What Is Blogging?

Social media has become a new version of blogging. Take Twitter for example. Twitter was known flatout as a microblogging platform. Now people are using platforms like Facebook, Instagram, and Medium to get more exposure than just posting on a personal website does. 

As a matter of fact, I’m even asking people to write a blog or eBook on their personal blog. My advice would be to try putting out native content on the platforms that make the most sense for you and your audience. Then, start engaging with those who you think should see it.

Whenever anyone asks me about what I do for earning money then I say, I do Blogging and I am a blogger. Then again one question asked me What is Blogging?

For me, Blogging is the act of sharing knowledge and information over the internet. Today many people are blogging to share their talent with their users or readers by writing articles and blog posts.

Let’s Take an Example to understand Blogging more deeply:

There is Boy and his name is Mr. Rahman and he loves cooking. he always teaches his friends and family members about his new dishes and recipes. One day he came to know about Blogging and he decides to make a blog about cooking. and start writing recipes for new dishes that he cooks every day or week. and now he is sharing his recipes with a huge number of people, now Mr. Rahman is blogging on the internet.

Types of Blogging

There are various types of blogging, each with its own focus and purpose. Here are some common types of blogging:

Personal Blogging

Personal blogging involves sharing personal experiences, thoughts, and insights with an audience. It can cover a wide range of topics, such as travel, lifestyle, parenting, food, or hobbies. Personal bloggers often use their blogs as a creative outlet or a way to connect with others who share similar interests.

Niche Blogging

Niche blogging focuses on a specific topic or industry. It targets a particular audience and covers in-depth information related to that niche. Examples of niche blogs include fashion blogs, technology blogs, finance blogs, health and wellness blogs, and many more. Niche bloggers establish themselves as experts in their field and provide valuable content to their audience.

Professional Blogging

Professional blogging involves creating content related to a specific profession or industry. It can be used to showcase expertise, share insights, offer advice, or provide resources to professionals in a particular field. Professional bloggers often aim to establish their authority and build a professional network through their blogs.

Business Blogging

Business blogging is focused on promoting a specific business or brand. It can be used to share updates, news, product information, and industry insights, and engage with customers. Business blogs aim to build brand awareness, drive traffic to the company's website, and establish a connection with customers.

Affiliate Blogging

Affiliate blogging involves promoting products or services through affiliate links. Bloggers write content that includes product recommendations, reviews, or tutorials and earn a commission when readers make a purchase through their affiliate links. Affiliate blogging can be a way to monetize a blog by partnering with relevant affiliate programs.

Guest Blogging

Guest blogging involves writing and publishing content on other blogs or websites as a guest contributor. It allows bloggers to expand their reach, gain exposure to a new audience, and build relationships with other bloggers or industry influencers. Guest blogging can help increase visibility, credibility, and traffic to your own blog.

News and Magazine Blogging

News and magazine blogging focuses on delivering timely news, updates, and articles on a specific industry or topic. It covers current events, trends, and analysis. News and magazine blogs often have multiple contributors and provide a platform for sharing different perspectives and opinions.

Multimedia Blogging

Multimedia blogging incorporates various forms of media, such as videos, podcasts, infographics, and images, into blog content. It offers a more dynamic and interactive experience for readers and allows bloggers to express their ideas through different media formats.

These are just a few examples of the types of blogging you can explore. It's important to choose a type that aligns with your interests, expertise, and target audience. Remember, you can also combine different types or create your own unique blogging style.

Blogging Benefits 

Blogging offers several benefits, both personal and professional. Here are some key advantages of blogging:

• Self-expression and creativity: Blogging provides a platform for self-expression and creativity. It allows you to share your thoughts, ideas, experiences, and expertise with a global audience. You have the freedom to choose your topics, writing style, and format, enabling you to showcase your unique voice and perspective.

• Building a personal brand: Blogging helps in building your personal brand and establishing yourself as an authority or expert in your niche. By consistently producing valuable and high-quality content, you can develop credibility and gain recognition in your industry. This can open up opportunities for collaboration, partnerships, speaking engagements, and professional growth.

• Sharing knowledge and helping others: Blogging allows you to share your knowledge, expertise, and insights with others. By providing valuable information, tips, tutorials, or advice, you can help your readers solve problems, gain new skills, or make informed decisions. The ability to positively impact and help others can be highly rewarding.

