Analysis of Lightening Protection System for Renewable Energy Sources

This report provides an in-depth analysis of lightening protection systems tailored for renewable energy sources, specifically focusing on a hybrid power system in the Kwazulu-Natal region of South Africa. The study begins by introducing the hybrid system, which integrates photovoltaic (PV), wind turbines, and fuel generators to provide power without connection to the mains supply. The report details the various components and their interconnections, including solar panels and power storage batteries. It emphasizes the importance of earthing and lightening control measures to protect installations from direct strikes and power overvoltages. The report then explores the earthing system requirements, including soil resistivity measurements and the components of an effective earthing system, such as earth electrodes, earthing conductors, and protective conductors. Furthermore, the report highlights the significance of these systems in preventing prolonged power outages and supporting local economies. The conclusion stresses the cost-effectiveness and ease of maintenance of these protection systems in off-grid renewable energy setups.

Lightening Protection
System for Renewable
Energy Solution
1.Introduction
2.The Hybrid system without mains
supply
3.Earthing system and requirements
4.Lightening control Measures
5.Conclusion
6.Reference

Introduction
 The project is commissioned in Kwazulu-Natal region, south
Africa. Its aim is to provide Earthing and lightening protection to
local electrical installation in the area.
 The area consists of power supply from three renewable
sources; PV, Wind and Fuel, hence the name Hybrid power
supply.
 The power supply is not connected to the mains power supply of
South Africa.
 Various Earthing and Lightening overvoltages systems are
installed to protect the installations.

The Hybrid system without
mains supply

The Hybrid system without mains supply
(cont.)
 All the power needed for various homes and other heavy uses,
and total lighting of the village including installation plant
comes from the hybrid energy source consisting of [2];
1.Photovoltaic generator (PV) [2]
2.Wind turbines
3.Fuel generator system
4.Solar panels
 All this power generated are linked to one another and
connected to various homes in the village.

The Hybrid system without mains supply
(cont.)
 In the villages in Kwazulu- Natal region, the hybrid power supply
is interconnected forming a network just like the national grid
system.
 Residents’ houses have solar panels and power storage
batteries [2]. And then this energy is supplemented by PVs, Fuel
energy and wind turbines. This ensures continuous power
supply to the homes regardless of fluctuations in wind energy
power supply, light intensity et cetera [1].
 In addition this stable and continuous power supply has led to
sprouting of various economic activities in the Kwazulu-Natal
area such light duty plants.

Lightening Control Measures
 Systems have been put in place which protect hybrid installations
against lightening and thunder strikes. They protect against;
1.Direct lightening and thunder strikes to the hybrid power
installations[2]
2.Power overvoltages in power supply systems and components
[2]
 Lightening protection is done in;
1. Wind turbine generators(WTG)
2. Electrical cables from WTGs
3. The building of the Hybrid system
4. Electrical cables connecting stations and houses within the
village

Lightening Control Measures
(cont.)
Lightning control schematic

Lightening protection systems
(cont.)
 To ensure overvoltages are earthed properly, air termination rods
and metal fixing cables are connected to small earth electrodes
called foundation earth electrodes (FEEs) as shown above [3][5].
 For equipotentialization to be achieved a copper wire is used to
connect base points of rods and the protected WTG [5].
 The electrical cables are protected from galvanic coupling
through separation of earth electrode cables as shown in the
above schematic diagram [3].

Lightening Control Measures
(cont.)
 The components and installations are in addition protected
against direct strikes of lightening and thunder as shown below
[2] [3];

Earthing system and
requirements Earthing is the process by excess voltages are directed to earth
and thus enhancing protection of system against damage that can
be caused by fault currents that is caused by lightening or
excessive power flow.
 objectives of an Earthing system includes;
1.Safeguarding people and animals from power dangers
2.Power installations and equipment safety
3.Improved voltage signal quality
4.Helps in power equipotentialization
 Various tests are done before Earthing system installations are
done [3]. They include;
1. Measuring soil resistivity
2. Type of soil

Earthing system and requirements
(cont.)
Components of an Earthing system

Earthing system and requirements
(cont.)
 Earth electrode (1) are the physical wires connecting to the soil
(earth) – conducting excess current to earth [3].
 Earthing conductor (2) connect Earthing terminal and the earth
electrode in the system [5] [4].
 Main protective conductive (3) protects all the other equipment
against electrical shocks that may be caused by power
overvoltages.
 Extraneous conductive part (4) conducts any potential from
parts outside electrical installation such as non-insulated walls
[1].

Conclusion
 Renewable energy hybrid systems that are off-grid are growing
world over and thus need of Earthing and Lightening protection
systems has increased as well.
 Without proper power overvoltage control and Earthing systems,
these systems will result in prolonged power outages, loss of
local economies that depend on systems powered by the same
energy supply such as telecommunications and light factories.
 And thus in the case of Kwazulu-Natal off-grid power supply, the
Earthing and protection systems if put in place can help a great
deal. This is because they are cost effective and easy to
maintain.

Reference
1. Kasikci I. Electrical Power Systems Basic Handbook. – Birsen Press, 2008. –
264 p.
2. Kasikci, I. Analysis and Design of Low Voltage Power Systems. – Wiley–VCH,
2004. – 399 p.
3. Cetin E. Design, Application, and Analysis of a Direct– Current Distribution
Grid for a Photovoltaic–Wind–Fuel Cell Hybrid Energy System, Ph. D. thesis. –
Ege University SolaEnergy Institute, 2010. – 183 p.
4. Zomeworks. UTRF–120 Passive Trackers, 2011. Online: http
://www.zomeworks.com.
5. Markowska R., Wiater J., Sowa A. Measurements of Surge Currents and
Potentials in a Radio Base Station forEstimation of Lightning Threat //
Electronics and Electrical
Engineering. – Kaunas: Technologija, 2011. – No. 1(107). –P. 93–98.