# Three-phase circuits

**Given**

**Find**

Z

_{A}, Z

_{C}(on condition of the currents balance) — ?

U

_{AB},U

_{BC},U

_{CA}— ?

Construct topographic diagram of voltages — ?

Construct vector diagram of currents — ?

## Solution

Find the current in the phase B:

From the condition of the currents balance follows that currents in A and C phases coincide on the module with the current in the phase B and differ from it at 120

^{o}:

Knowing currents and voltages in phases, we find phases resistances:

Write down phase voltages of the system in algebraic form:

Line voltages of the system:

Vector diagram of currents: