Curtiss-Wright EXLAR Tritex II AC, Инструкция по установке и обслуживанию

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Curtiss-Wright | Tritex II AC 90, 115 Rev. X PN39892 7/12/22 55
It is best to consider the energy in a regenerative event and the time
between these events when sizing a braking resistor for energy and
power. An example may provide the clearest presentation. A 100kg
vertical load is lowered 0.2m in a move repeated every 10 seconds.
Since 100kg exerts 980 Newtons, the move results in 196 Nt-m (or
Joules) of energy. Assuming roughly 90% conversion efficiency, the
regenerative event results in 180 Joules are delivered to the braking
resistor. Since this happens every 10 seconds, the average power to the
resistor is only 18 W. Though most resistors are not directly rated for
energy, short term overload ratings can be used, though these ratings
usually are for isolated events where the resistor can fully cool before
another event. Using half the energy rating with repetitive events is
generally appropriate. A resistor rated 100 W with an overload rating of 2
times continuous for 5 seconds which is 1000 Joules would be able to
handle repetitive 500 Joule events, so would be adequate for the
application.
Braking Resistor Connections