NPC Inverter Power Calculation

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Hi There,

I am working on a NPC inverter and motor model. I am using a PMSM model and the speed is directly controlled by a constant input (Sort like a back to back motor configuration and the speed is controlled by another motor, the motor in my simulation only does torque control, and the speed is controlled by the other motor).

I am trying to calculate the efficiency for the NPC inverter. The power loss is calculated using the PLECS thermal model, and control is implemented in Simulink. My question is:

  1. I measured the instantaneous input and output power of the inverter, and they are exactly the same. However, I have around 340W of power loss. To my understanding, Pin=Pout+Ploss, but it is not the case for my model.

  2. I calculated the mechanical power, and it’s not close to the output power of the invert at all.

Please let me know if you need any more details of the model. Thanks in advance.

Alex

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Are you able to post the model itself, along with the thermal files?