0
\$\begingroup\$

I am trying to design a PWM inverter in Orcad PSPICE where i am using a Vpulse source from library to generate MOSFET triggering pulses for H-bridge and it works fine for square waves.

But i if i want to generate sinusoidal pwm to drive the h-bridge how can i accomplish it in orcad pspice and drive the mosfets accordingly.

Previous method:

previous schematic

Desired PWM output in simulation

expected pwm

I figured out that sinusoidal pwm is generated by comparing a sinusoidal wave with triangular wave.Is there any way we could simulate sine pwm in orcad pspice and drive the h bridge accordingly different switching topologies.?

I would appreciate any help or suggestions that will help me to achieve my intended purpose of making prototype of sine wave pwm generation like as mentioned above in picture using orcad pspice.

Thank You for your time :)

\$\endgroup\$
2
\$\begingroup\$

Have you read this: http://homepages.which.net/~paul.hills/Circuits/PwmGenerators/PwmGenerators.html

Basically what you need is a comparator and a triangular shaped waveform. You feed the triangle to one input of the comparator and your sine wave to the other input. Then the output of the comparator will be the PWM signal you desire.

\$\endgroup\$
  • 1
    \$\begingroup\$ Thank you very much.So i guess i need to do so via an op amp or inbuilt comparator i trust.I'll get back after trying out.Thanks again for your patience and time. \$\endgroup\$ – Rookie91 Jul 9 '15 at 6:31
  • 2
    \$\begingroup\$ An opamp can also work yes, as long as it has enough bandwidth. In practice, comparators are mostly simple opamps build for speed. \$\endgroup\$ – Bimpelrekkie Jul 9 '15 at 6:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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