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
  • B62D5/046—Controlling the motor
  • B62D5/0463—Controlling the motor calculating assisting torque from the motor based on driver input
• • 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
  • B62D5/046—Controlling the motor
• • 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
• • 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
  • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
  • H02P21/14—Estimation or adaptation of machine parameters, e.g. flux, current or voltage

Definitions

• a method of controlling the power supply of a three-phase electric motor from a DC voltage source and a device for applying it to a wafer is a method of controlling the power supply of a three-phase electric motor from a DC voltage source and a device for applying it to a wafer.
• the present invention relates to a method for controlling the power supply of an electric motor.
• a vector control module which allows the determination and the establishment of an operating point of the engine
• a close control module which allows the control of the motor on this point of operation.
• the application US 2006/0113954 describes a solution for determining the operating point of the motor, by generating setpoint current values l q and Id in Park coordinates.
• the solution is based on the in place of two regulators: the first regulator generates a current Iq from the speed setpoint and the second regulator intervenes as a priority when a voltage saturation is detected and generates a current setpoint l d which tends to decrease the voltage at the motor terminals. In this case, only the voltage V q is saturated to respect the available voltage.
• the disadvantage of this type of solution is that it does not prevent transient phases during which the voltage saturation is not respected. Thus, this solution is by design not optimal and only curative. Moreover, the stability of such a system is not easy to demonstrate.
• the setting of the corrector is complex.
• the determined operating point or engine operating conditions determined are not allowed by a limited voltage source that would be used. This is particularly the case in the context of an automotive application, the determination of the operating point is particularly important insofar as the supply voltage is relatively low (12V battery) and can be significantly reduced under the effect of the intensity of the current discharged by it. A good determination of the operating point of the engine makes it possible to improve the engine performance despite its electromotive force.
• the object of the invention is to provide a control method of a motor overcomes the aforementioned drawbacks and improving control methods known from the prior art.
• the invention makes it possible to ensure that a determined operating point of the motor is compatible with the voltage source supplying this motor before attempting to operate. this engine under the conditions of this operating point.
• the invention also relates to a device for implementing such a method.
• the method according to the invention makes it possible to control the supply of a three-phase electric motor from a DC voltage source. It comprises a step of determining engine operating conditions in which values are assigned to engine control parameters corresponding to these operating conditions. It is characterized in that it comprises: - a test step for determining whether the values assigned to the control parameters are adapted to a characteristic of the DC voltage source, and then
• this test step is negative, a step of modifying the values assigned to the control parameters, then a step of operating the engine under the operating conditions defined by the values assigned to the control parameters.
• the control parameters can be direct and quadrature setpoint currents set in Park coordinates.
• the determining step may include:
• a phase of determining a first quadrature Park current value enabling the motor to produce this torque, with zero direct Park current, and the testing step can comprise:
• a first test phase to determine whether the first Park current value in quadrature and the zero Park direct current correspond to operating conditions of the motor at a voltage lower than the voltage available at the motor terminals.
• the operation step may include a motor operation phase determined by assigning the first value to the quadrature Park current and assigning the null value to the direct park current. .
• the modification step may comprise a phase of assigning a second non-zero value to the direct Park current
• the operation step may comprise a motor operation phase determined by the assignment of the first value to the quadrature Park current and the assignment of the second value to the direct Park current.
• the modification step may comprise a phase of assigning a third value to the quadrature Park current, the third value being less than the first value and a phase of assigning a fourth non-zero value to the current of Direct Park, and the operating step may include a motor operation phase determined by assigning the third value to the quadrature Park current and assigning the fourth value to the direct Park current.
