METHOD FOR MONITORING A FAN IN A MOTOR-FAN UNIT FOR A MOTOR VEHICLE

Abstract

The invention relates to a method for monitoring (1) a fan (21) of a motor-fan assembly for a motor vehicle, the monitoring method (1) comprising a step of recording (11) a usage profile (10) of the fan (21) at a given recording frequency (fe) in an internal memory of the motor-fan assembly. The usage profile (10) comprises at least some of the following data: an electrical power supply to the fan (21), and / or a rotational speed of the fan (21), and / or a duration of use of the fan (21) for each pair of electrical power supply and rotational speed of the fan (21). Figure 1

Description

Title of the invention: METHOD FOR MONITORING A FAN OF A MOTOR-FAN UNIT FOR A MOTOR VEHICLE

[0001] The technical context of the present invention is that of motor-fan units for motor vehicles, and in particular methods and systems for making such motor-fan units more reliable, measuring and diagnosing. More particularly, the invention relates to a method for monitoring a fan of such a motor-fan unit for a motor vehicle.

[0002] In the state of the art, the motor-fan unit is known, the function of which is to supply an air flow to an air-water heat exchanger of a cooling system for electrical components of a motor vehicle. In a known manner, such a motor-fan unit is a source of significant electrical consumption in a motor vehicle, and even more so in electrified motor vehicles.

[0003] Furthermore, as is known, electrified motor vehicles have more complex and greater needs than thermal motor vehicles:

[0004] - the cooling and heating cycles are more complex and more numerous intensified, due to the need for thermalization of the electric traction battery which represents very sensitive electrical equipment and on which the performance of the motor vehicle's traction chain depends;

[0005] - the power of the motor-fan units increases. Also, in order not to to dramatically increase the electrical storage capacity of the electric battery, it is necessary to optimize both the sizing and the regulation of the fan;

[0006] - monitoring a usage profile of the motor-fan unit, and of the fan itself even, is becoming more and more complicated due to the technical complexity of electrified motor vehicles and the numerous life phases to be taken into account.

[0007] In known motor-fan units, there is no communication link between a control law of the electric motor of the fan of said known motor-fan units - consumer of electrical energy of the motor vehicle - and a control system of the motor vehicle for which optimization of said electrical energy is desired. In addition, known motor-fan units do not allow the durability of the fan to be measured in order to diagnose or predict malfunctions. Indeed, motor-fan units whose electric motor driving the fan is of the direct current type are controlled by a simple relay, while motor-fan units whose electric motor The fan is of the brushless type and only transmits information related to possible internal faults in the motor-fan unit, which is insufficient for accurate diagnosis or prediction of future malfunctions.

[0008] The object of the present invention is to propose a new method for monitoring a fan of a motor-fan unit in order to respond at least to a large extent to the preceding problems and to further lead to other advantages.

[0009] Another aim of the invention is to enable the electrical consumption of the motor-fan unit to be reduced as much as possible.

[0010] Another aim of the invention is to enable easier diagnosis of the motor-fan unit during its life cycle, and to enable more precise detection, prediction or analysis of a malfunction thereof.

[0011] According to a first aspect of the invention, at least one of the aforementioned objectives is achieved with a method for monitoring a fan of a motor-fan unit for a motor vehicle, the monitoring method comprising a step of recording a fan usage profile at a given recording frequency in an internal memory of the motor-fan unit.

[0012] In the context of the present invention, the fan of the motor-fan unit is of the “Brushless” type, that is to say a brushless motor. More particularly, in the context of the present invention, the fan comprises a propeller which is driven by a synchronous polyphase electric motor with permanent magnets electronically regulated in torque and speed.

[0013] For this purpose, the fan is controlled by a control unit of the motor-fan unit which allows, simultaneously with the regulation of the electric motor, a measurement of the electrical power allocated to the fan propeller, thanks to an electronic regulation integrated via said control unit. The control unit includes the internal memory. The internal memory thus forms a compact and local recorder - that is to say directly at the motor-fan unit - of the usage profile of the fan. The invention according to its first aspect thus makes it possible to record locally and more easily the usage data - the usage profile - of the fan.

