Reducing Line Loss

To minimize line losses in three-phase circuits, two transformers are added: a step-up transformer at the source and a step-down transformer at the load.

Their inverse turn ratios ensure consistent load voltage and current.

The left transformer's secondary voltage is tenfold its primary voltage, and the impedance connected to the right transformer's secondary, as seen from the primary, is multiplied by a factor of 100.

Now, replacing the circuit with a single-mesh circuit, the mesh current represents the line current.

The current entering the left transformer's secondary end equals the negative line current, while at the primary, it is ten times the negative secondary current.

Similarly, the current entering the right transformer's primary end equals the line current, while at the secondary end, it is ten times the primary current.

The phase voltage at the load is determined, followed by calculating the power delivered by the source and to the load.

Estimating the power lost in the line reveals that 99.5 percent of the power supplied by the source reaches the load, with only 0.5 percent lost in the line.