• the control method may include a phase for determining a maximum intensity flowing in the motor and the testing step may include a second test phase to determine if the values assigned to Park currents are such that the square root of the sum of their respective squares is less than the maximum intensity that can be delivered by the voltage source.
• the operation step may include a motor operation phase determined by the values assigned to the Park currents.
• the modification step may comprise a phase of reduction of the values assigned to the Park currents so that these values satisfy the second test phase and the operation step can understand a phase of operation determined by the reduced values of Park currents.
• the device according to the invention makes it possible to control the supply of a three-phase electric motor from a DC voltage source. It includes hardware and software to implement the method defined above.
• the hardware means may comprise a first electronic module for defining motor control parameters in Park coordinates and a second electronic module for defining the characteristics of the motor phase supply signals.
• the power steering system according to the invention comprises a three-phase electric motor whose power supply is controlled by a device defined above.
• the motor vehicle comprises a power control device of a three-phase electric motor defined above or a power steering system defined above.
• the operating point F represented in a Fresnel diagram as the end of a vector v having origin O, must be origin of the Fresnel diagram and as the end of a vector zi having origin P, remains inside a circle of center P and radius Z.
• FIG. 1 is a diagram of an embodiment of a power control device for implementing a method according to the invention.
• FIG. 2 is a flow chart of an embodiment of the control method according to the invention.
• Figures 3 to 6 are Fresnel diagrams in which are represented different operating points of an engine.
• FIG. 7 is a flowchart explaining the logic of modifying the operating conditions of the motor so that they are compatible with the voltage source supplying the motor.
• Figure 8 is a detailed flowchart explaining the logic of modifying the operating conditions of the engine so that they are compatible with the voltage source supplying the motor.
• the installation 10 of FIG. 1 mainly comprises a three-phase motor 16, a device 17 for supplying the motor and a device 13 for controlling the supply.
• This engine is preferably an engine organ of a motor vehicle. It is preferably of the "brushless" type and therefore preferably comprises a rotor with permanent magnets.
• the power supply device 17 comprises a DC voltage source 14 such as, for example, a motor vehicle battery or a set formed by a battery and an alternator of a motor vehicle and a three-phase bridge 15 for generating supply voltages on the three phases of engine.
• the bridge 15 uses for this purpose the voltage supplied by the voltage source 14.
• the power control device 13 makes it possible to define the characteristics of the supply signals to be supplied to each of the phases of the motor in order to feed it in the most appropriate manner possible.
• a vector control module 11 which allows the determination and the establishment of an operating point of the engine and a close control module 12 which allows the servocontrol of the engine on this point of operation.
• the input of the vector control module is for example attacked by a torque setpoint C * supplied by another system of a vehicle.
• the module uses this instruction to establish values for engine control parameters, these parameters are preferably a current Park quadrature i q * and a current id * Direct Park.
• the values of these parameters are supplied to the close control module which converts them into characteristics of the signals to be supplied on the phases of the motor. Feedback of currents consumed in the phases is provided to the power control device.
• the power control device also comprises software means for implementing the control method according to the invention, that is to say software means for governing the operation of the control device in accordance with the control method according to the invention. 'invention.
• software means include algorithms implemented by programs.
• a first step 100 values are determined which are assigned to the control parameters of the engine. This determination is made in particular by using the torque setpoint C * supplied to the control device and the instantaneous rotation speed of the motor.
• the parameters may notably comprise the quadrature Park current i q * and the direct Park current id * .
• a second step 110 it is tested whether the values assigned to the control parameters are compatible with the characteristics of the DC voltage source used to power the motor. In particular, it is tested whether these parameters correspond or define operating conditions and particularly power conditions that can be provided by the voltage source, for example taking into account the voltage and the current that it is able to output.
• step 130 in which the motor is operated by supplying it under conditions defined by the values selected from the control parameters.
• step 120 in which the values of the control parameters are modified.
