The thermal design is an important aspect of power electronic systems and is particularly important in the increasing demands on compact designs and higher power densities. Caspoc allows to the user from the start of development to link the thermal behavior with the electric circuit to find an optimal solution for cooling the application. The calculation of switching and conduction losses is done in a simple way. The simulation speed is not adversely affected by the loss calculation because it is still connected ideal.
Instead of determining the switching losses of the transient current and voltage characteristics, Caspoc uses the characteristic losses from a device as specified on the datasheet. Typical data like Eon, Eoff and Ereverse-recovery depending current blocking voltage temperature and gating conditions can be used during the simulation to estimate the power loss and the therewith connected temperature rise.
Specialized models for fast loss prediction are available for Mosfets, IGBTs and even complete inverter structures.
The combination of ideal switch model and detailed loss data provides an efficient and accurate alternative is to simulations with detailed semiconductor models. The required look-up tables are entered with a built-in editor in Caspoc.
Next to the ideal semiconductor models are the detailed semiconductor models that can simulated the transient turn-on and turn-off of the semiconductor devices like a Mosfet, IGBT or Diode. The losses are calculated instantaneous and fed into a thermal model. The temperature directly influences the parameters of the semiconductor devise.
Conduction of heat from a heatsink to another or to the environment is modeled with thermal models that are connected to the semiconductors. In this way, you can determine the level of detail of the thermal structure model. There are special models for typical layers in IPM structures as well as detailed Cauer and Foster models to enter the thermal parameters like Rth and Cth from the datasheet directly.
