1
\$\begingroup\$

I am doing a simulation on LTSpice of a three level ANPC. The ground is connected to the neutral point (i.e in the middle point of the DC input) and the gate drivers are isolated by using a DC DC converter (so the voltage is floating). The thing is that I need to gate the transistors and I have the modulation done with signals that go from 0 to 5V.

I did this signals by using BV sources connected to the common ground: one carrier that goes from 0 to 0.5, another that goes from 0.5 V to 1V and the modulating sine in the middle.

How can I impose the PWM to the input of the gate driver? How should I shift the signals to the source level of the transistors?

Thank you in advance!

\$\endgroup\$
2
  • 1
    \$\begingroup\$ I normally cheat with the e-function. Set gain to 1 and it will provide indefinite speed and isolation. \$\endgroup\$
    – winny
    Commented Jun 17, 2018 at 21:58
  • 1
    \$\begingroup\$ See this answer for a possible solution to your case, and to get an idea on a simplified way to simulate what you want, faster. \$\endgroup\$
    – a concerned citizen
    Commented Jun 18, 2018 at 6:10

1 Answer 1

Reset to default
1
\$\begingroup\$

With a bv source you can use math equations, so just for simulations take if you want to stimulate a combination of signals you could do something like this:

bv=V(pwm)*V(gatesignal)+V(whatever)

Where pwm, gatesignal and whatever are net names. If you want to reference a current you can use I(netname)

If you want to physically realize this system you'll have to do it with analog multipliers and summing op amps

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.