SMPS simulation topic: how to get faster simulation speed with good accuracy in QSpice?

[PeterX]

Hi, all

Below is a two-phase buck converter eaxmple
2phase_buck_1.qsch (24.5 KB)

1. the simulation stop time is 20ms and it takes about 8s cpu time, the CPU usage of QSpice is only 4.5%, any method that can improve the usage of CPU for QSpice?
   

2. there’s inductor current imbalance output voltage spikes when do open-loop simulation, how to eliminate the undesired imbance and spikes without reducing the simulation speed?

–Peter

[bordodynov]

Unfortunately, in this world, you have to pay for everything. Here’s what I got:

2phase_buck_1_AB.qsch (25.2 KB)

[macsky]

How to remove this wiggle?

Hi All, I am currently testing this simple open loop SR buck and I am wondering if there is any way to absolutely remove the tiny wiggle at the output? I tried ttol=0.1ns and also disable fast math option, but it remains. open loop.qsch (16.3 KB) [image] and if I remove the deadtime circuit, it even makes this weird sudden ringing [image] Arief

I hope this is helpful for you. A similar issue about SMPS accuracy was discussed before.

[PeterX]

Hi, bordodynov

Thanks a lot, the new results have less current imbalance and voltage spikes, it’s ok for me.
And it really changes a lot:
.opt method=gear trtol2=0
indutor with Rser & Rpar
MOS & D model
timestep

Bad news is the simulation time x2, next i’ll try to speedup the simulation.

–Peter

[PeterX]

@Engelhardt
Hi, Mike
Is there any ways to set CPU threads number or make the full use of CPU to speed-up the simulation?

– Peter

[bordodynov]

Hi Peter,
Here it is customary to contact the Creator of Qspice in a personal email. Go to HELP and then to Obout QSPICE and see the address.

[PeterX]

Hi, mac

Thanks, * .option trtol2=0 is helpful.

–Peter

[PeterX]

Thanks for reminding.
I’ll send a mail to Mike.

–Peter