Single-Phase and Three-Phase Power Calculation Formulas
Single-Phase and Three-Phase Power Calculation Formulas
1. Single-Phase DC Circuit
- Voltage: V = I × R
- Current: I = V / R
- Resistance: R = V / I
- Power: P = V × I
2. Single-Phase AC Circuit
- Active Power: P = V × I × cos φ
- Current: I = P / (V × cos φ)
- Voltage: V = P / (I × cos φ)
3. Three-Phase Motor
- Active Power: P = √3 × V × I × cos φ
- Current: I = P / (√3 × V × cos φ)
- Voltage: V = P / (√3 × I × cos φ)
4. Three-Phase Transformer
- Capacity: kVA = (√3 × V × I) / 1000
- Primary Current: Ip = (kVA × 1000) / (√3 × Vp)
- Secondary Current: Is = (kVA × 1000) / (√3 × Vs)
- Active Power: kW = (√3 × V × I × cos φ) / 1000
Where: V = Voltage, I = Current, R = Resistance, P = Power, cos φ = Power Factor, and √3 = 1.732.