kVA kW kVAr Formula

kVA Calculation Formula:

\[ kVA = \sqrt{P_{kW}^2 + kVAr^2} \]

Apparent Power (kVA):

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1. What is the kVA kW kVAr Formula?

Definition: This formula calculates the apparent power (kVA) in a 3-phase electrical system based on the real power (kW) and reactive power (kVAr).

Purpose: It helps electrical engineers and technicians understand the relationship between different power components in AC circuits.

2. How Does the Formula Work?

The formula is based on the power triangle:

\[ kVA = \sqrt{kW^2 + kVAr^2} \]

Where:

\( kVA \) — Apparent power (kilovolt-amperes)
\( kW \) — Real power (kilowatts)
\( kVAr \) — Reactive power (kilovolt-amperes reactive)

Explanation: The apparent power is the vector sum of real power (which does actual work) and reactive power (which sustains electromagnetic fields).

3. Importance of Power Calculation

Details: Understanding these relationships is crucial for proper sizing of electrical equipment, power factor correction, and efficient power system design.

4. Using the Calculator

Tips: Enter the real power (kW) and reactive power (kVAr) values. Both values must be ≥ 0. The calculator will compute the apparent power (kVA).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between kW, kVA, and kVAr?
A: kW is real power, kVA is apparent power, and kVAr is reactive power. They form the sides of the power triangle.

Q2: How is power factor related to this formula?
A: Power factor (PF) = kW/kVA. It represents the ratio of real power to apparent power.

Q3: What's a typical power factor value?
A: Industrial systems typically aim for 0.85-0.95. A PF of 1 means all power is real power (no reactive power).

Q4: Can kVAr be greater than kVA?
A: No, kVAr is always ≤ kVA since it's one component of the apparent power.

Q5: How do I improve power factor?
A: By adding capacitors to reduce reactive power (kVAr) while maintaining the same real power (kW).