|
|
| Re: Canarsie CBTC (99025) | |||
 |
|||
| Home > SubChat | |||
|
[ Read Responses | Post a New Response | Return to the Index ] |
|
||
|
Re: Canarsie CBTC |
|
|
Posted by Jeff H. on Wed Jun 15 02:14:20 2005, in response to Re: Canarsie CBTC, posted by Stephen Bauman on Tue Jun 14 21:57:22 2005. It depends on what you mean by "closed loop", i.e. where doesthe loop close on itself? One of the setpoints is motor torque, but I doubt anyone would propose introducing a rotating strain gauge on the motor output shaft. So instead you measure a related variable. Modern induction motors are very consistent and presumably they are tested by the manufacturer for adherence to the curve. At manufacturing, factors such as stretching the enamel wire during the stator winding, cross-sectional area of the rotor conductors, and air gap, could affect the motor parameters by a few percent. Once in service, I would suspect temperature would be the #1 source of variability. The internal dimensions of the motor are not going to change measurably as these are ball and/or roller bearing motors, not sleeve bearings. The propulsion package mod on the Bomb cars was software only. |
|
|
|