The impedances of the equivalent circuit in any node are calculated using line-to-line voltages and line currents. This equivalent circuit incorporates all energetic phenomena, including the unbalance of all downstream loads.

The system is unbalanced, and I can only measure the line currents (I1, I2 & I3) and line-neutral voltages using an energy meter. The neutral current isn't measured directly. My main goal is to calculate the total power consumed by the entire system, which includes both the star and delta loads.

If we are dealing with a three-phase system which doesn’t have a neutral line, we can still use mesh analysis to find line currents I a, I b, and I c. This includes the delta-star, star-delta, and delta-delta three-phase (and three-wire) system.

Abstract: For analysis of three-wire three-phase linear systems, the transformations wye-delta and delta-wye from theorem of Kennelly are used. These transformations can be applied to balanced systems but not to unbalanced systems.

circuits - balanced, unbalanced, three wire, four wire, wye and delta circuits. The course is arranged so that power values may be determined from calculations or measurements and from either phase parameters or line