Method for operating a permanent magnet synchronous motor, and motor assembly

A method for operating a permanent magnet synchronous motor, the operating parameters of which are specified in a two-dimensional d/q coordinate system, the method comprising:

• receiving a torque request,
• converting the torque request into a first vector, a q coordinate of which corresponds to the torque request and a d coordinate of which is zero,
• representing a number of constraints as areas in the d/q coordinate system, each required area representing a constraint such that an operational vector should lie within the required area, and each prohibited area representing a constraint such that an operational vector should lie outside the prohibited area,
• checking whether the first vector lies within all of the required areas and outside all of the prohibited areas,
• if so, using the first vector as an operational vector,
• if not:
• determining respective highest q coordinates of the required areas, and reducing the q coordinate of the first vector to the lowest of the highest q coordinates of the required areas, thereby obtaining a second vector,
• checking whether the second vector lies within a first required area,
• if so, using the second vector as a third vector,
• if not, changing the d coordinate of the second vector, so that it lies on a limitation of the first required area with the smallest amount of the d coordinate, thereby obtaining a third vector,
• checking whether the third vector lies within a second required area,
• if so, using the third vector as a fourth vector,
• if not, changing the coordinates of the third vector along a change limitation up to the point of intersection between a limitation of the second required area with the change limitation with the highest q coordinate, thereby obtaining a fourth vector,
• determining an operational vector on the basis of the fourth vector,
• activating the permanent magnet synchronous motor by means of operational parameters that are indicated by the operational vector.