Springer Handbook of Power Systems

Fundamentals and the structure of energy supply with primary energy, final energy, energy carriers, reserves and resources, and the potential and use of renewable energy are presented in this chapter.

Past energy demand and CO₂ emissions are illustrated for all regions of the world and for the most important countries. The desired future development with regard to climate protection is discussed and illustrated with the aid of the most important indicators.

The 1.5^∘C climate target calls for rapid elimination of coal and oil for electricity production and the progressive reduction of the contribution of natural gas. This demands an enormous effort in the energy sector for the production of electricity using CO₂-free energy sources. This chapter discusses five ways to generate electrical energy as sustainably as possible. The resulting grid stability problems are briefly outlined.

Hydropower (Sects. 2.1–2.6) is one of the most important sources of energy for generating electricity. It is also ecologically sound (no CO₂ emissions) if the plant construction (river dams, reservoirs) respects nature and human settlements appropriately. In 2016, hydropower installations accounted for 16.6% of global electricity production. This section provides an overview of the planning, engineering and modeling of hydraulic power stations.

The efficiency of power generation from fossil fuels in thermal power plants has risen considerably over time and today reaches almost 60% in natural gas-powered, combined cycle power plants (Sect. 2.7). Nevertheless over 40% of the energy is still lost as waste heat. In combined heat and power (), useful heat is produced in addition to electrical energy, thus further increasing overall energy efficiency.

The potential of wind energy (Sect. 2.8) and the prerequisites for its economic use have already been briefly discussed in Sect. 1.​2.​3. This section deals in more detail with the technical and economic aspects of wind-energy use.

In Sect. 2.9 the basics of photovoltaics (photoelectric effect) and solar cells (structure, types, characteristics, efficiencies) are given. To use them optimally requires knowledge of the radiation intensity and thus the calculation of the apparent movement of the sun relative to the Earth. Photovoltaic is the renewable energy with the highest potential worldwide.

Fuel cells (Sect. 2.10) can be used to convert hydrogen as well as natural gas and other hydrocarbons (e. g., petrol, methanol) or biogas electrochemically directly into electrical energy. It is predictable that in the course of the next decades this technology will open up a wide range of applications for mobile and stationary applications.

High-voltage engineering is knowledge about power transmission at high voltages and about stress on equipment used in high-voltage transmission systems. The basis for the design of high-voltage equipment is stress on the insulation by the electric field, whereby the stress magnitude depends on the voltage type. The electric field distribution is given by relative permittivity for alternating current () and by conductivity for direct current () and homogeneity of the electrode arrangement. Evaluation of the electric strength requires statistical and adjusted test methods. Basic knowledge about the breakdown behavior in gases is the basis for understanding the breakdown in fluids and solids. The breakdown of fluids is influenced by moisture, impurities, and stressed volume. Solids suffer from the same parameters, but thermal and erosion breakdowns and residual life time are of interest. Different kinds of insulation gases, fluids and solids, inorganic and organic, as well as impregnated solids are used in high-voltage insulation, and each of them has its own characteristics, which requires a careful selection depending on the equipment and the expected electric stress. Generation of test voltages requires specialized voltage and current generators for AC, DC, and impulse voltages. The measurement of different voltage types also requires specialized measuring circuits, including partial discharge and dielectric characteristics measurement.

Additional information and supplementary exercises for this chapter are available online.

Electrical power systems and transport systems are subject to profound changes all around the world. This is accompanied by higher requirements for the components of stationary or mobile equipment of electrical power engineering. Especially a compact design, a higher current load under normal operating conditions, and in the case of a fault, disparate environmental conditions and the demand for higher availability, reliability, and safety are great challenges for designers, manufacturers, constructors, and operators.

This chapter gives an overview of current-conducting arrangements (conducting systems) whose load is cause by electric current and ambient conditions, the resulting thermal and mechanical stress, and the long-term and reliably necessary strength of the conducting components.

Fundamentals on the thermal behavior of equipment and analytical approaches to the calculation of temperatures at relevant spots are presented that have proven themselves over decades in practice. If necessary, they can be supplemented by numerical methods, which will not be explicitly discussed here. Regarding the mechanical-dynamical behavior of current-conducting arrangements exposed to short-circuit currents or thermal elongation due to current load, methods for determining the strain and the necessary strength are presented with regard to the material properties in the elastic range and the plastic range. Stationary electrical contacts and connections have been the subject of scientific research at TU Dresden for more than four decades and will be discussed here in an overview in terms of design, operating, and long-term behavior.

