Impedance Diagram

IMPEDANCE DIAGRAM

The impedance diagram on single-phase basis for use under balanced conditions can be easily drawn from the SLD. The following assumptions are made in obtaining the impedance diagrams.

Assumptions:

1.           The single phase transformer equivalents are shown as ideals with impedance on appropriate side (LV/HV),

2.           The magnetizing reactance of transformers are negligible,

3.           The generators are represented as constant voltage sources with series resistance or reactance,

4. The transmission lines are approximated by their equivalent    -Models,

5.           The loads are assumed to be passive and are represented by a series branch of resistance or reactance and

6.           Since the balanced conditions are assumed, the neutral grounding impedance do not appear in the impedance diagram.

Example system

As per the list of assumptions as above and with reference to the system of figure 2, the impedance diagram can be obtained as shown in figure