What is scientific reason behind skin effect of conductors?

In summary, skin effect of conductors is caused by the exponential decrease of AC current density from the surface, known as skin depth. This is defined by the depth at which current density reaches 1/e of its surface value. The equations for skin depth are based on factors such as resistivity, angular frequency, and absolute magnetic permeability. The increase in inductance and decrease in current lead to the calculation of AC resistance as 1.6 times the DC resistance. The power factor may also be affected by skin effect.
  • #1
djsourabh
69
0
What is scientific reason behind skin effect of conductors?
 
Engineering news on Phys.org
  • #2
djsourabh said:
What is scientific reason behind skin effect of conductors?

Let us know if you still have specific questions after reading this introductory article:

http://en.wikipedia.org/wiki/Skin_effect

.
 
  • #3
The AC current density J in a conductor decreases exponentially from its value at the surface JS according to the depth d from the surface, as follows:

where δ is called the skin depth. The skin depth is thus defined as the depth below the surface of the conductor at which the current density has fallen to 1/e (about 0.37) of JS. In normal cases it is well approximated as:
.
where
ρ = resistivity of the conductor
ω = angular frequency of current = 2π × frequency
μ = absolute magnetic permeability of the conductor

courtesy from wikipedia
how these equations came from?
 
  • #4
berkeman said:
Let us know if you still have specific questions after reading this introductory article:

http://en.wikipedia.org/wiki/Skin_effect

.

The AC current density J in a conductor decreases exponentially from its value at the surface JS according to the depth d from the surface, as follows:

where δ is called the skin depth. The skin depth is thus defined as the depth below the surface of the conductor at which the current density has fallen to 1/e (about 0.37) of JS. In normal cases it is well approximated as:
.
where
ρ = resistivity of the conductor
ω = angular frequency of current = 2π × frequency
μ = absolute magnetic permeability of the conductor

courtesy from wikipedia
how these equations came from?
 
  • #5
But actually the inductance L increases hence current decreases,
then why the ac 'resistance' is calculated as
Rac =1.6*Rdc ?
&
what happens to the power factor?
 

1. What is skin effect in conductors?

The skin effect is a phenomenon where an alternating current (AC) tends to flow only on the surface of a conductor, rather than evenly throughout its cross-section. This is due to the interaction between the AC and the magnetic field it creates, causing a higher concentration of current near the surface of the conductor.

2. What causes skin effect in conductors?

Skin effect is caused by the self-inductance of the conductor, which is a property that resists any change in the current flowing through it. In AC circuits, this self-inductance results in the current being concentrated near the surface of the conductor, where it has the least resistance and can flow more easily.

3. Why does skin effect occur more in high frequency circuits?

The skin effect becomes more pronounced at higher frequencies because the rate of change of the current is greater, leading to a stronger self-inductance effect. This is why skin effect is a more significant factor in high frequency circuits, such as those used in telecommunications and radio frequency applications.

4. How does skin effect affect the performance of conductors?

The skin effect can have several consequences on the performance of conductors. It can increase the resistance of the conductor, leading to power losses and decreased efficiency. It can also cause signal distortions and affect the overall performance of the circuit, especially in high frequency applications.

5. Can skin effect be reduced or eliminated?

Skin effect can be reduced or eliminated by using conductors with larger diameters or multiple strands, which provide more surface area for the current to flow through. Additionally, using conductors with lower resistivity materials, such as copper or silver, can help mitigate the effects of skin effect. In some cases, specialized techniques, such as skin effect correction techniques, can also be used to reduce its impact on circuit performance.

Similar threads

  • Electrical Engineering
Replies
9
Views
1K
  • Electrical Engineering
Replies
6
Views
1K
Replies
36
Views
2K
  • Electrical Engineering
Replies
15
Views
4K
  • Electrical Engineering
Replies
4
Views
2K
  • Electrical Engineering
Replies
8
Views
1K
Replies
12
Views
1K
  • Electrical Engineering
2
Replies
48
Views
5K
  • Electrical Engineering
Replies
10
Views
3K
  • Electromagnetism
Replies
2
Views
650
Back
Top