All results presented in this chapter are, to a great extent, results of scientific research at TU Dresden and have been taken from the course material presented to the students.

This chapter provides the background required to understand the main aspects of power systems analysis and operation under steady-state and transient or dynamic conditions. It is intended for senior undergraduate or graduate students of electrical engineering as well as practitioners, so readers are assumed to have a solid background knowledge of electrical engineering.

The main technical issues associated with power systems analysis are addressed, focusing in particular on alternating current () transmission lines, networks, load-flow and short-circuit calculations, stability analysis, frequency control, and electromagnetic transient appraisal. The chapter also references the most important and popular model frameworks and calculation/modeling tools that have been developed by researchers and engineers working within the electric power systems area in the last few decades. It is emphasized in this chapter that an understanding of the issues dealt with here is required to comprehend other chapters of this handbook devoted to distributed generation and smart grids, and this knowledge will also be needed to be able to operate upcoming power systems.

The chapter is divided into sections focusing on the following topics:

Additional information and supplementary exercises for this chapter are available online.

One of the most striking features in the development of rotating electrical machines has been the steady increase in their output. This marked increase was made possible by a combination of several factors, of which the most important include improvements in the magnetic properties of the sheet steel used for core material, as well as the development of insulating materials capable of withstanding relatively high temperatures, and better provision for cooling. This chapter is divided into two parts: Synchronous Machines and Induction Motors. For both types of machines considerations about insulating materials, cooling and construction are presented with a focus on the main aspects involved, as well as about their performance under different conditions of operation. Special emphasis was given to international standards. The effect of machine dimensions on the rating of synchronous and induction machines is included, as well as other design parameters. The application of variable frequency drives on induction motor speed control is highlighted. Some advanced technologies in synchronous generators and motors such as: superconducting generators and motors; per­manent magnet motors; switched reluctance motors and line start permanent magnet motors, as well as those related to die cast copper and linear induction motors are presented.

All industrialized countries depend on functioning and flawless power transmission and distribution at various voltage levels, which is achieved through the use of power transformers. This implies that power transformers are among the most important (and expensive) devices used in power transmission and distribution systems. Indeed, transformers are indispensable, as they are used to transition between voltage levels at the junctions of energy supply systems. A transformer failure can therefore cause an interruption in the power supply, which can have terrible consequences. However, many transformers remain in service for many decades without showing any notable malfunctions, and these devices are generally considered to be reliable and efficient.

In this chapter, the fundamental design and functional principles of a power transformer are described in detail, differentiating between its active and passive parts. Power transformer testing is also discussed, referencing various international standards. Finally, various types of transformers are briefly introduced. Thus, the chapter provides a comprehensive overview of all the basic technical aspects of power transformers, although the servicing, maintenance, and asset management of transformers are only outlined here, as a more detailed discussion of these important topics would require an additional chapter.

This chapter focuses on substation equipment, which is used in power systems to transport and distribute the electric energy from power-generation plants to households, offices, and factories efficiently. In transmission and distribution networks, switching equipment such as circuit breakers and disconnecting switches is required to open and close circuits in power systems. When a fault occurs, circuit breakers are needed to clear the fault quickly to ensure system stability. Circuit breakers must also be able to carry a load current without excessive heating and withstand the system voltage during normal and abnormal conditions.

Measuring equipment such as instrument transformers and overvoltage protection units such as surge arresters are also used in power systems. Surge arresters are installed at different locations in power systems to limit lightning-induced and switching-induced overvoltages to a specified protection level below the withstand voltage of the equipment.

It is also mainly devoted to technical description of switching equipment used in both high-voltage alternating current () and high-voltage direct current () power systems. Fundamental interrupting and switching phenomena for different switching equipment are discussed.

Readers should note that more detailed and specific information on switching equipment can be found in many technical brochures and documents published by CIGRE, including the CIGRE Green Book on switching equipment.

