There is a requirement to transmit 460 Hertz, 6000V ac supply over a distance of 7 km by a cable. So the output of the frequency convertor which is 460 Hz, 360 V is connected to a step up transformer is subsequntly connected to the high voltage cable of 6000 meters length. When the tail is open circuited, the cable draws a capacitive current of around 10 Amperes at 6000 Volts. Due to this the temperature of the frequency convertor is very sharp and trips due to overtemperature within a few minutes. It seems switching capacitive load is the main problem. Can any one suggest how to overcome the problem?

Kind regards,

N.Vedachalam,
India.

 

Consider open wire lines. This, by the way, is why such low frequencies are used for power transmission. You might try tuning the length to alter the reactance seen at the source but, 1 wavelength is about 650 km. so it's a safe bet it's going to stay capacitive. I can't think of anything offhand that wouldn't involve wasting huge amounts of power or generating extremely high voltages. One solution might be to decouple the line at the head end when the load is removed.

Regards

cww

 

I think it is better to use a high speed breaker at the head end to cut off the circuit immediately it detects inrush of capacitive current due to open at the tail end. Long distance transmission at 460 Hz will definitely lead to capacitive effect and you can not avoid the problem in a simple way.

Regards

A.Thakur