Cryogenic Operation of Silicon Power Devices


Book Description

The advent of low temperature superconductors in the early 1960's converted what had been a laboratory curiosity with very limited possibilities to a prac tical means of fabricating electrical components and devices with lossless con ductors. Using liquid helium as a coolant, the successful construction and operation of high field strength magnet systems, alternators, motors and trans mission lines was announced. These developments ushered in the era of what may be termed cryogenic power engineering and a decade later successful oper ating systems could be found such as the 5 T saddle magnet designed and built in the United States by the Argonne National Laboratory and installed on an experimental power generating facility at the High Temperature Institute in Moscow, Russia. The field of digital computers provided an incentive of a quite different kind to operate at cryogenic temperatures. In this case, the objective was to ob tain higher switching speeds than are possible at ambient temperatures with the critical issue being the operating characteristics of semiconductor switches under cryogenic conditions. By 1980, cryogenic electronics was established as another branch of electric engineering.




Valuation, Hedging and Speculation in Competitive Electricity Markets


Book Description

The challenges currently facing particIpants m competitive electricity markets are unique and staggering: unprecedented price volatility, a crippling lack of historical market data on which to test new modeling approaches, and a continuously changing regulatory structure. Meeting these challenges will require the knowledge and experience of both the engineering and finance communities. Yet the two communities continue to largely ignore each other. The finance community believes that engineering models are too detailed and complex to be practically applicable in the fast changing market environment. Engineers counter that the finance models are merely statistical regressions, lacking the necessary structure to capture the true dynamic properties of complex power systems. While both views have merit, neither group has by themselves been able to produce effective tools for meeting industry challenges. The goal of this book is to convey the fundamental differences between electricity and other traded commodities, and the impact these differences have on valuation, hedging and operational decisions made by market participants. The optimization problems associated with these decisions are formulated in the context of the market realities of today's power industry, including a lack of liquidity on forward and options markets, limited availability of historical data, and constantly changing regulatory structures.




Power System Oscillations


Book Description

Power System Oscillations deals with the analysis and control of low frequency oscillations in the 0.2-3 Hz range, which are a characteristic of interconnected power systems. Small variations in system load excite the oscillations, which must be damped effectively to maintain secure and stable system operation. No warning is given for the occurrence of growing oscillations caused by oscillatory instability, since a change in the system's operating condition may cause the transition from stable to unstable. If not limited by nonlinearities, unstable oscillations may lead to rapid system collapse. Thus, it is difficult for operators to intervene manually to restore the system's stability. It follows that it is important to analyze a system's oscillatory behavior in order to understand the system's limits. If the limits imposed by oscillatory instability are too low, they may be increased by the installation of special stabilizing controls. Since the late 60s when this phenomena was first observed in North American systems, intensive research has resulted in design and installation of stabilizing controls known as power system stabilizers (PSS). The design, location and tuning of PSS require special analytical tools. This book addresses these questions in a modal analysis framework, with transient simulation as a measure of controlled system performance. After discussing the nature of the oscillations, the design of the PSS is discussed extensively using modal analysis and frequency response. In the scenario of the restructured power system, the performance of power system damping controls must be insensitive to parameter uncertainties. Power system stabilizers, when well tuned, are shown to be robust using the techniques of modern control theory. The design of damping controls, which operate through electronic power system devices (FACTS), is also discussed. There are many worked examples throughout the text. The Power System Toolbox© for use with MATLAB® is used to perform all of the analyses used in this book. The text is based on the author's experience of over 40 years as an engineer in the power industry and as an educator.




Power Systems Restructuring


Book Description

The writing of this book was largely motivated by the ongoing unprecedented world-wide restructuring of the power industry. This move away from the traditional monopolies and toward greater competition, in the form of increased numbers of independent power producers and an unbundling of the main services that were until now provided by the utilities, has been building up for over a decade. This change was driven by the large disparities in electricity tariffs across regions, by technological developments that make it possible for small producers to compete with large ones, and by a widely held belief that competition will be beneficial in a broad sense. All of this together with the political will to push through the necessary legislative reforms has created a climate conducive to restructuring in the electric power industry. Consequently, since the beginning of this decade dramatic changes have taken place in an ever-increasing list of nations, from the pioneering moves in the United Kingdom, Chile and Scandinavia, to today's highly fluid power industry throughout North and South America, as well as in the European Community. The drive to restructure and take advantage of the potential economic benefits has, in our view, forced the industry to take actions and make choices at a hurried pace, without the usual deliberation and thorough analysis of possible implications. We must admit that to speak of "the industry" at this juncture is perhaps disingenuous, even misleading.




