Low speed inverter output full torque
I have an application that require running an 55Kw high efficiency induction motor at rated torque at any rpm from 5% to 100% of the rated rpm. It will be controlled by a frequency inverter with FOC.
This motor has independent cooling fan running with a separate motor that is capable of removing 5Kw heat from the motor. It will be controlled by an inverter with FOC. The motor is a good 95% efficient with cast copper rotor / not the regular cast aluminum. Can an induction motor give out full torque at 5% of its rated rpm with an inverter?? My concern is it may over heat at low frequency - not due to cooling fan because that is independent, but due to the other reasons.
This motor has independent cooling fan running with a separate motor that is capable of removing 5Kw heat from the motor. It will be controlled by an inverter with FOC. The motor is a good 95% efficient with cast copper rotor / not the regular cast aluminum. Can an induction motor give out full torque at 5% of its rated rpm with an inverter?? My concern is it may over heat at low frequency - not due to cooling fan because that is independent, but due to the other reasons.
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I am not as concerned about heat. Today's motors (yes this is a general statement) especially motors with copper rotor are designed to operate with inverters. They are designed to move the heat to the outer skin of the motor for dissipation, the addition of the separate fan for cooling adds to the life of the motor, the exception is if your ambient environment temperature exceeds 40 degree C.
To ensure best performance full torque at low speeds, is achieved if you operate in close loop or vector control, with some form of performance feedback, ie... encoder. - -> by: Admin