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Relation Between KVA and KW

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Last updated date: 17th Apr 2024
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Understand kVA kW Relation

KiloVolt-Amperes in short kVA is the unit estimating evident power and KiloWatt in short kW is the unit estimating real power. The connection between kVA and kW are corresponding. kW is the measure of 'actual power' an electrical framework has. This gives you how much power is being changed over into an effective, working yield. kVA, then again is the proportion of 'apparent' power. If kW is the amount of force you can work with, kVA reveals to you the amount that is being used in the framework by and large. On the off chance that the productivity of an electrical framework is excellent, at that point kW would be equivalent to kVA. 


kW to kVA Formula

In the kW to kVA calculations, the kW to kVA conversion formula is -


kW = kVA × PF


Where,


kW is the unit estimating real power.


kVA is the unit estimating apparent power.


PF is the Power Factor.


In the kW to kVA conversion, kW is directly relative to kVA, which implies that-


When kW increments, kVA will increment.


When kW declines, kVA will diminish.


When kVA declines, kW will diminish.


When kVA increments, kW will increment.


In mathematical terms, we can write it as:


kW = kVA x PF


kVA to kW Calculations

The conversion of kVA to kW; these two units of power are significant to solve many problems in Physics. kVA to kW formula is:


kVA= kW/PF


For example: If the Power factor is 0.2 and kW is 150 then kVA = 150/0.2 = 750 kVA.


kW to kVA Calculations

To convert kW to kVA; The power units are essential to solve kVA calculations in Physics. 

To convert kW to kVA-

kW=kVA×PF

Example: If the Power Factor is 0.2, and kVA is 150 then to convert kW to kVA 

 kW=150kVA×0.2 = 30kW


Convert kWH to kVA

Just like kW to kVA conversion, A kilowatt-hour (kWh) is the measure of the energy a circuit working at a kilowatt of power moves through the span of 60 minutes. This unit is equivalent to 3,600,000 joules. The kilovolt-ampere (kVA) is the power rating of a circuit conveying 1,000 volts and an ampere or 1,000 amperes and a volt. A single kilovolt-ampere is comparable to a kilowatt. To change over from kilowatt-hours to kilovolt-amperes, you have to know just the time the circuit takes to move the energy. Measure the time length for which the circuit runs. 


Difference Between kW and kVA

The main difference between kW (kilowatt) and kVA (kilovolt-ampere) is the power factor. kW denotes the unit of real power and kVA denotes the unit of apparent power. The power factor, which is defined and known, is, therefore, an approximate value (typically 0.8), and in the kW to kVA calculations, kVA value will always be more than the kW value.  


Under industrial as well as commercial generators, kW is most commonly used in the US generators. The majority of the rest of the world mainly uses kVA as the set of generators.


To explain it a bit more, the kW rating is primarily the result of power output a generator can supply based on the engine’s horsepower. kW is figured by the horsepower rating of the times of engine 0.746. For example, if you have a 600 horsepower engine, it has a kW rating of 473. The kilovolt-amperes (kVA) are the generator capacity end. Generator sets are displayed with both ratings usually. 


To determine the kW to kVA calculations ratio, the kW to kVA formula below is used.

0.8 (pf) x 750 (kVA) = 600 kW


Solved Questions

1. Convert the Real Power in Watts to Apparent Power in kVA (Kilovolt amps).

Solution: S in kilovolt-amps (kVA) which is the apparent power is equal to the P in watts (W) which is the real power, divided by 1000 times the PF:


S(kVA) = P(W) / (1000 × PF)W


Watts divided by 1000 times the power factor is equal to kilovolt-amps.


kVA = kW / (1000 × PF


Fun Facts

  1. A fraction of kVA is only accessed to do any work, and the rest fraction is considered current.

  2. kW represents the actual power that does the valid work.

  3. When we consider a DC circuit, the kW and kVA are both equal because of the reason that the current does not go out of phase. But in the case of AC circuits, many differences can be found. 


