PD IEC/TR 60071-4:2004

FOREWORD
1 Scope and object
2 Normative references
3 Terms and definitions
4 List of symbols and acronyms
5 Types of overvoltages
6 Types of studies
   6.1 Temporary overvoltages (TOV)
   6.2 Slow-front overvoltages (SFO)
   6.3 Fast-front overvoltages (FFO)
   6.4 Very-fast-front overvoltages (VFFO)
7 Representation of network components and numerical considerations
   7.1 General
   7.2 Numerical considerations
   7.3 Representation of overhead lines and underground cables
   7.4 Representation of network components when computing temporary
        overvoltages
   7.5 Representation of network components when computing slow-front
        overvoltages
   7.6 Representation of network components when computing fast-front
        transients
   7.7 Representation of network components when computing very-fast-front
        overvoltages
8 Temporary overvoltages analysis
   8.1 General
   8.2 Fast estimate of temporary overvoltages
   8.3 Detailed calculation of temporary overvoltages [2], [9]
9 Slow-front overvoltages analysis
   9.1 General
   9.2 Fast methodology to conduct SFO studies
   9.3 Method to be employed
   9.4 Guideline to conduct detailed statistical methods
10 Fast-front overvoltages analysis
   10.1 General
   10.2 Guideline to apply statistical and semi-statistical methods
11 Very-fast-front overvoltage analysis
   11.1 General
   11.2 Goal of the studies to be performed
   11.3 Origin and typology of VFFO
   11.4 Guideline to perform studies
12 Test cases
   12.1 General
   12.2 Case 1: TOV on a large transmission system including long
                lines
   12.3 Case 2 (SFO) - Energization of a 500 kV line
   12.4 Case 3 (FFO) - Lightning protection of a 500 kV GIS substation
   12.5 Case 4 (VFFO) - Simulation of transients in a 765 kV GIS [51]
Annex A (informative) Representation of overhead lines and underground
        cables
Annex B (informative) Arc modelling: the physics of the circuit-breaker
Annex C (informative) Probabilistic methods for computing lightning-related
        risk of failure of power system apparatus
Annex D (informative) Test case 5 (TOV) - Resonance between a line
        and a reactor in a 400/220 kV transmission system
Annex E (informative) Test case 6 (SFO) - Evaluation of the risk of
        failure of a gas-insulated line due to SFO
Annex F (informative) Test case 7 (FFO) - High-frequency arc
        extinction when switching a reactor
Bibliography
Figures
Tables

Gives guidance on conducting insulation co-ordination studies which propose internationally recognized recommendations.

This technical report gives guidance on conducting insulation co-ordination studies which propose internationally recognized recommendations

• for the numerical modelling of electrical systems, and

• for the implementation of deterministic and probabilistic methods adapted to the use of numerical programmes.

Its object is to give information in terms of methods, modelling and examples, allowing for the application of the approaches presented in IEC 60071-2, and for the selection of insulation levels of equipment or installations, as defined in IEC 60071-1.