Single Phase Shunt Reactor

[gk351]

Hello everyone. Im working at a DoD base in Greenland, and have some questions. They have a 4160V Power Plant that feeds the whole base. There is a remote area of the base (12 miles away) that is fed from the same power plant. They step the 4160v feeder to 69 kv. After the 69 kv Distribution XFMR, it goes through a Air Brake switch, then goes to 3 Single Phase Shunt Reactors. Then out of the reactors to 69kv underground cable, then at the other end, back into the other Distribution XFMR (69kv-4160V) and then into the Medium Voltage switchgear.

I guess I have a few questions. These reactors are loud. I mean a grunting loud. I was curious if this was normal. With an infrared camera, we saw temperatures of upwards of 150 degrees, but the cooling fins seemed to be working properly. We are currently waiting the results of an oil test to determine its di-electric strength.

My next question....What is the purpose of the reactors. I have read that a HV Distribution cable with a small load can produce a significant amount of capacitance. In our case, I wouldn't think our distance, nor the Voltage was high enough to cause this. The feeder circuit has a very small load, btw.

Any help or answers with this would be appreciated.

 

[72.5kv]

On very long transmission lines or in underground high voltage cables shunt reactors are put in to bring keep the voltage down. It is called the Ferrenti Effect. I your case your source voltage maybe 69kV but your receiving voltage could be 80kV. I have seen in one instance on a 500kv line when all the reactors where switched off, the voltage rises nearly 40Kv.

When those reactors are switched in, they are very load. Even in a station with a 500kV transformers, their grunt under load is much loader.

 

[gk351]

I appreciate the info. Well depending on the oil test results I will recommend checking oil levels, record load demand levels, and not any changes. Thanks again.