Apparatus for controlling rotary electric machine

• US 9,543,868 B2
• Filed: 06/01/2016
• Issued: 01/10/2017
• Est. Priority Date: 06/01/2015
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Takahashi, Hidekazu
• Primary Examiner(s): DUDA, RINA I
• Application Number:
  US15/169,860
• Publication Number:
  US 20160352269A1
• Time in Patent Office: 223 Days
• Field of Search: 318/432, 318/434, 318/400.01, 318/400.02
• US Class Current: 1/1
• CPC Class Codes: H02P 21/20 Estimation of torque
• CPC Class Codes: H02P 27/085 wherein the PWM mode is adapted on the running conditions of the motor, e.g. the switching frequency
• CPC Class Codes: H02P 6/28 Arrangements for controlling current H02P6/10 takes precedence

Abstract

In an apparatus, a first control unit performs current-feedback control, and a second control unit performs torque-feedback control. The torque-feedback control samples values of each output current at phases. The sampled values of each output current at the phases are referred to as phase-related sampled values of the corresponding output current. The apparatus causes the second control unit to sample values of each output current at the predetermined phases while the first control unit is performing the current-feedback control when switching the current-feedback control to the torque-feedback control. The second control unit uses the values of each output current sampled by the first control unit as the phase-related sampled values of the corresponding output current to start the torque-feedback control when the current-feedback control is switched to the torque-feedback control.

Claims

1. An apparatus for adjusting an output voltage from an inverter to a rotary electric machine to control the rotary electric machine, the apparatus comprising:

a first control unit configured to perform a current-feedback control routine, the current-feedback control routine being configured to;

set a sinusoidal voltage command based on command torque for output torque of the rotary electric machine and the output currents; and

compare the sinusoidal voltage command with a periodic carrier signal to control the output voltage accordingly;

a second control unit configured to perform a torque-feedback control routine, the torque-feedback control routine being configured to;

sample values of each of the output currents at predetermined phases, the sampled values of each of the output currents at the predetermined phases being referred to as phase-related sampled values of the corresponding output current;

control, based on the phase-related sampled values of each of the output currents and the command torque, a waveform of the output voltage; and

a switching control unit configured to;

switch control of the rotary electric machine between the current-feedback control routine and the torque-feedback control routine; and

cause the second control unit to sample values of each of the output currents at the predetermined phases while the first control unit is performing the current-feedback control routine when switching the current-feedback control routine to the torque-feedback control routine,

the second control unit being configured to use the values of each of the output currents sampled while the first control unit is performing the current-feedback control routine as the phase-related sampled values of the corresponding output current to start the torque-feedback control routine when the current-feedback control routine is switched to the torque-feedback control routine.

2. The apparatus according to claim 1, wherein:

the first control unit is configured to;

obtain a value of each of the output currents each time the periodic carrier signal becomes a predetermined phase; and

set the sinusoidal voltage command based on the command torque and the obtained values of the output currents; and

the switching control unit is configured to adjust a frequency of the periodic carrier signal while the first control unit is performing the current-feedback control routine such that;

the second control unit uses the values of each of the output currents obtained by the first control unit as the phase-related sampled values of the corresponding output current.

3. The apparatus according to claim 1, wherein:

the switching control unit is configured to synchronize phases of the obtained values of each of the output currents with the predetermined phases of the corresponding output current used for current sampling by the torque-feedback control routine.

4. The apparatus according to claim 2, wherein:

the switching control unit is configured to synchronize phases of the obtained values of each of the output currents with the predetermined phases of the corresponding output current used for current sampling by the torque-feedback control routine.

5. The apparatus according to claim 1, wherein:

the output voltage has a rectangular-pulse waveform during execution of the torque-feedback control routine; and

the second control unit is configured to perform, as the torque-feedback control routine, a rectangular-pulse control routine that adjusts a phase of the output voltage having the rectangular-pulse waveform.

6. The apparatus according to claim 1, wherein:

the rotary electric machine comprises a rotor; and

the switching control unit is configured to;

obtain a rotational speed of the rotor; and

perform switching of control of the rotary electric machine from the current-feedback control routine to the torque-feedback control routine when the rotational speed of the rotor exceeds a first rotational-speed threshold.

7. The apparatus according to claim 6, wherein:

the second control unit uses the values of each of the output currents obtained by the first control unit as the phase-related sampled values of the corresponding output current when the rotational speed of the rotor exceeds a second rotational-speed threshold, the second rotational-speed threshold being set to be lower than the first rotational-speed threshold.

8. The apparatus according to claim 1, wherein:

the switching control unit is configured to;

obtain a modulation ratio of the inverter; and

perform switching of control of the rotary electric machine from the current-feedback control routine to the torque-feedback control routine when the modulation ratio of the inverter exceeds a first modulation-ratio threshold.

9. The apparatus according to claim 8, wherein:

the second control unit uses the values of each of the output currents obtained by the first control unit as the phase-related sampled values of the corresponding output current when the modulation ratio of the inverter exceeds a second modulation-ratio threshold, the second modulation-ratio threshold being set to be lower than the first modulation-ratio threshold.