Motor energization control method

Abstract

The present invention provides a motor energization control method, which can continue to drive the motor to cross the dead point even if a phase failure occurs. When a phase failure occurs, when the electrical angle is on the side of a predetermined angle ahead of the torque dead center where the output torque is zero, and the rotational speed and steering torque of the electric motor (15) satisfy predetermined conditions, the electrical angle is set to Return, pass the phase current in the opposite direction until it reaches the first electrical angle (θ 4 ) to reverse the rotation of the electric motor (15). Then, the phase current is passed in the positive direction, and the electric motor (15) is rotated forward until it reaches the second electrical angle (θ 5 ), controlled in such a way as to cross the torque dead point by maintaining sufficient angular velocity.

Description

technical field [0001] The present invention relates to a motor energization control method used, for example, in an electric power steering device or the like. Background technique [0002] In recent years, in electric power steering devices, there has been an increasing demand for continuing to drive (assist) the electric motor through the remaining two normal phases without stopping the motor control when an abnormality occurs in one phase of the three-phase electric motor. . In such a phase failure, around the electrical angle corresponding to the failure, the motor torque decreases, creating a region where the steering wheel cannot be turned. Therefore, until now, it has been a problem to improve the steering feeling by going over the motor torque reduction region at the time of a phase failure. [0003] For example, Patent Document 1 discloses an electric power steering device that, when driven by a two-phase motor, when the sum of the steering torque and the steerin...

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Problems solved by technology

[0006] As another technique, there has been proposed a configuration in which the electric current command value is increased and corrected to accelerate the rotation of the motor when the electrical angle is in the acceleration range, thereby overriding the range where the motor torque decreases. However, when the vehicle speed is low such as when the vehicle is stopped , there is the problem that it is difficult to cross the region of reduced motor torque by simply accelerating

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