This simulator draws the heart of three-phase power: three sinusoidal voltages of the same size and frequency, each offset by 120 electrical degrees. A rotating phasor diagram and three sine waves run side by side so you can see that each phasor tip is the same thing as a point on its wave. A wye/delta switch and two sliders then show how the source configuration, phase voltage and frequency set what you would measure on the lines.
• A rotating phasor diagram with three colored phasors (L1, L2, L3) and a neutral point, plus a wye or delta label. • Three sine waves that scroll with the phasors, with a dot on each wave marking the phasor it belongs to. • A Wye (Y) / Delta (Δ) selector, a phase-voltage slider (60-480 V) and a frequency slider (45-65 Hz). • Readouts for phase voltage, line voltage, frequency and configuration, plus expandable notes, formulas and a worked example.
Three windings spaced 120 degrees apart in a generator produce voltages that add to zero at every instant. That is what lets a balanced three-phase system move power over three conductors (or four with a neutral) instead of the six that three independent single-phase circuits would need. The same spacing also makes the total instantaneous power of a balanced load constant, rather than pulsing twice per cycle like single-phase power.
In a wye source each winding runs from a common neutral to a line, so the line-to-line voltage is the vector difference of two phase voltages and equals √3 times the phase voltage. In a delta source the windings connect end to end around a loop with no neutral, so each winding sits directly between two lines and the line voltage equals the phase voltage. With 120 V phase windings, a wye system gives about 208 V line-to-line.
Three evenly spaced windings divide the 360-degree cycle into three equal parts. The resulting voltages sum to zero at every instant, so a balanced three-phase system needs fewer conductors than three separate single-phase circuits and delivers smooth, constant power to a balanced load.
In a wye connection the line-to-line voltage equals the phase voltage multiplied by the square root of three, about 1.732. A 120 V phase voltage therefore produces roughly 208 V between any two lines, which is the simulator's default reading when wye is selected.
The delta selector uses the delta relationship, where each winding connects directly between two lines, so the line voltage equals the phase voltage. The phasor picture stays the same; what changes is the line-voltage readout and the configuration label.
No. It shows an ideal, balanced three-phase source with equal amplitudes and exact 120-degree spacing. It does not model unbalanced loads, neutral current, harmonics or faults. See the Wye vs. Delta Systems lab for loaded wye and delta circuits.