what is the advantage of 11kv distribution transformer then 6.6kv?

Answer 1

For convenience, let's say that the voltage ratio is 2. Then for a given load in watts at the destination, doubling the distribution voltage reduces the current to half (P = I V).

The voltage drop in the distribution wires is equal to the current times the resistance of the wires (V = I R). Assuming that the same sized wires are used, doubling the distribution voltage reduces the voltage drop to half because the current is cut in half.

As a percentage of the distribution voltage, however, doubling the distribution voltage reduces the voltage drop in the wiring by a factor of 4! This leads to several possibilities:
• You can go 4 times the distance for a given wire size and load, or
• You can reduce the wire size for cost savings.

In practice, you may not be able to reduce the wire size by a factor of four, because the current was only cut in half. Since you have to be concerned about the self heating in the wire due to the current flowing through it, let's assume that the wire size (actually, cross-sectional area) used for the higher voltage is only cut in half to correspond with the current reduction. Then, for a given distance and load, you've got two distinct advantages of using a higher distribution voltage:

(1) The cost of the distribution wires is cut by a factor of nearly two, and
(2) As a percentage of the voltage, the voltage drop in the wiring is reduced by a factor of two. This results in better load regulation at the destination.

Answer 2

Ohms Law:

voltage = current x resistance

therefore;

current = voltage / resistance

Resistance of the conductor remains constant.

If you plotted current vs voltage on a grid you would see that its a square root relationship. A halving of current amounts to a four times decrease in line losses. Line losses represented by the curve you plotted.

In simple terms a higher voltage allows more current through the same conductor.

Answer 3

in regards to the transformer
no advantage over the size since they will both provide about the same load/size ratio (i think)

but 11kV system will provide more power over longer distances

Answer 4

Reducing the amount of current on the transmission lines. Almost doubling the voltage reduces the voltage drop by a factor of almost four

Answer 5

Using higher Voltages to transport energy decreases the amount of energy lost due to resistance. Therefore it is more efficient.

Answer 6

Half the copper.
Lower volt drop.
Less weight used overhead and thinner supports.
Lower snow and ice loading.
Lower cost transformer.
All in all, more cost effective and less waste.

Answer 7

less power loss in transmission, and able to use lighter(smaller diameter) lines due to the decrease in amperage

Answer 8

about 4.4kv