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Basic Theory

Three-Phase AC

Three-Phase AC Definition Composed of three AC sources with same frequency and phases 120° apart. Connection Methods Star Connection (Y) Delta Connection (△) Po…

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Three phaseWyeDeltaIndustrial power

Three-Phase AC

Definition

Composed of three AC sources with same frequency and phases 120° apart.

Connection Methods

Star Connection (Y)

Line voltage = √3 × Phase voltage
Line current = Phase current

Delta Connection (△)

Line voltage = Phase voltage
Line current = √3 × Phase current

Power Calculation

P = √3 × U × I × cos(φ)

Phase Sequence

A-B-C-A (Positive sequence)

A-C-B-A (Negative sequence)