Calculation of active power
Active power, also known as real power, is the portion of electrical power that performs useful work in a circuit—such as producing heat, light, or mechanical motion. Measured in watts (W) or kilowatts (kW), it represents the actual energy consumed by a load and is the basis for electricity billing. This tool calculates active power based on voltage, current, power factor, apparent power, reactive power, resistance, or impedance. It supports both single-phase and three-phase systems, making it ideal for motors, lighting, transformers, and industrial equipment. Parameter Description Parameter Description Current Type Select circuit type: • Direct Current (DC): Constant flow from positive to negative pole • Single-phase AC: One live conductor (phase) + neutral • Two-phase AC: Two phase conductors, optionally with neutral • Three-phase AC: Three phase conductors; four-wire system includes neutral Voltage Electric potential difference between two points. • Single-phase: Enter **Phase-Neutral voltage** • Two-phase / Three-phase: Enter **Phase-Phase voltage** Current Flow of electric charge through a material, unit: Amperes (A) Power Factor Ratio of active power to apparent power, indicating efficiency. Value between 0 and 1. Ideal value: 1.0 Apparent Power Product of RMS voltage and current, representing total power supplied. Unit: Volt-Ampere (VA) Reactive Power Energy alternately flowing in inductive/capacitive components without conversion to other forms. Unit: VAR (Volt-Ampere Reactive) Resistance Opposition to DC current flow, unit: Ohm (Ω) Impedance Total opposition to AC current, including resistance, inductance, and capacitance. Unit: Ohm (Ω) Calculation Principle The general formula for active power is: P = V × I × cosφ Where: - P: Active power (W) - V: Voltage (V) - I: Current (A) - cosφ: Power factor Other common formulas: P = S × cosφ P = Q / tanφ P = I² × R P = V² / R Example: If voltage is 230V, current is 10A, and power factor is 0.8, then active power is: P = 230 × 10 × 0.8 = 1840 W Usage Recommendations Monitor active power regularly to assess equipment efficiency Use data from energy meters to analyze consumption patterns and optimize usage Consider harmonic distortion when dealing with nonlinear loads (e.g., VFDs, LED drivers) Active power is the basis for electricity billing, especially under time-of-use pricing schemes Combine with power factor correction to improve overall energy efficiency