[0014] In the context of the present invention, the fan usage profile includes data relating to activations of the motor-fan unit - and more particularly of the fan itself - and which said motor-fan unit lists in the internal memory according to the powers requested by its electric motor. In other words, the usage profile includes data on the use of the fan and / or its control.

[0015] In the context of the present invention, the recording step is a step of transferring certain data - those relating to the fan usage profile - to the internal memory of the control unit for storage. The storage carried out on the internal memory is temporary storage, i.e. for a predetermined duration which depends on the size of the internal memory and the nature of the recorded data. By way of non-limiting example, the usage profile is stored on the internal memory for at least several hours, for example at least 8 hours.

[0016] In the context of the present invention, the recording frequency corresponds to a sampling frequency of the fan usage profile. In other words, the recording frequency corresponds to the inverse of a successive duration between two successive recordings of the fan usage profile on the internal memory of the control unit of the motor-fan unit.

[0017] Thus, the recording of these usage profiles of the fan of the motor-fan unit makes it possible to better measure its operation and the conditions of this operation. In other words, the monitoring method according to the invention makes it possible to directly record at the motor-fan unit statistical information regarding the use of the fan and its correct sizing, as well as information representative of - or making it possible to determine subsequently - risks of failure.

[0018] As a result, the availability of this data in the internal memory of the motor-fan unit makes it possible to better predict its possible malfunctions and to reduce the electrical consumption of the motor-fan unit.

[0019] The monitoring method according to the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:

[0020] - the usage profile includes (i) an electrical power supply to the wind fan, and / or (ii) a fan rotation speed, and / or (iii) a fan usage time. The electrical supply power, combined with the fan rotation speed, makes it possible to determine a fan torque. These data are relevant and representative for determining the fan usage conditions and for measuring any wear or failure;

[0021] - according to a first variant embodiment, the monitoring method comprises (i) a step of measuring an electric current supplying the fan, (ii) a step of measuring an electric polarization voltage of the fan, (iii) a step of calculating the electric power supplying the fan. In this first variant, the monitoring method takes advantage of the sensors embedded in the motor-fan unit to determine the electric power from the product of the electric current and the polarization voltage of the electric motor, measured by said sensors;

[0022] - alternatively, according to a second variant embodiment, the method of monitoring comprises (i) a step of reading a value of the electric current supplying the fan on an on-board network of the motor vehicle, (ii) a step of reading a value of the electric voltage supplying the fan on the on-board network, (iii) a step of calculating the electric power supplying the fan. In this second variant, the monitoring method uses data available on the on-board network, the control unit being configured to read on such an on-board network - typically a LIN network - a first variable comprising the electric current value and a second variable comprising the electric voltage value in order to, subsequently, determine the electric power from the product of the electric current and the polarization voltage of the electric motor thus obtained on the on-board network;

[0023] - the recording frequency depends on the fan usage profile. In par In particular, the recording frequency is proportional to the fan rotation speed. This configuration makes it possible to modulate a density of recorded values ​​according to the actual conditions of use of the fan of the motor-fan unit;

[0024] - advantageously, the recording frequency is between 20 Hz and 100 Hz. This configuration allows easy storage in the internal memory of the fan and / or the fan motor unit of data relating to the usage profile, without overloading the internal memory or avoiding excessive sizing of said internal memory;

[0025] - the monitoring method includes a step of saving the recorded data stored in the internal memory of the motor-fan unit to a storage memory of a computer of the motor vehicle. This advantageous configuration makes it possible to repatriate to the storage memory of the computer the data recorded locally in the internal memory, so as to allow more durable and longer-term storage;

[0026] - the backup step is performed at a backup frequency. In other words terms, the backup step is carried out periodically, in order to be able to transfer the data recorded in the internal memory before it becomes saturated;

[0027] - the backup frequency is different from the recording frequency. Indeed, the period required for transferring the data recorded in the internal memory does not need to be as short as that required for recording the usage profiles;

[0028] - generally speaking, the backup frequency is lower than the frequency recording. Preferably, the backup step is carried out at a backup frequency lower than the recording frequency. As a non-limiting example, the backup frequency is less than 30 pHz. In other words, the backup step is performed at most once every 9 hours or so.

