Method of verifying the operation of a motor propulsion plant fitted to an automotive vehicle and corresponding system
A method and system for verifying operation of a motor propulsion plant fitted to an automotive vehicle with electric or hybrid traction, the motor propulsion plant including an electric motor including a permanent-magnet rotor. The method includes: a regulation of currents of a stator and a measurement of direct and quadratic components of the currents; an application, in a model of the electric motor linking control signals to the direct and quadratic components of the currents, of a change of variable in which X=Iq3+Id3, Y=Iq−Id; determination of minimum and maximum bounds for X and Y to deduce therefrom minimum and maximum bounds for Iq and Id; and a comparison between the measured direct and quadratic components of the currents and the minimum and maximum bounds for Iq and Id.
1. A method for verifying operation of a power train with which a motor vehicle with electric or hybrid drive is equipped, the power train including an electric motor including a permanent magnet rotor and a stator, the method comprising:
regulating, via an electronic control unit, stator currents delivering control signals to the electric motor, the currents to be regulated and the control signals being expressed in a revolving reference frame including a direct axis and a quadratic axis;
measuring, via the electronic control unit, the direct and quadratic components of the currents:
applying, via the electronic control unit, in a model of the electric motor linking the control signals to the direct and quadratic components of the currents, a change of variable by computation of new variables X and Y according to relationships X=I q 3 +I d 3 and Y=I q -I d , in which I d and I q respectively denote the direct component of the current and the quadratic component of the current;
determining, via the electronic control unit, minimum and maximum bounds of the changed variables to deduce therefrom minimum and maximum bounds for the direct and quadratic components of the current;
comparing, via the electronic control unit, between the measured direct and quadratic components the currents and the minimum and maximum bounds; and
limiting, via the electronic control unit, use of the electric motor when one of the measured values is outside the determined bounds.
2. The method as claimed in claim 1 , further comprising:
measuring torque generated by the electric motor;
computing minimum and maximum bounds for the torque from the minimum and maximum bounds for the quadratic component of the current; and
comparing between the measured torque and the minimum and maximum bounds for the torque.
3. The method as claimed in claim 1 , further comprising generating at least one signal if one of the measured values is outside the determined bounds.
4. A system for verifying operation of a power train with which a motor vehicle with electric or hybrid drive is equipped, the power train including an electric motor including a permanent magnet rotor and a stator, the vehicle including means configured to regulate stator currents delivering control signals to the electric motor, the currents to be regulated and the control signals being expressed in a revolving reference frame including a direct axis and a quadratic axis, and means configured to measure direct and quadratic components of the currents, the system comprising:
an electronic control unit that is configured to
apply, in a model of the electric motor linking the control signals to the direct and quadratic components of the currents, a change of variable by computation of new variables X and Y according to relationships X=I q 3 +I d 3 and Y=I q -I d , in which I d and I q respectively denote the direct component of the current and the quadratic component of the current;
determine minimum and maximum bounds for X and Y for deducing minimum and maximum bounds for the direct and quadratic components of the current;
compare the measured direct and quadratic components of the currents and the minimum and maximum bounds; and
limit use of the electric motor when one of the measured values is outside the determined bounds.
5. The system as claimed in claim 4 , further comprising:
means configured to compute minimum and maximum bounds for torque from the minimum and maximum bounds for the quadratic component of the current; and
means for comparing a torque measured by means for measuring the torque of the vehicle and the minimum and maximum bounds for the torque.
6. The system as claimed in claim 4 , further comprising means configured to generate at least one signal if one of the measured values is outside the determined bounds.