Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

how to produce 120 deg phase generation in pwm generator

Status
Not open for further replies.

poornimargowda

Junior Member level 3
Joined
Oct 22, 2011
Messages
31
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
1,456
Please can anybody help me about how to generate 120 deg phase shifted pwm waveform for ac motor control?
 

Depends on how you generate the "pwm waveform". The phase shift applies to the modulating sine waveform, not the pwm carrier. Assumed you are generating the sine by a lookup table, the 120 and 240 degree phase shift isn't but an offset to the table index.
 
  • Like
Reactions: tpetar

    tpetar

    Points: 2
    Helpful Answer Positive Rating
Depends on how you generate the "pwm waveform". The phase shift applies to the modulating sine waveform, not the pwm carrier. Assumed you are generating the sine by a lookup table, the 120 and 240 degree phase shift isn't but an offset to the table index.

Hi, thank you for your reply. But one thing i did not understand for controlling the speed of the motor. Suppose if we modulate the 50 hz frequency with the carrier for generating pwm signal then what is the need of varying the motor frequency again from 1 Hz to 128 Hz in some cases?

Please reply me. actually i am controlling the ac motor using MC3PHAC controller but i did not get the internal working of this controller. So please help me...


Regards,
Poornima
 

Hi FVM, thank you for your reply. One more help i need. Please can you explain me the internal operation of MC3PHAC controller . Its a DSP based controller. I googled for it but did not get the right information. Please help me since i am doing my M.Tech project on this.

Thanks,
Poornima
 

Hi thank you for your reply.
I have read the datasheet but only the configuration in standalone and master mode is explained. i want the internal block diagram of mc3phac.

Regards,
Poornima
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top