MV RC Snubber Circuit

[YGOK]

In MV system (Operating Voltage:31.5kV), we are planning to energize the Shunt Reactor (800kVAr) with SF6 Circuit Breaker.

To suppress overvoltage, we will use RC Snubber circuit in front of the Reactor.

Resistor: 50ohm (5000W)

Surge Capacitor: 22kV-0.4 mikroF-60.8kVAr (2 in series)

Normally, the circuit design of RC is that First Resistor is energized then Capacitor is connected to neutral-ground.

If we change the circuit connection to First Capacitor is energized then resistor is conencted to neutral-ground.

What will happen?

For example:

*Resistor will not effectively damp the overvoltage?

*Capacitor will have the risk of high oscillation overvoltage? (May be the result in insulation failure)

*RC circuit will not complete its job in good performance?

Thanks,

 

[7anoter4]

In my opinion, the high-voltage lightning wave could have a 200 kHz component then if the amplitude of this component will not be more than the rated[31.5 kV] then the capacitor potential with respect to ground will get up to 31.5/sqrt(3) instead of 0-1.5 kV if the capacitor will be grounded.
At power frequency the voltage drop on the resistor will be negligible then the order of R and C it is not important.

 

[YGOK]

What I wonder that Resistor in Snubber Circuit will damp the high frequency oscillation with DC off-set.

If we use the capacitor in front of the resistor, can we damp the oscillation?