surge_arrester
Electrical
Hello,
I'm studying IEEE C62.22 and found the equation below to conservatively calculate the energy discharged by the surge arrester:
J = 2*D*Ea*Ia/v
Where:
Ea = arrester switching impulse discharge voltage in kV
Ia = switching impulse current in kA
D = line length in km
v = speed of light
There is another equation which states that
Ia = (Es - Ea)/Z
Where
Es = prospective switching surge voltage in kV
Z = surge impedance of the line in ohms
Are Ea and Ia values obtained from the surge arrester manufacturer's data? If yes, what's the purpose of the equation to solve for Ia?
I'm studying IEEE C62.22 and found the equation below to conservatively calculate the energy discharged by the surge arrester:
J = 2*D*Ea*Ia/v
Where:
Ea = arrester switching impulse discharge voltage in kV
Ia = switching impulse current in kA
D = line length in km
v = speed of light
There is another equation which states that
Ia = (Es - Ea)/Z
Where
Es = prospective switching surge voltage in kV
Z = surge impedance of the line in ohms
Are Ea and Ia values obtained from the surge arrester manufacturer's data? If yes, what's the purpose of the equation to solve for Ia?