8.10 : 线路损耗

Consider a balanced three-wire Y-to-Y circuit represented in the time domain, which can be transformed into a per-phase equivalent circuit.

First, the line current is determined, followed by the phase voltage at the load.

Then, the power delivered by the source is determined using the effective values of the sinusoidal phase voltage and line current.

Next, the power delivered to the load is calculated using the line current and the load resistance.

The power lost in the line is obtained using the line current and the line resistance.

Then, the total power delivered by the three-phase source, the total power received by the three-phase load, and the total power lost in the lines are determined.

A high percentage of power is lost in the line, which can be reduced by minimizing the line current.

However, this would reduce the load current, which would in turn decrease the power delivered to the load.

One way to reduce the line current without affecting the load current is to introduce transformers in the three-phase circuit.