10kw DC Motor Control

[shorehamtv]

We would like to to control the above traction motor on a train electronically using IGBT modules if possible, the problem is that the trains run on 125v DC, the initial start current is approx 90 A. The motors are very inductive and have destroyed many good contactors in the past due to insufficient contact gap and i wonder if there is a reliable semiconductor / drive module combination available. the trains are 4 speed (resistors) and the motors are series wound with reverible armature connections Thanx. John

 

[jbartos]

Suggestion: It may be better to go by the product manufacturer tech support. Visit

http://www.thomasregister.com

and type Controls: Electric Motor, DC under Product or Service that will return 13 companies to inquire about the best solution for your traction motor controls.

 

[shorehamtv]

Thanks for the reply I will try that - as for the manufacturer, the railway is the first electric railway in the UK and was built in 1886!!

 

[cbarn24050]

Hi, there are many IGBT modules that will do that quite easily.

 

[don01]

shorehamtv
I had a browse thru some of my older texts and tech stuff and haven't had a hit yet. Now this has had me thinking ( dangerous stuff). My memory says for traction and high inertia stuff the contactors were the big open face clapper type. (Cutler&hammer type O OO etc) with a blow out coil for the worst cases.

This gives me the idea you are probably using the more modern "block" contactor with say only 5~8 mm trvel on the contactor and this gives sustained arc on the contact face (ions & plasma blah blah blah).
Now suggestion 1) try to hunt up some old clapper types (repair = file up block of brass)
2) I know Melbourne Met supports a tramway musuem which has had a lot of press for upgrading some of the older generations for running and tourism etc. I haven't scored the address yet but will if I do. I am sure an approach to some one like this might get you some background pro con data if not a hot tip
3)there may be some value in flyback diodes but I know there is one more simple technique like coils in series but counter to the current flow and I cannot remember the !@#%$ details.

regards Don

 

[shorehamtv]

Thanks for the reply Don, you are correct, the old contactors are the clapper type with the large air gap and blow out coil, they were actually manufactured by Allen West of Brighton, England. However these had been replaced (not by us) with an a.c. rated type with an air gap of approx 5mm, these subsequently exlploded!. We have managed to refurbish some old clapper types which are now working well, but we would like to upgrade to an electronic control in order to satisfy the relevant inspectorate. Thanks again.
Regards John

 

[1x1x1x]

The company below makes avery reliable vacuum contactors for DC. Check with them they may have asolution for you.



Kilovac Corporation
P.O. Box 4422
Santa Barbara. CA 93140
Tel: 805-220-2020
Fax: 805-220-2075
Toll Free Hotline: 800-253-4560

 

[don01]

John
have not managed to hit the Melbourne gov site yet but am still working on it. These web sites look interesting and might give you something if you hit their "contact us" mail.

http://www.tram.co.nz

http://www.sydnetramwaymuseum.com.au

Yeh its that long!!!

http://www.btm.org.au

http://www.railfed.org.nz

these appear to be working mesuems so they may have been done the same path.

Regards
Don