Enfin une troisième partie est consacrée à l’autopilotage des machines synchrones à aimants sans capteur de position mécanique. C.5 Bloc Autopilotage. from publication: TECHNIQUES DE COMMANDE AVANCEES APPLIQUEES AUX MACHINES DE TYPE ASYNCHRONE | The goal of the. [CAR 90] CARTIGNIES M., Etude de l’autopilotage a partir des tensions d’une machine synchrone alimentée par onduleur de tension (controle en courant).
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The invention relates to a method for controlling an alternator-starter for starting autopilot or recovery of a heat engine of a motor vehicle.
Machines of this type are known to the art, including the patent application WO-A In this document, the alternator-starter is a reversible alternator 30 which is adapted for use in a motor vehicle heat engine on the one hand, as an electric generator, and, on the other hand, as electric motor in particular for start the engine of the vehicle.
These systems allow stopping the engine during the vehicle stop phases, and to reboot or restart the dice the appearance of a stimulus such as the initial loading of the driver or another criterion to generate io of fuel savings. To operate reversibly, the alternator-starter is connected in rotation to the crankshaft via a flexible transmission member, for example by a transmission belt. The resisting torque autopilotagw the engine is equal to the sum of a pair of take-off taking into account the inertia of the moving parts of the engine and the frictional forces 25 opposing to their movement, and a compression torque fluid contained in the cylinders of the engine.
For this purpose, it is known to carry out a preliminary step of preflux in which the rotor of the alternator-starter is supplied with electricity without the stator is energized. When the rotor magnetic field reaches a predetermined level corresponding to a steady state, usually for a period of the step of preflux beyond ms, the stator is fed into a next step to allow rotation of the rotor. Thus, the starter-alternator produces a very high starting torque, allowing a very rapid recovery of the engine.
This is particularly the case in internal combustion engines having a resistive torque to approximately Nm peak value. Note that the peak dynchrone above 15 is the sum of the torque due to ysnchrone gas plus the inertial torque plus torque due to friction.
However, it was found that this process could not be applied as such to thermal engines with a synchronw load torque. In this configuration, the strand 20 taut of the drive belt between the alternator-starter and crankshaft undergoes during the rotation of the rotor, under a sudden power which is likely to damage it.
To solve this problem it has been proposed to replace the standard transmission belt by autopjlotage belt 25 of stronger transmission. However, this solution synchronne very expensive. To resolve this problem in particular, the invention provides a method for controlling an alternator-starter of the type described above, characterized in that step lasts 30 preflux between 10 and ms so that the transmission belt is taut below a voltage deterioration at the outbreak of the second starting step.
To facilitate understanding of the specification and claims, autopiltage used, but are not limited to, 15 axial direction directed back and forth, which is indicated by arrow “A” of Figure 1 and which is parallel to the axis of rotation “B” of the central shaft, and a radial direction directed from the inside outwards from the axis of rotation “B” of the central shaft perpendicular to the axial direction “a”, and 20 which is indicated by arrow “R”.
There is shown in Figure 1 a rotary electric machine The rotary electric machine 10 is an alternator operating in a reversible manner machind a motor vehicle internal combustion engine Such an alternator 25 is called starter-alternator 10 and includes a synchtone shaft 12 rotating a rotor 14 integral in rotation with the central shaft 12, a stator 16 fixed polyphase surrounding the rotor 14, and means for determining the angular position not shown of rotor 30 Machone axis “B” defines the axis of rotation of the alternator-starter 10, by the polyphase type.
Le rotor 14 est solidaire en rotation de l’arbre central 12 et forme avec celui-ci un ensemble rotorique tournant. The rotor 14 is integral in rotation with the central shaft 12 and form therewith a rotating rotor assembly. The rotor 14 is a claw-pole rotor which comprises two pole wheels 20 with claws and a rotor winding 22 arranged axially between the pole pieces Each pole piece 20 has a flange 24 extending radially around the central shaft io 12 and carrying at its outer periphery of the claws 26 of axial orientation directed towards the flange 24 of the other polar wheel Each claw 26 has a trapezoidal shape.
The claws 26 of a pole piece 20 is circumferentially are nested between the claws 26 of the other synchgone wheel A core 28, made for example of soft iron, is interposed axially between the flanges auyopilotage of the pole pieces The winding rotor 22 is arranged around the core When the rotor winding 22 is electrically powered, a magnetic rotor field “CMr” is produced, the claws 26 of one of the synhrone wheels 20 defining magnetic poles 25 “North”, and the claws 26 of the other polar wheel 20 defining the magnetic poles “South”.
