Power SyStem tranSientS Theory and Applications By Akihiro AmetAni nAoto nAgAokA Yoshihiro BABA teruo ohno

Power SyStem tranSientS Theory and Applications By Akihiro AmetAni nAoto nAgAokA Yoshihiro BABA teruo ohno

Contents:

1. Theory of Distributed-Parameter Circuits and the Impedance/Admittance Formulas

2. Transients on Overhead Lines

3. Transients on Cable Systems

4. Transient and Dynamic Characteristics of New Energy Systems

5. Numerical Electromagnetic Analysis Methods and Their Applications to Transient Analyses

6. Electromagnetic Disturbances in Power Systems and Customers

7. Problems and Application Limits of Numerical Simulations

Introduction:

When lightning strikes a building or a transmission tower, an electric current flows into its structures, which are made of electrically conductive materials such as steel and copper. The electric current produces a high voltage called “overvoltage” (or abnormal voltage), which can damage or break electrical equipment installed in the building or in the power transmission system. The breakdown may shut down the electrical room of the building, resulting in a blackout of the whole building. If the breakdown occurs in a substation in a high-voltage power transmission system, a city where electricity is sup plied by the substation can experience a blackout. An overvoltage can also be generated by switching operations of a circuit breaker or a load switch, which is electrically the same as a breaker in a house. A phenomenon during the time period in which an overvoltage occurs due to lightning or switching operation is called transient, while electricity being supplied under normal circumstances is called steady state. In general, a transient dies out and reaches a steady state within approximately 10 μs (10−6 s) in the lightning transient case and within approximately 10 ms (10−3 s) in the switching transient case. Occasionally, a transient sustains for a few seconds if it involves resonant oscillation of circuit parameters (mostly inductance and capacitance) or mechanical oscillation of the steel shaft of a generator (called subsynchronous resonance). In order to design the electrical strength of electrical equipment and to ensure human safety during a transient, it is crucial to perform a transient analysis, especially in the field of electric power engineering.