[0029] According to a second aspect of the invention, there is provided a motor-fan unit for a motor vehicle, the motor-fan unit comprising:

[0030] - an electric fan driven by an electric motor;

[0031] - a control unit electrically connected to the electric motor, the unit of control comprising an internal memory and being configured to implement the monitoring method according to the first aspect of the invention or according to any of its improvements.

[0032] In the context of the present invention, the control unit is a computer of the motor-fan unit of the motor vehicle. The control unit advantageously comprises at least one microprocessor and / or at least one microcontroller and at least one internal memory - temporary or permanent - as used in the computer field. The control unit takes the form of an electronic card and / or an integrated circuit.

[0033] In the context of the present invention, the fan of the motor-fan unit is of the “Brushless” type, i.e. a brushless motor. More particularly, in the context of the present invention, the fan comprises a propeller which is driven by the electric motor. The electric motor is of the synchronous polyphase type with permanent magnets. The electric motor is electronically regulated in torque and speed by the control unit.

[0034] According to a third aspect of the invention, there is provided a motor vehicle comprising a motor-fan unit in accordance with the second aspect of the invention.

[0035] Advantageously, the motor vehicle is of the electrified motor vehicle type. In the context of the present invention, an electrified motor vehicle is of the electric or hybrid motor vehicle type. Generally, a powertrain of such an electrified motor vehicle is rotated by an electric machine, electrically powered by an electric traction battery, in order to generate a motor torque used to set the motor vehicle in motion. Additionally or alternatively, the electric machine is configured to recover mechanical energy from the powertrain and convert it into electrical energy, thus producing a braking torque on said powertrain and making it possible to recharge the electric traction battery.

[0036] Various embodiments of the invention are provided, integrating according to all of their possible combinations the different optional characteristics set out here.

[0037] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and of several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0038] [Fig.l] illustrates a block diagram of the monitoring method according to the first aspect of the invention;

[0039] [Fig.2] illustrates a schematic view of the motor-fan unit according to the second aspect of the invention.

[0040] Of course, the features, variants and different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0041] In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view.

[0042] In the figures, the elements common to several figures retain the same reference.

[0043] With reference to FIGURES 1 and 2, the invention relates to a motor-fan unit 2 for a motor vehicle, the motor-fan unit 2 comprising an electric fan 21 driven by an electric motor 22 and a control unit 23 electrically connected to the electric motor 22, the control unit 23 comprising an internal memory 24. The control unit 23 is a computer 3 of the motor-fan unit 2 of the motor vehicle. The control unit 23 comprises at least one microprocessor and / or at least one microcontroller and at least one internal memory 24 - temporary or permanent - as used in the computer field. The control unit 23 typically takes the form of an electronic card and / or an integrated circuit.

[0044] The fan 21 of the motor-fan unit 2 is of the “Brushless” type, that is to say a brushless motor. More particularly, the fan 21 comprises a propeller which is actuated and set in rotation by the electric motor 22. The electric motor 22 is of the synchronous polyphase type with permanent magnets. The electric motor 22 is electronically regulated in torque and speed by the control unit 23.

[0045] Such an electric motor 22 and such a control unit 23 comprise electronic devices which make it possible to measure several operating parameters of the electric motor 22 and / or the fan 21.

[0046] The control unit 23 authorizes, simultaneously with the regulation of the engine electric 22, a measurement of the electrical power allocated to the propeller of the fan 21, thanks to an electronic regulation integrated by said control unit 23. For this purpose, the control unit 23 is configured to implement a monitoring method 1 comprising a step of recording 11 of a usage profile 10 of the fan 21 at a given recording frequency fe in an internal memory 24 of the motor-fan unit 2.

[0047]

[0048] The recording step 11 is a step of transferring certain data - those relating to the usage profile 10 of the fan 21 - to the internal memory 24 of the control unit 23 for storage. The storage carried out on the internal memory 24 is temporary storage, i.e. for a predetermined duration which depends on the size of the internal memory 24 and the nature of the recorded data. By way of non-limiting example, the usage profile 10 is stored on the internal memory 24 for at least several hours, for example at least 8 hours.

[0049] The usage profile 10 includes:

[0050] - an electrical power supply to the fan 21, and / or

[0051] - a rotation speed of the fan 21, and / or

[0052] - a duration of use of the fan 21.

