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Kva Reactive

Reference data and engineering information about kva reactive for electrical applications.

kvareactive

Overview

Engineering reference data for Kva Reactive in electrical engineering.

Key Formulas

Ohm's Law

V=IRV = IR

Voltage = Current × Resistance.

Power

P=VI=I2R=V2/RP = VI = I^2R = V^2/R

Electrical power.

Energy

E=PtE = Pt

Energy = Power × Time.

Variables

Symbol Description Unit
VV Voltage V
II Current A
RR Resistance Ω
PP Power W

Apparent Power Definition

Apparent power (S) is the total power supplied to an electrical circuit, encompassing both the real work done (active power) and the power stored and returned by reactive components. It represents the vector sum of active and reactive power and is measured in volt-amperes (VA).

Detailed Formulas

The relationship between apparent, active, and reactive power follows a Pythagorean triangle:

S=Q2+P2S = \sqrt{Q^2 + P^2}

Single-Phase Circuits: S=U⋅IS = U \cdot I

Three-Phase Circuits: S=3⋅U⋅I=1.732⋅U⋅IS = \sqrt{3} \cdot U \cdot I = 1.732 \cdot U \cdot I

Active Power (P): Single-Phase: P=U⋅I⋅cos⁡(ϕ)=U⋅I⋅PFP = U \cdot I \cdot \cos(\phi) = U \cdot I \cdot PF Three-Phase: P=3⋅U⋅I⋅cos⁡(ϕ)=1.732⋅U⋅I⋅PFP = \sqrt{3} \cdot U \cdot I \cdot \cos(\phi) = 1.732 \cdot U \cdot I \cdot PF Direct Current: P=U⋅IP = U \cdot I

Reactive Power (Q): Single-Phase: Q=U⋅I⋅sin⁡(ϕ)Q = U \cdot I \cdot \sin(\phi) Three-Phase: Q=3⋅U⋅I⋅sin⁡(ϕ)=1.732⋅U⋅I⋅sin⁡(ϕ)Q = \sqrt{3} \cdot U \cdot I \cdot \sin(\phi) = 1.732 \cdot U \cdot I \cdot \sin(\phi)

Component Explanations

Active Power (P): Also known as real or true power, this is the power that performs actual work in the load. It is measured in watts (W) and is consumed by the resistive elements of the circuit. When voltage and current are in phase, the power factor (PF) equals 1.

Reactive Power (Q): This is the imaginary power consumed by reactive elements like inductors and capacitors. It represents an energy exchange between the source and the load, with no net power consumed over a full cycle. It is measured in volt-amperes reactive (VAR).

Power Factor Impact: Reactive power should be minimized because it increases the total current in the circuit, leading to higher losses (I2RI^2R) in the power lines without performing useful work. This increased reactive current causes the apparent power to rise and the power factor to decrease.

References