The Power Plant

Learn About Power System Transients In New Book

Transients are a nuisance for power system designers that can hamper performance and in the worst case cause damage to equipment. A new book, Power System Transients: Theory and Applications, is intended to help design engineers understand and mitigate the effects of transients.

Authored by Akihiro Ametani, Naoto Nagaoka, Yoshihiro Baba, and Teruo Ohno and published by CRC Press, the 516-page book discusses the basic theory of transient phenomena. Containing 265 illustrations, the book covers lumped- and distributed-parameter circuit theories—and a physical interpretation of the phenomena. It covers novel and topical questions of power system transients and associated overvoltages.

Chapter 1 describes a transient on a single-phase line from the physical viewpoint and how this is solved analytically by an electric circuit theory. Included are the impedance and admittance formulas of an overhead line. Simple formulas that can be calculated using a pocket calculator are also explained so that a transient can be analytically evaluated.

This chapter also presents the simulation tool electromagnetic transients program (EMTP), originally developed by the US Department of Energy, Bonneville Power Administration.

Wave propagation characteristics and transients in an overhead transmission line are described in Chapter 2. And, the distributed-parameter circuit theory is applied to solve the transients analytically. Various simulation examples are demonstrated, together with a comparison with field test results. Subjects include:

·      Switching Surge on Overhead Line

·      Fault Surge

·      Lightning Surge

·      Theoretical Analysis of Transients: Hand Calculations

·      Frequency-Domain Method of Transient Simulations

Transients in a cable system are covered in Chapter 3. Using formulas simple enough to be applied using a pocket calculator, the book presents analytical methods for transient analysis. It examines the theory of numerical simulation methods such as the EMTP (circuit-theory based approach) and numerical electromagnetic analysis. The book highlights transients in clean or sustainable energy systems such as smart grids and wind farms, since they require a different approach than overhead lines and cables. Simulation examples provided include arcing horn flashover, a transient in a grounding electrode, and an induced voltage from a lightning channel. Subjects covered in this chapter include:

·      Impedance and Admittance of Cable Systems

·      Wave Propagation and Overvoltages

·      Studies on Recent and Planned EHV AC Cable Projects

·      Cable System Design and Equipment Selection

·      EMTP Simulation Test Cases

Chapter 4 analyzes the basic characteristic of wave propagation on the distributed-parameter circuit theory, together with EMPT simulation examples. The chapter also describes transients in wind farms based on EMPT simulations. Because their generating capacity is small, a number of wind generators are connected together in a substation, which allows the voltage to be stepped up for power transmission. A transient analysis in wind farms, mega solars and smart grids requires a different approach than those in overhead lines and cables. A transient in a wind farm involving electronic circuits is affected by the dynamic behavior of power transistors/thyristors, which is a basic element of the power electronic circuit.

The basic theory of numerical electromagnetic analysis (NEA) is the subject covered in Chapter 5. The chapter provides a brief summary of the methods and demonstrates application examples. Some of the examples compare field test results with EMPT simulation results. Subjects include:

·      Problems of Existing Impedance Formulas Used in Circuit-Theory-Based Approaches

·      Existing Problems in Circuit-Theory-Based Numerical Analysis

·      Numerical Electromagnetic Analysis for Power System Transients

Electromagnetic compatibility related problems in low-voltage control circuit in a power station and substation is the subject of Chapter 6. The influence of the disturbances on system operations and the countermeasures are explained along with case studies. Disturbances due to lightning on home appliances are explained based on collected statistical data, measured results, and EMTP/FDTD simulation results.

The final chapter, 7, discusses “Problems and Application Limits of Numerical Simulations.” This chapter covers:

·      Problems of Existing Impedance Formulas Used in Circuit-Theory-Based Approaches

·      Existing Problems in Circuit-Theory-Based Numerical Analysis

·      Numerical Electromagnetic Analysis for Power System Transients

Book details

ISBN 9781466577848

Publisher: Taylor and Francis Group (http://www.taylorandfrancis.com) of CRC Press (http://www.crcpress.com)