Motor control with voltage harmonic shaping
AssigneeTRW Inc.
InventorChristoper David Dixon
Life of this patent
Estimating the term…
Abstract
A control system for an electric motor (10) comprises a current sensing means (14) arranged to produce a current sensing output indicative of electric current in the motor, current control means (20) arranged to receive a current demand and to control voltages applied to the motor, and correction means (26) arranged to receive the current sensing output and the current demand, and use them to generate a correction signal. The current control means (20) is arranged to receive the correction signal and to use the correction signal to correct the voltages applied to the motor.
Claims21
A control system for an electric motor comprising:
- a current sensing means arranged to produce a current sensing output indicative of electric current in an electric motor;
- a current controller arranged to receive a current demand and to control voltages applied to the electric motor;
- and
- a harmonic compensation controller arranged to operate in both (1) a high speed mode of operation of the motor, wherein the harmonic compensation controller identifies a distortion frequency and at least partially isolates a distortion frequency component from a fundamental frequency component of the current sensing output by filtering, and (2) a low speed mode of operation of the motor, wherein the harmonic compensation controller receives the current sensing output and the current demand as separate inputs and uses the separate current sensing output and the current demand inputs to generate a correction signal,
- wherein the current controller is arranged to receive and use the correction signal to correct voltages applied to the electric motor.
A combined control system and electric motor assembly comprising:
- an electric motor;
- and
- a control system including:
- (1) a current sensor that produces a current sensing output signal that is indicative of an electric current in the electric motor;
- (2) a current controller that receives a current demand signal and controls voltages applied to the electric motor;
- and (3) a correction circuit that operates in both (a) a high speed mode of operation of the electric motor, wherein the correction circuit identifies a distortion frequency and at least partially isolates a distortion frequency component from a fundamental frequency component of the current sensing output signal by filtering, and (b) a low speed mode of operation of the electric motor, wherein the correction circuit receives the current sensing output signal and the current demand signal as separate inputs and uses the separate current sensing output and the current demand inputs to generate a correction signal to the current controller, which uses the correction signal to correct voltages applied to the electric motor.
A control system for an electric motor comprising:
- a current sensing means arranged to produce a current sensing output indicative of electric current in an electric motor;
- a current controller arranged to receive a current demand and to control voltages applied to the electric motor;
- and
- a harmonic compensation controller arranged to operate in both (1) a high speed mode of operation of the motor, wherein the harmonic compensation controller identifies a distortion frequency and at least partially isolates a distortion frequency component from a fundamental frequency component of the current sensing output by filtering, and (2) a low speed mode of operation of the motor, wherein the harmonic compensation controller receives the current sensing output and the current demand as separate inputs and uses the separate current sensing output and the current demand inputs to generate a correction signal,
- wherein the current controller is arranged to receive and use the correction signal to correct voltages applied to the electric motor.
Dependencies are inferred from the claim text.