Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D5/00—Power-assisted or power-driven steering
  • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
  • B62D5/0457—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
  • B62D5/0481—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such monitoring the steering system, e.g. failures
  • B62D5/0487—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such monitoring the steering system, e.g. failures detecting motor faults
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D5/00—Power-assisted or power-driven steering
  • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
  • B62D5/0457—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
  • B62D5/0481—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such monitoring the steering system, e.g. failures
  • B62D5/0484—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such monitoring the steering system, e.g. failures for reaction to failures, e.g. limp home
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P2209/00—Indexing scheme relating to controlling arrangements characterised by the waveform of the supplied voltage or current
  • H02P2209/01—Motors with neutral point connected to the power supply
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
  • H02P29/02—Providing protection against overload without automatic interruption of supply
  • H02P29/032—Preventing damage to the motor, e.g. setting individual current limits for different drive conditions

Definitions

• the invention relates to a method for controlling a multi-phase electric motor for electric power steering of a motor vehicle.
• Electric power steering devices use a polyphase electric motor to help the driver orient the vehicle wheels.
• this type of mechanical relay may have reliability defects over time. Indeed, these relays are more and more solicited, especially in the case of vehicles equipped with "stop & start” system. This type of system cuts off power to the power steering system at each stop of the vehicle causing the opening of the mechanical relays.
• the invention aims, among other things, to meet this need and achieves it by means of a method for controlling a multi-phase electrical power steering motor of a motor vehicle, said motor comprising a stator having:
• the opening state of the electrical relays being controlled by means of an electric current flowing in said impedance.
• the method according to the invention makes it possible to control the opening of the phases of the electric motor by electrical relays thus increasing the reliability and the longevity of the control of the opening of the phases.
• control of electrical relays by means of an electric current makes it possible to increase the reliability of the control with respect to a voltage control and to dispense with a protection device of the zener diode type.
• the method according to the invention may also comprise one or more of the following characteristics, considered individually or in any technically possible combination:
• the electric motor is a three-phase motor
• each electrical relay comprises a field effect transistor
• the impedance is connected on the one hand to the gate of the field effect transistor and on the other hand to the neutral of the winding; and or
• the impedance is connected on the one hand to the gate of the field effect transistor and on the other hand to one of the electrodes of the transistor other than the gate, in particular at the source; and or
• the electric current is controlled by a current generator and an isolated power supply; and or
• the stator comprises a plurality of impedances of the same value, each impedance being dedicated to a phase and being interposed between the control electrode of the electrical relay for opening said phase and the neutral of the winding; and or
• the same impedance is common to the phases of the stator and is interposed between each control electrode of an electrical relay and the neutral of the winding;
• the impedance is a resistive impedance
• the impedance is greater than or equal to 2k ⁇ and less than or equal to 101 ⁇ ;
• the electric current flowing in the impedance has an intensity greater than or equal to 1 mA and less than or equal to 5 mA.
• the invention also relates to a method for controlling a multi-phase electric motor for electric power steering of a motor vehicle, said motor comprising a stator having:
• the opening state of the electrical relays being controlled by means of an electric current flowing in said impedance, said electric current being determined by a current generator powered by an isolated power supply.
• This method according to the invention may comprise one or more of the characteristics described above.
• This method according to the invention may also comprise one or more of the following characteristics, considered individually or in any technically possible combination: said insulated power supply is connected to a second power supply delivering an energy to said motor via a control unit; in particular the power supply comprises a secondary circuit connected to said second power supply;
