Switching losses are shown 0 with thermal modelling

General
1

Hello PLECS team,

I am new to PLECS. So i have a model from one vendor who used rectifier with transformer and primary and secondary side switches with GaN. They used MOSFET with diode to simulate the GaN switch.

My Issues are

  1. They provided .xml files and lookup tables are until 20A but when i am simulating my instantaneous current is more than 20A. how do i solve this . do i have to extrapolate or interpolate the values myself to .xml files? or leave it as warning rather than error if so will it effect loss calculation
  2. There is a transformer in the circuit but i do not have data about transformer from vendor only scopes . How to i calculate the transformer losses. just like efficiency calculator in your demo model is there any way to calculate those and add it to total loss for loss calculation?
  3. when i try to get the individual switching losses of switches it is showing a flat line with probe connected to scope..why do i am getting it as 0?
2
  1. They provided .xml files and lookup tables are until 20A but when i am simulating my instantaneous current is more than 20A. how do i solve this . do i have to extrapolate or interpolate the values myself to .xml files? or leave it as warning rather than error if so will it effect loss calculation

PLECS will automatically extrapolate beyond the end of the look-up table. However, given the data was not characterized beyond this point one would likely want to be especially cognizant of how this relates to the device’s ratings and the duration of the high current transient.

  1. There is a transformer in the circuit but i do not have data about transformer from vendor only scopes . How to i calculate the transformer losses. just like efficiency calculator in your demo model is there any way to calculate those and add it to total loss for loss calculation?

Calculating transformer losses is not trivial. If your vendor did not provide information about the component, its design, and its losses then you will have limited ability to model it in more detail.

  1. when i try to get the individual switching losses of switches it is showing a flat line with probe connected to scope..why do i am getting it as 0?

There are several potential reasons - from a modeling issue, a measurement issue, to ZVS. Please post a model for better guidance.