• Networking and community building: Blogging enables you to connect with like-minded individuals, industry professionals, and a wider community. Through comments, social media interactions, and collaborations, you can engage with your audience and build relationships. Networking with others in your niche can lead to new opportunities, partnerships, and the exchange of ideas.

• Improving writing and communication skills: Blogging involves consistent writing, which can help you sharpen your writing skills over time. It allows you to practice articulating your thoughts, organizing information, and communicating effectively. These skills can be beneficial not only in blogging but also in various personal and professional endeavors.

• Personal growth and self-reflection: Blogging encourages self-reflection and personal growth. As you write and share your experiences, you may gain new insights, learn from feedback, and evolve as a person. It can be a means of documenting your journey, setting goals, and holding yourself accountable.

• Monetization opportunities: Blogging offers various monetization opportunities, allowing you to generate income from your blog. You can monetize your blog through methods such as advertising, sponsored content, affiliate marketing, selling digital products or services, or by offering memberships or online courses. While monetization may not be the primary focus for every blogger, it can be a way to earn passive income or turn your blog into a profitable business.

• Improved digital presence and SEO: By regularly publishing high-quality content, blogging contributes to enhancing your online presence and search engine optimization (SEO). Search engines like Google appreciate fresh and relevant content, and a well-optimized blog can attract organic traffic and increase your visibility online.

It's important to note that blogging requires consistency, dedication, and patience. It may take time to build an audience and see significant results. However, the benefits mentioned above make blogging a valuable endeavor for personal and professional growth, knowledge sharing, and potentially even financial success.

What is the Function of an Earthing or Grounding Transformer?

Generally, an Earthing or Grounding Transformer is not a three-phase transformer, but a single-phase transformer with the primary (HV end) rated voltage equal to the system phase-to-neutral voltage and the secondary (LV end) rated voltage of either 240V or 11oV.

To avoid any switching transient in the Transformer primary of the transmission system, or a big noise may damage the Transformer. To avoid such spurious signal grounding is provided in the primary. The grounding also affects third harmonics from switching transient.

29 Tips to Earn from Online Without Investment

29 Tips to Earn Online Without Investment

1. Travel Writer

Considered by many as the ultimate travel job, writing for online publications can help you buy your next mug of beer. Work your way to becoming the next Hunter S. Thomson by learning about the craft and querying your next inspired idea.

2. Wield that camera

National Geographic may not be knocking your door down, but that doesn’t mean that your photos don’t deserve an audience. Try selling your landscape and portrait shots to travel publications or submit them to a stock photography company such as Shutterpoint.com, Andes Press Agency, and Getty Images.

3. Video journalism

With the advent of Youtube amateur videos are in great demand. Become a backpack filmmaker, set up your own blog, or simply sell it to tourism sites.

National Geographic may not be knocking your door down, but that doesn’t mean that your photos don’t deserve an audience.

4. Busking

If you’re talented (or even if you aren’t), this is a great way to earn money. Just make sure you’re not taking someone else’s “spot” and check the legalities of performing in a certain area. Or if the police come, you could just run away really fast.

5. Work at a Bookstore

It’s a great way to show off your “intellectual” side whilst devouring the latest books. Keep in mind that most may require a work permit before they hire you. A great alternative is to bunk in Paris’ famed Shakespeare and Company where the owner offers free beds and work in exchange that you promise to read at least one book a day.

6. Online Poker

This is the perfect money-making means for risk-takers. Many travelers have funded their trips from their winnings on Online Poker. Make sure to weigh the risks of wiping out your bank account and developing a gambling problem.

7. Massage

Have you been known to make your dates swoon with your suave massage moves? Maybe it’s time you put your seduction skills to good use by working as a freelance masseuse. Find willing clients on the beach or a location where people are looking to relaaaaxxxx. Invest in some scented oil, clean nails, and your most disarming smile and you’ll have enough funds for your own spa treatment.

 

8. FarmWork

Fruit picking and farm work are one of the favorite possibilities for hippies, idealists, and masochists. Though it is literally hard labor, it’s a paying job with invaluable perks, like meeting new people, enjoying the outdoors, and having a unique experience.

One of the best resources is Transitions Abroad, Matador’s Guide to WWOOFING, and Finding Paying Work in Europe.

9. Construction

If you’d like to fatten your wallet whilst trimming your waistline, then take on some short-term construction work. Who knows, with your newly sculpted abs and beefy biceps, you may find other uses for that tool belt.

