Since no model has been provided, I am assuming that you are using the example model "power_igbtconv" available in the "IGBT" block documentation from Specialized Power System (SPS) library:
As stated, the switching transitions are nil and there is no overlap of switch current and voltage waveforms at these transitions. To ensure the overlap starts appearing, I modified the example model in the following ways:
- Discretized the model in the "powergui" block to observe the transitions better by changing the sample time as required (<100e-6s time-period of IGBT to see the transitions)
- Introduced a small amount of series resistance-capacitance across the switch to prevent the sudden voltage transition.
- Changed the IGBT block parameter "Lon" from 0 to prevent sudden current transition.
When the modified example model is run, the transition losses start to appear. The parameters require iterative tuning for better modelling the switching transitions. I have attached the modified model with this answer.
Instead of modifying the block from SPS library to model switching losses, I would recommend using the "IGBT (Ideal, Switching)" block from Simscape Electrical library because:
- The block provides options to specify the amount of turn-on and turn-off loss as well as a thermal port to model the switching events that generate thermal loss in the switch. Please refer to the following documentation to know more about this block as well as the parameters to model switching losses under the "Thermal Losses" section:
- The block supports pre-defined parameterization to model IGBTs used in the industry. You can find the various pre-defined IGBT components here:
I hope this answers your query.
