Transformer Analysis: Comparing Measured and Analytical Values

[greg997]

I am asked to compare analytical values of the loaded transformer with measeured values of the transformer. I have got no clue how to do that. The transformer is singl ephase 230/115V with rated secondary current 0.43 A.
According to open circuit test the Rcore = 15.9kOhm, Xcore = 10.5kOhm. From SC test Req= 80 Ohm,
Xeq = 33.8 Ohm, Zeq = 86.8 Ohm

I have values of load test as follows. The load is connected to secondary R= 150k Ohm,
Vp = 211V, Ip= 24 mA, Pp = 3.2W, Vs = 115.1, Is=0.75 mA.

I am not sure what to do with that data. I also don't know how to find actual efficiency of the transformer. What is the power output of that transformer?
Thank you

 

[rude man]

What exactly is "Rcore" and "Xcore"? Also your "ewq" parameters. How exactly were they measured?

What you should have measured id

 

[earlofwessex]

I am asked to compare analytical values of the loaded transformer with measeured values of the transformer. I have got no clue how to do that. The transformer is singl ephase 230/115V with rated secondary current 0.43 A.
According to open circuit test the Rcore = 15.9kOhm, Xcore = 10.5kOhm. From SC test Req= 80 Ohm,
Xeq = 33.8 Ohm, Zeq = 86.8 Ohm

I have values of load test as follows. The load is connected to secondary R= 150k Ohm,
Vp = 211V, Ip= 24 mA, Pp = 3.2W, Vs = 115.1, Is=0.75 mA.

I am not sure what to do with that data. I also don't know how to find actual efficiency of the transformer. What is the power output of that transformer?
Thank you

have you been introduced to an equivalent circuit model? I would guess that you have to compare your results from the 150k loaded experiment, to the results from the open and short circuit experiments.

 

[rude man]

What exactly are "Rcore" and "Xcore"? Also your "eq" parameters. How exactly were they measured?

What you need is:

with no other connections to the transformer:
primary inductance L₁₁
primary resistance R₁
secondary inductance L₂₂
secondary resistance R₂

with primary excited:
secondary voltage, open-circuit secondary: V₂(oc)
secondary voltage, loaded secondary: V₂(150K)

You might also determine the reverse voltage gain, i.e. V₁(oc) and V₁(150K) with V2 excited, although that should be redundant.

EDITED:
Not sure what the intent here is. Looks like you are to do just the unexcited measurements (the first four) and then assume a fully coupled transformer (k = 1.0) and compare the caculated output voltage with the measured one. But I'm just guessing.

 

[DeeNos]

for your question. I would approach this problem by first understanding the purpose of comparing the analytical and measured values of the transformer. This comparison is likely being done to evaluate the accuracy and effectiveness of the analytical model in predicting the behavior of the transformer in real-world conditions.

To compare the analytical and measured values, we can start by looking at the open circuit and short circuit test results. These tests provide information about the core resistance and reactance of the transformer, which are important parameters in determining its overall performance. We can compare the measured values of Rcore and Xcore with the analytical values to see if there are any significant differences. If there are, we can investigate the reasons for these discrepancies and potentially adjust the analytical model to better match the real-world results.

Next, we can look at the load test results. This test provides information about the transformer's performance under a specific load. We can compare the measured values of voltage, current, and power with the analytical values to see how well the model predicted the behavior of the transformer under this load. Again, any discrepancies can be investigated and the model can be adjusted if needed.

To find the actual efficiency of the transformer, we can use the formula: efficiency = (output power/input power) x 100%. In this case, the input power would be the primary voltage multiplied by the primary current, and the output power would be the secondary voltage multiplied by the secondary current. Using the given values, we can calculate the efficiency and compare it with the efficiency predicted by the analytical model.

As for the power output of the transformer, we can calculate it by multiplying the secondary voltage by the secondary current. In this case, the power output would be approximately 86.3 mW.

In summary, comparing the analytical and measured values of the transformer allows us to evaluate the accuracy of the analytical model and make any necessary adjustments. This can help improve the performance and efficiency of the transformer in real-world applications.