Extended Power Range Modification
Induction motors powered from the Mains have a power constrained by the relatively constant frequency and voltage of the mains.
When the induction motor is powered from a VF drive, both the voltage and frequency are manipulated electronically by the drive and this allows smooth variable speed control to be achieved.
Electronic Innovations Pty. Ltd. have manipulated this ability of the drive to independently control voltage and frequency, to develop the EPR modification for Induction motor drive systems.
In most motor setups up to 37kW it is possible to achieve a power increase of at least 60% with no increase in heat stress on the motor. That is to say a 3kW motor becomes a 4.8kW and an 11kW becomes a 17.6kW, and so on.
How does this work?
By extending the speed range over which the rotor flux can be maintained at 100%, a motor drive combination can produce full torque up to a higher than base speed.
This results in greater power. It does however require minor modifications to both motor and drive.
Consider Gearing
In the case where more power and speed is required this works ideally as no change to the mechanical setup is required.
In other cases where more power at the same speed is required, a change to the mechanical gear ratio from the motor to the load will be required whereby the higher motor speed is geared to the original output speed with say a pulley size change.
In this situation, after gearing, extra power is available over the full speed range.
A side product of the extended magnetising range is the greatly improved servo response of the system in this extended speed range.
So what power drive is needed?
Just to show that its not completely magic, you do need to use a suitable drive that is rated at the actual power you intend to get out of the motor, not the original power rating of the motor.
Also a suitable six wire motor is a requirement for the EPR modification.
Please contact Electronic Innovations Pty. Ltd. to discuss applications of the EPR modification, as normally the changes can be made in a day.
We can also provide upgraded VF drives at excellent prices if required.