Method for controlling an electric machine for a mobility device

Abstract

The present invention relates to a method (10) for controlling an electrical machine comprising at least one electric motor (2), an electronic assembly (3), formed by at least one inverter, and at least one sensor, the frequency (F2) for controlling the motor (2) being greater than the frequency (F1) for acquiring data from the sensor making it possible to control the motor (2). Abstract figure: Figure 2

Description

Title of the invention: Method for controlling an electric machine for a mobility device

[0001] The present invention relates to the field of mobility devices, in particular motor vehicles, and more specifically aims at a method of controlling an electric machine for an electric propulsion system allowing the transmission of power to drive the wheels of such devices.

[0002] The electric propulsion system allowing the transmission of power in a motor vehicle, aims to drive at least one wheel of the vehicle in rotation, by transmitting the torque supplied by a drive shaft, in particular electric or hybrid.

[0003] Usually, the motor is controlled by acquiring data from sensors, for example current and / or position. The sensor values ​​are read and a command is sent to the motor based on the value read from the sensor. It is known today to control the motor at the same frequency as the acquisition of data from the sensors.

[0004] A disadvantage arises from the fact that if the chosen frequency is in the range audible to humans, that is to say less than approximately 20 kHz, the control of the machine is a source of noise. A second disadvantage arises from the fact that if the frequency is too high, it is necessary to have a more powerful computer and therefore with a higher cost.

[0005] The present invention therefore aims to overcome one or more of the drawbacks of the systems of the prior art by proposing an improved method of controlling an electric machine for an electric propulsion system.

[0006] For this purpose, the present invention proposes a method for controlling an electrical machine comprising at least one electric motor, an electronic assembly, formed by at least one inverter, and at least one sensor, the frequency of control of the motor is different from the frequency of acquisition of the data from the sensor making it possible to control the motor.

[0007] Such a control method 10 therefore allows an acoustic and economic gain.

[0008] According to an embodiment of the invention, in which the control frequency is higher than the acquisition frequency.

[0009] According to one embodiment of the invention, the motor control frequency is equal to at least 2 times the sensor acquisition frequency.

[0010] According to one embodiment of the invention, the acquisition frequency of the sensors is between 5 and 15 kHz and the control frequency between 10 and 30 kHz.

[0011] According to one embodiment of the invention, the acquisition frequency of the sensors is equal to 10 kHz.

[0012] According to one embodiment of the invention, the control frequency is equal to 20 kHz.

[0013] The invention also relates to an electric machine for a mobility device comprising an electric motor controlled by the control method according to the invention.

[0014] The invention also relates to the use of the electric machine according to the invention in a propulsion system for a mobility device.

[0015] The invention also relates to a mobility device, and for example a two-wheeler of the motorcycle or scooter or automobile type, comprising an electric machine according to the invention.

[0016] Other aims, characteristics and advantages of the invention will be better understood and will appear more clearly on reading the description given below, with reference to the appended figures, given by way of example and in which:

[0017] [Fig.l]: [Fig.l] is a schematic cross-sectional representation of an electrical machine according to one embodiment of the invention,

[0018] [Fig.2]: [Fig.2] is a schematic representation of the control method according to the invention.

[0019] The invention relates to a method for controlling an electric machine, for example a propulsion system for a mobility device. The present invention is aimed in particular at use in a mobility device with 2, 3, 4 wheels or more, and for example, a motor vehicle or a motorcycle, in propulsion, alternator-starter or hybrid mode, a motor vehicle, but also at use in any land, air, or sea vehicle, intended for the transport of passengers or goods, light, intermediate or heavy, or even construction machinery or agricultural machinery.

[0020] In the context of the invention, a propulsion system is a system which allows propulsion and comprises the elements allowing the transmission of power from the engine to the wheel.

[0021] The illustrated electrical machine [Fig.l] comprises at least one motor 2, an electronic assembly 3 with a computer 6 and at least one sensor 31.

[0022] According to one embodiment of the invention, the sensor 31 is a position and / or current sensor, or any other sensor of the same type allowing the machine to be controlled.

[0023] According to one embodiment of the invention, the electric machine comprises a reducer 4 for transmitting the torque, illustrated in dotted lines in [Fig.l] to represent the optional mode.

[0024] According to one embodiment of the invention, the motor 2 is an electric motor comprising a rotor 21 and a stator 22.

[0025] The electronic assembly 3 comprises the elements necessary for the operation of the electric motor 2.

