1. What is Active Power?

Active power (real power) is the actual power consumed by electrical equipment to perform work, measured in watts (W). It represents the useful power transferred from source to load in an AC circuit.

2. How Does the Calculator Work?

The calculator uses the active power formula:

Where:

• \( P \) — Active power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)
• \( PF \) — Power factor (unitless, between 0 and 1)

Explanation: The formula accounts for both the magnitude of voltage and current, as well as the phase difference between them through the power factor.

3. Importance of Power Factor

Details: Power factor represents the efficiency of power usage. A PF of 1 means all power is active power (ideal resistive load). Lower PF indicates reactive power component, which doesn't perform useful work but increases current flow.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (between 0 and 1). All values must be valid (voltage > 0, current > 0, 0 ≤ PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between active, reactive and apparent power?
A: Active power (W) does useful work, reactive power (VAR) sustains electromagnetic fields, and apparent power (VA) is the vector sum of both.

Q2: What causes low power factor?
A: Inductive loads (motors, transformers) and nonlinear loads (electronics) typically cause low power factor.

Q3: How can power factor be improved?
A: Power factor correction capacitors, synchronous condensers, or active PFC circuits can improve power factor.

Q4: What's a typical power factor value?
A: Industrial facilities: 0.8-0.95, homes: 0.9-1.0. Pure resistive loads have PF=1.

Q5: Why is power factor important?
A: Utilities often charge penalties for low power factor as it increases current for same active power, requiring larger infrastructure.