Overhead transmission lines have formed the backbone of electric power systems over their history of more than 125 years, being at the same time the largest man-made artifacts on Earth. Another peculiarity of overhead lines is that their study encompasses quite a few engineering disciplines, such as electrical, mechanical, civil, and environmental. As system operation issues of lines are covered in Chap. 5, this chapter concentrates on line components. It starts by explaining the design philosophy of lines, with an emphasis on the calculation of typical line loads, mainly coming from wind and ice, and includes the latest findings on electromagnetic fields () and health. It continues by treating the individual line components, from material selection, manufacturing processes, stress calculations, to special applications. For instance, for conductors, the most costly and important component of a line, emphasis is placed on different types of conductor, their material properties, and what is called their internal mechanics, including sag–tension calculations. However, sufficient space is also dedicated to the ever-important issue of conductor vibrations, thermal rating and monitoring, bundle conductors, as well as new types of conductor. Similarly for insulators, after an in-depth presentation of pollution issues, the focus is on three different types of insulator, i. e., porcelain, glass, and composite. Conductor fittings are addressed next, covering, beside the different types of clamps and joints, also conductor hardware for vibration control, such as Stockbridge and spacer dampers. Line supports, being the most visible component of a line, have seen a significant shift in recent years towards esthetic structures and compactness, while their foundations have benefited from improved designs and new site investigation techniques. The final sections cover construction and maintenance, including new technologies such as robotics, and line uprating and upgrading, the latter reflecting the increasing trend towards augmenting the power transfer capacity of existing lines, as it is not always easy to build new lines. The goal of this chapter is thus to provide the reader with all the basic information required to understand how an overhead line is designed, constructed, and maintained and help in taking the right decisions regarding material selection, the calculation of external loads and internal stresses, and the choice of appropriate standards and testing procedures. Some 300 references facilitate these tasks.

Additional information and supplementary exercises for this chapter are available online.

This chapter on insulated cables comprises 13 sections. Section 10.1 is an introduction to this topic that highlights the role of CIGRE in the development of insulated cables, while Sect. 10.2 gives the current state of cable development, describes modern high-voltage () alternating current () systems and the various types of cables used in them, and explores emerging trends in cable design.

Some basics of the theory of insulated conductors are given in Sect. 10.3 to prepare the reader for subsequent sections, including discussions of electrical fields, electrical characteristics of cable systems. In Sect. 10.4, the basic design aspects of insulated cable systems are introduced, such as insulation coordination, ageing mechanisms, special bonding issues, calculation of cable characteristics and rating.

In Sect. 10.5, various applications of insulated cables are described. The main configurations of cable systems in networks are described and the technical issues associated with each configuration are discussed: matching Cable and OHL ratings, Harmonic resonance, Ferranti effect, magnetic field. Offshore generation cables are explored in depth.

10.6 covers cable design and manufacturing. Major steps in the manufacturing processes of lapped and extruded cables are described. Various options for extrusion lines are compared. Submarine cable armoring is discussed. The manufacture of accessory components is also described, including the various molding and casting processes, which depend on the materials used.

10.7 deals with the construction, laying, and installation of cable systems. Traditional techniques are reviewed and innovative techniques are introduced, such as trenchless technologies: mechanical laying, pipe jacking, microtunneling and horizontal drilling. Installation in tunnels or shared structures is detailed. The main installation configurations are illustrated using examples.

In Sect. 10.8, issues relating to testing are addressed. As indicated in the introduction to the chapter, testing has been a major issue since insulated cables were first invented and used. The introduction of extruded HV and (extra-high voltage) cables would have been impossible without stringent testing procedures.

Various aspects of the operation of insulated cable systems are covered in Sects.10.4–10.8. Fluid-filled and extruded cable systems operation have been presented. Also briefly described are monitoring techniques that can optimize equipment usage: management of the overload capacity of underground systems, partial discharge () monitoring, and sheath condition monitoring. Strategies for protecting against short circuits are also addressed. To complete this information, Sect. 10.9 is covering the maintenance of land and submarine cable systems and the various diagnostic techniques that are available. Repair and methodologies that are used to limit repair times, such as fault location, are also included in this section. Main failure causes of cable systems are inventoried. Appropriate maintenance strategies are proposed, and tools for asset management are overviewed. Examples of maintenance guidelines, fault-location techniques, and rapid-response repair are also briefly presented.

Appropriate maintenance strategies are proposed, and tools for asset management are overviewed. Examples of maintenance guidelines, fault-location techniques, and rapid-response repair options are given for land and submarine cables.

10.10 introduces the various options for upgrading and uprating existing cable systems. The life expectancy of an underground cable system is usually more than thirty years, which makes it difficult to predict the changes that will occur in the cable environment or how the operating conditions will evolve during the expected lifetime of a cable system. Addressing the need for a cable system to meet a higher demand can be highly problematic. Replacing a power link or installing an additional circuit requires significant financial investment. It may even be impossible for the operator to extend the system in some congested areas. The difficulties involved in obtaining planning permission for new sites also favor extending the lifespans of existing facilities, often with the goal of transmitting higher power with higher reliability in order to minimize the duration of asset unavailability.

