In this chapter, lightning surge analyses on a WPP were performed using ARENE (section 9.5) and PSCAD/EMTDC (section 9.6). The analyses simulated a WPP using a simple model with WTs, boost transformers, SPDs, and a gird-interactive transformer connected with a collection system. From the results of several analyses the following conclusions were obtained: (1) A back-flow surge can propagate to other WTs from the WT that has been directly struck by winter lightning via the earthing system and the collection line in a WPP. (2) Burnout incidents of SPDs could quite easily occur even in a WT far from the lightning-struck WT. (3) Installing multiple earthing wires to the collection line in a WPP can reduce the burnout incidents due to winter lightning. (4) The earthing wire may not help, especially for summer lightning, to reduce the EPR (earth potential rise) of WTs and the grid-interactive transformer.

Chapter Contents:

• 9.1 Introduction
• 9.2 Winter lightning and back-flow surge
• 9.3 Earthing system of wind turbines and wind power plants
• 9.3.1 Earthing system of WTs
• 9.3.2 Earthing system in WPPs
• 9.4 Wind power plant models for lightning surge analysis
• 9.4.1 WPP model
• 9.4.2 Model for winter lightning
• 9.4.3 Model for surge protection device (SPD)
• 9.4.4 Comparison analysis between ARENE and PSCAD/EMTDC
• 9.5 Mechanism of SPD's burnout incidents due to back-flow surge
• 9.5.1 Analysis of the surge propagations in WPP
• 9.5.2 Detail analysis on surge waveforms
• 9.6 Effect of overhead earthing wire to prevent back-flow surge
• 9.6.1 Model of a collection line in a WPP
• 9.6.2 Observation of waveforms around SPDs
• 9.6.3 Evaluation of the possibility of the SPD's burning out
• 9.6.4 Evaluation of potential rise of earthing system
• 9.7 Conclusions
• Symbols and abbreviations
• Acknowledgments
• References

Inspec keywords: earthing; lightning protection; wind power plants; surge protection

Other keywords: PSCAD/EMTDC; back-flow surge; earthing system; ARENE; lightning surge; winter lightning; boost transformers; grid-interactive transformer; SPD; WPP; EPR; earth potential rise; wind power plants; collection systems

Subjects: Wind power plants; Power system protection