Analysis of Subsynchronous Resonance in Power Systems


Book Description

4. 2 Analysis of induction generator effect: frequency scanning method 83 4. 3 Analysis of torsional interaction(TI) 87 4. 4 State equations and eigenvalue analysis 96 4. 5 An algorithm for computing torsional modes 108 4. 6 Countermeasures for SSR III 4. 7 Torsional oscillations in parallel connected turbine generators 120 121 5. INTERACTIONS WITH POWER SYSTEM STABILIZER 5. 1 Introduction 121 5. 2 Basic concept in the application of PSS 122 5. 3 Design of PSS 126 5. 4 Torsional interaction with PSS 130 5. 5 A case study 132 6. INTERACTIONS WITH HVDC CONVERTER CONTROL 137 6. 1 Introduction 137 6. 2 HVDC converters and control 138 6. 3 Modelling of HVDC system for study of torsional interactions 147 6. 4 Analysis of torsional interactions -A simplified approach 153 6. 5 A case study 156 6. 6 A simplified damping torque analysis 161 6. 7 Control of torsional interaction 167 7. INTERACTIONS WITH SHUNT COMPENSATORS 169 7. 1 Introduction 169 7. 2 Static Var Compensator 171 7 . 3 Torsional Interactions with SVC 186 7. 4 Static Condenser(STATCON) 189 7. 5 Torsional interactions with STATCON 196 7. 6 A simplified analysis of torsional interaction with voltage controller 200 8. INTERACTIONS WITH SERIES COMPENSATORS 205 8. 1 Introduction 205 8. 2 Thyristor Controlled Series Compensator 206 8. 3 Modelling of TCSC for SSR studies 216 8. 4 Mitigation of SSR with TCSC 223 8. 5 Static Synchronous Series Compensator (SSSC) 229 8.




Computational Techniques for Voltage Stability Assessment and Control


Book Description

This book provides comprehensive details on continuation power flow, and reviews concepts in bifurcation theory and continuation methods for assessing power system voltage stability. The author proposes a uniform framework that provides computational approaches for both short-term and long-term voltage stability phenomena. Readers can access the author’s web-based simulation tools, which are based on the advice in this book, to simulate tests of systems up to the size of 200 busses.




Robust Power System Frequency Control


Book Description

Frequency control as a major function of automatic generation control is one of the important control problems in electric power system design and operation, and is becoming more signi?cant today because of the increasing size, changing structure, emerging new uncertainties, environmental constraints and the complexity of power systems. In the last two decades, many studies have focused on damping control and vo- age stability and the related issues, but there has been much less work on the power system frequency control analysis and synthesis. While some aspects of frequency control have been illustrated along with individual chapters, many conferences and technical papers, a comprehensive and sensible practical explanation of robust f- quency control in a book form is necessary. This book provides a thorough understanding of the basic principles of power system frequency behaviour in wide range of operating conditions. It uses simple frequency response models, control structures and mathematical algorithms to adapt modern robust control theorems with frequency control issue and conceptual exp- nations. Most developed control strategies are examined by real-time simulations. Practical methods for computer analysis and design are emphasized. This book emphasizes the physical and engineering aspects of the power s- tem frequency control design problem, providing a conceptual understanding of frequency regulation, and application of robust control techniques. The main aim is to develop an appropriate intuition relative to the robust load frequency regulation problem in real-world power systems, rather than to describe sophisticated mat- matical analytical methods.




Synchronized Phasor Measurements and Their Applications


Book Description

This book provides an account of the field of synchronized Phasor Measurement technology, its beginning, its technology and its principal applications. It covers wide Area Measurements (WAM) and their applications. The measurements are done using GPS systems and eventually will replace the existing technology. The authors created the field about twenty years ago and most of the installations planned or now in existence around the world are based on their work.




Fundamentals of Power Semiconductor Devices


Book Description

Fundamentals of Power Semiconductor Devices provides an in-depth treatment of the physics of operation of power semiconductor devices that are commonly used by the power electronics industry. Analytical models for explaining the operation of all power semiconductor devices are shown. The treatment here focuses on silicon devices but includes the unique attributes and design requirements for emerging silicon carbide devices. The book will appeal to practicing engineers in the power semiconductor device community.




Digital Control of Electrical Drives


Book Description

Provides broad insights into problems of coding control algorithms on a DSP platform. - Includes a set of Simulink simulation files (source codes) which permits readers to envisage the effects of control solutions on the overall motion control system. -bridges the gap between control analysis and industrial practice.