삼상 산업용 전력
고강도 산업 시스템을 위한 계산입니다. 모터 및 공장 배전반의 복잡한 √3 벡터 수학을 처리합니다.
산업 구성
삼상 AC
매개변수를 입력하면 결과가 실시간으로 업데이트됩니다.
현재 결과는 선전압 승수(√3 ≈ 1.732)와 시스템 효율 손실을 고려합니다. 모터 FLA 검증에 적합합니다.
삼상 전력 공식
삼상 전력은 동일한 전압과 전류에서 단상보다 73% 더 많은 전력을 전달합니다 — 추가 도체는 단 하나뿐입니다.
유효 전력 (kW)
P = √3 × V × I × PF √3(1.732) 계수는 세 전류 파형 간의 120° 위상 오프셋을 고려하여 일정한 순간 전력 전달을 생성합니다.
피상 전력 (kVA)
S = √3 × V × I 피상 전력은 역률과 관계없이 전원이 제공해야 하는 총 용량입니다. 변압기와 발전기 규격 산정에 사용됩니다.
Understanding Three-Phase AC Power
Three-phase power is the standard for industrial and commercial electrical distribution. It consists of three sinusoidal voltages, each offset by 120°, that together produce a constant, smooth power delivery. This makes three-phase motors smoother and more efficient than single-phase equivalents — and allows a given amount of power to be transmitted with less conductor material.
Why √3 (1.732)?
The three-phase power formula uses the square root of 3 because of the vector relationship between line voltage and phase voltage. In a balanced three-phase system, line-to-line voltage (V_LL) equals √3 times the line-to-neutral phase voltage (V_LN). For example, 208V line-to-line corresponds to 120V phase voltage (208 ÷ 1.732 ≈ 120).
Three-Phase Advantages
- Constant Power Delivery: The three phases sum to a constant total at every instant — unlike single-phase which pulses at twice the supply frequency. This makes motors run smoother with less vibration.
- Higher Power Density: A three-phase system delivers 73% more power than single-phase at the same conductor size and voltage, making it far more economical for large loads.
- Simpler Large Motor Design: Three-phase induction motors have no starting capacitors or split-phase windings — the rotating magnetic field forms naturally from the three phases.
- Lower Neutral Current: In a balanced three-phase system, the neutral conductor carries zero current, saving conductor material in distribution systems.
Common Three-Phase Voltages
- 208V / 120V: US commercial — line-to-line / line-to-neutral. Common in office buildings and light industrial.
- 480V / 277V: US industrial standard. Used for large motors, HVAC, and industrial equipment.
- 400V / 230V: International (IEC) standard across most of Europe, Asia, and Australia.