10. Work in a hostel

Many hostels hire part-time workers in exchange for cheaper rates on rooms. Cleaning up after travelers may seem pretty disgusting, but it’s an opportunity for quick cash, a free bed, and some new friends.

11. Painting

You don’t have to cut off your ear to get a painting gig, but you can put your artistic abilities to good use by offering your services for home, office, or building refurbishments.

12. Dishwasher or Kitchen Staff

Grab some leftovers without having to resort to dumpster diving. Experience the stress, camaraderie, and craziness of working in a restaurant’s kitchen. It may even open your eyes to a new career path like it did for bad-ass chef extraordinaire, Anthony Bourdain.

Get prodded and poked by nervous science students in the UK, US and in Europe as a guinea pig.

13. For the love of science…or some cash

If you were the type of kid that purposely ignores the expiration date on milk cartons just to “see what would happen,” then this is the job for you. Get prodded and poked by nervous science students in the UK, US and in Europe with Get Paid to Guinea Pig.

14. Donate Blood

So what if you feel a bit woozy? A train to Russia is not cheap. Sissy. Plus, you’re helping save lives.

15. Modeling

Do you enjoy staring at your reflection on train windows and hostel mirrors? Then throw down that backpack for a few hours and head off to the glamorous world of commercial and print modeling. Often found in the gigs section of craigslist ads and city job sites, these opportunities require little more than a few cheesy poses.

16. Movie Extra

Run through the streets of Berlin with Jason Bourne or flee Godzilla’s rampage in Tokyo by working as a movie extra. You can check out casting agencies, local job posts or even the local couchsurfing group where independent film makers often post openings. It’s a great way to rub elbows with international celebrities (or at least tell your friends you did), earn some fast cash and possibly get discovered.

17. Recycle

Yes, saving the environment does pay. In most European cities, you can get cash back for the bottles you collect. Scour the hostel lounge and trash cans for some empty containers which you can take to the local supermarket where you’ll be given enough chance to finally buy that banana you’ve been eyeing.

Play the streets as a busker / Photo Kafka4prez.

18. Sports events

Run after wayward golf balls or mop up the latest spillage from the Tae Kwon Do championships. For sports enthusiasts, it’s a great way to earn some money whilst gaining insight into the local games.

19. Trim some bushes

No, not those, perverts. Knock on a few doors and ask if they need any cleaning, yard work, or repairs done. Though you may be chased off by Rover (or Ganesh if you’re in India), with a rumbling stomach, anything is worth a try.

20. Expositions

If you consider yourself a master of setting up tents, then challenge yourself by working at an exposition. Find these jobs on the city classified pages and help put up the displays, tarps and booths for a quick and easy buck.

21. Write Content

If you’ve been annoying your friends and family back home with your lengthy emails, then maybe its time to get paid by writing about other things than yourself. Work for a site that pays per hits such as blogit.com, helium.com and Associatedcontent.com.

22. Resell stuff

Don’t quite know what to do with that weird doll you got in Romania? Then sell it in your next location. From convincing your bunkmate to buy your lucky charms to auctioning fleamarket finds on ebay, reselling unusual travel goods can turn into quite the lucrative on-the-road business.

23. Handicrafts

If you’ve got a knack for crochet or can weave a basket at hyper speed, then selling some of your crafts can be used towards funding your next bus ticket. At the very least, you could make yourself something warm for those homeless evenings.

24. Festival Stalking

One of the best ways to combine a crazy cultural adventure, lots of drinking and enough dough for your next hangover spot is to work the festival circuit. You could either apply for a gig in one of the stands or push your own agenda by selling homemade space cakes, jell-o shots or setting up a kissing booth.

25. Sail Away

Sail off towards the sunset by working on a yacht or a cruise ship. You can find work by perusing crew job sites or simply asking people by the harbor if they have any leads. It provides a sense of freedom, a means to sustain to yourself and a way to get to your next stop.

26.Launch a blog

“If you have something interesting to say, grow your readership, post ads and earn some dough,” says Rachel. Start your blog at a free site (go to blogger.com or wordpress.com ), then go to Google AdSense ( google.com/adsense) or the affiliate program at Amazon.com ( affiliate-program.amazon.com) to feature advertising on your site. With AdSense, you make a little bit every time someone clicks on one of the ads hosted on your site. With Amazon’s program, you earn a small commission when someone clicks through on an ad and makes a purchase at Amazon. The income will start small, but if you build your following, your cash flow will increase. Rachel typically makes several hundred dollars per month from ads or affiliate links on her blog.

