Why Twisted Conductor Used in Transmission Line?

Why Twisted Conductor Used in Transmission Line
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Why Twisted Conductor Used in Transmission Line ? Twisted conductors are used in transmission lines to reduce Electromagnetic radiation and crosstalk, resulting in improved signal transmission quality. Twisting wires cancels out interference and noise, while also enhancing rejection of external electromagnetic interference, thus enhancing signal integrity and reducing potential disruptions.

Why Twisted Conductor Used in Transmission Line

Why Twisted Conductor Used in Transmission Line

Reducing Crosstalk, the Unwanted Chatter

Imagine you’re trying to have a conversation on a busy street. Untwisted transmission lines are like that – the signals from one line can easily interfere with those on another, creating garbled messages. Twisting the conductors is like whispering – the wires change positions constantly, making it harder for crosstalk to eavesdrop.

Shielding from Noisy Neighbors

The world is full of electromagnetic noise, from power lines to radios. Just like unwanted chatter, this noise can disrupt the delicate signals in transmission lines. Twisted conductors act like a shield, averaging out the noise picked up by each wire and keeping the signal clear.

Why Twisted Conductor Used in Transmission Line

Balancing the Current for a Smoother Ride

Think of a seesaw – for it to stay balanced, the weight on each side needs to be equal. Twisted conductors help achieve this balance in electrical circuits. By keeping the currents in the two wires the same and opposite, they ensure a smoother flow of information.

More than Just Talk: Strength in Unity

In windy conditions or on long spans, transmission lines can face some serious stress. Twisting the conductors adds a bit of extra muscle, helping them resist wind and ice loads, and reducing the risk of snapping.

Twisted Pair In Signal Transmission

Twisted conductors are used in transmission lines because they reduce interference and crosstalk, as well as cancel out electromagnetic interference. Compared to a single conductor or an untwisted balanced pair, a twisted pair reduces electromagnetic radiation from the pair and crosstalk between neighboring pairs. It also improves the rejection of external electromagnetic interference. The twisting of the wires helps cancel exterior electromagnetic interference, and by twisting wires that carry an equal and opposite amount of current through them, the interference/noise from one wire is effectively canceled by the interference/noise from the other. Twisting also reduces the strength of noise signals and cancels out external waves by moving a part of the noise in the direction of the signal and another part in the opposite direction.

Why Twisted Conductor Used in Transmission Line

Implementing Twisting In Conducting Cables

To prevent noise, signal interference, and crosstalk during transmissions, twisting is introduced into conducting cables. Twisting reduces the strength of noise signals and cancels out external waves by moving a part of the noise in the direction of the signal and another part in the opposite direction.

FAQ’s

Why transmission cables are twisted?

This usually refers to “twisted pair” cables, not individual conductors in power lines. Twisted pairs are used in telecommunication and data transmission to reduce:

  • Electromagnetic interference (EMI): The twist cancels out noise picked up from external sources like power lines or nearby cables.
  • Crosstalk: Twisting minimizes interference between neighboring pairs of wires within the same cable.

What are twisted pair cables used for?

They’re widely used for:

  • Telephone lines: Traditional landline connections still rely on twisted-pair cables.
  • Ethernet networks: Cat5e and Cat6 cables for connecting computers and networking devices are twisted pairs.
  • Audio and video signals: Microphone and instrument cables often use twisted pairs for clean signal transmission.

Which type of conductor is used in transmission line?

Overhead transmission lines typically use bare conductors made of:

  • Aluminum Conductors, Steel Reinforced (ACSR): This combines the high conductivity of aluminum with the strength of steel for long spans and durability.
  • Aluminum Conductor, Galvanized Steel Reinforced (ACSR/GS): Similar to ACSR, but with an additional galvanized steel layer for increased corrosion resistance.

Why should cables not be twisted?

In power transmission lines, individual conductors shouldn’t be twisted. It doesn’t offer the same benefits as with twisted-pair cables and can cause:

  • Increased corona discharge: Twisting exposes more conductor surface area, leading to energy loss via air ionization.
  • Vibration issues: Twisted conductors might be more susceptible to wind-induced vibrations.

Does twisting wires reduce inductance?

Yes, slightly. Twisting slightly shortens the effective length of the parallel conductors, resulting in a small decrease in inductance. However, this effect is usually negligible in power transmission lines compared to other factors.

Which conductor is best for transmission line?

The “best” conductor depends on various factors like cost, weight, strength, and conductivity. ACSR and ACSR/GS are widely used for their cost-effectiveness and balance of properties.

Which conductor is used for shortest span?

High-conductivity materials like pure copper offer lower resistance, allowing for shorter spans. However, cost and weight often make them impractical for long-distance transmission lines.

What are the 3 types of conductors?

In general, conductors can be categorized based on material:

  • Bare conductors: Uninsulated conductors used for overhead lines, typically made of aluminum, copper, or alloys like ACSR.
  • Insulated conductors: Covered with insulating materials like plastic or rubber for underground or underwater use.
  • Busbars: Thick, rigid conductors used for high-current applications within substations and switchgear.

Why copper conductor is not used for transmission lines?

Although highly conductive, copper is expensive and heavy, making it impractical for long spans and large-scale transmission projects. ACSR and other aluminum-based conductors offer a cost-effective alternative with good conductivity.

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