Three-phase generator basics – Coil displacement Statement: “A simple three-phase generator consists of three conductive loops separated by 120°.” Is this correct?

Introduction / Context:
Three-phase generation produces three sinusoidal voltages of equal magnitude and frequency, phase-displaced by 120°. Understanding physical coil placement illuminates why the phase displacement is 120° and underpins vector relationships of line and phase quantities in Y and Δ connections.

Given Data / Assumptions:

• Three coils (or coil groups) placed in stator slots of an AC generator.
• Air-gap flux is approximately sinusoidally distributed.
• Mechanical arrangement achieves electrical displacement of 120° between phases.

Concept / Approach:

When three identical coils are placed 120° apart (electrical) and the rotor field sweeps past them, each coil experiences a sinusoidal EMF phase-shifted by 120°. This yields a balanced three-phase set, the foundation for efficient power generation and transmission.

Step-by-Step Solution:

Verification / Alternative check:

Phasor diagrams of a balanced generator show equal magnitudes separated by 120°. Slot/pole combinations in practical machines are chosen to approximate this geometry closely.

Why Other Options Are Wrong:

“False” or “60° separation” contradicts standard three-phase architecture. Δ versus Y affects terminal relationships, not internal coil spacing that sets phase displacement.

Common Pitfalls:

Confusing mechanical degrees with electrical degrees in fractional-slot designs; the fundamental remains a 120° electrical phase separation for three-phase sets.

Final Answer:

True.