# Modeling of Salient pole SM

**URL:** <https://forum.plexim.com/t/modeling-of-salient-pole-sm/2906>\
**Category:** PLECS\
**Created:** [March 9, 2026, 4:46am UTC](https://forum.plexim.com/t/modeling-of-salient-pole-sm/2906 "2026-03-09T04:46:21Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Smartgrid](https://avatars.discourse-cdn.com/v4/letter/s/b3f665/32.png) [@Smartgrid](https://forum.plexim.com/u/Smartgrid)\
**Post date:** [March 9, 2026, 4:46am UTC](https://forum.plexim.com/t/modeling-of-salient-pole-sm/2906/1 "2026-03-09T04:46:21Z")

</div>

Hello,

I am currently modeling a six-phase **salient pole synchronous machine** and I have a few questions regarding the available modeling options.

1. What is the main difference between the **Rotor Reference Frame** model and the **VBR (Voltage Behind Reactance)** model when modeling a salient pole synchronous machine?

2. When performing simulations, are there any specific considerations or limitations when choosing between these two modeling approaches?

3. In the VBR modeling approach, there are options such as **Stator VBR** and **Full VBR**. Could you explain the difference between these two methods and in which situations each one should be used?

Any clarification or guidance would be greatly appreciated.

Thank you.

---

<div class="post-metadata">

**Author:** ![Bryan\_Lieblick](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/bryan_lieblick/32/10_2.png) [@Bryan\_Lieblick](https://forum.plexim.com/u/Bryan_Lieblick)\
**Post date:** [March 10, 2026, 7:08pm UTC](https://forum.plexim.com/t/modeling-of-salient-pole-sm/2906/2 "2026-03-10T19:08:10Z")

</div>

These are great questions. Since the answer would be helpful to many users I have extended the [Electric Machine FAQ](https://forum.plexim.com/t/electric-machine-faq/2698#p-5853-rotor-reference-frame-vs-voltage-behind-reactance-model-formulations-10) post comparing the VBR and RRF implementations.