Rotary electrical machine with excitation provided with a digital regulator device

• US 9,007,036 B2
• Filed: 10/28/2010
• Issued: 04/14/2015
• Est. Priority Date: 11/13/2009
• Status: Active Grant

• Current Assignee: Valeo Equipements Electriques Moteur (Valeo SE)
• Original Assignee: Valeo Equipements Electriques Moteur (Valeo SE)
• Inventors: Tisserand, Pierre, Chassard, Pierre, Labiste, Laurent
• Primary Examiner(s): Gonzalez, Julio
• Assistant Examiner(s): NGUYEN, VIET P
• Application Number:
  US13/505,411
• Publication Number:
  US 20120326677A1
• Time in Patent Office: 1,629 Days
• Field of Search: 322/28, 322/24, 322/20, 322/44, 322/22
• US Class Current: 322/44
• CPC Class Codes: H02J 7/2434 with pulse modulation
• CPC Class Codes: H02P 9/24 due to variation of make-to-break ratio of intermittently-operating contacts, e.g. using Tirrill regulator
• CPC Class Codes: H02P 9/48 Arrangements for obtaining a constant output value at varying speed of the generator, e.g. on vehicle H02P9/04 - H02P9/46 take precedence
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

The rotary electrical machine is capable of functioning as a generator and outputs a continuous output voltage (Ub+) that is adjustable by an excitation current. The digital regulator (2) of the machine comprises an excitation current control means (7) and a control loop (6) that includes a device (10) for measurement, by sampling, of the output voltage (Ub+), the measurement device generating a signal sampled at a predetermined first sampling frequency (F1 e). The machine has a bandwidth that is limited by a predetermined first cutoff frequency (F1 c). The measurement device includes an apparatus for oversampling such that the first sampling frequency (F1 e) is greater than twice the first cutoff frequency (F1 c), and the control loop also includes an apparatus (12) for decimating the sampled signal.

Claims

1. A rotary electrical machine with excitation (1) provided with a digital regulator device (2), said rotary electrical machine adapted to operate as a generator and supply an output voltage (Ub+) adjusted by an excitation current (Ie), and having a pass-band limited by a first predetermined cut-off frequency (F1c), said digital regulator device (2) comprising:

control means (7) for control of the said excitation current (Ie); and

a regulator loop (6) comprising input means (10) for measurement by sampling of said output voltage (Ub+) which generates a sampled signal at a first predetermined sampling frequency (F1e), and output means (13) for generation of a control signal (PWM) which controls said control means (7) according to said sampled signal and a set value (Uo), wherein said input means (10) for measurement comprise oversampling means such that said first sampling frequency (F1e) is more than twice said first cut-off frequency (F1c), and wherein said regulator loop (6) additionally comprises means (12) for decimation of said sampled signal.

2. The rotary electrical machine with excitation (1) according to claim 1, wherein said means (10) for measurement generates said sampled signal on a first predetermined number of bits (B1), and wherein said regulator loop (6) further comprises means (11) for filtering said sampled signal, such that said sampled signal comprises, after processing by said means (11), a second predetermined number of bits (B2) which is greater than said first number of bits (B1).

3. The rotary electrical machine with excitation (1) according to claim 2, wherein said filtering means comprise a filter of the averaging type (11) which produces a sliding average on a predetermined number of samples (N) of said sampled signal.

4. The rotary electrical machine with excitation (1) according to claim 3, wherein said control signal (PWM) is a rectangular signal which has a variable cyclical ratio, and wherein said means for generation comprise a digital comparator (13) which generates said control signal (PWM) by comparison of said sampled signal (U) with a reference signal (R) which is obtained by the addition of said set value (Uo) to a counting signal (C1) which is provided by a countdown counter, or a look-up table, on a third number of bits (B3) which operate at a first predetermined clock frequency (F1h).

5. The rotary electrical machine with excitation (1) according to claim 2, wherein said means (12) for decimation implement a change of frequency, such that said sampled signal has a second sampling frequency (F2e) which is lower than said first sampling frequency (F1e).

6. The rotary electrical machine with excitation (1) according to claim 4, wherein said control signal (PWM) is a rectangular signal which has a variable cyclical ratio, and said means for generation comprise a digital comparator (13) which generates said control signal (PWM) by comparison of said sampled signal (U) with a reference signal (R) which is obtained by the addition of said set value (Uo) to a counting signal (C2) which is provided by a reversible counter, or a look-up table, on a third number of bits (B3) which operate at a second predetermined clock frequency (F2h).

