Method and system for controlling a motor vehicle alternator, and motor vehicle alternator including such a system

摘要

A method for controlling a motor vehicle alternator, in which an error value, resulting from the comparison between the voltage produced by the alternator and a set value, is processed in a filtering means by applying a transfer function, which determines a gain to be associated with the error value on the basis of the rotational frequency of the alternator, in order to control the adjustment of the field current allowed by the alternator. The transfer function of the filtering means is modified on the basis of the rotational speed of the alternator by attenuating the gain over a given frequency range when the rotational speed decreases.

主权项

1. A method for regulating a motor vehicle alternator (2) designed to be coupled to a thermal engine (10) of said vehicle for producing a supply voltage for an on-board network (4) of said vehicle, said method comprising the step of comparing said voltage (Up) produced by said alternator with a set value (Uref) in a control loop (12) in order to determine the value of an excitation current (Iex) to be circulated in said alternator for the production of a voltage equivalent to said set value, wherein an error value (Err) derived from the comparison between said voltage produced and said set value is processed in a filtering means (26) by applying a transfer function which determines a gain to be associated with said error value according to a speed of rotation of the alternator in order to control the regulation of the excitation current allowed by said alternator, wherein said transfer function of said filtering means is modified according to said speed of rotation of said alternator by attenuating said gain in a given frequency range when said speed of rotation decreases, and wherein said gain of said transfer function is determined for a given frequency between a maximum threshold (H1) corresponding to the gain of said original transfer function, and a minimum threshold (H2) determined for preservation of stability said alternator, with said maximum threshold being preserved when said speed of rotation of said alternator is equal to, or higher than, a first given limit speed (V1), and with said minimum threshold being selected when said speed of rotation of said alternator is equal to, or lower than, a second given limit speed (V2).