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US 12,117,804 B2Granted
Electric motor speed control apparatus and electric motor speed control method
AssigneeTMEIC Corporation
InventorsUfot Ufot Ekong, Takumi Ito, Masashi Nakamura
Life of this patent
Estimating the term…
Abstract
The electric motor speed control apparatus in an embodiment comprises a rotation speed estimation unit and a control unit. The rotation speed estimation unit generates an estimated value of a rotation speed of an electric motor by using a result of FFT analysis of a speed detection signal ωFBK, which is based on a detection result from a resolver for detecting the rotation speed of the electric motor, and the speed detection signal ωFBK. The control unit implements speed control so as to reduce deviation between the estimated value of the rotation speed and a speed command value for speed control of the electric motor.
Claims8
An electric motor speed control apparatus comprising:
- a rotation speed estimation unit that generates an estimated value of a rotation speed of an electric motor by using a result of FFT analysis of a speed detection signal ωFBK, which is based on a detection result from a resolver for detecting the rotation speed of the electric motor, and the speed detection signal ωFBK;
- and
- a control unit that implements speed control so as to reduce deviation between the estimated value of the rotation speed and a speed command value for speed control of the electric motor;
- wherein
- a shaft of the electric motor and a shaft of the resolver are coupled, and when the control unit is controlling the electric motor at a constant speed, fluctuations in the speed detection signal ωFBK are generated due to eccentricity of the shaft of the resolver with respect to the shaft of the electric motor;
- and
- the rotation speed estimation unit generates an estimated value of the rotation speed by
- when deciding on a phase difference between the estimated value of the rotation speed and the speed detection signal ωFBK, defining one phase difference among phase differences with values different from each other, and adding the estimated value of the rotation speed and the speed detection signal ωFBK, with the defined phase difference provided therebetween,
- repeatedly implementing computations in which the phase difference value is changed, and the estimated value of the rotation speed and the speed detection signal ωFBK are added,
- selecting, from among the repeated implementations, the phase difference for which a component from the fluctuations due to eccentricity is reduced as a result of the adding computations, and
- using the selected phase difference to add the estimated value of the rotation speed and the speed detection signal ωFBK.
8 more elements
An electric motor speed control method that includes:
- steps of generating an estimated value of a rotation speed of an electric motor by using a result of FFT analysis of a speed detection signal ωFBK, which is based on a detection result from a resolver for detecting the rotation speed of the electric motor, and the speed detection signal ωFBK;
- and
- implementing speed control so as to reduce deviation between the estimated value of the rotation speed and a speed command value for speed control of the electric motor;
- wherein
- a shaft of the electric motor and a shaft of the resolver are coupled, and in controlling the electric motor at a constant speed, fluctuations in the speed detection signal ωFBK are generated due to eccentricity of the shaft of the resolver with respect to the shaft of the electric motor;
- and
- the step of generating an estimated value of the rotation speed is included, by
- when deciding on a phase difference between the estimated value of the rotation speed and the speed detection signal ωFBK, defining one phase difference among phase differences with values different from each other, and adding the estimated value of the rotation speed and the speed detection signal ωFBK, with the defined phase difference provided therebetween,
- repeatedly implementing computations in which the phase difference value is changed, and the estimated value of the rotation speed and the speed detection signal FBK are added,
- selecting, from among the repeated implementations, the phase difference for which a component from the fluctuations due to eccentricity is reduced as a result of the adding computations, and
- using the selected phase difference to add the estimated value of the rotation speed and the speed detection signal ωFBK.
8 more elements
Dependencies are inferred from the claim text.