IEEE 11-2000 pdf download

IEEE 11-2000 pdf download.IEEE Standard for Rotating Electric Machinery for Rail and Road Vehicles.
4.1 Classes of ratings
This standard recognizes three classes of ratings: continuous rating, I h rating, and short time overload
rating.
4.2 Continuous ratings and temperature-rise tests
4.2.1
The continuous rating of a machine applied in duty that is long compared to the thermal time constant of the machine generally will be the point of greatest continuous tractive effort with the highest continuous flux level. The test shall be performed with inputs as in service unless 4.6.1 applies. It shall be ascertained that no other point is limiting.
4.2.2
The continuous rating of a machine applied in duty that has short cycles compared to the thermal time constant of the machine will be the steady rating that produces the same heating with the same ventilation in the same time as the duty cycle. This continuous rating is calculated from speed, time, distance, nns current, etc., over the duty cycle. Ripple in dc or harmonics in ac change during the duty cycle so it may not be possible to provide the continuous rating point with waveforms as in service. Subclause 4.6.1 may apply.
A duty cycle test shall be performed with the pulse control to be used in service to demonstrate that the temperature rises are comparable to those at the calculated continuous rating. The machine shall be operated in simulation of the actual duty cycle, including dwell time, as realistically as possible. The cycle shall be repeated until temperature rises have leveled. The test shall end at a temperature rise peak, if appreciable.
4.2.3
Where agreed, a machine may be tested to find the greatest continuous rating that will meet temperature rise limits with assurance. Such a rating must be used with care that other conditions have not changed to render the rating inapplicable.
4.2.4
A continuous temperature test shall be continued until the temperature rises that can be observed during the test have attained steady final values. See Table I in 5.1. In order to abridge the long time required to attain steady temperatures, reasonable overload or reduction of ventilation during the preliminary heating period is permissible.
4.3 Initial temperature of machine for temperature-rise test to determine I h rating
The temperature-rise test to determine the 1 h rating shall commence only when the windings and other parts
of the machine are within 4 °C of the cooling-air temperature at the time of starting the test.
4.4 Making of short-time overload test
The short-time overload capacity of the machine shall be determined by one or more temperature-rise tests following the continuous rating test at the highest continuous current. The cooling curve of the earlier rating test shall be plotted as taken, and the overload shall be applied when the extrapolation of this curve indicates that the proper initial armature temperature rise has been reached. The overload shall then be applied under normal ventilation conditions and at the voltage that corresponds to the test current on the machine characteristic and shall be maintained constant for a period estimated to reach the final temperature rise given in Table 2 in 5.1. The short-time overload rating of the machine may be calculated from a test that does not differ in final temperature rise from that in Table 2 by more than ±10 °C.
4.5 Ventilation during temperature-rise test
The test shall be carried out with the machine arranged as in service, with all those parts that would affect the temperature rise of the machine in place, but without any ventilation corresponding to that produced by the motion of the vehicle itself.
4.6 Waveforms during temperature-rise tests
4.6.1
Smooth current or sine wave power may he used rather than pulse-controlled if the ripple or harmonic content would be so low that the added losses may be neglected or accounted for.
4.6.2
Rating test(s) shall be repeated with smooth current or sine wave supply to establish reference for further type tests. If type test equipment can not reach the rating point, another point at the same flux level may have to be used.
4.6.3
Heat run(s) on waveforms as in service are required on one machine deemed typical. Other type tests are
compared to the reference test(s).
4.7 Voltage during temperature-rise test
The voltage applied to a machine during the temperature-rise test shall be the rated voltage as defined in 4.8.