ROTARY ELECTRICAL MACHINE WITH EXCITATION PROVIDED WITH A DIGITAL REGULATOR DEVICE

• US 20120326677A1
• Filed: 10/28/2010
• Published: 12/27/2012
• 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
• Granted Patent: US 9,007,036 B2
• Time in Patent Office: Days
• US Class Current: 322/28
• 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. Rotary electrical machine with excitation (1) provided with a digital regulator device (2) which can operate as a generator, and supplies an output voltage (Ub+) which is adjusted by an excitation current (Ie), and thus has a pass-band which is limited by a first predetermined cut-off frequency (F1c), said digital regulator device (2) comprising means (7) for control of the said excitation current (Ie) and a regulator loop (6) comprising at its input means (10) for measurement by sampling of the said output voltage (Ub+) which generate a sampled signal at a first predetermined sampling frequency (F1e), and at its output means (13) for generation of a control signal (PWM) which control said control means (7) according to said sampled signal and a set value (Uo), wherein said means (10) for measurement comprise oversampling means such that said first sampling frequency (F1e) is more than twice said cut-off frequency (F1c), and wherein said regulator loop (6) additionally comprises means (12) for decimation of said sampled signal.

2. Rotary electrical machine with excitation (1) according to claim 1, wherein said means (10) for measurement generate said sampled signal on a first predetermined number of hits (B1), and wherein said regulator loop (6) additionally 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. 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. 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).

5. 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 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).

6. 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. 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 the said first cut-off frequency (F1c) and half of said first sampling frequency (F1e).

8. 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. 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):

the said second cut-off frequency (F2c);

the said third cut-off frequency (F3c);

the said first clock frequency (F1h);

the said second clock frequency (F2h);

the said first sampling frequency (F1e);

the said second sampling frequency (F2e);

the attenuation ratio (A).

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

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

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

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

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

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

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

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

said first number of bits (B1) is 10;

said second number of bits (B2) is 15;

said third number of bits (B3) is 8;

said fourth number of bits (B4) is 32;

the attenuation ratio (A) is ⅛

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