Method and device for controlling a reluctance electric machine

Abstract

In a method of controlling a reluctance polyphase electric machine (36), in particular an automobile motor, the currents injected into each coil of the stator of the machine (36) are deduced by a transformation of a pair (Id, Iq) of excitation currents (Id) and of armature current (Iq) defined in a reference frame (d, q) rotating with the rotor of the machine, such that: - the excitation current (Id) is composed of a fundamental sinusoidal signal, to which are added successively other odd harmonics of increasing order when the torque setpoint of the machine increases, - the armature current (Iq) is a signal proportional to the estimated or measured electromotive force of the machine.

Description

technical field

[0001] The subject of the invention is a method for controlling a motor known as a synchronous reluctance motor, and a motor suitable for being able to be controlled according to this method. Background technique

[0002] A synchronous reluctance machine comprises a series of stator windings defining the poles of the machine and a rotor which has been made of ferromagnetic material eg with a series of notches to make it easier to build up a magnetic field inside the rotor in certain specific directions.

[0003] Furthermore, the rotor can consist of a layered structure in order to limit the current flow within the rotor.

[0004] Such motors are often less expensive to produce than motors whose rotors include windings or permanent magnets. For a given current strength, the maximum torque that can be achieved depends inter alia on the control method.

[0005] Specifically, the mechanical power produced by an electric motor is proportional to the current inje...

Examples

Embodiment Construction

[0043] figure 1 A typical geometry of the rotor of a reluctance machine known as a "sinusoidal synchronous reluctance machine" is shown.

[0044] In this example, the rotor is shown in a plane perpendicular to the axisymmetric axis Z of the rotor.

[0045] The mass of the rotor 1 made of ferromagnetic material is indented by a notch 2 defined by a curved surface portion of a generatrix parallel to the axis z. In the example shown, the contour of the recess 2 is defined by a cylindrical portion of the shaft centered outside the outer circumference of the rotor 1 .

[0046]The end of the notch 2 is close to but not engaged with the outer circumference of the rotor 1 . The notches 2 delimit a smaller rectangular direction along which the orientation of the magnetic field induced inside the rotor 1 tends to be. Such a minimum reluctance axis is for example given by figure 1 Axis 3 or Axis D identification. exist figure 1 Also shown in is an axis q marked 4 perpendicular to b...

technical field

[0001] The subject of the invention is a method for controlling a motor known as a synchronous reluctance motor, and a motor suitable for being able to be controlled according to this method. Background technique

[0002] A synchronous reluctance machine comprises a series of stator windings defining the poles of the machine and a rotor which has been made of ferromagnetic material eg with a series of notches to make it easier to build up a magnetic field inside the rotor in certain specific directions.

[0003] Furthermore, the rotor can consist of a layered structure in order to limit the current flow within the rotor.

[0004] Such motors are often less expensive to produce than motors whose rotors include windings or permanent magnets. For a given current strength, the maximum torque that can be achieved depends inter alia on the control method.

[0005] Specifically, the mechanical power produced by an electric motor is proportional to the current inje...

Examples

Embodiment Construction

[0043] figure 1 A typical geometry of the rotor of a reluctance machine known as a "sinusoidal synchronous reluctance machine" is shown.

[0044] In this example, the rotor is shown in a plane perpendicular to the axisymmetric axis Z of the rotor.

[0045] The mass of the rotor 1 made of ferromagnetic material is indented by a notch 2 defined by a curved surface portion of a generatrix parallel to the axis z. In the example shown, the contour of the recess 2 is defined by a cylindrical portion of the shaft centered outside the outer circumference of the rotor 1 .

[0046]The end of the notch 2 is close to but not engaged with the outer circumference of the rotor 1 . The notches 2 delimit a smaller rectangular direction along which the orientation of the magnetic field induced inside the rotor 1 tends to be. Such a minimum reluctance axis is for example given by figure 1 Axis 3 or Axis D identification. exist figure 1 Also shown in is an axis q marked 4 perpendicular to b...

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