Electricity: single generator systems – Combined control of generator and driving means – Simultaneous control
Reexamination Certificate
1998-12-14
2001-04-10
Ponomarenko, Nicholas (Department: 2834)
Electricity: single generator systems
Combined control of generator and driving means
Simultaneous control
C322S014000
Reexamination Certificate
active
06215283
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and a device for controlling an alternator for a motor vehicle, of the type in which the intensity of an excitation current for the alternator is controlled depending on the operating conditions of the engine and of the vehicle.
2. Description of the Related Art
Known from the prior art, especially from document FR 2,594,273, is a device for controlling an alternator which allows its excitation current to be modulated depending on the operating conditions of the engine and/or of the vehicle so as to overexcite it when decelerating and to de-excite it when accelerating. Such a device makes it possible to improve the overall efficiency of the engine/alternator assembly. However, this improvement is limited by the need to restrain the de-excitation phases so as not to discharge the battery excessively. This is because such a device, looking only at the instantaneous operating conditions of the engine, may not allow a de-excitation phase to be maintained below a certain level of charge of the battery and forces the alternator to be put back into service even if conditions more propitious to recharging the battery should arise subsequently.
SUMMARY OF THE INVENTION
The object of the present invention is therefore to provide a method and a device for controlling an alternator for a motor vehicle which makes it possible to take into account the operating conditions over the entire journey and to improve the optimization of the alternator/engine assembly.
These objects of the invention are achieved, as well as others which will appear in the rest of the present description, by means of a method for controlling an alternator delivering an electrical current which supplies power to electrical consumers in a motor vehicle equipped with an internal combustion engine and which recharges a battery, in which method the intensity of an excitation current for the alternator is controlled depending on operating conditions of the engine and of the vehicle over a journey. According to the invention, for each journey, an initial state of charge of the battery is determined, a probable time profile of the rotary speeds of the alternator is computed for this journey, the current absorbed by the consumers is measured, an optimum time profile of the excitation current for the alternator is determined such that, at the end of the journey, the final state of charge of the battery is at least equal to a predetermined threshold, and the intensity of the excitation current is controlled according to the current profile determined. Advantageously, the measurement of the current absorbed is periodically updated and the optimum excitation profile to be applied to the alternator is recomputed at each update.
According to a first embodiment of the invention, the time profile of the rotary speeds of the alternator is computed from recordings made during previous journeys.
According to a second embodiment of the invention, the time profile of the rotary speeds of the alternator is computed from information relating to the intended journey and provided by a navigation device on board the vehicle.
Advantageously, in this embodiment, information relating to the density of the traffic over the journey in question, supplied by an RDS-type traffic information receiver coupled to the navigation device, is also used.
According to an important characteristic of the invention, the optimum time profile of the excitation current is computed in such a way that the efficiency of the alternator is a maximum if its rotary speed is greater than a predetermined threshold and the excitation current is zero otherwise.
The invention also provides a device for implementing the method, comprising, in combination, means of communication with at least one of the engine management and navigation devices, measurement means suitable for determining the state of charge of the battery and the intensity of the current delivered to the electrical consumers in the vehicle, computing means and storage means suitable for computing, from information transmitted by the communication means, at the start of each journey, a probable time profile of the rotary speeds of the alternator for this journey and for determining, depending on the information provided by the measurement means, an optimum time profile of the excitation current for the alternator such that, at the end of the journey, the final state of charge of the battery is at least equal to a predetermined threshold, and means for controlling the intensity of the excitation current delivered to the alternator.
REFERENCES:
patent: 4308492 (1981-12-01), Mori et al.
patent: 4651081 (1987-03-01), Nishimura et al.
patent: 5256959 (1993-10-01), Nagano et al.
patent: 5280232 (1994-01-01), Kohl et al.
patent: 5343970 (1994-09-01), Severinsky
patent: 5608310 (1997-03-01), Watanabe
patent: 5637985 (1997-06-01), Kakizaki et al.
patent: 5808367 (1998-09-01), Akagi et al.
patent: 5929609 (1999-07-01), Joy et al.
patent: 5982155 (1999-11-01), Rechdan et al.
patent: 4108751A1 (1991-09-01), None
patent: 0179985A2 (1986-05-01), None
patent: 2594273 (1987-08-01), None
Degardins Pascal
Desroches Philippe
Weil Hans-Georg
Greenberg Laurence A.
Lerner Herbert L.
Ponomarenko Nicholas
Siemens Automotive S.A.
Stemer Werner H.
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