Eddy Current ( advantage and disadvantage)  and its Application 

whenever  a magnetic flux linked with a conducting material circuit changes, a voltage is induced in it. consider a solid iron core which a time varying flux in it linked .This core is may be made up of concentric shells. Each shells may be treated as a closed coil and is linked with some portion of the flux. 

Hence , a voltage induced in the coil which causes a current to flow in it's closed shell. such current which does not flow in any clearly defined  path is called Eaddy Current.  Heat is generated due to the eddy currents through the core .and power loss due to this current loss is called Eaddy Current Loss

Eddy current figure 

The Eaddy Current loss per unit volume of magnetic core which are time-varying flux is given.

                           
      where , Bm = maximum flux density
                        f = frequency of excitation
                        t= thickness of core
                      ρ = Resistivity of the core material

Application of eddy current

• Eddy current breaking is used in induction energy meters.

• Eddy current heating is used for heating metals. for example melting and other heat treatment.

Advantage of eddy current

• This is not contact inspection process which does not affect the work.

• Used in speedometer

• This process is used for inspection

• Also used in an induction furnace process

Disadvantage of eddy current

•  Heat losses is more

• 2. complex design its means inspection is more difficulties and not accurate

• 3.  There is more leakage of  flux occurred in it

• 4.  It Minimize  the efficiency by increasing temperature

• 5.  In increases the power loss by increasing temperature in transformer core