[0053] The electrical supply power, combined with the rotation speed of the fan 21, makes it possible to determine a torque of the fan 21.

[0054] Such a user profile is relevant and representative of the conditions of use of the fan 21 to enable any wear or failure to be measured. Consequently, such knowledge of the usage profile 10 enables preventive maintenance of the motor-fan unit 2 to be carried out.

[0055] These data, and more particularly the electrical power supplying the fan 21, can be obtained in different ways.

[0056] According to a first variant embodiment, the monitoring method 1 comprises (i) a step of measuring an electric current 101 supplying the fan 21, (ii) a step of measuring an electric voltage 102 polarizing the fan 21. In this first variant, the monitoring method 1 takes advantage of the sensors embedded in the motor-fan unit 2 - and in particular of the electronic devices embedded on the electric motor 22 and / or the control unit 23 - to determine the electric supply current and the electric supply voltage which will subsequently be used to calculate the electric supply power of the fan 21.

[0057] According to a second variant embodiment, the monitoring method 1 comprises (i) a step of reading a value of electric current 103 supplying the fan 21 on an on-board network of the motor vehicle, (ii) a step of reading a electrical voltage value 104 supplying the fan 21 to the on-board network. In this second variant, the monitoring method 1 uses data available on the on-board network, the control unit 23 being configured to read from such an on-board network - typically a LIN network - a first variable comprising the electrical current value and a second variable comprising the electrical voltage value in order to subsequently calculate the electrical power supplying the fan 21.

[0058] Following one or other of the previously mentioned embodiment variants, the monitoring method 1 then comprises a step 105 of calculating the electrical power supplying the fan 21. The electrical power supplying the fan 21 is calculated from the product of the electrical current and the polarization voltage of the electric motor 22, measured by the sensors in the case of the first embodiment variant, or obtained on the on-board network in the case of the second embodiment variant.

[0059] The recording frequency fe of the usage profile 10 in the internal memory 24 of the control unit 23 depends on said usage profile 10 of the fan 21. In particular, the recording frequency fe is proportional to the rotation speed of the fan 21. Advantageously, the recording frequency fe is between 20 Hz and 100 Hz.

[0060] Indeed, the invention according to its first aspect thus makes it possible to make the motor-fan unit 2 its own recorder of its usage profile 10 in order to be able to provide statistical information on the use of the fan 21, its correct sizing and its possible risks of failure.

[0061] The objective is therefore to determine and store data that makes it possible to identify a number of iterations and / or a duration during which the fan 21 of the motor-fan unit 2 is configured in a given power class. In other words, the usage profiles 10 of the fan 21 are regularly recorded on the internal memory 24 of the control unit 23 in order to determine at least how many times and / or how long said fan 21 has been configured in any one of these power classes.

[0062] Indeed, the motor-fan unit 2 according to the invention comprises a plurality of power classes, each power class corresponding to an electrical power supply to the fan 21 and to a rotation speed, that is to say ultimately to a predetermined torque. By way of non-limiting example, the motor-fan unit 2 comprises at least 10 power classes, each power class having the same power width as the other power classes.

[0063] According to a particularly advantageous effect of the invention, the usage profile 10 recorded in the internal memory 24 thus comprises, for each power class, a first counter associated with the minutes of use of said fan 21 in said power class, and a second counter associated with the seconds of use of said fan 21 in said power class. More generally, the usage profile 10 recorded in the internal memory 24 thus comprises, for each power class, at least one counter associated with a duration of use of said fan 21 in said power class,

[0064] Thus, the monitoring method 1 according to the invention firstly comprises such a local recording of the usage profiles 10 in the internal memory 24 of the fan 21 and of the motor-fan unit 2.

[0065] Subsequently, the monitoring method 1 comprises a step 12 of saving the data recorded in the internal memory 24 of the motor-fan unit 2 to a storage memory 31 of a computer 3 of the motor vehicle. This saving step 12 thus takes the form of a step of transferring the data recorded in the internal memory 24 of the motor-fan unit 2 to the storage memory 31 of the computer 3, so as to allow more permanent and longer-term storage.

