Hello everyone, my name is NAGENDRA. I would like to simulate the IGBT gate driver Circuit. But, i could not find the HCPL3120 Optocoupler in the altair Psim Library. could you please tell me where and how can i get HCPL3120 in altair Psim?

PSIM has basic optocoupler models you can use:

If your project is to investigate the detailed characteristics of the gate driver HCPL3120, you need build a circuit with PSIM elements according the to the datasheet parameters.

If you only use this gate driver to drive IGBT, and your project is designing a power converter system, you may use one of the PSIM's On-Off Controller to represent this driver.