• the current generator is activated to open the electrical relays via a transistor connected to a control terminal of the current generator;
• the method comprises providing a current generator having a transistor having two signal terminals and a control terminal, a first signal terminal being connected to the control electrode of the electrical relay, a second signal terminal and the control terminal being connected to a respective resistor, said resistors being connected by their other terminal to the isolated power supply.
• FIG. 1 represents a first configuration of an electric power steering motor that can be controlled by a method according to the invention
• FIG. 2 represents a second configuration of an electric power steering motor that can be controlled by a method according to the invention
• FIG. 3 represents another configuration of an electric power steering motor that can be controlled by a method. according to the invention.
• the invention relates to a method for controlling a multi-phase electric motor for electric power steering of a motor vehicle.
• the method according to the invention is remarkable in that the opening state of at least one electrical relay of at least one of the electric phases of the motor is controlled by means of an electric current flowing in an impedance.
• control of the opening state of the electrical phases of the electric power steering motor assisted by an electric current and not by a voltage makes it possible to limit the number of electrical connections necessary to control the state of opening of the electrical phases of the electric motor. engine.
• the method of the invention makes it possible to control an electric power steering motor in a configuration shown in FIG.
• the multi-phase power steering electric motor comprises a stator 1.
• the opening state of the electric motor stator phases is controlled by means of a current generator 2.
• the electric steering motor assisted is controlled by a steering unit 3.
• the stator 1 comprises a star-connected electrical winding defining three electrical phases 12, 14, 16 of the stator, for example by means of electric coils. Between each of three electrical phases 12, 14, 16 and the neutral of the electric winding is arranged an electrical relay 22, 24, 26.
• An impedance 30 is disposed between the neutral of the electric winding and the control electrode of each of the electric relays 22, 24, 26.
• the same impedance 30 is common to the three electrical phases 12, 14, 16 of the stator.
• this configuration makes it possible to limit the number of components and wires between the current generator 2 and the stator 1. Indeed, only one wire is necessary to control the current state of opening of the electrical relays 22, 24, 26. Moreover, a single impedance makes it possible to control the states of opening and closing of all the electrical relays of the stator 1.
• the current generator 2 may comprise an isolated power supply, for example a flyback type converter.
• the use of a current generator and an isolated power supply makes it possible to eliminate the risks of overvoltage coming from the vehicle battery.
• the impedance 30 is a resistive impedance.
• the impedance 30 is a resistance having a value greater than or equal to 2 k ⁇ and less than or equal to 10 k ⁇ .
• the electric current flowing in the impedance 30 may have an intensity greater than or equal to 1 mA and less than or equal to 5 mA.
• the electrical relays 22, 24, 26 may be field effect transistors (MOS).
• MOS field effect transistors
• the gates of the field effect transistors correspond to the control electrode of the electrical relays.
• the impedance 30 is connected on the one hand to the gates of the field effect transistors and on the other hand to the neutral of the winding.
• the impedance 30 is connected on the one hand to the gate of each of the field effect transistors and on the other hand to a second electrode of the field effect transistor, for example the sources of the field effect transistors. field effect transistors.
• the third electrode of each of the field effect transistors is connected to the control unit 3.
• the configuration of FIG. 1, in which the electrical relays 22, 24, 26 are arranged between the phases 12, 14, 16 and the neutral of the electric winding, makes it possible to control the electrical relays by means of a current electric using only one connection between the electric power steering motor and the current generator 2.
• the method of the invention makes it possible to control an electric power steering motor having a configuration as shown in FIG. 2.
• the electric power steering motor represented in FIG. 2 comprises a stator 1.
• the state of opening of the electric phases of the stator of the electric motor is controlled by means of a current generator 2
• the electric power steering motor is driven by a steering unit 3.
• the stator 1 comprises a star-connected electrical winding defining three electrical phases 12, 14, 16 of the stator, for example by means of electric coils and electrical relays 22, 24, 26 for opening said phases.