27. Give your opinion

At MySurvey.com, Surveyhead.com or ValuedOpinions.com, you can sign up to take surveys about products and services and get paid for it. Sites typically pay $2 to $5 per completed survey and will send you a check or deposit to your PayPal account, or gift cards or merchandise once you reach $20 in your survey account. Scam alert! There are lots of survey sites out there, but not all are trustworthy. Avoid participating in anything that charges a fee up front to participate. “I try to take three or four surveys each week while the kids are watching TV, and that brings in $20 to $30 per month,” says Rachel.

28. Search the Internet

Rachel loves to scour the Web, and one of her favorite things to do is use Swag Bucks ( swagbucks.com) as her search engine instead of, say, Google or Yahoo. By doing this, she earns Swag Bucks points — called “SBs” on the website — redeemable for merchandise like Target gift cards and beauty products. (Maximize the number of points you earn by installing the Swag Bucks toolbar on your computer.) You can also earn more Swag Bucks points by taking the site’s daily poll and by participating in the company’s “trusted surveys.” But be warned, it could take awhile to accumulate SBs. A $300 Apple gift card, for example, costs 37,000 SB. If you don’t want prizes, you can trade your Swag Bucks points for PayPal deposits into your account.

29. Do online tasks

Have a few extra minutes with nothing to do? Companies like Amazon.com’s Mechanical Turk ( mturk.com) will pay you to complete little tasks that they need done, such as searching the Web for certain products or answering questions and giving opinions. There’s usually a time limit of anywhere from 10 minutes to an hour, and pay ranges from a few cents to a few dollars. This may not sound like a lot, but do enough tasks and you’ve earned yourself some extra spending money.

Being on the road with very little or no cash may seem daunting at first, but the challenge of using your imagination to provide for yourself will make the experience all the more exciting and valuable.

How to Calculate Transmission Line Tower Height?

Height of Tower Structure for High Voltage Transmission Lines:

Towe height is the major factor to design an overhead transmission line tower structure. The tower design philosophy mainly consider the factors tower height, base width, top damper width and cross arm's length. Typical tower height ranges from 15 to 55 m (49 to 180 ft).

Height of tower is determined by-

H=h₁+h₂+h₃+h₄

where,

h₁ =Minimum permissible ground clearance;

h2 =Maximum sag;

h3 =Vertical spacing between conductors;

h4 =Vertical clearance between earthwire and top conductor.

Minimum Ground Clearance Calculation

The short cut method of calculation formula for minimum ground clearance is as-

CL=5.182+0.305*K

where, 

K=(v-33)/33

As per Indian Electricity rules, 1956; the minimum permissible ground clearance is as below:

Permissible Ground Clearance:

Sl.No	Voltage Level	Ground Clearance(m)	Telecommunication Clearance(mm)	Railway Clearance(m)
1	<=33kV	5.20	2440	7.9/6.7
2	66kV	5.49	2440	7.9/6.7
3	132kV	6.10	2740	8.5/7.3
4	220kV	7.01	3050	8.8/7.6
5	400kV	8.84	4880	11.2/10.0

You may read more detail to know about 

Working Safety Clearance and Phase Gap Between Exposed Live Conductor

Maximum Sag and Tension calculation formula for overhead transmission lines conductor:

The sag in overhead transmission line conductor refers to the difference in level between the point of both supports and the lowest point on the conductor, simply the dip of the conductor between the two-level supports is called sag.

Factors affecting the sag

Conductor weight: Sag of the conductor is directly proportional to its weight. The weight of the conductors is increased due to ice loading.

Span: The Sag is directly proportional to the square of the span length. Longer span gives more sag. 

Tension: The sag is inversely proportional to the tension in the conductor. Higher tension increases the stress in the insulators and supporting structures.

Wind: It increases sag in the inclined direction.

Temperature – The sag is reduced at low temperatures and is increases at higher temperatures.

We can use the following two formulas to calculate maximum sag and tension calculation, Parabolic formula for span length equal or less than 300m and Catenary formula for span length greater than 300m.