[0066] Subsequent to this backup step 12, the monitoring method 1 comprises a step of resetting the internal memory 24 of the control unit 23 of the motor-fan unit 2, so as to empty said internal memory 24 and authorize the writing of new usage profiles 10.

[0067] The backup step 12 is carried out at a backup frequency fs. In other words, the backup step 12 is carried out periodically and before the internal memory 24 of the motor-fan unit 2 is saturated.

[0068] The backup frequency fs is different from the recording frequency fe. Generally, the backup step 12 is performed at a backup frequency fs lower than the recording frequency fe. By way of non-limiting example, the backup frequency fs is less than 30 pHz. In other words, the backup step 12 is performed at most once every 9 hours approximately.

[0069] All the data recorded during the different recording steps are transferred to the storage memory 31 of the computer 3 during the backup step 12. The storage memory 31 and the computer 3 are here considered as being external to the control unit 23 and to the motor-fan unit 2.

[0070] Thus, the monitoring method 1 according to the invention makes it possible to secure the activation and use of the motor-fan unit 21 without adding electronic components and by exploiting those already existing on the control unit 23 in particular. In addition, such a monitoring method 1 makes it possible to obtain better knowledge of the usage profile 10 of the motor-fan unit 21 over the long term, to optimize its sizing according to the usage profile 10 and the power classes, and finally to anticipate possible failures.

[0071] In summary, the invention relates to a method 1 for monitoring a fan 21 of a motor-fan unit 2 for a motor vehicle, the monitoring method 1 comprising a step 11 of recording a usage profile 10 of the fan 21 at a given recording frequency fe in an internal memory 24 of the motor-fan unit 2. The usage profile 10 comprises at least part of the following data: an electrical power supply of the fan 21, and / or a rotation speed of the fan 21, and / or a duration of use of the fan 21 for each pair of electrical power supply and rotation speed of the fan 21.

[0072] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the different characteristics, forms, variants and embodiments of the invention can be associated with each other in various combinations insofar as they are not incompatible or mutually exclusive. In particular, all the variants and embodiments described above can be combined with each other.

Claims

Claims

1. Method for monitoring (1) a fan (21) of a motor-fan unit (2) for a motor vehicle, the monitoring method (1) comprising a step of recording (11) a usage profile (10) of the fan (21) at a given recording frequency (fe) in an internal memory (24) of the motor-fan unit (2).

2. Monitoring method (1) according to the preceding claim, in which the usage profile (10) comprises: - an electrical power supply to the fan (21); and / or - a rotation speed of the fan (21); and / or - a duration of use of the fan (21).

3. Monitoring method (1) according to any one of claims 1 or 2, wherein the monitoring method (1) comprises: - a step of measuring an electric current (101) supplying the fan (21); - a step of measuring an electric voltage (102) polarizing the fan (21); - a step of calculating (105) the electric power supplying the fan (21).

4. Monitoring method (1) according to any one of claims 1 or 2, in which the monitoring method (1) comprises: - a step of reading an electric current value (103) supplying the fan (21) on an on-board network of the motor vehicle; - a step of reading an electric voltage value (104) supplying the fan (21) on the on-board network; - a step of calculating (105) the electric power supplying the fan (21).

5. Monitoring method (1) according to any one of the preceding claims, wherein the recording frequency (fe) depends on the usage profile (10) of the fan (21).

6. Monitoring method (1) according to the preceding claim, wherein the recording frequency (fe) is between 20 Hz and 100 Hz.

7. Monitoring method (1) according to any one of the preceding claims, wherein the monitoring method (1) comprises a step of saving (12) the data recorded in the memory internal (24) of the motor-fan unit (2) to a storage memory (31) of a computer (3) of the motor vehicle.

8. Monitoring method (1) according to the preceding claim, wherein the backup step (12) is carried out at a backup frequency (fs) lower than the recording frequency (fe).

9. Motor-fan unit (2) for a motor vehicle, the motor-fan unit (2) comprising: - an electric fan (21) driven by an electric motor (22); - a control unit (23) electrically connected to the electric motor (22), the control unit (23) comprising an internal memory (24) and being configured to implement the monitoring method (1) according to any one of the preceding claims.

10. Motor vehicle comprising a motor-fan unit (2) according to the preceding claim.

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