Location Of Pfc Capacitor

[subhat]

dear mark

we use 25 kv capacitor banks with 13% detuned reactor for traction application for PF improvement and harmonic filtering. at present these capacitors are provided at traction substation(132/25 kv) which is feeding the traction supply for approx 50 kms line on each side of substation.

is it advisable to provide some capacitor banks at the last end of the traction supply point i.e approx 50 kms. from substation. will there be some advantage if total capacitor bank requirement is distributed alongthe line.

subhat

[marke]

Hello subhat

 

At present, you have 50KM of uncorrected lines. If you correct at the end of these lines, you will reduce the current in thes lines and that will reduce the i2r losses in the lines. (this assumes that the power factor at the end of the lines is low)

If you are paying for power at the traction substation, then the i2r losses will be increaing the KWHr costs. The length of the lines could result in reaonable losses and potential savings. Additionally, you will be able to increase the loading on the lines.

 

The effect of correcting at the end of the lines, will be a reduction in KWHrs lost, and an increase in the voltage at the end of the lines. some load, such as induction motors will reduce the current draw if the voltage increases which will further reduce the copper losses in the lines.

 

The major disadvantage of correcting at the end of the lines, is the potential of line resonances. You would need to control the capacitors such that they were not connected when the load was light.

 

Best regards,