[0026] According to one embodiment of the invention, the electronic assembly 3 is an inverter 3.

[0027] According to one embodiment of the invention, the inverter 3, the electric motor 2 and the reducer 4 are arranged one after the other along a longitudinal axis A. The longitudinal axis A is the longitudinal axis of the motor 2.

[0028] According to one embodiment of the invention, the inverter 3 is fixed to the motor 2 which is itself fixed to the reducer 4 along a motor shaft 5. The motor 2 is thus arranged between the inverter 3 and the reducer 4.

[0029] According to one embodiment of the invention, the inverter 3 is arranged at any location allowing the propulsion system to operate.

[0030] The electric motor 2 via the reducer 4 when it is present thus makes it possible to drive at least one wheel in rotation.

[0031] According to one embodiment of the invention, the control of the motor 2, and more particularly of the stator 21, is carried out by means of the inverter 3.

[0032] According to one mode of relationship, the control of the motor 2 is carried out by means of the computer and the transistors of the inverter 3.

[0033] The control method 10 illustrated [Fig.2] is carried out by a control loop. This control loop comprises the acquisition 11 of values ​​measured by at least one sensor 31 at a frequency F1 and comprises the control of the motor, as a function of the value of the sensor 31, at a frequency F2.

[0034] More precisely, at least one step 11 consists of acquiring the value of the current of a phase measured by a current sensor and / or the value of the rotation speed of the rotor by a speed sensor. This acquisition step 11 is done at a frequency FL. A following step 12 consists of controlling the motor, at a frequency F2 as a function of the value measured by the sensor so that it operates at a desired speed and / or current value.

[0035] In the context of the invention, the frequency Fl is different from the frequency F2.

[0036] In the context of the invention, the frequency F2 for controlling the motor is greater than the acquisition frequency Fl of the sensors.

[0037] According to one embodiment of the invention, the motor control frequency F2 is a multiple, and for example a multiple of 2 or 3 or 4 or 5 or more, of the sensor acquisition frequency F1. More precisely, the motor control frequency F2 is equal to 2 times the sensor acquisition frequency F1.

[0038] According to one embodiment of the invention, the acquisition frequency Fl of the sensors is between 5 and 15 kHz and the control frequency F2 between 10 and 30 kHz.

[0039] According to one embodiment of the invention, the acquisition frequency Fl of the sensors is equal to 10 kHz.

[0040] Such an acquisition frequency value makes it possible not to overload the computer 6.

[0041] According to one embodiment of the invention, the control frequency F2 is equal to 20 kHz.

[0042] Such a driving frequency value, which is at the limit of the human audible frequency, makes it possible to limit the noise generated by the electrical machine.

[0043] Such a control method 10 thus makes it possible to limit acoustic nuisances, without needing a more powerful and more expensive computer.

[0044] Such a control method 10 therefore allows an acoustic and economic gain.

[0045] The scope of the present invention is not limited to the details given above and allows embodiments in many other specific forms without departing from the scope of the invention. Therefore, the present embodiments should be considered for illustrative purposes, and may be modified without departing from the scope defined by the claims.

Claims

Claims

1. Method (10) for controlling an electric machine (1) comprising at least one electric motor (2), an electronic assembly (3), formed by at least one inverter, and at least one sensor (31) characterized in that the frequency (F2) for controlling the motor (2) is different from the frequency (Fl) for acquiring data from the sensor (31) making it possible to control the motor (2).

2. A driving method (10) according to claim 1, wherein the driving frequency (F2) is greater than the acquisition frequency (F1).

3. Control method (10) according to one of claims 1 to 3, in which the frequency (F2) for controlling the motor is equal to at least 2 times the acquisition frequency (F1) of the sensor.

4. Control method (10) according to one of claims 1 to 3, in which the acquisition frequency (F1) of the sensors is between 5 and 15 kHz and the control frequency (F2) between 10 and 30 kHz.

5. Control method (10) according to one of claims 1 to 4, in which the acquisition frequency (Fl) of the sensors is equal to 10 kHz.

6. Method (10) of control according to one of claims 1 to 5, in which the control frequency (F2) is equal to 20 kHz.

7. Electric machine (1) for a mobility device comprising an electric motor (2) controlled by the control method (10) according to one of claims 1 to 6.

8. Use of the electric machine (1) according to claim 7 in a propulsion system for a mobility device.

9. Mobility device, comprising an electric machine (1) according to claim 7.

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