# Question about Vd

**URL:** https://community.simplefoc.com/t/question-about-vd/1064
**Category:** Uncategorized
**Created:** [July 22, 2021, 8:04pm UTC](https://community.simplefoc.com/t/question-about-vd/1064 "2021-07-22T20:04:13Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![quentin](https://community.simplefoc.com/letter_avatar_proxy/v4/letter/q/e47c2d/32.png) [@quentin](https://community.simplefoc.com/u/quentin)
#### Post date: [July 22, 2021, 8:04pm UTC](https://community.simplefoc.com/t/question-about-vd/1064/1 "2021-07-22T20:04:13Z")

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Here are my Vq and Vd in “FOC Current” + “angle control”:

 ![image](https://community.simplefoc.com/uploads/default/original/2X/1/1396990485e91bba738f7580b59f35eb3022e16f.png)

Vq seems ok and reacts as expected when I change the angle.

However, Vd seems flat and non-reactive. Is it normal?

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<div class="post-metadata">

### Author: ![Antun\_Skuric](https://community.simplefoc.com/user_avatar/community.simplefoc.com/antun_skuric/32/21_2.png) [@Antun\_Skuric](https://community.simplefoc.com/u/Antun_Skuric)
#### Post date: [July 23, 2021, 11:11am UTC](https://community.simplefoc.com/t/question-about-vd/1064/2 "2021-07-23T11:11:04Z")

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Hey @quentin,

Yes that is exactly how it’s supposed to be.  
The current control loop is trying to keep the d component of the current equal to 0.

The reason is because only the q component of the current actually generates the torque, and the d component, at least for the BLDC motors, will generate only the heat. 😃