Tesis

372
VOLTAGE DIP EVALUATION AND PREDICTION TOOLS

Task Force C4.102

February 2009

TF C4.102

VOLTAGE DIP EVALUATION AND PREDICTION TOOLS

Members: Juan A. Martínez-Velasco – Spain (Convenor) Nick Abi-Samra – USA MyoT. Aung – United Kingdom Math Bollen – Sweden Saša Ž. Djokić – United Kingdom Nikos Hatziargyriou – Greece Roberto C. Leborgne – Sweden Jovica V. Milanović – UnitedKingdom Gabriel Olguin – Sweden Melanie Schilder – South Africa

Copyright © 2009 “Ownership of a CIGRE publication, whether in paper form or on electronic support only infers right of use for personal purposes. Are prohibited, except if explicitly agreed by CIGRE, total or partial reproduction of the publication for use other than personal and transfer to a third party; hence circulation on anyintranet or other company network is forbidden”. Disclaimer notice “CIGRE gives no warranty or assurance about the contents of this publication, nor does it accept any responsibility, as to the accuracy or exhaustiveness of the information. All implied warranties and conditions are excluded to the maximum extent permitted by law”.

ISBN :978-2-85873-059-9

TABLE OF CONTENTS
1 Introduction 1.1Power quality 1.2 Voltage dips 1.3 Scope and content of the report 2 Voltage Dip Characterization 2.1 2.2 2.3 2.4 2.5 3 Introduction Residual voltage and duration Phase angle jump Other characteristics Three-phase voltage dips 1 1 3 7 8 8 8 9 10 11 11 11 13 13 15 17 18 18 19 20 20 21 21 21 22 24 25 25 25 27 28 28

Equipment Behaviour 3.1 3.2 3.3 3.4 3.5 Introduction Voltage tolerance Computer andconsumer electronics Sensitive loads Equipment testing and sensitivity

4

Voltage Dip Mitigation 4.1 4.2 4.3 4.4 Introduction Improving the system Installing mitigation equipment Improving equipment immunity

5

Simulation Tools 5.1 5.2 5.3 5.4 5.5 Introduction Calculation of event characteristics Voltage dip studies Solution techniques Comparison of simulation tools

6

Modelling forVoltage Dip Calculations 6.1 6.2 6.3 6.4 Introduction Lines and cables Transformers Modelling of protection systems

6.5 Modelling of power electronics equipment 6.6 Load modelling 6.7 Models for bulk-power and distributed generators 7 Voltage Dip Evaluation 7.1 Introduction 7.2 Voltage dip calculation 7.3 Stochastic assessment pf voltage dips 8 Voltage Dip Indices 8.1 8.2 8.3 8.4 8.5 9 10Introduction Indices for event characterization Indices for site characterization Indices for system characterization Voltage dip index evaluation

32 34 37 41 41 44 48 73 73 73 76 78 79 95 97

Conclusions References

1. Introduction
1.1 Power quality

Electric power systems are designed to generate electric energy economically and with the minimum ecological disturbance and to transfer thisenergy over transmission lines and distribution networks with the maximum efficiency and reliability for delivery to customers at virtually fixed voltage and frequency. The optimal level of investment in designing such a system is to be achieved by means of a trade-off between reliability and costs. Some of the recent developments in electrical energy sector have led the change in design andoperation of power systems, i.e.:  Due to the re-regulation of the electricity industry, there is no longer a single vertically structured system but a number of independent companies linking electricity generation with end users and competing among themselves for customer. Distribution companies are under considerable pressure to improve the quality of the service they provide. Achieving theseimprovements requires very large investments. If, after having made these investments, they succeed in providing a better quality of service than their peers can achieve, the Regulator will reward them with a higher rate of return. On the other hand, a failure to deliver on promises of better quality of service is likely to result in severe financial penalties. It is thus essential to the future of...