As the share of power generated from wind energy continues to increase due to environmental concerns and to reduce carbon footprints, the case study proposed is designing an effective wind energy system for a smart building environment to reduce the burden on the grid. Incorporating wind energy systems into grid-connected buildings increases the reliability of the microgrid system for smart building environments. Applying smart techniques with integrated automation in the built environment can play a key role in decreasing peak demand for load development in smart cities. This can also enhance the overall efficiency of power grids, reduce waste, and enable the effective use of energy resources. Furthermore, researchers are finding new ways to collect energy from renewable sources and power-built environments due to dwindling fossil fuel resources and increased environmental awareness. The analysis of wind-connected power systems has been initiated to satisfy the increasing demand for reliable supply systems by consumers. This has prompted the use of wind energy systems with controlled techniques to enhance the reliability of power systems and reduce carbon footprints generated by fossil fuel-based power systems. Therefore, the main purpose of this work is to understand the economic prospects of wind energy sources for smart building environments, reliability analysis of wind energy sources-based power systems, reduce carbon footprints, and balance power demand through wind energy systems. The Progressive Wind Model Taylor-Sequence Proliferation (PWMTSP) and Innovative Six Parameters Based Progressive Beta Creative Model (ISPBPBCM) approaches are proposed to understand the reliability of wind energy-based power systems in smart building environments. The work also provides an economic analysis of the proposed low-cost wind power system with different capacities for residential consumers in selected geographic location. Eight cases are considered for the proposed effective wind energy system for smart building environments ranging from 2 MW to 32 MW. Hence, the economic analysis of the proposed systems is discussed for residential users. All eight cases are eco-friendly and reduce carbon emissions as these generated units from wind energy sources need not be purchased from fossil fuel-based plants, which increases the reliability of the proposed system. The expected energy not supplied (EENS) in the planned work increases as wind power capacity increases. Loss of load expectation (LOLE), loss of load probability (LOLP), and failure rate all decrease with the installation of more wind power systems. Moreover, it can be seen that mean time to repair (MTTR) improves when wind energy capacity rises incrementally from 2 MW to 32 MW. The proposed method is anticipated to be adaptable to various types of wind energy systems where dependability is a crucial component of system design and scalable to large wind integrated power systems.