1. What is AC Electrical Power?

AC electrical power refers to the rate at which electrical energy is transferred by an alternating current circuit. In AC systems, the power calculation must account for the phase difference between voltage and current, represented by the power factor (cos φ).

2. How Does the Calculator Work?

The calculator uses the AC power formula:

Where:

• \( P \) — Real power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)
• \( \cos \phi \) — Power factor (dimensionless, 0-1)

Explanation: The formula calculates real power, which is the actual power consumed by the load and converted into useful work.

3. Importance of Power Factor

Details: Power factor represents the efficiency of power usage in AC circuits. A power factor of 1 indicates perfect efficiency, while lower values indicate poor power utilization and increased reactive power.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor as a decimal between 0 and 1. All values must be positive, with power factor ranging from 0 to 1.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between real power and apparent power?
A: Real power (P) is the actual power consumed, while apparent power (S = V×I) includes both real and reactive power. Power factor = P/S.

Q2: What causes low power factor?
A: Inductive loads like motors, transformers, and fluorescent lighting cause current to lag voltage, resulting in lower power factor.

Q3: How can power factor be improved?
A: Power factor correction capacitors can be added to counteract inductive reactance and bring power factor closer to 1.

Q4: What are typical power factor values?
A: Residential: 0.85-0.95, Industrial: 0.7-0.9, Pure resistive load: 1.0, Induction motor at full load: 0.85-0.9.

Q5: Why is power factor important for utilities?
A: Utilities often charge penalties for low power factor because it increases transmission losses and requires larger equipment capacity.