Real And Reactive Power Calculator

Power Equations:

\[ P = V \times I \times \cos(\phi) \] \[ Q = V \times I \times \sin(\phi) \]

Real Power (P):

Reactive Power (Q):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Real and Reactive Power?

Real power (P) is the actual power consumed by a circuit to perform work, measured in watts (W). Reactive power (Q) is the power that oscillates between the source and load without performing real work, measured in volt-amperes reactive (VAR).

2. How Does the Calculator Work?

The calculator uses the power equations:

\[ P = V \times I \times \cos(\phi) \] \[ Q = V \times I \times \sin(\phi) \]

Where:

\( V \) — Voltage in volts
\( I \) — Current in amps
\( \phi \) — Phase angle between voltage and current in degrees
\( P \) — Real power in watts (W)
\( Q \) — Reactive power in volt-amperes reactive (VAR)

Explanation: The equations calculate the real and reactive components of power in AC circuits based on the voltage, current, and their phase relationship.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for designing electrical systems, determining power factor, sizing components, and optimizing energy efficiency in AC circuits.

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, phase angle between -360 and 360 degrees).

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power (cos φ), representing the efficiency of power usage in a system.

Q2: When is reactive power important?
A: Reactive power is crucial for maintaining voltage levels in transmission systems and for the operation of inductive loads like motors and transformers.

Q3: What does a negative phase angle indicate?
A: A negative phase angle typically indicates a capacitive load, where current leads voltage in the circuit.

Q4: How does power factor affect electrical systems?
A: Low power factor increases current flow for the same real power, leading to higher losses, larger equipment sizing, and potential utility penalties.

Q5: Can this calculator be used for three-phase systems?
A: This calculator is designed for single-phase AC systems. Three-phase calculations require additional factors like the square root of 3 (√3).