Your question is quit interesting and I would like to suggest a rephrase of the question to the following:
May we use a drive designed for variable torque applications with a constant torques application?
And according to a little reading I did it mostly have to do with sizing and maybe firmware/software that is designed/has algorithm to handle torques and overloading in specific ways.
A few links:
What are the characteristics of Variable Torque and Constant Torque?
Variable torque drive for constant torque application
From
here:
- VFDs do not produce horsepower (hp)
- VFDs do not produce torque
- VFDs supply current that, with the correct voltage and frequency, makes the motor run at the desired speed
And from
this pdf:
"The most important consideration when choosing a Variable Frequency Drive (VFD) is to know the type
of load that is being applied to the motor because it will determine the size and cost of the VFD. The VFD
must have sufficient current capability so that the motor can produce the required torque for the load"
"In order to keep a constant torque, which is
directly related to current, the voltage going
from the VFD to the motor is increased as the
speed increases. On a 460 Volt motor, 460 Volts
is only applied to the motor when the speed
reaches 60 Hz. Constant torque is achieved
because the VFD is increasing the voltage to the
motor as it increases the speed. "
And this is probably what they meant by squared torque( very poor terminology in my opinion) :
"Variable Torque Loads
Variable torque loads require much lower torque
at low speeds and the torque increases rapidly at
high speeds. As the motor spins faster, the load
on the motor increases. These types of loads are
approximately represented by assuming that the
load torque required is proportional to the
square of the speed. For example, if speed
increases by a factor of 3, torque increases by a
factor of 9.
ššššš¢š ā ššššš D "
Then there is a
derating curves:
"The following Variable Torque (VT) and Constant Torque (CT) derating curves are for drives with 3-phase input power.
The 230VAC, CT curves also apply equally whether the drive is supplied with 3-phase or 1-phase input power."