Method and apparatus for active voltage control of electric motors
AssigneeGM Global Technology Operations LLC
InventorsBrian A Welchko, Keith A Rodman
Life of this patent
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Abstract
Methods and apparatus are provided for dynamic voltage control of electric motors. An inverter provides an output voltage to an electric motor based on a gate voltage. The method includes determining a speed of the electric motor and modifying the gate voltage based on the speed of the electric motor. The apparatus includes a gate drive circuit and a controller coupled to the gate drive circuit. The gate drive circuit provides a gate voltage to a switch network, and the switch network produces the output voltage in response to the gate voltage. The controller modifies the gate voltage based on a speed of the electric motor.
Claims12
A method for controlling an inverter, the inverter operable to provide an output voltage to an electric motor, the method comprising:
- determining if a commanded output frequency of the inverter does not exceed a first pre-determined threshold;
- determining, if the commanded output frequency does not exceed the first pre-determined threshold, if a commanded stator current of the inverter exceeds a second pre-determined threshold;
- producing a first command if the commanded stator current exceeds the second pre-determined threshold, the inverter receiving a first gate voltage in response to the first command and providing the output voltage in response to the first gate voltage;
- and
- producing a second command if the commanded stator current does not exceed the second pre-determined threshold, the inverter receiving a second gate voltage in response to the second command and providing the output voltage in response to the second gate voltage, the first gate voltage greater than the second gate voltage.
An inverter for providing an output voltage to an electric motor and configured to receive a commanded output frequency and a commanded stator current, the inverter comprising:
- a gate drive circuit having an input and having an output configured to couple to a switch network, the gate drive circuit configured to provide a gate voltage to the switch network, the switch network operable to produce the output voltage in response to the gate voltage;
- and
- a controller coupled to the input of the gate drive circuit, the controller configured to:
- modify the gate voltage based on a speed of the electric motor;
- determine if the commanded output frequency does not exceed a second first pre-determined threshold;
- determine, if the commanded output frequency does not exceed the first pre-determined threshold, if the commanded stator current of the inverter exceeds a second pre-determined threshold;
- produce a first command if the commanded stator current does not exceed the second pre-determined threshold, the switch network receiving a first gate voltage in response to the first command and providing the output voltage in response to the first gate voltage;
- and
- produce a second command if the commanded stator current exceeds the second pre-determined threshold, the switch network receiving a second gate voltage in response to the second command and providing the output voltage in response to the second gate voltage, the second gate voltage greater than the first gate voltage.
Dependencies are inferred from the claim text.