from in the arc increases more than proportional

from the figure it is evident that energy in the arc
increases more than proportional to the increase in current.This is because of
the fact that as current increases electrode erosion increases thus arc length
also increases and hence arc energy will increase.Al electrode has a steeper
increase in arc energy compared to Cu electrode,it is because in Al electrode,
erosion is more compared to Cu electrode.From few test conducted we could
obtain an equation using quadratic regression, this is only valid within limits
of experimental setup.

 

From figure we can observe that energy in the arc
increases linearly with initial electrode gap.The equation defining this result
can be obtained by linear regression.Since few test cases were used for
defining equation ,it is only valid within limits of experimental setup.If electrode
gap is reduced below 17mm then arc energy will deviate from its linearity and
move towards zero.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

 

Experimental

A cubic container of volume Vp=0.343 m3
,corresponding to the size of typical medium voltage SF6 switch gear was
considered as full scale prototype.This container was made out of 4mm thick welded
steel plates to prevent repture due to pressure rise.As per IEC62270-200 air
replaces SF6 during testing condition so container is filled with air at
atmospheric pressure.

Similar to the prototype container, two small scale
containers were also made with a scaling factor of 1/3 and 1/10 aproximately.Volumes
of the scaled model were

Model 1 :Vm1=0.118 m3= 1/3 Vp

Model 2 :Vm2=0.0359m3=1/10Vp

Pressure relief discs with a relative burst pressure
pburst =1.6 bar was used for the testing.Discs had a opening of 110mm
diameter.Since pressure rise inside the compartment is not dependent on size of
discs, same discs were used in all compartments.Prototype compartment had two
discs to ensure that pressure rise does not damage the compartment.

  

x

Hi!
I'm Simon!

Would you like to get a custom essay? How about receiving a customized one?

Check it out