• the logic for modifying the values of these parameters is described in detail below. Once these values have been modified, the test step 110 is looped.
• the aim of the vector control is to allow the motor, at available voltage between phases E and electrical speed of rotation ⁇ data, to provide a torque (proportional to the quadrature current iq) as close as possible to that demanded by the speed loop.
• the direct quantities (indexed d) correspond to the projections on the vertical axis of the various vectors and the quantities in quadrature (indexed q) correspond to their projections on the horizontal axis.
• the operating point F represented in a Fresnel diagram as end of a vector v having origin O (the origin of the Fresnel diagram), remains inside a circle of center O and radius V,
• Values are initially assigned to the control parameters determining the operating conditions of the engine. For example, as seen previously, we assign a value i q c to Park's current in quadrature and the null value to the direct Park current. This determines the position of an operating point denoted F 0 in the Fresnel frame.
• a first test phase 200 it is tested whether the point of
• This perpendicular Zl q Zi q this is the right of the operating points of the constant torque motor. If there is an intersection, we call F c the first intersection encountered since F 0 (for example if
• the Park current is maintained in quadrature at the value i q c and a non-zero value is set for the direct Park current.
• the operating point is moved to the right until it meets the circle corresponding to the maximum allowable voltage.
• This displacement is obtained by injecting a direct Park current to modify the vectors PF C , PA and AF C as shown in Figure 4. This displacement is called displacement constant torque.
• a test phase identical to phase 230 is used to determine whether the intensity of the motor current in the phases is not too high.
• the quadrature Park current is reduced to a value less than the value i q c and a non-zero value is set for the direct Park current.
• the operating point is moved to the right (OH) to meet the circle corresponding to the maximum allowable voltage.
• This displacement is obtained by modifying the currents of Park to modify the vectors PF n PA and AF r as shown in Figure 5. This displacement is called reduced torque displacement, insofar as it reduces the Park current in quadrature and thus the motor torque.
• V3 intersection exists it is named Fj and used in a phase 280 as the operating point of the engine.
• the values of the control parameters are modified so as to reach this operating point Fj.
• the appropriate Park currents are fixed.
• This displacement is obtained by modifying the currents of Park to modify the vectors PFj, PA and AFj as represented in FIG. 6. This displacement is called displacement at imposed intensity.
• the control parameters are changed in another way. For example Park currents are set to zero.
• the system having sent the torque setpoint C * is informed that there is no operating point of the motor corresponding to this setpoint. Thus, it can again establish a new instruction, this time more adapted to the engine and its feeding device.
• v a , b, c or Vabc Motor phase voltages
• Vd, Vq or v dq Motor voltages in Park coordinates
• ⁇ r Mechanical rotation speed of the motor
• ⁇ Motor current pulsation
• FIG. 8 a detailed logic of assigning values to the Park currents in each of the cases described above with reference to FIG. 7 is described in FIG. 8.
• the phases of assigning values to the Park currents are referenced as in FIG. 7.
• the phases 260 and 280 are split into phases 260a and 260b depending on whether the motor drives a load or is driven by this load and in phases 280a and 280b depending on whether the motor drives a load or is driven by this charge.
• the other phases referenced 300 to 370 are test phases corresponding to a digital translation of the logic described above with reference to FIG.
• the computation of the points of operation of the engine is entirely analytical and based on geometrical reasoning on the Fresnel diagram: once the analytical expressions obtained, their computation in real time is fast and optimal.
• the motor control parameters (generated in Park coordinates) are defined by calculations performed automatically based on the physical characteristics of the motor (resistance, inductance and electromotive force coefficient).
• the proposed solution has the following advantages: the algorithm structure is deterministic: the operating point is always optimal,
• Such a control method can in particular be used to actuate a power steering system.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Power Engineering (AREA)
• Control Of Ac Motors In General (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)

Applications Claiming Priority (2)

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Family Cites Families (5)

• 2007
  • 2007-08-03 FR FR0705700A patent/FR2919772B1/fr not_active Expired - Fee Related
• 2008
  • 2008-07-21 WO PCT/FR2008/051369 patent/WO2009019390A2/fr active Application Filing
  • 2008-07-21 EP EP08826991A patent/EP2176947A2/de not_active Withdrawn

Non-Patent Citations (1)

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