What is SIL in power system? Abstract: In electric power systems, good electric power transmission is vital to occupy the load requirements. Power transmission capacity on transmission lines restricted by Surge Impedance Loading (SIL). When

## What is SIL in power system?

Abstract: In electric power systems, good electric power transmission is vital to occupy the load requirements. Power transmission capacity on transmission lines restricted by Surge Impedance Loading (SIL). When the transmission line loaded at its SIL value, then the transmission line will be purely resistive.

## What is the surge impedance loading of 400 kV line?

200 Ω

Surge impedance of Phase, 400 kV transmission line is 200 Ω.

**Why is it called surge impedance?**

Surge Impedance is the characteristic impedance of a lossless transmission line. It is also called Natural Impedance because this impedance has nothing to do with load impedance. Since line is assumed to be lossless, this means that series resistance and shunt conductance is negligible i.e. zero for power lines.

**Why surge impedance loading is important?**

Surge Impedance Loading is a very essential parameter when it comes to the study of power systems as it is used in the prediction of maximum loading capacity of transmission lines.

### What is the use of surge impedance?

### What is the difference between surge impedance and characteristic impedance?

Characteristics impedance = sq rt(Z/Y). The characteristics impedance is calculated for the transmission line with losses. The term Surge impedance is reserved for the special case of loss less line. For the loss less line the resistance(R) and conductance(G) are zero.

**Which is the best definition of surge impedance loading?**

Surge impedance loading or the natural loading of the line is defined as the load that can be delivered by a line having no resistance (loss-less line). Where the loading is driven at unity power factor.

**What happens when surge impedance is less than SIL?**

Surge impedance loading depends on the voltage of the transmission line. Practically surge impedance loading always less than the maximum loading capacity of the line. If the load is less than the SIL, reactive volt-amperes are generated, and the voltage at the receiving end is greater than the sending end voltage.

## How is surge impedance related to series inductor?

The above quantity has a dimension of resistance is known as Surge impedance of the line. When a purely resistive load of value equal to surge impedance is connected at the receiving end of the line, then the reactive power generated by the shunt capacitor will be completely absorbed by the series inductor of the transmission line.

## When to use SIL or characteristics impedance loading?

Hence SIL or surge impedance loading is the power delivered by the line when the line is terminated by the surge impedance (Z 0) or characteristics impedance (Z C) of the line. The expression of SIL gives the maximum power that can be delivered by a line. This expression is useful in designing transmission lines.