Life Cycle Assessment is discussed in Sect. 10.11. A new technology—superconducting cables—offers interesting options for both AC and cable systems, as described in Sect. 10.12. Finally, other undergrounding options (gas insulated lines, s) are briefly described in Sect. 10.13.

This chapter presents an overview of aspects of engineering associated with high-voltage substations, providing the reader with information on the use and application of substations, a description of the various primary, secondary and auxiliary components, and the planning and design of substations through to construction and commissioning. Substations are long-lived assets, and the chapter provides information on the management of substations throughout their life cycle. Information on future trends for substations is also included. Parts of this chapter refer to sections of the Springer Substations Greenbook published in 2018 [11.1].

High voltage direct current () is an economic alternative to alternating current () transmission to transmit power over long overhead lines when the transmission distance exceeds 500 – 1000 km. It is practically the only solution for transmitting power with long underground/submarine cables or to connect two nonsynchronous systems.

Two types of converter technologies are available: the line-commutated converter () utilizing thyristor valves and the voltage-source converters (s) utilizing insulated gate bipolar transistors (s).

In this chapter, these technologies are introduced together with the corresponding system architectures. Also direct current () grids are introduced. DC grids will facilitate the interconnections between systems and the expansion in renewables integration in the grid.

A protection system is an essential requirement for the safe and reliable operation of an electric power system. An electric power system is part of an infrastructure that covers a large area and in which faults cannot be avoided in general. The protection system must guarantee that faulty equipment is disconnected from the system as quickly as possible in order to ensure the continued operation of the rest of the electric power system.

At the beginning of this chapter, the general requirements for a selective protection system and its basic concepts are presented. This is followed by a description of the criteria that can be used to detect faults in electric power systems. Current and voltage transformers are required to measure high voltages and currents. The selection and dimensioning of these are described in the following. The basic selective protection functions are explained and their implementation is described in the following section. Additional functions that are used to increase the performance and selectivity of the protection system are also presented. At the end of this chapter, some examples are presented to illustrate the structure of the protection system for selected electric equipment.

This chapter presents an overview of power distribution networks. The description of the main components of a distribution network are given and various power flow models for the steady state analysis of distribution networks are formulated. The increasing penetration of distributed energy resources into the distribution level has transformed distribution networks into active ones. The basic functions of an advanced distribution management system for the control and monitoring of a distribution network are presented. Furthermore, methods for the operation of the network under normal and emergency operating conditions and for distribution network planning are presented.

From the classical pumped storage and its recent evolution as flexible speed-variable pump–turbines to the most recent high-power and high-energy density batteries coupled to smart grid configurations, the chapter will present the main characteristics and properties of each components. In addition, compressed-air technologies, flywheels, as well electrical magnetic and capacitive storage components are introduced. For large-capacity and so-called seasonal storage, the hydrogen storage principle is described.

Finally, system arrangements and applications are described as storage as a grid component, storage for renewable energies, hybrid power plants, or uninterruptible power sources.

Examples of recent realizations of large-scale storage plants complete the chapter.

Additional information and supplementary exercises for this chapter are available online.

Power quality concerns the electrical interaction (through voltages and currents) between the electricity grid and equipment connected to it. The field of power quality is subdivided into different types of disturbances, each of which represent one specific deviation from the ideal voltage and/or current. Section 17.1 will introduce the power-quality field, including terminology and a brief history. One of the disturbance types, waveform distortion, or harmonics, is discussed in detail in Sect. 17.2. Other types of disturbances are discussed briefly in Sect. 17.3.

The reliability and cost of electricity is critical to the success of modern economies. Infrastructure needed to provide the desired services requires large amounts of capital expenditure and governments are keen to ensure prices are kept to a minimum while maintaining the required reliability. To this end, electricity markets have been introduced to allow electricity generating and retailing companies to compete. At the same time regulations have been put in place to minimize anticompetitive activities and ensure that any monopoly services are charged at fair and reasonable rates.

This chapter explores the design and operation of electricity markets and regulation in relation to power systems. It briefly considers the evolution of the electricity industry and provides a general description of the range of market models used and the associated regulation applied to assist their efficient operation. Practical examples from various countries around the world are also provided.