40220432 (Overvoltages and Its Protection)

Course Name: Overvoltages and Its Protection

Course Number: 40220432

Program: Undergraduate program

Type: Elective

Credits: 2

Term Offered: Fall

Prerequisite(s): Physics, High Voltage Engineering

Instructor(s): Shuiming Chen, Jinliang He


Weibo Zhang, Jinliang He and Yuming Gao. Overvoltages in Power System and its Insulation Coordination, Tsinghua University Press, 2002. (in Chinese)


Guangrun Xie. Overvoltages in Power system. China Waterpower Press, 1985.

Ji Liu. Electric Equipment Protection against Overvoltage. China Electric Power Press, 1982

Course Description:

     The course is about the protection of overvoltages in power system and electronic system (be called surge) including lightning and inner overvoltage. The origin, propagation, and its suppression are analyzed in detail, effect of lightning on substation and transmission line are discussed, and power frequency overvoltage, switching overvoltage in power system are included, finally, the insulation coordination in power system and surge in electronic system are also introduced. Though the professional training, the students should master the PSCAD/EMTDC software.

Course Objectives and Outcomes:

     Numbers in brackets are linked to department educational outcomes

1.Students should master various overvoltages in power system. [1, 5,11]

2.Students should understand the surges in electronic system. [1,10]

3.Students are familiar with the PSCAD/EMTDC software. [4,5,7]

Course Topics:

1.Introduction to transmission line theory. The concept of lumped circuit and distribution circuit.

2.Lightning, including origin, discharge process, current waveform, measurement, surge arrestor.

3.Effects of lightning overvoltage on transmission line.

4.Effects of lightning overvoltage on substation. Including direct strike and invade wave.

5.Power frequency overvoltages, including power frequency voltage rise due to Faraday effects, unbalanced faulted, load rejection, and resonance.

6.Switching overvoltages, including three phases energized, one phase reclosing.

7.Insulation coordination, including common, statistic method and simple statistic method.

8.Surge in electronic system, including lightning, interaction effect between power and communication line, protection technology.

9.Introduction to IEC 62305 serial standards, IEEE C62 serial standards.

Experiment(s): though professional training, master the PSCAD/EMTDC software.


Design of lightning invading overvoltage in substation

 Understand the concept of lightning invading overvoltage in substation, and the Electro-Magnetic models of various equipments in power system, Check the effects of tower ground resistance and operation modes on overvoltage in substation.

Analysis of switching overvoltages in transmission line operation

 Master the computational methods of switching overvoltages, including three phases energized, one phase reclosing, etc.

Analysis of VFTO in GIS

Understand the Very Fast Transient Overvoltages in Gas Insulted Substation, including origin, mechanism and computation of VFTO.

Lightning protection of campus food and drink balance system

Design the lightning protection of food and drink balance system over the campus.


Course Assessment:

     Homework measures, 30 points.

     Final professional training(Report, speech and explain), 70 points.