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#1 Sep 15, 2021
caliber
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Last seen: 3 years 1 month ago
Joined: 2021-09-13 05:38

Hi I'm facing simulation issues in pspice while simulating isolated grounds.Kindly help

Dear sir/madam,

Good morning.

I'm facing simulation issues while simulating isolated grounds in the circuit.

I'm using isolated drivers UCC21530 and UCC21750 which are isolated drivers in a 3 phase inverter circuit.

So i'm creating isolated ground by connecting the respective grounds with 100MEG ohm and which in turn connected actual Pspice ground.

I'm connecting grounds through 100MEG ohm to differentiate between low voltage ground(Low voltage grounds or driver primary side circuits are connected to Pspice ground)

and high voltage ground.

Top Mosfet driver.JPG

 

 

Mid Mosfet driver.JPG

 

Bottom Mosfet driver.JPG

Inverter circuit.JPG

 

Before transient analysis error.JPG

 

Q1,Q2 gate voltage with dead time.JPG

 

Transient analysis error.jpg

After this convergence error came,

 

Convergence error.JPG

Kindly check circuit ground connections and kindly provide simulation settings parameters to make circuit converge with different ground.

I'm using Autoconvergence and parameters changes as below,

In General settings:

Speed_level=5

RELTOL=0.05

VNTOL=1.0u

ABSTOL=1.0p

CHGTOL=0.01p

GMIN=1.0E-12

ITL1=150

ITL2=20

ITL4=10

Autoconverge:

Changes made only in below parameters and all are default values as in Autoconvergence.

RELTOL=0.08

ABSTOL=1.0E-5

VNTOL=0.0001

In Analog advanced settings,

DMFACTOR=0.01

TRTOL=25

Thank you

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