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In electrical science what are the apparent power , active power and reactive power ?

Electrical Power Generation Electrical Design
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Question added by Moris Ghobrial , GM planning & WH , Alexandria Carbon Black Company
Date Posted: 2016/05/05
Upvote (1) Views (12) Followers (13) Answers (10) Report Question
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karthikeyan Karuppiah
by karthikeyan Karuppiah , Sales Support Specialist , ABB Industries LLC

Active Power: (P) Alternative words used for Real Power (Actual Power, True Power, Watt-full Power, Useful Power, Real Power, and Active Power) In a DC Circuit, power supply to the DC load is simply the product of Voltage across the load and Current flowing through it i.e., P = V I. because in DC Circuits, there is no concept of phase angle between current and voltage. In other words, there is no Power factor in DC Circuits. But the situation is Sinusoidal or AC Circuits is more complex because of phase difference between Current and Voltage. Therefore average value of power (Real Power) is P = VI Cosθ is in fact supplied to the load. In AC circuits, When circuit is pure resistive, then the same formula used for power as used in DC as P = V I   Reactive Power: (Q)  Also known as (Use-less Power, Watt less Power) The powers that continuously bounce back and forth between source and load is known as reactive Power (Q) Power merely absorbed and returned in load due to its reactive properties is referred to as reactive power The unit of Active or Real power is Watt where 1W = 1V x 1 A. Reactive power represent that the energy is first stored and then released in the form of magnetic field or electrostatic field in case of inductor and capacitor respectively. Reactive power is given by Q = V I Sinθ which can be positive (+ve) for inductive, negative (-Ve) for capacitive load. The unit of reactive power is Volt-Ampere reactive. I.e. VAR where 1 VAR = 1V x 1A. In more simple words, in Inductor or Capacitor, how much magnetic or electric field made by 1A x 1V is called the unit of reactive power.   Apparent Power: (S) The product of voltage and current if and only if the phase angle differences between current and voltage are ignored. Total power in an AC circuit, both dissipated and absorbed/returned is referred to asapparent power The combination of reactive power and true power is called apparent power In an AC circuit, the product of the r.m.s voltage and the r.m.s current is called apparent power. It is the product of Voltage and Current without phase angle The unit of Apparent power (S) VA i.e. 1VA = 1V x 1A. When the circuit is pure resistive, then apparent power is equal to real or true power, but in inductive or capacitive circuit, (when Reactances exist) then apparent power is greater than real or true power. 

haitham muhammad dorgham
by haitham muhammad dorgham , site engineer , samaar consulting and contracting

actually it depends on the nature of circuit components .. and regarding the generation it depends on the inputs to the generation systems whether the steam or the field  .. so that on the relation between the circuit voltage and current waveforms .. so it can be easily to figure out the nature ,formula ,and the difference between  each power once when drawing the current & voltage waveform for different loads resistor , inductive and capacitive as well . power = waveform of voltage * waveform of current for resistor loads the power in all cycles will be positive so it is given power consumed so u can name it as active power .for capacitive or inductive loads the power will be the same magnitude with different sign each1/4 of  the cycle it fluctuated between the source and the load it return back to the source again and again so we can name it as reactive power .what about if the circuit components are all these loads ?  both active and reactive power would appear in the circuit .and the angle between current and voltage will be between0 and degree as u see it is not just values but values and angles so the total power will the vector summation of  both act.and react. powers .u can deduce different formula to represent the upper relation for example:apparent power = active power /cos(the angle between V and I waveforms ) apparent power=reactive power/sine (the angle )cos(the angle) is called as the power factor or the load factor as u see it depends on the nature of  loads ... in other words for the circuit supplied by AC source to incandescent lamp ,the power factor is1 as the the angle between v and current waveforms for this load is nothing .. so for this load the reactive power would be nothing as well , the total apparent power will be equal to the active power .

Bilal Abid
by Bilal Abid , Management Trainee (Electrical) , PTCL

Active Power:

The power which is consumed by load .It measures in KW

Reactive Power:

the power which is required for excitation of components like capacitor , inductor. it is measures in kvar

Apparent Power :

the total power (reactive +active ) is called apparent power .it is measures in Kva

 

Apparent power =Active power+Reactive power

Kva=KW+Kvar

 

ANSHAD CHIRAPPULLY

Apparent power is In an AC circuit, the product of the rms voltage and the rms current . When the impedance is a pure resistance, the Apparent power is the same as the true power. But when reactance exists, the apparent power is greater than the true power.but We know that reactive loads such as inductors and capacitors dissipate zero power, yet the fact that they drop voltage and draw current gives the deceptive impression that they actually do dissipate power. This “phantom power” is called reactive power

Sattar Abdulkarim Mohamed
by Sattar Abdulkarim Mohamed , Country Sales Director , Ideal Technical Solutions

Thank you for your invitation. I agree with Mr. Karthi's answer as he has explained the Apparent power, Active power & Reactive power in detail.

mohammed alyafey
by mohammed alyafey , trainee , southern can making company

apparent power is the sum of the active and the reactive power measured in volt-amperes (VA) S=IZ

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active power is the real power that does actual work, it is measured in watts (W) P=I^2 R

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reactive power or reactive inductive power which is the stored power Q=S sinφ it measured in Volt-Amps-Reactive (VAR)

 

Mushreq Abdulmajeed
by Mushreq Abdulmajeed , Senior Project Supervisor , Lagoon Spring Company

I apologize I am civil eng.

Diroz Alam
by Diroz Alam , Senior Electrical Enineer , Omrania & Associates

  • Total power in an AC circuit, both dissipated and absorbed/returned is referred to as apparent power. Apparent power is symbolized by the letter S and is measured in the unit of Volt-Amps (VA).
  • Power dissipated by a load is referred to as Active power. Active power is symbolized by the letter P and is measured in the unit of Watts (W).
  • Power merely absorbed and returned in load due to its reactive properties is referred to as reactive power. Reactive power is symbolized by the letter Q and is measured in the unit of Volt-Amps-Reactive (VAR).

 

 

 

 

 

Power triangle relating appearant power to true power and reactive power.

 

 

Shahed Ali Mir
by Shahed Ali Mir , Project Engineer , Saudi Electricity Company

Apparent Power = Sq. rt (Active Power^2 + Reactive Power^2)=VI

Active Power = V*I*Cos(theta)

Reactive Power = V*I*Sin(theta)

 

Abdulrahman Alyami
by Abdulrahman Alyami , Electrical Engineer - Cathodic Protection , SNC-Lavalin Fayez Engineering

True Power: is the power being used or dissipated in resistive element.

Reactive Power: is the power being stored and returned by reactive element.

Apparent Power: is the combination of the both True and Reactive power. It is also the product of the RMS values of Voltage and Current.

 

 

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