Overview

As we have discussed earlier in Chapter 1 that the transmission line parameters include series resistance and inductance and shunt capacitance. In this chapter we shall discuss the various models of the line. The line models are classified by their length. These classifications are

• Short line approximation for lines that are less than 80 km long.
• Medium line approximation for lines whose lengths are between 80 km to 250 km.
• Long line model for lines that are longer than 250 km.

These models will be discussed in this chapter. However before that let us introduce the ABCD parameters that are used for relating the sending end voltage and current to the receiving end voltage and currents.