Points to Remember with the Relation Between KVA and KW

The Relation between KVA and KW is one the most interesting topics from the Class 11 and 12 Physics part which deals with Electrical concepts and their applications. At a higher level, the relationship between KVA and KW is one of the most talked-about in electrical engineering and electronics engineering. Hence, the relation between KVA and KW finds its relevance in school-level exams as well as higher technical examinations as well. 


Hence, students should be ready with all the basic concepts at their fingertips which will ensure that they will be able to answer any questions appearing from the topic of the relation between KVA and KW. Vedantu has come to the rescue and solved all the queries of the students by providing free and necessary learning materials which will ensure that students will be able to grasp important concepts and tips and tricks to make sure they will be able to remember them as well. Here are the points to remember in the relation between KVA and KW:

  • KVA is used to represent the apparent power in the circuit. On the other hand, KW is used to determine the true power in the circuit. True power and apparent power, both are the components of power in the circuit.

  • KW or true power or actual power is the measure of how much power has been useful in the circuit, which means KW represents how much power has been able to generate the output in the power system. 

  • KVA is the measure of the power that can be generated from the power circuit. It does not necessarily mean that all of KVA or the apparent power will be useful or will be able to generate any output in the system. We can say that apparent power is the calculated power or the expected power provided by the power circuit. However, the actual power generated by the circuit is lower than the apparent power.

  • The relationship between apparent power and true power is established with the help of the efficiency of the power factor. Students can learn about power factors on Vedantu.

FAQs on Relation Between KVA and KW

1. What is the Power Factor? 

The power factor (pf) is commonly characterized as the proportion between kilowatts (kW) and kilovolt amps (kVA) that are drawn from an electrical load. The pf on the nameplate of a generator relates the kVA to the kW rating both. Generators with higher power factors all more effectively move energy to the connected load, while generators with a lower power factor are not as proficient and result in expanded force costs. The standard power factor for a three-stage generator is generally 0.8. In an electric power framework, a load with a low power factor draws more flow than a load with a high power factor for a similar measure of usable power moved.

2. Why are Generators and also Alternators Determined in kVA and not kW?

The alternator conductors are determined for a clear current, and the protection at an attractive framework is intended for a positive voltage free of p.f. (Cos θ) of the load. Consequently, apparent power estimated in kVA is viewed as the rated power of the alternator. 


The primary manufacturers consider while structuring electrical gadgets and machines which give electric force like transformers, UPS, alternators and generators, etc. are a burden and force factor. As they don't know precisely what the power factor is and which sort of burden will be associated with the gadget and machines. So they design and rate the electrical device based on its maximum output of current that the conductors can safely carry.

3. What should be the ideal value of the power factor in the circuit? Why is it difficult to achieve this value in large circuitry?

The power factor is determined by the cosine of the angle between kVA and kW. Ideally, there should not be any phase difference between kVA and kW i.e angle =0 and cos(0)=1. Hence, the ideal value of the power factor should be 1. This will imply that the energy generated in the circuit is used completely. This will also provide maximum efficiency. However, in large circuitry, there are capacitors and inductors which bring lead or lag and hence the angle becomes greater than zero. Hence, it is difficult to achieve the ideal value in this case. 

4. What is the difference between kVA and kW and when will be they equal in value?

kW is the actual power that is consumed by the circuit. It is also known as the true power. This power is the power consumed by the load in the circuit. On the other hand, kVA is known as the apparent power and it is the power that a source is capable of providing to the load in the circuit. kW is affected by the power factor while kVA is independent of the power factor. kVA and kW are equal if and only if the power factor equals 1.

5. What is the relationship between kW and kVA? How will this be useful to students in examinations?

The relationship between kW and KVA is given by the formula kW=kVa*Power factor. These concepts are helpful to understand the power generated by the source that is to be provided to the load and the power consumed by the load. The power factor is affected by the active components in the circuits. These concepts are useful as there are questions based on these concepts in the examination. Students can be asked to find the power factor or the power consumed by the circuit (that is kW) or the power provided by the source to the load (that is kVA). Students should read these questions very carefully. Students should go through the well-written information about these concepts on Vedantu so that they will gain an edge over their peers in the examination.

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