7. The rotary electrical machine with excitation (1) according to claim 1, wherein said regulator loop (6) additionally comprises an analogue low-pass filter (18) which precedes said means (10) for measurement, and has a third cut-off frequency (F3c) contained between said first cut-off frequency (F1c) and half of said first sampling frequency (F1e).

8. The rotary electrical machine with excitation (1) according to claim 1, wherein said regulator loop (6) also comprises a voltage divider (19) which precedes said means (10) for measurement, with a predetermined attenuation ratio (A) which is designed for an operating range of said means (10) for measurement.

9. The rotary electrical machine with excitation (1) according to claim 1, wherein said regulator loop (6) additionally comprises a communication protocol decoder (24) which decodes a control signal (23), with a data bus (21) to establish said set value (Uo), and a configuration bus (20) to establish at least one parameter from amongst the following, on the basis of said decoded control signal (23):

a second cut-off frequency (F2c);

a third cut-off frequency (F3c);

a first clock frequency (F1h);

a second clock frequency (F2h);

said first sampling frequency (F1e);

a second sampling frequency (F2e);

an attenuation ratio (A).

10. The rotary electrical machine with excitation (1) according to claim 1, wherein:

said first cut-off frequency (F1c) is substantially equal to 20 Hz;

a second cut-off frequency (F2c) is substantially equal to 84 Hz;

a third cut-off frequency (F3c) is substantially equal to 1 kHz;

a first clock frequency (F1h) is equal to 64 KHz;

a second clock frequency (F2h) is equal to 128 KHz;

said first sampling frequency (F1e) is equal to 64 KHz;

a second sampling frequency (F2e) is equal to 8 KHz;

a first number of bits (B1) is 10;

a second number of bits (B2) is 15;

a third number of bits (B3) is 8;

a fourth number of bits (B4) is 32;

an attenuation ratio (A) is 1/8.

11. The rotary electrical machine with excitation (1) according to claim 1, wherein said regulator loop (6) additionally comprises a digital low-pass filter (17) which precedes said output means (13) of said regulator loop (6) and has a second cut-off frequency (F2c) contained between said first cut-off frequency (F1c) and half of a first operating frequency (F1s) or between said first cut-off frequency (F1c) and half of a second operating frequency (F2s).

12. The rotary electrical machine with excitation (1) according to claim 11, wherein said regulator loop (6) additionally comprises an analogue low-pass filter (18) which precedes said means (10) for measurement and has a third cut-off frequency (F3c) contained between said first cut-off frequency (F1c) and half of said first sampling frequency (F1e).

13. A digital regulator device (2) for a rotary electrical machine with excitation (1), the rotary electrical machine having a pass-band limited by a first predetermined cut-off frequency (F1c) and operable as a generator for supplying an output voltage (Ub+) adjusted by an excitation current (Ie), said digital regulator device (2) comprising:

control means (7) for control of the said excitation current (Ie); and

a regulator loop (6) comprising input means (10) for measurement by sampling of said output voltage (Ub+) which generates a sampled signal at a first predetermined sampling frequency (F1e), means (12) for decimation of said sampled signal and output means (13) for generation of a control signal (PWM) which controls said control means (7) according to said sampled signal and a set value (Uo), wherein said input means (10) for measurement comprise oversampling means such that said first sampling frequency (F1e) is more than twice said first cut-off frequency (F1c).

14. A regulator loop (6) for a rotary electrical machine adapted to operate as a generator and supply an output voltage (Ub+) adjusted by an excitation current (Ie), said regulator loop (6) comprising:

input means (10) for measurement by sampling of said output voltage (Ub+) which generates a sampled signal at a first predetermined sampling frequency (F1e); and

output means (13) for generation of a control signal (PWM) which controls control means (7) for controlling of the said excitation current (Ie) according to said sampled signal and a set value (Uo); and

means (12) for decimation of said sampled signal;

said input means (10) comprising oversampling means such that said first sampling frequency (F1e) is more than twice said first cut-off frequency (F1c).

15. The regulator loop (6) according to claim 14, further comprises means (11) for filtering said sampled signal, such that said sampled signal comprises, after processing by said means (11), a second predetermined number of bits (B2) which is greater than said first number of bits (B1).

16. The regulator loop (6) according to claim 15, wherein said filtering means comprise a filter of the averaging type (11) which produces a sliding average on a predetermined number of samples (N) of said sampled signal.

17. The regulator loop (6) according to claim 15, wherein said means (12) for decimation implement a change of frequency, such that said sampled signal has a second sampling frequency (F2e) which is lower than said first sampling frequency (F1e).