Slow AC Sweep PSIM.

Aly Elsayed

I’m using PSIM for my capstone project and Altair student license. I’m trying to get the frequency response(AC Sweep) of the system I designed but it’s very slow. I’m basically driving an inductive load H-bridge through an algorithm I designed. I found AC Sweep(2) with improved speed but still my simulation is slow. To quantify numbers:

- A 500Hz point would take ~4:30 mins to get simulated using the regular AC Sweep.

- A 500Hz point would take ~6:30 mins to get simulated using AC Sweep(2). It takes more time than the above AC Sweep.

It also seems the AC Sweep to be much slower at low frequencies. I would appreciate any advice to speed up my simulation.

Best,

Aly

Rhonda_20369

"It also seems the AC Sweep to be much slower at low frequencies."

This is because PSIM simulates the real switch mode of the system, instead of linearizing your circuit like other software.

The AC sweep and AC sweep (2) use time domain simulation to obtain the waveforms, and then extract the AC component for each frequency. Over the frequency range, the time step size is the same. 

When the frequency is low, the simulation takes more steps to finish each cycle. For example, if the step size is 1usec, with frequency=10KH, each cycle takes only 100 steps. But if the frequency is 100Hz, each cycle takes 10,000 steps.

 

Would you try AC sweep (multi-sine)?

With this block, you should run time domain simulation to find the time for the system to reach steady state.

Then, use the steady state time in the AC sweep (multi-sine) block.

 

There is a video tutorial compare those AC sweep blocks:

How to Perform an AC Sweep with PSIM

You can also find this in your PSIM's "Help >> Video Tutorials >> Overview and getting started".