Dynamic breaking with AC locomotives

[Brhodes]

Since AC induction motors do not generate electricity as DC traction motors can be made to do, how does dynamic breaking work on AC locomotives?
Bert Rhodes, Melbourne, FL

[Hugh Jampton]

Were you not happy with the answers given previously???

http://www.trains.com/community/forum/topic.asp?TOPIC_ID=35802

[wabash1]

well the engineer puts the handle into dynamic and then increases it til he gits the desired retarding affect he is looking for then when he is done with that he probley go into power again

[adrianspeeder]

Wow, double posting to the max...[#dots]

[daveklepper]

Motors used on diesel-electrics, as far as I know, are not straight induction motors, which are synchronous motors operating at line frequency. They are non-synchonouse hysterises motors which slip and have far greater torque availability. The difference in operating characteristics, is that that the synchronous ac motor will run at constant speed up to the point where you load it beyond capacity and then it will simply stop (not suddenly, just stop). The non-synchronous hysterises motor will gradully slip as it is loaded. This type of motor can also generate electricity, which can be fed into resistor grids just like a dc motor.

The physical characteristics that differentiate the two types of motors are:

The rotating bars of the straight induction motor are straight across "horizontal."

The rotating bars of the non-synchronous hysterises motor are slanted, skewed.