inverter/motor efficiency across voltage range
inverter/motor efficiency across voltage range
(OP)
are there any general rules of thumb concerning inverter/motor efficiency across a voltage range?
for example if we are looking at a range of DC input from 400-1200V, and we assume inverter/motor can be optimized for any voltage input, is there any overall efficiency benefit of a higher voltage level compared to lower?
I'm sure i'm overly simplifying problem but would love to learn how motor speed, inverter IGBT/MOSFET, and other features impact efficiency based on voltage level.
Thanks!
for example if we are looking at a range of DC input from 400-1200V, and we assume inverter/motor can be optimized for any voltage input, is there any overall efficiency benefit of a higher voltage level compared to lower?
I'm sure i'm overly simplifying problem but would love to learn how motor speed, inverter IGBT/MOSFET, and other features impact efficiency based on voltage level.
Thanks!
RE: inverter/motor efficiency across voltage range
Also, are you referring to using an AC motor with a DC input to it? For that, you must understand that the DC input must match the PEAK voltage of the AC motor design, nit the RMS voltage. So for example if you have a 460V motor, the DC input must be higher by the sq. rt. of 2, so 650VDC if you want to get full output capability from that motor.
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RE: inverter/motor efficiency across voltage range
The system cost might be a factor as well: higher voltage results in lower currents for a given power rating. This means smaller conductor cross-section - but larger insulation thickness and/or spacing for the conductors. At the motor end, it may mean a physically larger machine (to accommodate the increased clearance and creepage requirements for the higher voltage). It also typically means more turns in a given winding, since the magnetic force required to do the actual mechanical work is directly proportion to the product of (amps x turns).
Running a high-volt low-amp drive can sometimes mean a lower drive cost as well, depending on whether the limiting factor in the design is the voltage at discrete points in the circuit or the current carried through those points.
The bottom line is to try and optimize the SYSTEM (drive plus motor plus conductors between) in terms of cost, physical space, efficiency, and other performance-related criteria.
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RE: inverter/motor efficiency across voltage range
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