Valeo Equipements Electriques Moteur

Guillaume Duthilleul

Pierre Tisserand

Pierre Chassard

Pierre Sardat

Marc Tunzini

Laurent Labiste

Laurent De Lamarre

Olivier Grammont

Vincent Gendron

Romuald Morvany

Victor Dos Santos

Pierre-François Ragaine

Jeremy Lagrange

The excitation circuit according to the invention controls an excitation current (lexc) in an excitation winding () of an alternator by means of an on-board network voltage control loop (Vbat+,) of the vehicle, and comprises a first MOS power transistor () which is connected between a first positive supply terminal Vbat+ (), and a first excitation terminal (), and is controlled by the control loop by means of a first control circuit (), a second MOS power transistor (), which is connected between the first excitation terminal and a second excitation terminal () which is connected to a ground terminal () and acts as a free wheel diode, whilst being controlled by means of a second control circuit (). According to the invention, the circuit additionally comprises a control loop () of a drain-source voltage (Vds) of the second transistor.

Excitation circuit of a motor vehicle alternator, voltage regulator, and alternator which incorporates it

A synchronous rectification alternator for a motor vehicle is disclosed. The alternator includes a stator, a rotor, and a synchronous rectification system for rectifying into a DC voltage the alternating voltages supplied by the stator, and a voltage regulator for regulating the DC voltage. The alternator also includes fault detection for detecting faults in the synchronous rectification and supplying fault detection information to the voltage regulator. In one version, the fault information is supplied to the voltage regulator at fault inputs also receiving phase signals representing the alternating voltages supplied by the stator. At least one of the items of fault information is used to cause, in the voltage regulator, opening of an excitation circuit supplying current to an excitation coil of the rotor so as to produce, in the voltage regulator, a fault indication. The opening of the excitation circuit is preferably caused through a suitable command of a fast demagnetization transistor included in the excitation circuit.

Vehicle alternator having synchronous rectification and electronic fault management

A method comprises the transmission to a regulator () of the alternator of width-modulated pulses (PWM) exhibiting a duty ratio representative of a setpoint value (Vref) continuously included between a first reference duty ratio (DC) and a second reference duty ratio (DC), and the detection of these pulses by the regulator so as to generate the setpoint value. The method also comprises the transmission to the regulator of other width-modulated pulses (PWM) exhibiting a specific duty ratio (EXOF_R) which is less than the first reference duty ratio (DC) and ties between a low duty ratio (DCL) and a high duty ratio (DCH), and the detection of these other pulses by the regulator, in a first step, and the generation of an opening signal (EXOF) for a circuit for excitation of the alternator, in a second step, following this latter detection.

Method of controlling the regulation of a motor vehicle alternator, and corresponding devices

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Salles, France

Guillaume Duthilleul