Method for determining the angular deviation between the rotor and the stator of an electric machine of a motor vehicle

Abstract

The invention relates to a method for determining the angular deviation between a rotor of an electric machine for driving a motor vehicle, the rotor being supplied with a rotor excitation current and voltage, the stator being supplied with multiple phases on three phases Stator phase currents and voltages, wherein the method comprises the steps of: verifying that the electric machine is stopped; applying a rotor excitation signal for a period of time capable of causing partial magnetization of the rotor; applying a condition capable of causing activation and rapid demagnetization of the rotor A rotor de-excitation signal of , while measuring the stator phase currents during the demagnetization, and while maintaining zero voltage between the phases of the stator; corresponding to the stator phase currents measured by applying the Park-Clark transform and according to The measurements of the electrical position of the rotor are used to determine a plurality of forward stator currents and a plurality of quadrature stator currents; determine the maximum value between these forward stator currents and between these quadrature stator currents; if the maximum quadrature An angular deviation error signal is sent if the absolute value of the stator current value is greater than a threshold; an angular deviation in radians is determined by calculating the tangent arc of the ratio of the maximum value of the quadrature stator current to the maximum value of the positive stator current correction value.

Description

technical field [0001] This invention relates to the technical field of electric machines, and more particularly to the control of such machines. Background technique [0002] The principle of a synchronous machine, also known as a synchronous AC motor, is based on the interaction of two magnetic fields to generate a drive or resistive torque. One of these fields is called the rotor excitation field, since this field is associated with the rotor (the rotating part of the machine). The other field is called the stator field because this field is associated with the stator (the stationary part of the machine). Stator fields are caused by magnetic fluxes generated by phase-alternating currents flowing through the machine. The currents are controlled to produce a flux that is synchronous with respect to the rotor, ie rotates at the same speed as the rotor. Thus, the stator field is controlled in quadrature, ie controlled at a fixed 90° phase offset from the rotor field. Such...

AI Technical Summary

Problems solved by technology

If this determination is omitted or not performed correctly, the motor cannot produce any driving torque or may even produce a torque in the opposite direction from the desired direction, which may lead to undesirable and potentially dangerous effects

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