Parabolic formula:

L =S+(S³.q²)/24.H²

D =(S².q)/8H

T/q =(S².q)/8H +H/q

q =√(w²+p²)

Catenary formula:

L =(2H/q)Sinh (Sq/2H)

D =H/q[Cosh(Sq/2H)-1]

T/q =D+H/q

q =√(w²+p²)

Where,

q = resultant load on the conductor per unit length;

S = Span length;

D = Sag of the conductor at its lowest point;

L = Length of the conductor in span;

T = Tension at either point of support;

H = Horizontal tension at the lowest point.

Vertical spacing between conductors

Conductor spacing or phase distance may calculate in different ways.

Mecom Formula:

Spacing (cm) = 0.3048*V+4.010(D/W)√S

wher,

V = System volltage in kV;

D = Diameter of conductor in cm;

S = Cable sagin cm;

W = Weight of conductor in Kg/m.

VDE Formula:

Spacing (cm) = 07.5√S + V²/2000

wher,

V = System volltage in kV;

S = Cable sagin cm.

Still formula:

Spacing (cm) = 5.08 + 1.814* V + [l/27.8]             

wher,

l = Average span length(m)

NESC formula:

Spacing (cm) = 0.762*V + 3.681√S + L/√2

Where,

V= Voltage of system in KV;

S= Sag in cm;

L= Length of insulator string in cm.

Swedish formula: 

Spacing (cm) = 6.5√S + 0.7*E

Where,

E= Line Voltage in KV;

S= Sag in cm.

French formula:

Spacing (cm) = 8.0√(S + L) + E/1.5

Where,

E= Line Voltage in KV;

S= Sag in cm;

L= length of insulating string(cm).

Vertical clearance between earth wire and top conductor

Tower top clearance is the vertical clearance between earth wire and top conductor which is governed by the angle of shielding. The shield angle varies from about 250 to 300, depending on the configuration of conductors. Tower top clearance shall be taken 1.5 and 2.25 m for 132 kV and 220 kV respectively for 00 swings.

Tower height and strength may vary considering the line diversion or the line direction angle as below:

Type A Tower (Tangent Tower with suspension string)

Used on straight runs and up to 2° line diversion;

Type B Tower (Small Angle Tower with tension string)

Used for line deviation from 2° to 15°;

Type C Tower (Medium Angle Tower with tension string ).

Used for line deviation from 15° to 30°;

Type D Tower (Large angle tower with tension string)

Used for line deviation from 30° to 60°;

Type E Tower (Dead End Tower with tension string)

Used for line termination & starting;

Special tower-

Suspension Tower (Span ≈ 1000 m)  

Used for River crossing, Mountain crossing etc.;

Transposition Tower

Used for transposition of the tower.

Comparison Of HVAC and HVDC Transmission Network

What is HVAC vs HVDC

Electrical power needs to transmit a distance from its generation station to transmission and distribution between users. Initially, transmission system born as a DC system, but finally stopped it and grew as an AC system. Now again retaining and developing HVDC for power transmission.

The feature comparison between HVDC and HVAC is as below:

Investment cost:

Considering the power carrying conductors, DC transmission requires fewer conductors than AC transmission - 2 conductors per DC circuit whereas three conductors per 3 phase AC circuit. 

HVDC needs smaller tower for line support thus, HVDC transmission line would cost lesser than an HVAC line. 

But, the terminal converter stations in HVDC are much more expensive which are not required for HVAC transmission. 

Over a certain line length what is called break-even distance, HVDC line becomes cheaper than HVAC. The break-even distance for overhead lines is around 600 km and for submarine lines, it is around 50 km.

Losses:

There are no skin effect losses in the DC system. Corona losses also significantly lower in the case of the DC system comparing the AC system. An HVDC line has considerably lower losses compared to HVAC over longer distances.

Controllability:

There is better voltage regulation in the HVDC system due to the absence of inductance. Also, the HVDC system offers greater controllability compared to HVAC.

Asynchronous interconnection:

We worldwide there are 50 Hz or 60Hz AC system is existed, it is not possible to the interconnection between different frequency 50 Hz and 60Hz AC power grids. But in the DC system, there is no issue about frequency.

Interference with nearby communication lines:

Interference with nearby communication lines is lesser in the case of HVDC overhead line than that for an HVAC line.

Short circuit current:

In longer distance HVAC transmission, short circuit current level in the receiving system is high. An HVDC system does not contribute to the short circuit current of the interconnected AC system.

