AC sweep and Frequency Response of Almost Any System

SPICE-based tools typically perform AC analysis in the time domain which requires the converter to be converted to an average model. This approach excludes all but the most simple converter topologies and control methods. Although it is useful for undamped LC frequency responses, these aren't complex switching converters.

PSIM and DSIM can perform an AC sweep to determine the frequency response of a converter in the time domain. We then extract the gain and phase information of the signal of reference vs. the injected perturbation.

This allows us to do a response on almost any

- Converter topology

- Control technique

○ Average

○ peak

○ DCM

○ CCM, etc.

- Interconnected system with supervisory control

○ Load sharing

○ Droop control

- Digital z-domain with included phase delay from digitization.

Since 2021b, we support AC Analysis with DSIM, which allows for AC sweeps of large power converters, microgrids, etc. With that, we are able to sweep almost anything and get the frequency response of simple converters as well as complex converters.

In this webinar, we cover how to set up these sweeps for various converter types and control techniques.

Examples will include:

- Simple buck

○ Average control

○ Peak control

○ 2 loop

○ z-domain

- Phase shift full bridge active secondary

- Resonant converter

- MMC converter

○ leg current and voltage balancing

- Droop-controlled parallel converters

- PFC CCM