Hello everyone,

As you have noticed I asked many questions related to AC sweep(PLECS BLOCKSET) and I start to get familiar with it.

my question here is related to the value of the System period length, in the help it described it as follow:1- The period length of the unperturbed system.

I found as well another explanation but not sure if it is the referring to it exactly :

2-System period

The system period is the least common multiple of the periods of all sources (signal or electrical) in the model. If the parameter setting does not reflect the true system period or an integer multiple thereof, the analysis will yield a meaningless result or fail to converge altogether. A system period of 0 is equivalent to defining the system as non-periodic. When set to auto, which is the default, PLECS will try to determine the system period automatically.

in my design of the DC-DC boost converter with peak current mode control, when I run the AC sweep (Verr to Vout ) the default value was 1e-5 and my bode plot was meaningless and the value of Vout does not reach the steady state (I expect 16V as Vout and Vin is 5V) and stays around 3V which means never reached the steady state where the perturbation must be happen.

I have changed the value to 1e-2 and I can see the difference and the steady state of Vout=16V are reached and I see the oscillations of different frequencies.

my questions how does this value affect the frequency response because of it still not clear to me?

how do I obtain a fast bode plot as it takes very long time(I use a switching frequency of 3Mhz and my frequency range is from 100 to 1Mhz)?

best regards,