# Flow of Phase currents

#### electronicsLearner77

Jul 2, 2015
306
I am really confused with phase currents direction of flow, please help to understand i am referring to the below link phase current flow
and referring to the diagram

and i am using the 3 shunt topology, my main question is if you are using the FOC and SVPWM used we will be imposing the sine currents on the U,V,W terminals.

During the initial duration Phase1 and Phase3 is positive and hence the current will be flowing from the inverter to the windings and this happens according to me when the top Mosfet is ON. But the three phase current sensing can only be done when the low mosfet is ON. As per the 1st diagram the current still flows from the Mosfet to the windings even if the high Mosfet is Off and the low Mosfet is ON. I am just not able to understand this. I am just pasting the diagram again to show the ground

I feel like the current is flowing from ground to the windings. I am not clear on this. Please advise.

#### Delta Prime

Jul 29, 2020
2,125
I feel like the current is flowing from ground to the windings. I am not clear on this. Please advise
Please do not use( please advise) that is passive aggressive. Polyphase three wire wye connection (using proper nomenclature would help as well)
Is reference from phase to phase not ground! Of course that phase is separated by 120°.
I hope this helps

#### electronicsLearner77

Jul 2, 2015
306
Thank you for the support. But i find difference in concepts when using the inverter to generate sine wave and directly using the sine sources, when using the inverter it is far more difficult for me to understand.

#### Delta Prime

Jul 29, 2020
2,125
Well then maybe you're taking too big of a bite. And I'm not going to lecture you. You must be assessed! I'm not a teacher this is the only way I can gauge where you need help. Try reading as much as you can and tell me if it applies to your situation. And I may have been a tad aggressive towards you. Get used to it (just kidding) I'll be more sympathetic to your plight. Now go away! you have reading to do. You may now address me as Professor.

#### Attachments

• snoa665c.pdf
747.6 KB · Views: 2

#### electronicsLearner77

Jul 2, 2015
306
I will try my best to understand.

#### Delta Prime

Jul 29, 2020
2,125
Now I feel horrible.
Briefly go through it . If it does not apply.Move on.
These are techniques and they may not apply. I'm not going to test you or ask you any thing like that. you're not in school
The professor thing was a joke.
Quite frankly all the incumbents here are my superiors intellectually. I'm here to have fun I hope you are too. I'll break it down for you but I need to know where you're at.

#### Delta Prime

Jul 29, 2020
2,125
You have this development board?
This is where you should be!!
This is where I would be.

Last edited:

#### Delta Prime

Jul 29, 2020
2,125
Or do you just wish to learn about inverters?
This you cannot learn from the top down.
This is intermediate level there is a prerequisite that means you need a foundation built on theory, the fundamentals of the individual components themselves. And mathematical laws associated with electronic circuitry.

Last edited:

#### electronicsLearner77

Jul 2, 2015
306
Or do you just wish to learn about inverters?
I am writing software (FOC) to spin the PMSM motor, so i am asking the questions i have.

#### Delta Prime

Jul 29, 2020
2,125
Why didn't you say that in the first place!!!!! You must be familiar with reference frames.Research Clark transforms.

#### Attachments

• BBPRMMAGSYNART.pdf
384.9 KB · Views: 3

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