Electric Power Systems with Renewables (eBook)

Simulations Using PSSE

Swaroop Guggilam, Ned Mohan (Autoren)

eBook Download: EPUB

2023 | 2. Auflage
320 Seiten
Wiley (Verlag)
978-1-119-84489-1 (ISBN)

Infos

Electric Power Systems with Renewables

Concise, balanced, and fundamentals-based resource providing coverage of power system operation and planning, including simulations using PSS^®E software

Electric Power Systems with Renewables provides a comprehensive treatment of various topics related to power systems with an emphasis on renewable energy integration into power systems. The updated use cases and methods in the book build upon the climate change science and renewables currently being integrated with the grid and the ability to manage resilience for electrifying transportation and related power systems as societies identify more ways to move towards a carbon-free future.

Simulation examples and software support are provided by integrating the educational version of PSS^®E. The newly revised edition includes new topics on the intelligent use of PSS^®E simulation software, presents a short introduction to Python (a widely used software in the power industry), and provides new examples and back-of-the-chapter homework problems to further aid in information retention.

Written by two highly qualified authors with significant experience in the field, Electric Power Systems with Renewables also contains information on:

• Electric energy and the environment, covering hydro power, fossil-fuel based power plants, nuclear power, renewable energy, and distributed generation (DG)
• Power flow in power system networks covers basic power flow equations, the Newton-Raphson procedure, sensitivity analysis, and a new remote bus voltage control concept
• Transformers and generators in power systems, covering basic principles of operation, a simplified model, and per-unit representation
• High voltage DC (HVDC) transmission systems-current-link, and voltage-link systems

Associated with this textbook, there is a website from which the simulation files can be downloaded for use in PSS^®E and Python. It also contains short videos to simplify the use of these software. This website will be regularly updated.

Electric Power Systems with Renewables serves as a highly useful textbook for both undergraduate and graduate students in Electrical and Computer Engineering (ECE). It is also an appropriate resource for students outside of ECE who have the prerequisites, such as in mechanical, civil, and chemical engineering. Practicing engineers will greatly benefit with its industry-relevant approach to meet the present-day needs.

Ned Mohan, PhD, joined the University of Minnesota in 1975, where he is currently a Regents Professor and Oscar A. Schott Professor of Power Electronic Systems. He is a Fellow of the IEEE and a member of the National Academy of Engineering.

Swaroop Guggilam, PhD, is an Engineer Scientist III, Electric Power Research Institute, Inc. His research areas include frequency control, transmission operations and planning, voltage control and stability, and optimization of distributed energy resources. In addition, the following three contributors bring the industry relevance to this textbook: Bruce F. Wollenberg, Prof. Emeritus at the University of Minnesota, Douglas Brown at Siemens, Inc., and Pratap Mysore with years of experience in relaying and protection at Xcel Energy.

Textauszug

1
INTRODUCTION TO POWER SYSTEMS:A CHANGING LANDSCAPE

Electric power systems are technical wonders; and according to the National Academy of Engineering [1], electricity and its accessibility are the greatest engineering achievements of the twentieth century, ahead of computers and airplanes. In many respects, electricity is a basic human right. It is a highly refined “commodity,” without which it is difficult to imagine how a modern society could function. It has saved countless millions from the daily drudgery of backbreaking menial tasks.

Unfortunately, a billion people in the world have either no access or no reliable access to electricity [2]. Added to this challenge is the fact that burning fossil fuels such as coal and natural gas to produce electricity results in carbon dioxide and other greenhouse gases. These greenhouse gases are causing global warming and climate change, the gravest threat facing human civilization.

Therefore, we as electric power engineers are faced with twin challenges. How we generate electricity using renewables such as wind and solar, how we transmit and deliver it, and how we use it are key factors to meet these challenges.

1.1 NATURE OF POWER SYSTEMS

Power systems encompass the generation of electricity to its ultimate consumption in operating everything from computers to hairdryers. In the most simplistic form, a power system is shown in Figure 1.1, where power from a single generating station is being supplied to consumers.

FIGURE 1.1 A single generating station supplying consumers (in color on the accompanying website). Source: [3] / U.S Department of Energy / Public Domain.

The system shown in Figure 1.1 is for illustration purposes only and shows the various components of a power system if such a system were to be constructed. It consists of a generating station, possibly producing voltages at a 20 kV level, a transformer that steps up this voltage to much higher transmission voltages for long-distance transmission of power, and then another transformer to step down the voltage to supply consumers at various voltages. In this book, we will look at all these components.

However, as mentioned, the system in Figure 1.1 is for illustration only. In practice, for example, the North American grid in the United States and Canada consists of thousands of generators, all operating in synchronism. These generators are interconnected by over 200,000 miles of transmission lines at 230 kV voltage levels and above, as shown in Figure 1.2. Such an interconnected system results in the continuity and reliability of service if there is an outage in one part of the system and provides electricity at the lowest cost by utilizing the lowest-cost generation as much as possible at a given time.

FIGURE 1.2 Interconnected North American power grid (in color on the accompanying website). Source: [4].

This power system has evolved over several decades, and a good history of it can be read in [5].

