Method for managing an alternator combined with at least one power battery and driven by a heat engine

Abstract

The invention relates to a method for managing a motor vehicle provided with a first battery connected to an alternator and to an electrical network of the vehicle, the alternator being drivable so as to operate either at a strictly positive low alternator voltage (Valt_basse) or at a high alternator voltage (Valt_haute) strictly higher than the low alternator voltage, wherein the method comprises estimating the strength (I(SOC)) of the potential recharging current that the first battery could absorb if it was, at that moment, powered by the high alternator voltage (Valt_haute). The method further comprises estimating a first alternator yield (Rend1) corresponding to the current speed of rotation (omega) of the alternator, and to the strength of the consumed current (Ires) actually fed into the network, estimating a second alternator yield (Rend2) corresponding to the current speed of rotation of the alternator and to the sum of the strengths (I(SOC)+Ires) of the potential recharging current (I(SOC)) of the battery and of the consumed current (Ires), and imposing a high alternator voltage if the difference between the first yield and the second yield is higher than a first threshold (Delta).

Description

technical field [0001] The invention relates to an electric power supply system for a motor vehicle with propulsion generated by a heat engine or thermoelectric hybrid propulsion, and notably to an electric power supply system comprising several different types of batteries. Background technique [0002] Rather, it may be desirable to use different types of batteries in parallel, for example, from the good ability of a lead battery to power a cold start and from the high specific energy and better charging and discharging cycles of batteries of the lithium-ion type. Benefit from high durability. [0003] Thus patent application US 2011001352 describes a system in which there are two types of batteries whose no-load voltage and internal resistance are chosen such that, for a constant alternator voltage, it is preferably discharged and The lithium battery is then recharged, so the lead battery goes through a smaller number of charge and discharge cycles. [0004] The use of ...

AI Technical Summary

Problems solved by technology

The maximum energy capacity of lithium batteries is therefore limited by this

[0006] Such a system makes it possible to increase the life of lead batteries, but makes it necessary to limit the performance of these lithium batteries used

Furthermore, the constant voltage of the alternator must be chosen high enough to enable the lead and lithium batteries to be recharged simultaneously, which causes an excessive consumption of fuel compared to a system equipped only with lead batteries

[0007] Patent application WO 01 / 52382 makes it possible to switch on or deactivate the alternator depending on the state of charge of a battery or a group of batteries of the vehicle and also depending on the type of driving of the vehicle

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