What does surge impedance mean?

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.

What is SIL surge impedance loading?

SIL is defined as the maximum load (at unity power factor) that can delivered by the transmission line when the loads terminates with the value equal to surge impedance (Zs) of line. Simply if any line terminates with surge impedance then the corresponding loading in MW is known as Surge Impedance loading (SIL).

What is the range of surge impedance?

about 400 ohms
An impedance which renders the line as the infinite line is known as surge impedance. It has a value of about 400 ohms and phase angle varying from 0 to -15 degrees for overhead lines and around 40 ohms for underground cables.

What is the significance of surge impedance loading?

The significance of surge impedance is that if a pure resistance load that is equal to the surge impedance is connected to the end of line with no resistance, a voltage surge introduced by the shunt capacitor to the sending end of the line would be completely absorbed by the series inductance at the receiving end of the transmission line.

How does surge impedance effect on transmittion line?

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.

What is surge impedence?

The characteristic impedance or surge impedance (usually written Z0) of a uniform transmission line is the ratio of the amplitudes of voltage and current of a single wave propagating along the line; that is, a wave travelling in one direction in the absence of reflections in the other direction.

What are the characteristics of transmission line?

Characteristics The voltage standing wave ratio of the open circuited transmission line is infinity. The magnitude of voltage reflection co-efficient is one. The phase angle of voltage reflection co-efficient for the open circuited transmission line is in phase. The first node of maximum voltage is at λ/2.