varistor simulation request

jae sung jo

Although the varistor characteristics were simulated using hyperperspice, the transient analysis does not show the characteristic values I expect, and only the DC sweep analysis simulates the correct characteristics. For your information, we simulated a varistor product called S20K275 from TDK. While I-V curves are good for dc sweeps, transient analysis results in incorrect overcurrent flow at low voltages. Also, I would like to ask you to add the varistor model itself to the psim, not the hyperspice. Thank you.

NikosDimitrakopoulos

Dear User,

Thanks for raising this topic. PSIM allows for highly customizable component designs. You can leverage math blocks, controlled sources and lookup tables to build custom models.

A varistor can be modeled as a voltage-controlled resistor as its resistance changes in response to variations in voltage. The non-linearitites can be modeled with a lookup table. You can digitize the graph from the datasheet and use a lookup table to model the variable resistor effect:

Using the Lookup Table to Make a Variable Resistor

To give you an idea of what is possible, please feel free to explore our more complex articles on:

How to create a variable capacitor in PSIM

How to create a variable inductor in PSIM