Field-oriented control of a permanently excited synchronous reluctance machine

1. A method for the field-oriented control of a permanently excited synchronous machine with reluctance torque comprising:

a) determining a flux-generating current component and a torque-generating current component as a function of a required torque;

b) determining (a) a voltage component in a flux direction as a function of the flux-generating current component and (b) a voltage component perpendicular to the flux direction as a function of the torque-generating current component;

c) upon determining a differential amount by subtracting a vectorial sum of the voltage components from a maximum voltage, obtaining a first current differential value, via output from a PI-voltage controller, based on the differential amount;

d) upon determining an input voltage component based on a sum of the flux-generating current component and the first current differential value, determining an input current component based on the input voltage component;

e) determining an achieved torque based on the input current component;

f) upon determining a second differential amount by subtracting the achieved torque from the required torque, obtaining a second current differential value, via a PI-torque controller, based on the second differential amount;

g) determining a second input voltage component based on a sum of the torque-generating current component and the second current differential value; and

h) controlling the permanently excited synchronous machine based on the input voltage component and the second input voltage component.

2. The method of claim 1 , further comprising obtaining the flux-generating current component and the torque-generating current component via a first characteristic diagram, wherein the first characteristic diagram is one-dimensional.

3. The method of claim 1 , further comprising upon determining a differential by subtracting the input current component from the sum of the flux-generating current component and the first differential value, determining an updated input voltage component based on the differential.

4. The method of claim 3 , further comprising determining the updated input voltage component based further on an angular frequency of a rotor or a flux linkage.

5. The method of claim 1 , further comprising, upon determining a constant required torque, iteratively determining the input voltage component and the second input voltage component.

6. The method of claim 1 , further comprising determining the achieved torque based further on flux linkages.

7. The method of claim 1 , wherein the permanently excited synchronous machine is a drive unit of a motor vehicle.

8. A controller for the field-oriented control of a permanently excited synchronous machine with reluctance torque, programmed to:

a) determine a flux-generating current component and a torque-generating current component as a function of a required torque;

b) determine (a) a voltage component in a flux direction as a function of the flux-generating current component and (b) a voltage component perpendicular to the flux direction as a function of the torque-generating current component;

c) upon determining a differential amount by subtracting a vectorial sum of the voltage components from a maximum voltage, obtain a first current differential value, via output from a PI-voltage controller, based on the differential amount; and

d) upon determining an input voltage component based on a sum of the flux-generating current component and the first current differential value, determine an input current component based on the input voltage component;

e) determine an achieved torque based on the input current component;

f) upon determining a second differential amount by subtracting the achieved torque from the required torque, obtain a second current differential value, via a PI-torque controller, based on the second differential amount;

g) determine a second input voltage component based on a sum of the torque-generating current component and the second current differential value; and

h) control the permanently excited synchronous machine based on the input voltage component and the second input voltage component.

9. The controller of claim 8 , wherein the controller is further programmed to obtain the flux-generating current component and the torque-generating current component via a first characteristic diagram, wherein the first characteristic diagram is one-dimensional.

10. The controller of claim 8 , wherein the controller is further programmed to, upon determining a differential by subtracting the input current component from the sum of the flux-generating current component and the first differential value, determine an updated input voltage component based on the differential.

11. The controller of claim 10 , wherein the controller is further programmed to determine the updated input voltage component based further on an angular frequency of a rotor or a flux linkage.

12. The controller of claim 8 , wherein the controller is further programmed to, upon determining a constant required torque, iteratively determine the input voltage component and the second input voltage component.

13. The controller of claim 8 , wherein the controller is further programmed to determine the achieved torque based further on flux linkages.

14. The controller of claim 8 , wherein the permanently excited synchronous machine is a drive unit of a motor vehicle.