500V/100A CD motor driver using SCRs 1

[gentrain5]

Hi folks,

I have to design a 500V/100A (armature)CD motor driver using SCRs bridge for the first time and I'm looking for helpful information and tips. I'll appreciate recommendations on websites and other resources, thanks

 

[jbartos]

Suggestion: Visit

http://www.chipcenter.com/power/powp342.html

http://www.ml-electronics.co.uk/motor_drive.htm

http://www.engin.umich.edu/class/me552/Fall01/lab3.pdf

http://www.motorcontrol.com/

etc. for more info

 

[UKpete]

Do you mean a DC motor? At your power level I don't think SCRs are used in the output stages any longer. The problem with them is that they are not self-commutating (they won't switch off once triggered unless the voltage across them reverses, so they need complicated commutating circuits when used with DC).

More common are MOSFETs, or IGBTs at higher power levels, see jbartos's first link. Incidentally, the DC motor control uses a chopper (i.e. a single semiconductor device in series with the DC supply), the bridge circuit is used in 3-phase AC motor control.

A power electronics text book would be a possible place to start.

 

[MarcoHenry]

First, you have to take in account that building a 6-scr DC drive is not a simple design. You need some means to limit-current such a current spillover circuit or a current minor loop. The output of this goes to the drive circuit. The drive circuit is somehow complicated since it has to sinchronize with ac line. One integrated circuit for handling this is the TCA785 from siemens, you need 3 of this and a lot of PCB space. Also there are manufacturers that has a complete board to fire the 6 SCR's. Semikron used to have something in the 700 to 900 dlls range, but it seems that they now are offering for half-control only(i.e. the upper 3 SCR's only)
Regards
Marco
marcohenrygin@hotmail.com

 

[gentrain5]

Hi everyone,

First that all, I want to thank all of you for your helpful posts. The DC motor drive I need to design is for motor test purposes (500V/100A armature non regenerative, 150-300V field). We plan to use the 6 pulse firing board (model FCOG-6100)from ENERPRO. We are also looking also for the SCR assembly vendor. If anyone has used ENERPRO products before or has any advice about the SCRs please let me know.

Thanks.

 

[jbartos]

Suggestion: Visit

http://www.enerpro-inc.com/html/firing.html#fcog6100

etc. for more info

 

[MarcoHenry]

I looked at the ENERPRO specs. It looks nice. But again, this is only a Gate-driver board only. What you need to build around that board are at least two loops: The outer loop voltage/speed regulator and its output goes to the lower current loop. Also you need at least two protections: Instantaneous over current, and Inverse-time overload. Current limit is achieved by the current loop.I manufacture DC drives, analog and digital and we have an option with no SCRs for an external power bridge. That is the reason of advicing of the complexity of the task.

 

[jbartos]

Suggestion: Visit

http://www.robotroom.com/HBridge.html

http://www.intersil.com/data/AN/AN9/AN9324/AN9324.pdf

http://vodka.tky.hut.fi/~jap/Electronics/MotorCtrl/

http://www.technologicalarts.com/myfiles/mc11acc.html

http://www.bobblick.com/techref/projects/hbridge/hbridge.html

http://www.mskennedy.com/pdf/4201rc.pdf

etc. for more info on the global solution including features, control loops, etc.