Definition

From the SLD, it is simple to draw the impedance diagram for single-phase operation under balanced conditions. The impedance diagrams are generated under the following presumptions.

Resistance and reactance together make up impedance. Everything and anything that prevents electrons from moving freely within an electrical circuit is essentially considered to be an obstruction. So it has an impact on the electrical circuit’s ability to generate current. It can be found throughout all conceivable electrical circuits and in every circuit component.

Assumptions:

1. The idealised single phase transformer equivalents are depicted with the appropriate side’s impedance (LV/HV).
2. Transformers’ magnetizing reactance is minimal.
3. In this diagram, the generators are shown as sources of constant voltage with series resistance or reactance.
4. The equivalent models are used to approximate the gearbox lines.
5. The loads are depicted by a series branch of resistance or reactance and are assumed to be passive.
6. The neutral grounding impedance is not shown in the impedance diagrams because balanced conditions are assumed.

Example – The impedance diagram shown in figure can be obtained using the above list of assumptions and the system in figure 2.