AC Sweep

The AC Sweep uses the Steady-State Analysis to compute the transfer function of a periodic system at discrete analysis frequencies. For each frequency the following steps are executed:

1. Apply a sinusoidal perturbation to the system under study.

2. Find the periodic steady-state operating point of the perturbed system.

3. Extract the system response at the perturbation frequency using Fourier analysis.

The perturbation frequencies are defined by specifying the sweep range and the number of points to be placed within this range on a linear or logarithmic scale.

Note

The period length of the perturbed system is the least common multiple of the unperturbed system period and the perturbation period. In order to keep this number and thus the simulation time small the algorithm may slightly adjust the individual perturbation frequencies.

In PLECS Standalone, the operating point can be defined as “non-periodic” (DC). In this case, no sweep is executed, but the Bode plot is computed directly from the state space matrices at the steady-state.