As mentioned earlier, even though the actual power system may consist of tens of thousands of generators and hundreds of thousands of miles of transmission lines, it is possible to zoom in on a subset of such an extremely large system. This is illustrated in Figure 1.3, as an example, which consists of only 10 generators. Although power transmission systems are always three-phase (except in high-voltage DC [HVDC] transmission systems), we represent them with one line in the figure, in a so-called one-line diagram.

FIGURE 1.3 A one-line diagram of the IEEE 39 bus system, known as the 10-machine New England Power System (in color on the accompanying website). It has 10 generators and 46 lines. Source: [6].

1.2 CHANGING LANDSCAPE OF POWER SYSTEMS DUE TO UTILITY DEREGULATION

Power systems today are undergoing major changes in how they are evolving in their structure and meeting load demand. In the past (and still true to some extent), electric utilities were highly centralized, owning large central power plants as well as the transmission and distribution systems, all the way down to the consumer loads. These utilities were monopolies: consumers had no choice but to buy power from their local utilities. For oversight purposes, utilities were highly regulated by Public Service Commissions that acted as consumer watchdogs, preventing utilities from price gouging, and as custodians of the environment by not allowing avoidable polluting practices.

The structure and operation of power systems are beginning to change, and the utilities have been divided into separate generation and transmission/distribution companies. There is distributed generation (DG) by independent power producers (IPPs), and there are distributed energy resources (DERs) to generate electricity by whatever means (wind, for example); they must be allowed access to the transmission grid to sell power to consumers. The impetus for the breakup of the utility structure was provided by the enormous benefits of deregulation in the telecommunication and airline industries, which fostered a large degree of competition, resulting in much lower rates and much better service to consumers. Despite the inherent differences between these two industries and the utility industry, it was perceived that utility deregulation would similarly profit consumers with lower electricity rates.

This deregulation is in transition, with some states and countries pursuing it more aggressively and others more cautiously. To promote open competition, utilities are forced to restructure by unbundling their generation units from their transmission and distribution units. The objective is that the independent transmission system operators (TSOs) wheel power for a charge from anywhere and from anyone to the customer site. This fosters competition, allowing open transmission access to everyone: for example, IPPs. Many such small IPPs have gone into business, producing power using gas turbines, windmills, and PV plants.

Operation in a reliable manner is ensured by independent system operators (ISOs), and financial transactions are governed by real-time bidding to buy and sell power. Energy traders have gotten into the act for profit: buying energy at lower prices and selling it at higher prices in the spot market. Utilities are signing long-term contracts for energy, such as gas. This is all based on the rules of the financial world: forecasting, risks, options, reliability, etc.

As mentioned earlier, the outcome of this deregulation, still in transition, is far from certain. However, there is every reason to believe that the deregulation now in progress will continue, with little possibility that the clock will be turned back. Some fixes are needed. The transmission grid has become a bottleneck, with little financial incentive for TSOs to increase capacity. If the transmission system is congested, TSOs can charge higher prices. The number of transactions and the complexity of these transactions have increased dramatically. These factors point to anticipated legislative actions needed to maintain electric system reliability.

1.3 INTEGRATION OF RENEWABLES INTO THE GRID

In addition to the deregulation mentioned, there is a great deal of emphasis on generating power using renewables such as wind and solar rather than fossil fuels such as coal and natural gas that emit greenhouse gases. The cost of power from these renewables has been declining and, in many cases, is lower than the cost of conventional sources. In making this comparison, we must realize that renewables are intermittent, and thus their value goes down as their penetration into the grid increases.

At present, the amount of electricity produced by renewables is small, as shown in Figure 1.4 for the United States.

FIGURE 1.4 Generation of electricity by various sources in the United States (in color on the accompanying website). Source: [7].

However, due to climate concerns, the portion of electricity from renewable sources will undoubtedly grow, and our study of power systems must include how we can accommodate them in the grid.

1.4 TOPICS IN POWER SYSTEMS

The purpose of this textbook is to provide a complete overview of power systems meeting present and future energy needs. As we can appreciate, the interconnected power system with thousands of generators and hundreds of thousands of transmission lines between them is vast and complex. Therefore, the question in front of us is how we can impart the fundamental concepts and learn the workings of various components while pointing to the real tools used in industry to study such systems in their entirety.

It should be recognized that there can be planning studies that may have over 90,000 buses—e.g. the entire Eastern Interconnection System in the United States. However, the authors have taken the three-bus example shown in Figure 1.5 to explore various fundamental concepts. To extend these concepts to the study of the real system, the authors have decided to use PSS®E [8] from Siemens, which is one of the most widely used software packages in the utility industry in over 140 countries. The analysis of this three-bus simple system is shown in Figure 1.6 using PSS®E.

FIGURE 1.5 A three-bus example system.

FIGURE...

Produkt-Details

• Erscheint lt. Verlag: 7.2.2023
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Physik / Astronomie
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Schlagworte: Electrical & Electronics Engineering • electric power systems • Elektrische Energietechnik • Elektrotechnik u. Elektronik • Energie • Energietechnik • Energy • Erneuerbare Energien • Leistungselektronik • Power Electronics • renewable energy
• ISBN-10: 1-119-84489-4 / 1119844894
• ISBN-13: 978-1-119-84489-1 / 9781119844891