ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Electrical Transmission and Distribution Systems

Updated on January 6, 2015

The electrical energy is generated at generating station is conveyed to the consumers, through a network of transmission and distribution systems.

Source

Transmission system:

The energy or power can be transferred from a power station to loads (i.e. consumers) is known as transmission.

They are types of transmissions

AC transmissions system

DC transmissions system and

The overhead (OH) lines and underground systems,They are:

  • DC-2 wire system
  • DC-3 wire system
  • AC 1-phase 2 wire system
  • AC 3-phase 3wire system

Over head (OH) system:

The transmission line which is placed above earth surface or the cross arms of towers is known as OH system.

Underground system:

The transmission line placed below the earth (or) ground is known as the underground system.

Components required for the OH lines:

  • Cross arms
  • Earth wires
  • Danger plates
  • Guard wires.etc

  • Towers
  • Conductors
  • Insulators
  • Poles

Towers (or supports):

The conductors are carried from one place to another place by poles with the help of cross arms and insulators.

Types of poles:

  • Wooden poles (upto 20kv)
  • Steel poles (upto 33kv)
  • Reinforced cement concrete ( RCC poles) (upto 11kv)
  • Towers (above 11kv)

Tower: Towers are placed according to the voltage should be transmitted. (Above the 132kv)

Types of Towers:

  • Rigid self supporting lattice towers
  • Semi-flexible towers
  • Flexible towers (guyed tower)

Source

Conductors:

It is one of the most important materials in the transmission and distribution system of electrical power most of capital (money invested). All the conductors are used for OH lines. Generally in a standard conductor there is one centre wire and around, they are successive layers of wires. Therefore, the numbers of individual wires are calculated by the formula is 3n (n+1) +1 where n = 1, 2, 3, 4…

Materials used for conductors:

The most commonly used materials in OH lines are

They are

  • Copper
  • All aluminum standardized conductors (AAC or AASC)
  • Aluminum Conductor Steel Reinforced (ACSR)
  • Galvanized Steel-Cadmium Copper

Among these materials commonly used material is ACSR conductor.

Source

Insulators:

The function of insulator is to provide insulation resistance for the leakage current from OH line to Earth.

Materials used in insulators:

  • Porcelain
  • Glass
  • Steatite
  • Various artificial materials

Different types of Insulators:

  • Pin type Insulators
  • Suspension type
  • Strain type
  • Shackle type

DC transmissions:

The first electrical central station was built by Thomas Alva Edison at Pearl Street in New York. And it was begun in the year of 1882 with operating DC voltage at 110Volts. Nowadays, modern civilization depends on the consumption of electrical energy for agricultural, commercial, domestic and social purpose. The transmission system is called as DC transmission system. It supplies the bulky power transmission over a long distance.

Types of transmission system:

The types of transmission system are depends up on the rating of voltages. They are

  1. High voltage AC transmission (H VAC)- upto 220KV
  2. Extra- High voltage AC transmission (EH VAC)- 220 to 760KV
  3. Ultra- High voltage AC transmission (UH VAC)- above 760KV
  4. High voltage DC transmission (HVDC)- upto 600KV

Principles of HVDC:

It is mainly consists of rectifier (converter) and inverter for converting AC to DC and DC to AC at receiving end and sending end. The role of rectifier and inverter station can be reversed by suitable converter control. It requires mainly converter stations, transformers, AC substation at starting end, smoothing reactors, electrode line, earth electrode, HVDC transmission line, inverter stations etc...

HVDC system which are working condition throughout the world:

1. New Zealand (back to back) - 250KV, 600MW

2. Pacific intertie (US)-400KV, 1600MW

3. Itaipu (Britain)-300KV, 1575 MW

4. Black water (Back to back) (US)-56KV, 200MW

5. Sakuma (back to back) (Japan)-250KV, 300MW

Types of HVDC systems

  1. Mono polar HVDC Transmission system
  2. Bipolar HVDC Transmission system
  3. Homo polar HVDC Transmission system
  4. Back to Back coupling system
  5. Multi terminal HVDC Transmission system

Advantages of AC transmission:

  • Maintenance of ac substation is simple
  • Low voltage can be easily step up or step down by using transformer
  • Electrical power can be generated at high voltages

Advantages of DC transmission:

  • It requires two conductors only
  • There is no losses
  • Easily constructed

Distribution system:

The conductor carries the current or electrical energy is conveyed from a bulk power source (substation) to the consumer or load is called distribution.

There are two types of distribution systems, They are:

1. Primary distribution (high voltages)

2. Secondary distribution (low voltages)

Primary distribution:

It is defined as the power is conveyed for distribution and also to the back to back supply consumers (voltages, 11KV, 6.6KV, 3.3KV Etc..) is known as primary distribution.

Secondary distribution:

It is placed between the primary distribution system and consumers and are supply the power to at different consumers are loads (voltages, 440volts, 230volts) is known as secondary distribution.

Source

Types of distribution systems

Under scheme connection

1. Radial distribution system

2. Ring distribution system

3. Parallel distribution system

4. Inter connection distribution system

Substation:

The inter connection of operates, used for step down or step up voltage for consumer utilized level that place is called substation.

The substation consists of the Transformers, Conductors, Feeders, Relays, Bus bars, Insulators, Fuses, current transformers (CT), potential transformers (PT) etc..

Source

Types of sub stations:

  1. Static sub stations
    • Primary sub station
    • Secondary sub station
    • Distribution system
  2. Indoor sub stations
  3. Outdoor sub stations
    • Pole mounted (11kv/440volts)
    • Plinth mounted (11kv/440volts)
  4. Underground sub stations

Layouts of sub stations:

1.33/11kv sub station

2.132/11kv sub station

© 2015 KALYAN CHAKRAVARTHY THADAKA

Comments

    0 of 8192 characters used
    Post Comment

    No comments yet.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)