: single phase transformer

In summary, the conversation revolves around a single phase transformer with a 2200/220 V, 500kVA, 50Hz rating. The transformer has been tested using the open circuit method, with V(l) = 220V, I(l) = 85A, and P(oc) = 1800W. The short circuit test was also conducted, with V(h) = 95V, I(h) = 227.3A, and P(sc) = 8.2kW. The relevant questions include determining the equivalent resistance referred to the low voltage side, the resistance of the low side winding, the transformer copper loss during the open circuit test, the transformer core loss at rated voltage,
  • #1
alnywk
14
0
urgent : single phase transformer

Homework Statement



A 2200/220 V, 500kVA, 50Hz distribytion transformer has been tested by means of the open circuit. the test data obtained is as follow:
open circuit test: V(l)= 220V, I(l)= 85A, P(oc)= 1800W
short circuit test V(h)=95V, I(h)=227.3A P(sc)= 8.2kW



2. Relevant question

1.equivalent resistance referred to the low voltage side (state all assumption)

2. resistance of the low side winding only

3.transformer copper loss of the secondary winding during the open circuit test

4. transformer core loss when rated voltage is applied

5. explain if it justified to use the power input during the open circuit test as core loss?






The Attempt at a Solution

 
Physics news on Phys.org
  • #2
It is so clear that you want us to do your homework. Here is a hint. OC tests are used to find parameters on the primary side, and SC tests are for the secondary side. Once you find out your core loss, you can assume it to be a constant and not varying with load. Only the Cu losses will change with load.
 
  • #3


1. The equivalent resistance referred to the low voltage side can be calculated using the open circuit test data, as follows:
R_eq = (V_oc^2 / P_oc) - R_l
Where V_oc is the open circuit voltage, P_oc is the open circuit power, and R_l is the resistance of the low voltage winding. Assuming that the transformer is ideal and has no leakage inductance, the equivalent resistance is equal to the resistance of the low voltage winding.

2. The resistance of the low side winding only can be calculated using the open circuit test data and the equivalent resistance, as follows:
R_l = R_eq - (V_oc^2 / P_oc)

3. The transformer copper loss of the secondary winding during the open circuit test can be calculated using the open circuit test data and the equivalent resistance, as follows:
P_cu = I_l^2 * R_l
Where I_l is the current in the low voltage winding.

4. The transformer core loss when rated voltage is applied can be calculated using the short circuit test data, as follows:
P_core = P_sc - P_cu
Where P_sc is the short circuit power and P_cu is the transformer copper loss calculated in question 3.

5. It is not justified to use the power input during the open circuit test as core loss. The open circuit test measures the core loss and the transformer copper loss together, so using the power input as core loss would not accurately reflect the actual core loss. It is important to use the short circuit test data to calculate the core loss separately from the copper loss.
 

1. What is a single phase transformer?

A single phase transformer is an electrical device that is used to transfer electrical energy between two or more circuits through the process of electromagnetic induction. It consists of a primary and secondary winding, which are connected by a magnetic core. It is commonly used in residential and commercial applications to step up or step down the voltage of an electrical supply.

2. How does a single phase transformer work?

A single phase transformer works by passing an alternating current (AC) through the primary winding, which creates a changing magnetic field. This changing magnetic field induces a current in the secondary winding, which is connected to the load. The ratio of the number of turns in the primary and secondary windings determines the output voltage of the transformer.

3. What are the different types of single phase transformers?

The two main types of single phase transformers are step-up and step-down transformers. Step-up transformers increase the voltage from the primary to the secondary winding, while step-down transformers decrease the voltage. Other types include autotransformers, which have a single winding that serves as both the primary and secondary, and isolation transformers, which provide electrical isolation between the primary and secondary windings.

4. What are the advantages of using a single phase transformer?

Single phase transformers are compact, efficient, and have a long lifespan. They are also relatively inexpensive compared to other types of transformers. Additionally, they can be easily connected in parallel or series to increase the voltage or current output, making them versatile for different applications.

5. What are the common applications of single phase transformers?

Single phase transformers are commonly used in household appliances, such as refrigerators and air conditioners, to step down the voltage for safe use. They are also used in industrial machinery, power distribution systems, and renewable energy systems, such as solar and wind power. They are essential for the reliable and safe distribution of electricity in various settings.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
7
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
4
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
3K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
6
Views
3K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
6K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
29
Views
4K
Back
Top