• the electrical phases 12, 14, 16 are arranged between the electrical relays 22, 24, 26 and the neutral of the electric winding.
• Impedances 32, 34, 36 are arranged between the control electrodes of each of the electrical relays 22, 24, 26 and the neutral of the electric winding.
• the impedances 32, 34, 36 have substantially the same value.
• the impedances 32, 34, 36 are preferably resistive impedances.
• the values of the resistors 32, 34, 36 are preferably greater than or equal to 2 k ⁇ and less than or equal to 10 k ⁇ , the electric current flowing in each of the impedances 32, 34, 36 may have an intensity greater than or equal to 1 mA and less or equal to 5 mA.
• phase-opening electrical relays 22, 24, 26 are preferably field-effect transistors whose grids constitute the control electrodes.
• the sources of the field effect transistors 22, 24, 26 are connected to the electrical phases 12, 14, 16, and the drains of these field effect transistors are connected to the control unit 3.
• the configuration according to FIG. 2 makes it possible to control the state of opening of the phases of the stator 1 by means of electric currents generated by the current generator 2. According to the configuration of FIG. 2, three connections are made between the current generator 2 and the stator 1 to control the opening state of the three phases 12, 14,16.
• the opening state of the electrical relays would be controlled by means of a voltage generator.
• a voltage control of the open state of the electrical relays as configured according to FIG. 2 requires six connections between the voltage generator and the stator (two connections per electrical relay to be controlled).
• the electrical relays are not necessarily limited to MOS, the impedance is not limited to a resistive impedance and the electric power steering motor is not necessarily three-phase.
• FIG. 3 represents an exemplary configuration in which the current generator 2 is powered by an isolated power supply 50.
• the example of FIG. 3 is moreover similar to that illustrated in FIG. 1 or that illustrated in FIG. 2.
• the power supply 50 comprises an isolation barrier separating a primary circuit from a secondary circuit.
• the current generator 2 is connected to a terminal of the power supply 50, in particular the secondary circuit is connected to the current generator 2.
• the secondary circuit can then be connected to the voltage Vbat d a second power supply which supplies the motor via the control unit 3.
• the neutral N of the electric winding has a floating electrical potential which fluctuates between the voltage Vbat of the second power supply and zero.
• the voltage delivered by the power supply 50 must deliver a voltage Vbat + X volts.
• the current generator 2 comprises a bipolar transistor 210.
• the collector 210a of the transistor 210 is connected to the control electrode of the electrical relay 26.
• the emitter 210b of the transistor 210 is connected to a resistor 220.
• the gate 210c of the transistor 210 is connected to a resistor 230.
• the terminals of the resistors 220, 230 which are not connected to the transistor 210 are connected to the isolated power supply 50.
• the components 210, 220, 230 of the current generator 2 make it possible to deliver a constant current in a simple way. However, the current generator 2 could have another configuration to deliver a constant current.
• the variation of the neutral potential N is not seen upstream, that is to say say at the level of the power supply supplying the disconnection or the connection of the electrical relays 22, 24, 26. Only the voltage Vce between the collector 210a and the emitter 210b is impacted by the fluctuation of the potential of the neutral N.
• the example illustrated in FIG. 3 may comprise a bipolar transistor 300 connected to the gate 210c of the transistor 210 of the current generator 2.
• the transistor 300 makes it possible to activate or deactivate the current generator 2 to open or close the electric relay 26.
• the transistor 300 is controlled in closing to ground the terminal 210c of the transistor 210 of the current generator 2.
• the transistor 300 is controlled in opening.
• the signal controlling the transistor 300 may come from a control unit such as a microcontroller, or may result from a loss of power in the vehicle.
• the example illustrated in FIG. 3 may comprise a temperature sensor on the return to earth from the neutral N. This return to ground is represented by a branch comprising a resistor 60 between the neutral N and ground.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Power Steering Mechanism (AREA)
• Control Of Ac Motors In General (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=50179683

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (6)

• 2013
  • 2013-10-31 FR FR1360694A patent/FR3012695B1/fr active Active
• 2014
  • 2014-10-30 WO PCT/FR2014/052771 patent/WO2015063427A2/fr active Application Filing
  • 2014-10-30 EP EP14805999.1A patent/EP3063051A2/de not_active Withdrawn
  • 2014-10-30 CN CN201480059286.9A patent/CN105683025A/zh active Pending

Non-Patent Citations (1)

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