Factors Determining the Effectiveness of a Wind Turbine

Raghavender Goud Deshagoni

Ph.D. Student, Smart Power and Renewable Energy Systems Group,

Victoria University of Wellington, New Zealand

Factors Determining the Effectiveness of a Wind Turbine Generator Lightning Protection System

1

Introduction

2

Hub

Introduction

• The reduced costs for wind energy are due to a surge in energy generation from individual WTG by the expanding size and escalated installations at high altitudes

3

Wind turbine

200 m

Wind Farm Optimization

4

https://www.emd.dk/wind-energy-consultancy/wind-farm-layout-optimizations/

• A wind farm layout is primarily optimized for AEP output and wake loss reduction

• Noise constraints

• Avoidance of obstacles and protected lands

• Visualization and shadow flicker issues

• Power grid connection


Wind Farm Optimization5



6

Wind Farm Optimization

https://www.wasp.dk/was

p#details__wind-

resource-mapping

https://www.wasp.dk/wasp#details__wind-resource-mapping

Wind Farm Optimization7

Lightning Strikes on Wind Turbines8

Wind Turbine Lightning Protection System

• External lightning protection system

• Internal lightning protection system

• Earthing system

9

Down Conduction Path

10

Lightning strike

Blade

Blade Blade

Interface between rotor and nacelle

Tower

Ground

Down Conduction Path

11

Lightning strike

Interface between nacelle and tower

Tower

Ground

Rotor

Effectiveness of WTG LPS12

ELPS = f (EX, EI, EG)

External LPS

EX

Internal LPS

EI

Grounding system

EG

Air-termination

system

Down conduction

system

Equipotential

bonding system

Surge protection

Grounding

resistance

Impulse coefficient

(A)

Ground potential

rise

Interception

efficiency

Sizing efficiency

Sizing efficiency

Required lightning

protection level

Effectiveness of WTG LPS13

Table: Effectiveness of air-termination system

Table: Effectiveness of down conduction system

Effectiveness of WTG Grounding

• Low-Frequency resistance

• Impulse coefficient

• Potential distribution

• Step and Touch voltages

14

CASE STUDY

15

Soil Resistivity Measurement

16

• Wenner Method

Soil Stratification

17

LPL Parameters18

Lightning Discharge Current

• First short positive lightning discharge current waveform

• Rise time : 10 μs

• Time to half : 350 μs

19


• First short negative lightning discharge current waveform

• Rise time : 1 μs


20


• Subsequent short lightning discharge current waveform

• Rise time : 0.25 μs


21

Wind Turbine Grounding System

22

Electrode Configurations

23


24


25

Results26

Fig. WTG grounding resistance for different lightning protection levels.

Results27

Fig. Impulse coefficient of the WTG grounding system for first short negative

lightning discharge current parameters.

Results

28

Fig. Impulse coefficient of the WTG grounding system for subsequent lightning

discharge current parameters.

Results29

Fig. Potential distribution of the WTG grounding system at 5 kHz.

Results30

Fig. Potential distribution of the WTG grounding system at 4.1 MHz.

Results31

Fig. Potential distribution of the WTG grounding system at 50 MHz.

Conclusions

• Using advanced electromagnetic simulation tools it is possible to

predict the behaviour of a WTG LPS at the design stage.

• Combining information about several aspects of the WTG LPS

allows us to predict the overall effectiveness of the LPS.

• Having the ability to succinctly describe LPS behaviour will

facilitate safer wind farms and faster adoption of wind as a form of

clean, renewable energy.

32

IEEE IAS ESW-201933

IEEE IAS ESW-201934

35

Thank you

Documents

Factors Determining the Effectiveness of a Wind Turbine