Overvoltage Protection and Isolation Coordination

Overvoltage Protection and Isolation Coordination

Term: Summer


This thursday, 16th of april 2020, there will be a test-meeting on zoom at 11:00 am. By participating, you can make sure that you may follow properly the lectures of this summer term. The link as well as the password will be sent via a TuCan message shortly.

Information regarding the start of the lecture

As there will be no face-to-face courses until 1th of june at TU Darmstadt, the first lectures will be held via a conference tool (More information will follow soon). The times and dates are listed beneath.

Start of the lecture is april, 20th, 2020.

Due to the current developments (Information coronavirus) the exam for the lecture insulation coordination and overvoltage protection will also be postponed.

New exam date is saturday 11th of July 2020 13:00 till 16:00 o'clock.

A new date for exam preparation will folllow soon


  • Introduction: Definition and aims of Isolation co-ordination according to IEC 60071
  • Determination of representative overvoltages:
    • Origin and classification of overvoltages (Operating voltage and temporary overvoltages, Slow front overvoltages, Fast front overvoltages)
    • Travelling wave effects on lines
    • Characteristics of overvoltage protective devices
  • Determination of co-ordination withstand voltage:
    • Insulation strength for different voltage shapes and geometric configurations
    • mathematical description of flashover probabilities
  • Determination of required withstand voltage:
    • Atmospheric correction
    • Safety factor for internal and external insulations
  • Standard withstand voltage and testing procedures

Dates of the lecture in SS 2020

Dates of the exercise in SS 2020


The exam will take place on saturday, 11th of July from 13:00 till 16:00 o'clock in room S306/052.

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The bonus work may be completed with groups of two students and has to be handed in until the exam date.

Upon completion of the tasks a bonus of 20 Points will be added to the exam grade.

Additional reading

Please refer to chapter one of the slides of the lecture

A good overview about Isolation coordination is provided by:

Hileman, Andrew R.: Insulation Coordination for Power Systems, CRC Press, 1999

And regarding transient phenomena:

Haginomori, E.; Koshiduka, T., Arai, J. and Ikedam H.: Power System Transient Analysis: Theory and Practice using Simulation Programs (ATP-EMTP), John Wiley & Sons, 2016:

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