Determine Transformer KVA output and Power Factor

Za+Zb. In this case, it is used to determine the percentage of the total load taken by transformer A. The calculation for Za is incorrect, it should be 0.098<66.04. Using this corrected value, the calculations for Sa and Sb are also corrected to 3146<-27.65 and 2354<-43.47 respectively. In summary, the kva output for transformer A is 3146kva and for transformer B is 2354kva, with a power factor of 0.423 leading for transformer A and 0.286 leading for transformer B.
  • #1
maluzha
1
0
1. Two transformers T1 and T2 in parallel supply a common load at a lagging pf of 0.8, their per unit impedance are 0.04+j0.09 and 0.01+j0.07 at the same kva ratings of 3000KVA each and load power = 5500KVA

Determine the kva output of each transfromer and power factor

This is how i worked it:
Za=0.04+j0.09
Zb= 0.01+j0.07
Zt=0.05+j0.16

Za/(Za+Zb)= 0.048<66.04/0.168<72.65
=0.286<-6.61
Zb/(za+Zb)=0.071<81.86/0.168<72.65
=0.423<9.21
Sa=5500<-36.86*0.423<9.21 = 2326<-27.65
Sb= 5500<-36.86*0.286<-6.61 = 1573<-43.47

Sa+Sb gives a total of 3899kva which is wrong!
 
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  • #2
Za should be .098<66.04

Why is it Za/(Za+Zb) don' understand this part.

Thanks
 
  • #3
Za/Za+Zb is the ratio of Za to the total load
 

1. How do I calculate the KVA output of a transformer?

The KVA (kilovolt-ampere) output of a transformer can be calculated by multiplying the primary voltage by the secondary voltage and dividing the result by 1000. For example, if a transformer has a primary voltage of 480 volts and a secondary voltage of 240 volts, the KVA output would be (480 x 240) / 1000 = 115.2 KVA.

2. What is the significance of determining the KVA output of a transformer?

Determining the KVA output of a transformer is important because it provides information about the maximum amount of power that the transformer can deliver. This information is crucial for selecting the appropriate transformer for a specific application and ensuring that the transformer is not overloaded, which can cause damage or failure.

3. How is power factor related to transformer KVA output?

Power factor is the ratio of real power (kW) to apparent power (KVA). A transformer's KVA output is its apparent power, and the real power it can deliver is dependent on its power factor. A transformer with a lower power factor will have a lower real power output compared to its KVA rating.

4. How can I improve the power factor of a transformer?

The power factor of a transformer can be improved by adding power factor correction capacitors to the circuit, which helps to reduce the amount of reactive power flowing through the transformer. Regular maintenance and keeping the transformer operating within its design limits can also help to improve power factor.

5. Can the KVA output and power factor of a transformer be measured?

Yes, the KVA output and power factor of a transformer can be measured using specialized equipment such as power analyzers. These measurements can help to determine the overall efficiency and performance of the transformer and identify any potential issues that may need to be addressed.

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