How To Calculate True Power

True Power Formula:

\[ P = V \times I \times \cos(\theta) \]

True Power (P):

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1. What is True Power?

True power (also known as real power) is the actual power consumed by a circuit to perform useful work. It is measured in watts (W) and represents the energy that is converted into useful output such as heat, light, or mechanical work.

2. How Does the Calculator Work?

The calculator uses the true power formula:

\[ P = V \times I \times \cos(\theta) \]

Where:

\( P \) — True power (watts)
\( V \) — Voltage (volts)
\( I \) — Current (amps)
\( \theta \) — Phase angle between voltage and current (degrees)
\( \cos(\theta) \) — Power factor

Explanation: The formula calculates the actual power consumed in an AC circuit by accounting for the phase difference between voltage and current through the power factor (cosθ).

3. Importance of True Power Calculation

Details: Calculating true power is essential for determining the actual energy consumption in electrical systems, designing efficient power systems, calculating electricity costs, and ensuring proper sizing of electrical components.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, and phase angle in degrees. All values must be valid (voltage > 0, current > 0, angle between -360 and 360 degrees).

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between true power and apparent power?
A: True power is the actual power consumed, while apparent power is the product of voltage and current without considering the power factor. Apparent power is measured in volt-amperes (VA).

Q2: What does the power factor represent?
A: The power factor (cosθ) represents the ratio of true power to apparent power. It indicates how effectively electrical power is being converted into useful work.

Q3: When is the power factor equal to 1?
A: The power factor equals 1 when the voltage and current are in phase (θ = 0°), which occurs in purely resistive circuits.

Q4: What causes a low power factor?
A: A low power factor is typically caused by inductive loads (motors, transformers) that create a phase difference between voltage and current.

Q5: Why is true power important for energy billing?
A: Utility companies typically bill based on true power consumption (kWh) rather than apparent power, as it represents the actual energy used to perform work.