What are the advantages of HVDC Power system?

The major advantages of the HVDC power transmission system are as below:

i) The use of this system reduces the number of conductors and insulators in the power system. As a result line cost is reduced.

ii) As a result of using this system, the amount of Phase to phase and ground to ground clearance is less.

iii) As a result of using this system pole or tower can be installed very cheaply.

iv) The amount of corona loss in this system is much less.

v) The power loss of the line is greatly reduced.

vi) No reactive power is generated or absorbed in the HVDC system. So no reactive power compensation is required in this system.

vii) HVDC system does not have any frequency of current so skin effect and proximity effect does not occur in the transmission line.

What are the disadvantages of an HVDC transmission system?

The major disadvantages of an HVDC transmission system are as below:

i) The cost of circuit breakers used in HVDC systems is much higher.

ii) No transformer is used to change the voltage level in this system.

iii) The cost of this system is much higher as the converter substation is connected to the sending end and receiving end terminals of the transmission line.

iv) The inverter used in the converter substation has limited capacity.

v) The two terminals of the inverter and rectifier device create harmonic, which is used to reduce the active filter. Using an active filter is very expensive.

vi) A heat loss is created in the converter substation, which is reduced using an active cooling system.

Most powerful underground power transmission cable system- 640 kV extruded HVDC cable

The world recognized cable manufacturer NKT claims that their 640 kV extruded DC cable system is the latest result of the intensive investment in research and development in the field of HVDC transmission technology. It sets a new world record for extruded HVDC cable technology enabling the integration of renewable power and connecting energy markets.

They said by using cables, efficient power delivery can also be made through densely populated or environmentally sensitive areas. A single pair of 640 kV extruded HVDC cables could, for example, transmit enough green power to supply three million households.

Underground Power Cable: Environment and Health Issues

Power Plant Cooling Tower

Impact of Power Cable Uses in Environmental and Human Health:

Technology changing every day, every moment! High voltage electricity transmission underground cable system also taking over instate of the overhead power line. Though underground high voltage electricity transmission more technically challenging and expensive than installing overhead lines; but to get enough space for an overhead line, especially in an urban area is very difficult now. So, it’s the demand of time for the underground cabling system. Of course, we have to keep in mind the potential impact on the environment and the health of cable installations.

The overhead conductor is more harmful to human and other animals than underground cables.

When a vehicle is parked under a high voltage transmission line an electrostatic field is developed in it. When a person who is grounded touches it a discharge current flows through the human being. In order to avoid this parking, lots are located below the transmission lines the recommended clearance is 17 m for 345 kV and 20 m for  400 kV lines.

EFFECT ON ANIMALS

Many researchers are studying the effect of the Electrostatic field on animals. In order to do so, they keep the cages of animals under a high Electrostatic field of about 30 kV/m. The results of these Experiments are shocking as animals (are kept below high Electrostatic field their body acquires a charge & when they try to drink water, a spark usually jumps from their nose to the grounded Pipe) like Hens are unable to pick up grain because of the chattering of their beaks which also affects their growth. 

EFFECT ON PLANTS

High power transmission lines affect the growth of plants.

Physiological parameter was primarily due to the effect of reduced cell division and cell enlargement.

From various practically study it was found that the response of the crop to EMF from 110 kV and 230 kV Power lines showed variations among themselves. Based on the results the growth characteristics like shoot length, root length, leaf area, leaf fresh weight, specific leaf weight, shoot/root ratio, total biomass content and total water content of the four crop plants were reduced significantly over the control plants.

SHORT TERM HEALTH PROBLEM

• Headaches.
• Fatigue.
• Insomnia.
• Prickling and/or burning skin.
• Rashes.
• Muscle pain

LONG TERM HEALTH PROBLEM

• Risk of damaging DNA.
• Risk of Cancer.
• Risk of Leukemia.
• Risk of Neurodegenerative Disease.
• Risk of Miscarriage.

Insulating in Overhead Power Line and Underground Cable:

Conductors, no matter they are overhead or underground that transmit electricity must be electrically insulated. But there is one major difference between overhead lines and underground cables is the way they are insulated. Overhead lines are insulated by open-air surrounding conductor whereas underground cable conductors are fabricated wrapped in layers of insulating material.  Air insulation is the simplest and free from nature for overhead current-carrying conductor. Air also flow through the bare overhead conductors and remove the produced heat. On the other hand for cable system, conductors are buried into the ground which high-quality insulation is required to withstand the very high voltage. Produced heat dissipation into the environment for underground cable conductor and their surrounding insulation in different installation method is a major issue for impact on nearby flora and fauna.

