Methods, systems and apparatus for generating voltage commands used to control operation of a permanent magnet machine

Patent metadata

Field	Value
Publication number	US-9211806-B2
Application number	US-201213453705-A
Country	US
Kind code	B2
Filing date	Apr 23, 2012
Priority date	Apr 23, 2012
Publication date	Dec 15, 2015
Grant date	Dec 15, 2015

Abstract

Embodiments of the present disclosure relate to methods, systems and apparatus for generating voltage commands used to control operation of a permanent magnet machine.

First claim

What is claimed is:

1. A method for generating voltage command signals for controlling a permanent magnet machine, the method comprising:
generating a pair of synchronous reference frame voltage command signals at a processor based on inputs comprising a torque command signal (Te*), an angular rotation speed (ωr) of the permanent magnet machine, and a DC input voltage (V DC ), wherein generating the pair of synchronous reference frame voltage command signals comprises:
generating a d-axis voltage command signal (Vd*(kT s1 )) and a q-axis voltage command signal (Vq*(kT s1 )), wherein the d-axis voltage command signal (Vd*(kT s1 )) and the q-axis voltage command signal (Vq*(kT s1 )) are each updated at a first rate; and
generating a modified d-axis voltage command signal (Vd*(kT s1 +mT s0 )) and a modified q-axis voltage command signal (Vq*(kT s1 +mT s0 )), wherein the modified d-axis voltage command signal (Vd*(kT s1 +mT s0 )) and the modified q-axis voltage command signal (Vq*(kT s1 +mT s0 )) are computed and updated at both the first rate and a second rate,
wherein the first rate is a relatively slower rate and the second rate is a relatively faster rate than the first rate; and

selecting, as the synchronous reference frame voltage command signals that are output to control the permanent magnet machine:
the d-axis voltage command signal (Vd*(kT s1 )) and the q-axis voltage command signal (Vq*(kT s1 )) in response to a first selection signal that is generated whenever a torque transient value (ΔTe*) is less than or equal to a transient threshold; and
the modified d-axis voltage command signal (Vd*(kT s1 +mT s0 )) and the modified q-axis voltage command signal (Vq*(kT s1 +mT s0 )) in response to a second selection signal that is generated whenever the torque transient value (ΔTe*) is greater than the transient threshold.

2. A method according to claim 1 , wherein the step of generating comprises:
receiving first inputs comprising: the first torque command signal Te*(kT s1 ), the angular rotation speed samples (ωr(kT s1 )), and the DC input voltage (V DC (kT s1 )), and
applying the first inputs to a set of voltage command lookup tables to generate the d-axis voltage command signal (Vd*(kT s1 )), and the q-axis voltage command signal (Vq*(kT s1 )) at the first rate;
computing torque transient values (ΔTe*) each representing a difference between the second torque command signal Te*((k+1)T s1 ) and the first torque command signal Te*(kT s1 ), and comparing each torque transient value (ΔTe*) to the transient threshold;
generating the first selection signal whenever one of the torque transient values (ΔTe*) is determined to be less than or equal to the transient threshold, and generating the second selection signal whenever one of the torque transient values (ΔTe*) is determined to be greater than the transient threshold; and
further comprising:
outputting, as the synchronous reference frame voltage command signals:
the d-axis voltage command signal (Vd*(kT s1 )) and the q-axis voltage command signal (Vq*(kT s1 )) in response to the first selection signal; and
the modified d-axis voltage command signal (Vd*(kT s1 +mT s0 )) and the modified q-axis voltage command signal (Vq*(kT s1 +mT s0 )) in response to the second selection signal.

3. A method according to claim 2 , further comprising:
applying the first inputs to a first set of current command lookup tables to generate the first d-axis current command signal (Id*(kT s1 )), and the first q-axis current command signal (Iq*(kT s1 ));
receiving second inputs comprising: the second torque command signal Te*((k+1)T s1 ), the angular rotation speed (ωr(kT s1 )), and the DC input voltage (V DC (kT s1 )), wherein the second torque command signal Te*((k+1)T s1 ) is shifted by one first rate sampling time with respect to the first torque command signal Te*(kT s1 ); and
applying the second inputs to a second set of current command lookup tables to generate a second d-axis current command signal (Id*(k+1)T s1 )), and a second q-axis current command signal (Iq*(k+1)T s1 )).