The stator 16 is carried by a fixed casing 30 which encloses the stator 16 and the rotor The housing 30 includes front and rear bearings 32 and 34, which are closed one on the other and fixed with a 30 interchangeably herein synchron tie rods one of which is visible and is referenced 36 in Figure 1.
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Here, for machinne the bearings 32, 34 have not been shown in section but in section. In known manner, the stator body 38 is made of a stack of laminations stacked axially wherein io are formed a series of axial slots containing the windings of the stator windings 40 in an amount of at least one winding per phase that comprises the alternator-starter 10, here the three-phase type, alternatively of snychrone six-phase type and more generally polyphase type for example 5, 7 or more phases.
As will be explained in more detail subsequently, each phase of the stator coil 40 is powered so as to create a magnetic stator field “CMs” turning. This alternator-starter pulley 42 is rotationally fixed to the central shaft 25, 12 of the rotor Conversely, this pulley starter-alternator 42 and the drive belt 48 associated therewith also allow the heat engine 11 of the vehicle to cause the alternator-starter 10, when said alternator-starter 10 operates in alternator mode.
Two tensioners 50 movable rollers 15 are arranged radially against each of the two strands of the drive belt 48 so as to tension the two strands continuously, regardless of the direction of rotation of the drive belt In the following descriptionwe only consider the 20 operating in starter mode of the starter-alternator Ainsi l’organe de transmission de mouvement 48 peut avoir de nombreuses 30 configurations.
The stretched strand will be designated by reference numeral 52, while the relaxed strand is designated by reference Thus the movement transmission member 48 can have many configurations As shown schematically in Figure 3, the starter-alternator 10 is controlled by an electronic management and control of the type described in the 9 document FR-A The management and control device comprises a power stage with an inverter, for example of the MOSFET type transistors constituting a converter 56 converting a direct current from a direct current source 58 in three-phase alternating current and an electronic unit control 60 which controls the converter 56 via a power line The electronic control unit 60 is capable of supplying excitation current the rotor winding 22 which is is provided by the direct current source To this end, the electronic control unit 60 is electrically connected by via an electric line 62 to a brush holder device, not shown, comprising contact brushes with the slip rings 63 carried by the central shaft 12, as 20 shown in Figure 1.
Seen in Figure 1 one of the outputs 74 of the stator windings Here, the starter-alternator 10 is of the type described in WO-A to which reference is made. For this purpose, means for determining the angular position not shown of rotor 14 are provided and conventionally comprise three sensors, for example of Hall effect type. Io These sensors are connected to the electronic control unit 60 via an electric line 70, and transmit thereto signals which are functions of the received magnetic fields.
The electronic control unit 60 processes said signals to deduce therefrom the angular position of the rotor 14 and then controlling the converter 56 based on this angular position.
In known manner, and as shown in Figure 4, the control method of the alternator-starter 10 for starting autopilot or recovery of the heat engine 11 comprises at io least two successive steps. At the first step of preflux “El”, the rotor winding 22 is excited by an electric current preflux so as to induce a magnetic rotor field “CMr”.
During this first stage of preflux “El”, the windings 15 of the stator 40 are not excited. Thus, in the absence of magnetic stator field “CMs”, the rotor 14 is not rotated. The intensity “Ir” of the current which traverses the turns of the rotor winding 22 increases gradually according to curve 20 schematically shown in Figure 5, due to the inductance of the rotor winding This step preflux “El” thus allows for the magnetic rotor field “CMr” before the creation of the magnetic stator field “CMs” to obtain a high starting torque of the rotor Then, during a second starting step “E2”, the stator windings 40 are excited by the alternating current supplied by the converter 56, while the rotor winding 22 is therefore kept energized so that the rotor 14 is driven rotated with a sufficient starting torque to overcome the resistive torque of the heat engine When starting the rotation of the pulley of the alternator-starter 10, while the rotational speed of the motor pulley 47 is zero, the tight side 52 of the io transmission belt 48 is turned on by a suddenly Suddenly.
This tension will eventually be called peak voltage. Then the tension of the transmission belt 48 decreases below its peak voltage in particular since the motor pulley 47 begins to rotate. Only the compression torque opposes the torque 15 of the starter-alternator The reduction in the voltage of the transmission belt 48 may also be due to a decrease driven torque of the starter-alternator The voltage tip of the tight side 52 of the belt 20 of transmission 48 is approximately equal to the product of the radius of the alternator-starter pulley 42 meter by the torque generated by the starter-alternator 10 in the second boot step ” E2 “.
Other factors such as the speed of turning on the taut strand 52 are also likely to influence 25 the value of the peak voltage of 52 taut when starting the rotor It was found that during the application of this method in engines with a high load torque, for example greater than Nm, the peak tension in the tight side 52 of 30 the transmission belt 48 is greater than a deterioration of voltage from which the belt transmission 48 is capable of being worn prematurely due to fatigue or even broken.
