Tuesday, May 26, 2015

Power factor

Today we started class with learning about apparent power and power factor.
The apparent power in VA is the product of the rms values of voltage and current.
It is measured in volt-amperes or VA to distinguish it from the average or real power, which is measured in watts.

we did following problem in class



Here's another problem we did..

Power factor is the cosine of the phase difference between voltage and current. It is also the cosine of the angle of the load impedance.



complex power: Complex power is important in power analysis because it contains all the information pertaining to the power absorbed by a given load.The complex power may be expressed in terms of the load impedance Z

P  is the average or real power and it depends on the load’s resistance R.  Q depends on the load’s reactance X and is called the reactive (or quadrature) power

 Apparent Power and Power Factor Lab

Purpose of this lab is to use apparent power and power factor to quantify the AC power delivered to a load and the power dissipated by the process of transmitting this power.

following is the Pre-lab calculations that we did.  the theoretical values of the circuit: Current, Voltage, Average Power, Apparent Power, and Power Factor:



following circuit was built using 1mH inductor  . 2 Resistors  of RL =10 ohm and RT = 10, 47,100

We used analaog discovery to provide input voltage and measure the output

we changed RT values. All of the circuits will have the same input of 1V at 5Khz:

output graph of 10 ohm 

output of 47 ohm

output of 100 ohm


Part 2 LAB:
In part 2 we inserted 10 micro F capaciotr in parallel with inductor and Resister load

output of cirucuit with 5Khz

Following are our calculated and measured results. we calculated % difference. 


As you can see above, our values resulted in higher % difference with theoratical values. Capacitor circuit had lower % error.

Summary: we learned about apparaent power and power factor. we did la to measure circuits apparent power. 

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