4. A method according to claim 3 , wherein generating the modified d-axis voltage command signal (Vd*(kT s1 +mT s0 )) and the modified q-axis voltage command signal (Vq*(kT s1 +mT s0 )), comprises:
processing the d-axis voltage command signal (Vd*(kT s1 )), the q-axis voltage command signal (Vq*(kT s1 )), the first d-axis current command signal (Id*(kT s1 )), the first q-axis current command signal (Iq*(kT s1 )), the second d-axis current command signal (Id*(k+1)T s1 )), and the second q-axis current command signal (Iq*(k+1)T s1 )) to compute the modified d-axis voltage command signal (Vd*(kT s1 +mT s0 )) and the modified q-axis voltage command signal (Vq*(kT s1 +mT s0 )).

5. A method according to claim 4 , wherein the second d-axis current command signal (Id*(k+1)T s1 )) is shifted by one first rate sampling time with respect to the first d-axis current command signal (Id*(kT s1 )), and wherein the second q-axis current command signal (Iq*(k+1)T s1 )) is shifted by one first rate sampling time with respect to the first q-axis current command signal (Iq*(kT s1 )).

6. A method according to claim 5 , wherein the first rate corresponds to a relatively slower frequency processing, and wherein the second rate corresponds to a relatively higher frequency processing.

7. A method according to claim 6 , wherein the first rate corresponds to a first period (T s1 ) and wherein the second rate corresponds to a second period (T s0 ), wherein there are multiple second periods during each first period.

8. A method according to claim 7 , wherein the second rate is equal to a PWM rate or switching frequency (f SW ).

9. A method according to claim 7 , wherein the modified d-axis voltage command signal (Vd*(kT s1 +mT s0 )) and the modified q-axis voltage command signal (Vq*(kT s1 +mT s0 )) are computed multiple times at the second rate during one of the first periods (T s1 ) to avoid large step changes in the pair of synchronous reference frame voltage command signals such that commanded torque is produced over time in a more linear fashion than the synchronous reference frame d-axis voltage command signal (Vd*(kT s1 )) and the synchronous reference frame q-axis voltage command signal (Vq*).

10. An open loop voltage control system for generating voltage command signals for controlling a permanent magnet machine, the system comprising:
a voltage command processor module receives inputs comprising a torque command signal (Te*), an angular rotation speed (ωr) of the permanent magnet machine, and a DC input voltage (V DC ), and that is configured to generate, based on the inputs, a pair of synchronous reference frame voltage command signals comprising:
a d-axis voltage command signal (Vd*(kT s1 )) and a q-axis voltage command signal (Vq*(kT s1 )), wherein the d-axis voltage command signal (Vd*(kT s1 )) and the q-axis voltage command signal (Vq*(kT s1 )) are each updated at a first rate; and
a modified d-axis voltage command signal (Vd*(kT s1 +mT s0 )) and a modified q-axis voltage command signal (Vq*(kT s1 +mT s0 )), wherein the modified d-axis voltage command signal (Vd*(kT s1 +mT s0 )) and the modified q-axis voltage command signal (Vq*(kT s1 +mT s0 )) are each computed and updated at both the first rate and a second rate, wherein the first rate is a relatively slower rate and the second rate is a relatively faster rate than the first rate; and

select, as the synchronous reference frame voltage command signals that are output to control the permanent magnet machine:
the d-axis voltage command signal (Vd*(kT s1 )) and the q-axis voltage command signal (Vq*(kT s1 )) in response to a first selection signal that is gene

Assignees

• Perisic Milun
• Hiti Silva
• Gallegos-Lopez Gabriel
• Gm Global Tech Operations Inc

Inventors

• Perisic Milun
• Hiti Silva
• Gallegos-Lopez Gabriel

Classifications

• B60L15/025 Primary

  using field orientation; Vector control; Direct Torque Control [DTC] · CPC title

• H02P21/0035

  Electricity · mapped topic

• H02P2207/05

  Synchronous machines, e.g. with permanent magnets or DC excitation · CPC title

• Y02T10/643

  Cross-Sectional Technologies · mapped topic

• Y02T10/64

  Electric machine technologies in electromobility · CPC title