Motor torque compensation of an induction electric motor by adjusting a slip command during periods of supposed change in motor temperature
- Brighton, MI
- Livonia, MI
The present invention maintains constant torque in an inverter driven AC induction motor during variations in rotor temperature. It is known that the torque output of a given AC induction motor is dependent upon rotor temperature. At rotor temperatures higher than the nominal operating condition the rotor impedance increases, reducing the rotor current and motor torque. In a similar fashion, the rotor impedance is reduced resulting in increased rotor current and motor torque when the rotor temperature is lower than the nominal operating condition. The present invention monitors the bus current from the DC supply to the inverter and adjusts the slip frequency of the inverter drive to maintain a constant motor torque. This adjustment is based upon whether predetermined conditions implying increased rotor temperature or decreased rotor temperature exist for longer that a predetermined interval of time.
- Research Organization:
- EATON CORP
- DOE Contract Number:
- AC07-84NV10366
- Assignee:
- Eaton Corporation (Cleveland, OH)
- Patent Number(s):
- US 5086264
- OSTI ID:
- 868163
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
torque
compensation
induction
electric
adjusting
slip
command
periods
supposed
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temperature
maintains
constant
inverter
driven
variations
rotor
output
dependent
temperatures
nominal
operating
condition
impedance
increases
reducing
current
similar
fashion
reduced
resulting
increased
monitors
bus
dc
supply
adjusts
frequency
drive
maintain
adjustment
based
predetermined
conditions
implying
decreased
exist
interval
time
slip frequency
induction motor
electric motor
operating condition
motor torque
torque output
dc supply
predetermined interval
maintains constant
constant torque
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