Measurement and Analysis of Overvoltages in Power Systems

Jianming Li

• Publisher: Wiley
• Year: 2018
• Print ISBN:
  9781119128991
• Edition: 1
• eBook ISBN:
  9781119129042
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

Measurement and Analysis of Overvoltages in Power Systems

Jianming Li, Professor, State Grid Corporation, China

A combination of theory and application, this book features practical tests and analytical techniques comprehensively with engineering practicality as its focus. Based on years of research and industry experience, the author introduces many scientific research methods such as overvoltage simulation studies, dynamic simulation experiment platform development and application, and overvoltage pattern recognition. Readers will get a good grounding in the various sources of overvoltages in power systems, methods in on-line measurements as well as explanations of overvoltage formation mechanisms and monitoring analysis methods.

•Systematically examines sources, online measurements, analytical techniques, and simulations of overvoltages, with an emphasis on engineering practicality 

•Presents practical engineering examples analyzing overvoltages and improving system operation, based on field experiments and data analysis  

•Features overvoltage simulations and waveform analysis in transmission systems

Measurement and Analysis of Overvoltages in Power Systems is intended as an all-in-one guide for engineers and researchers in power systems engineering. It can be used as a reference text for graduate students and lecturers of electrical engineering.

Chapter 1
Overvoltage Mechanisms in Power Systems

1.1 Electromagnetic Transients and Overvoltage Classification

1.1.1 Electromagnetic Transients in Power System

In the case of system faults or switching operations, the operating parameters of the system will change sharply. The system may transit from one operation state to another, or it may be damaged partially or entirely with operating parameters considerably deviated from the normal values. If countermeasures are not taken, the system is hard to restore to normal operation, which may have dramatic consequences on the national economy and on people's livelihoods.

Changes in operation states cannot be completed instantaneously, so there will be a transition, known as the transient process. Transient processes in power systems are generally divided into the electromagnetic transient process and the electromechanical transient process. The electromagnetic transient process refers to the changing dynamics of the electric field and the magnetic field as well as the corresponding voltage and current of each component in the power system, while the electromechanical transient process refers to the dynamics of mechanical movement of electric machine rotors caused by electromagnetic torque changes in generators and motors.

Although the electromagnetic and electromechanical transient processes take place simultaneously and are interrelated, it is difficult and complicated to perform a unified analysis because a lot of influencing factors have to be taken into account due to the constantly expanding scale and increasingly complex structure of modern power systems. Also, the changing rates of the two processes vary widely. For example, the speed of the rotating machinery such as generators and motors will not change immediately because of the inertia in electromagnetic transient analysis. In this case, the transient process mainly depends on the electromagnetic parameters of each system component; the speed changes of the generator and the motor are therefore generally not considered, so electromechanical transients can be ignored. In electromechanical transient analysis such as the analysis of static stability and transient stability, the rotating machinery speed has already changed, thus the transient process depends on both the electromagnetic and electromechanical parameters (speed and angular displacement). In this case, the electromagnetic transient process is often ignored. Comprehensive consideration of both electromagnetic and electromechanical transients is only necessary when analyzing problems such as sub-synchronous resonance phenomena caused by generator shaftings or calculating transient torque of the generator shafting after major disturbances.

The main purpose of electromagnetic transient analysis is to analyze and calculate transient overvoltages and overcurrents which might occur in the case of system faults or switching operations for reasonable and feasible design of electrical equipment. Generally, the equipment insulation levels are decided by overvoltages arising from power system electromagnetic transients, and standards for high voltage tests are made accordingly, to determine the possibility of the safe operation ...

Table of contents

• Cover
• Title Page
• Copyright
• Table of Contents
• Preface
• Chapter 1: Overvoltage Mechanisms in Power Systems
• Chapter 2: Transducers for Online Overvoltage Monitoring
• Chapter 3: Online Overvoltage Monitoring System
• Chapter 4: Wave Process of Incoming Surges and Transient Response Characteristics
• Chapter 5: Typical Field Tests and Waveform Analysis in UHVDC Transmission Systems
• Chapter 6: Overvoltage Digital Simulation
• Chapter 7: Entity Dynamic Simulation of Overvoltages
• Chapter 8: Overvoltage Pattern Recognition in Power Systems
• Bibliography
• Index
• End User License Agreement