Technology for Cable Insulation System:

Fluid filled or Gas Insulated Cables: Mainly the first generation cables are fluid-filled, in these cables insulation is provided by paper, impregnated with fluid or insulated oil under pressure, wrapped around the central copper conductor. Lead or Aluminium sheath uses to cover this paper layer and to prevent corrosion of the sheath PVC, MDPE or HDPE outer the jacket is used.

Alternatively gas insulation lines are used for insulation where Aluminium conductors are supported by insulators contained within sealed tubes which are pressurized with a Nitrogen or Sulphur Hexafluoride (SF6) gas to provide the main insulation. The main advantage is that SF6 is a greenhouse gas and the system is cost benefit for sealing end system.

XLPE Insulated Cables: As a result of change and advance in cable technology fluid-filled cables are moving back and XLPE cables are coming at the front everywhere. In these smart cables, the core conductor is insulated by XLPE means Crossed Linked Polyethylene material. It requires less maintenance and no auxiliary fluid equipment to monitor and manage for XLPE cables.

Underground Cable Installation Methods, Requirement and Impact:

For high voltage or extra high voltage underground cable installation mainly three types of method are following:

Direct Buried;

Deep Tunnels;

Surface or Trench.

Direct Buried is the traditional method for high voltage cables installation system where trenches are approximately 1.5m wide and 1.2m deep for each circuit. To maintain the rated current carrying capacity of cable thermally stable backfilling is required with properly graded sand. Space required for cable easement corridor: 20m – 40m, 55m width; Joint bays intervals:  500m – 800m; working space required for join bays, power roller for excavating cable trench, sand bed, backfilling material, handling cable drum in site etc.

Deep Tunnel is generally used in urban locations where direct bury installation would cause unacceptable disruption. Typically 4m and 12m for joint bay diameter depth of a tunnel around 25m to 30m and maintains proper slope to provide free drainage. Two head house buildings order of 16m x 16m x 7m high require for maintenance and for installation of the cables at each end. A cooling and ventilation system and rail-mounted access vehicle is required for emergency exit, inspection, maintenance and repair. River or railway crossing can be made in this system.

Surface or Trench is excavated and is constructed concrete trenches where cables are laid directly within the trench which is capped with reinforced concrete covers laid flush with the ground surface. Surface or trench are used in urban situations or and within the substation compounds needed to take reduced land.

Environmental Impact on Underground Cable Installation:

The major environmental issues associated with the installation of direct buried or cut and cover tunnel cables are the disruption to traffic, noise, vibration, visual intrusion and dust generation and deposition due to the excavation of trenches along the route. Heavy goods vehicle traffic will also be generated by the work, cable crossing major roads, removing spoil and bringing in plant and materials, including backfill, to trenches. About 30m x 80m land area required for each circuit of high voltage cable sealing end compound and a significant space required for a terminal tower construction.

Nearly all installations require joints at specific intervals along the route and joint bays maybe 30m to 40m in length and 5m in width. The majority of the jointing accessory assembling is carried out on site. Sometimes cooling system pipe is laid alongside cable and pumping equipment and heat exchangers are required above ground and these must be sited which cause noise on the locality. Direct buried cable produce heat which harmful for on and near vegetation and insects.

EMFs or Electric and Magnetic Field Effect of Underground Cable:

The conductor which energized or having the presence of voltage there is electric field present surround it, when current flow continues magnetic field also present there surround the conductor, this mainly happens for the overhead electric line. But underground cable able to eliminate its electric field totally as it is screened out by the sheath around the cable; but it still produces magnetic fields. EMFs field strength is stronger to the centre of the field or near to the conductor and gradually weakened at the outer point from the centre. In a general sense overhead line is farther than an underground cable to human, so it should overhead line is safer than an underground cable. However, as the individual cables are installed much closer together than the overhead conductors which result in the magnetic field from cables falling more quickly with distance than the magnetic field from overhead lines. The overall result is that the cable produces a lower field than the overhead line; means the EMFs effect is smaller for underground cable than the overhead line.