overvolages in long distance T/lines

1. Connect more load
2. Reduce supply voltage

my question was for overvoltage on long distance tranmission lines operating on no Load.

The answer is the same.

Not trying to be a wise guy, but if there's no load, then one could save a lot of money by not installing long transmission lines.

What is the voltage at the source to the lines and what is the voltage at the end of the lines?

Is there a capacitor bank at the end of the lines?

What do the lines provide power to? Was there a load on these lines at one time that has since been removed?

Long distance T/Lines are used usually Transmitting Energy from Remote generating stations to the load centres at Extr High Voltage; like 500Kv, 220Kv. If the load centre is Isolated under fault conditions, the line would be operating at no Load resulting thereby overvoltage at the recieving end and also at the Bus Bar,which may cause damage to the connecting equipment. The phenominon is termed as the Ferrante Effect, which is overcome by use of Shunt Reactors which compensates the capacive effect of the Transmission Line operating at No Load. Further input is welcomed.

Long distance T/Lines are used usually Transmitting Energy from Remote generating stations to the load centres at Extr High Voltage; like 500Kv, 220Kv. If the load centre is Isolated under fault conditions, the line would be operating at no Load resulting thereby overvoltage at the recieving end and also at the Bus Bar,which may cause damage to the connecting equipment. The phenominon is termed as the Ferrante Effect, which is overcome by use of Shunt Reactors which compensates the capacive effect of the Transmission Line operating at No Load. Further input is welcomed.

"The phenominon is termed as the Ferrante Effect, which is overcome by use of Shunt Reactors which compensates the capacive effect of the Transmission Line operating at No Load."

Are the reactors inserted at the end of the T/lines as a load or are they placed between the lines and earth ground in parallel with the line capacitance?

The shunt reactors are inserted at the recieving end not as a load, but they being shunt reactors connected with the line through a bus bar, which serves as load when the actual load centre is isolated from the line any way.

Inayat, I have never found a satisfactory solution to Ferranti rise. I have heard that static voltage compensators exist which will work to reduce voltage (produce lagging VARS), and the design is supposed to be similar to the more common systems to add capacitance. However, I've never been able to actually find a manufacturer. I usually just specify the receiving end components to have a higher maximum voltage (typically 150% of nominal line voltage).

For those unfamiliar with the Ferranti Effect, this presentation provides a good explanation.

Shunt reactors are usually used to overcome such a problem. However, it is not necessary to be connected at the receiving end of the transmission line.

For example, a very famous reactor was installed in a location called Nag3 Hammady in Egypt on a line of 500KV between Aswan and Cairo. Nag3 Hammady lies in the first third portion from Aswan. (Aswan-Cairo = 1000km).

The reason this reactor is very famous for old electrical engineers in Egypt is that it was destroyed during war of attrition by means of Israel air-force, resulting in rising the receiving voltage in Cairo to unacceptable limits.

Samak

Reduce the main source of transients in the system

Switching

Compensating for a poor planned system will cause more problems in the long run.

Regards.

My reply to Posts #6, 8 & 9
We in Communication call it:
Source [Generator], Sink [Load], Transmission Lines as in Electricity [Conveying Media]
Stub [Termination of Vacant node @ Zo] No node be kept off-load
If the Sink is open or Short-circuited high-Signals will develop at NODEs @ Lambda/4, Lambda/2
etc etc.
These are called Reflections due Mismatch of Source & Sink, as in Maximum Transfer-Theorem Max Power will only be transferred if Sink's Impedance [zo] is = to Source impedance [Zin] but opposite in phase Zo = (-)Zin, which means that load should dissipate [not react]

I think that all the theorems & Laws are LAWs [not just good things].

Sometimes back in a discussion on Power Transmission-Lines in CR4, I pointed out to some colleague that SKIN-EFFECT is not important at Power frequencies 50/60 Hz to which he briefed that "SKIN-EFFECT" is as important in Power Transmission as these are in Hi-Frequency Communication.

Thanks for the gentle-man who made it clear that LAWs are every-where LAWs & we have to abide them