Maxwell Linear Generator (Input Power < Output Power and losses?)

[mos962]

TL;DR Summary

I am performing the FEM simulation for the linear generator. There were no issues with the simulation, but the law of energy conservation does not hold with the simulation results.

Hello Everyone

There was no error or warning during the simulation of my model. I am simulating a 2D model. However, when I got the results, I observed an output power of 95.95 W and an input power of 99.33 W. But when I added the losses of the model, which are 6.129 W (total losses), the combined value of output power + losses exceeds the input power, which is not understandable.

There are a couple of issues I am facing:

Analysis step size:
When I increased the analysis step size from 1 ms to 4 ms, the output power dropped from 96 W to 84 W, which is a significant and unexpected drop. I understand that a smaller step size should generally give more accurate results. However, I still have some confusion regarding the step size of 1 ms. I also reduced the mesh size to half of its original value, but this did not affect the output power in the 1-ms step size Model.

Software version differences:
Initially, I used Maxwell 14.0 software, which gave me an output power of 96.05 W and an input power of 100.28 W. Later, I switched to ANSYS Electronics R2022 (the values mentioned above paragraph are from the ANSYS software), because I needed a detailed loss analysis of the parts, which was not possible with Maxwell 14.0.

The confusion here is that the model remained the same — I did not change a single parameter — but the two software versions produced different results.

The values mentioned above are peak values. I am designing a 50 W (RMS) linear generator.

I'll appreciate it.

Thanks in advance

Regards

 

[berkeman]

Welcome to PF.

It does sound like an imprecision or other issue in the calculations by the simulation software. Have you tried contacting Maxwell Technical Support?

 

[mos962]

Thank you for replying,

For the time being, I didn't contact them because I was unsure about the explanation, such as whether it was due to confusion on my end or a software problem.

I will contact them now.

But I am not sure it's the calculation issue, because keeping aside the losses, the value between the two software programs themselves contradicts the other