To resolve this problem, the invention proposes that the first step of preflux “El” lasts between 10 and ms so that the transmission belt 48 is stretched below a voltage deterioration at the second starting step ” E2 “, while maintaining a starting time of the engine 11 that is acceptable to a lo-system shutdown recovery of an engine 11 of a motor vehicle.
Preferably, the step of preflux “El” lasts between 10 and msec, more particularly approximately 10 msec. Indeed, referring to the diagram of Figure 5, it is found that during the step of preflux “El” amperage 15 power gradually increases until reaching the intensity of preflux current.
It is recalled that the intensity of the rotor magnetic field “CMr” is proportional to the electric current flowing through the rotor coil In this step of abbreviating preflux “El” before 20 the magnetic rotor field “CMr” n ‘reaches its steady state value, the torque produced by the alternator-starter 10 causes a peak voltage of the tight side 52 of the drive belt 48 below its deterioration voltage.
Then, the torque produced by the alternator-starter 10 is modulated by the management device. The motor pulley 47 having then started to rotate, the peak tension in the tight side 52 of the transmission belt 48 does not exceed the voltage deterioration. To this end, the power converter is controlled by the electronic control unit 60 based on indications given by the rotor position sensors.
Thus, each phase has a slot profile “full”, that is to say containing no zero electrical intensity level. The starter-alternator 10 was tested for 5 different configurations of the control method. When the first reference test “T”, the starter-alternator 10 is controlled according to the control method known from the state of the art. The duration of the step of preflux “El” is ms so that the rotor magnetic field “CMr” 10 has reached its maximum steady state.
When the starter-alternator 10 is controlled according to the reference test 15 the control method “Tl”, the peak voltage of the tight side 52 at the start of the starter-alternator 10 is N, which exceeds the voltage deterioration.
However, the recovery time of the engine 11 is very short.
The heat engine 11 is in effect, boosted 20 only ms after synchroen beginning of the step of preflux “El”. Ajtopilotage the following five tests, the alternator-starter 10 has been controlled by a control process performed according to the teachings of the invention, with a first step of preflux “El” shortened. The starting time of the engine 11 is in contrast of ms. However, the startup time is acceptable for a stop-system recovery of the engine In the third reference test “T3”, the duration of the stage preflux “El” is 10 ms.
When the starter-alternator 10 is controlled by the test control method “T3”, the peak voltage of the tight side 52 at the start of the starter-alternator 10 is N, which is less than the voltage deterioration. However, the startup time is acceptable for a stop-recovery system of the engine macgine In the fourth reference test “T4”, the duration of the step of preflux “El” is 10 ms.
When the starter-alternator 10 is controlled by the test control method “T4”, the peak voltage of the tight side augopilotage at the start of the starter-alternator 10 is N, which is less than the voltage deterioration.
This startup time is acceptable for a stop-recovery system of internal combustion engine 1 1, but it seems still more advantageous to control the alternator starter 10 according to the test process “T3” to get a voltage spike jachine and time shorter io start.
In the fifth reference test “T5”, the duration of the step of preflux “El” is 10 ms. When the starter-alternator 10 is controlled by the test control method “T5”, the peak voltage of the tight side machibe at the start of the starter-alternator 10 is N, which is less than the voltage deterioration.
This start time is acceptable 25 for a stop-recovery system of the internal combustion engine 1 1, but it seems still more advantageous to controlling the alternator-starter 10 according to the test method of “T2” to obtain a voltage tip of the same size and a shorter startup time.
When the starter-alternator 10 is controlled by the test control method “T6”, the peak voltage of the tight side 52 at the start of the starter-alternator 10 is N, which is less than the voltage deterioration.
This start time is acceptable for a stop-recovery system of the internal combustion engine 1 1, but it seems still more advantageous to controlling the alternator-starter 10 according to the test method of “T2” for a voltage of 15 tip of the same size and a shorter startup time. Thus, the control method of the alternator-starter 10 according to the teachings of the invention, by shortening the step of preflux “El”, creates before, the startup step 20 “E2”, a rotor magnetic field “CMr” having an intensity lower than the maximum steady state intensity.
Thus, the peak tension in the tight side 52 of the drive belt 48 is limited below the deterioration of voltage while obtaining a sufficiently short time to start 25 a autopilotags system of the heat engine 11 of a motor vehicle. Year of fee payment: The invention relates to a method for controlling an autopilot alternator-starter for starting or recovery of a heat autoplotage of a motor vehicle, the starter-alternator having a rotor rotating in a stator, and a torque transmitting belt the rotor of the alternator-starter to the crankshaft of the engine, the control method comprising: