On Tue, 2013-05-14 at 18:15 -0400, Cecil Thomas wrote: > One of the greatest of the advantages of a wound field motor.... No > magnets to degauss. The only thing challenging really quick stops is > inertia. > > I was once involved in the power industry and saw the results of a > mis-timmed synrconizing breaker closure on a 600 MW generator turning > 3600 rpm. The inertia of the rotor which was now magnetically locked > to the stator took the stator and its housing for a ride, ripping the > generator from the foundation and rotating it about 45 degrees. Good > news is that there is a lot of scrap copper in one of those babies.
Ouch! That caused more than a little bump in the voltage/frequency of what ever power pool it was connected to. My father used to tell the story about the superintendent of the Coulee project walking into the left power house one day and grabbing the handle and taking one of the units off line.....and while all the engineers held their breath and tried not to fill their britches put it back on line with only a small bump. Units are much harder to replace than circuit breakers and even those tend to have long lead times. ....worth just a pence... ;-) Dave > > The other advantage is of course that when you have the motor running > at full speed with max armature current you can go even faster by > reducing the field current. You give up torque of course but the > extra speed tends to keep the horsepower constant. > > Cecil > ------------------------------------------------------------------------------ > AlienVault Unified Security Management (USM) platform delivers complete > security visibility with the essential security capabilities. Easily and > efficiently configure, manage, and operate all of your security controls > from a single console and one unified framework. Download a free trial. > http://p.sf.net/sfu/alienvault_d2d > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ AlienVault Unified Security Management (USM) platform delivers complete security visibility with the essential security capabilities. Easily and efficiently configure, manage, and operate all of your security controls from a single console and one unified framework. Download a free trial. http://p.sf.net/sfu/alienvault_d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
