Controller anti-windup for permanent magnet synchronous machines
View Patent ↗Technical solutions are described for preventing controller windup in a motor control system. An example system includes a first anti-windup module that receives a commanded voltage and a limited voltage command. The limited voltage command is applied to an electric motor, where the first anti-windup module generates a first modified current command by modifying a current command that is applied to the motor control system. The modification is based on a ratio of the commanded voltage and the limited voltage command. The system further includes a second anti-windup module that receives the commanded voltage and the limited voltage command. The second anti-windup module generates a second modified current command by modifying the first modified current command. The modification based on a difference between the commanded voltage and the limited voltage command.
1. A system for preventing controller windup in a motor control system, the system comprising:
an anti-windup module that receives a commanded voltage and a limited voltage command that is applied to an electric motor, the anti-windup module generates a modified current command, the modification based on a difference between the commanded voltage and the limited voltage command determined by subtracting the commanded voltage from the limited voltage command, the modified current command used to generate a torque using an electric motor.
2. The system of claim 1 , further comprising:
a limiting module that determines the limited voltage command in response to the commanded voltage exceeding an available voltage of a motor power source.
3. The system of claim 1 , further comprising:
a current command generator that generates the current command that is input to the motor control system based on a torque command indicative of an amount of torque to be generated using the electric motor.
4. The system of claim 1 , wherein the anti-windup module uses an integrator back calculation to generate the modified current command, the integrator back calculation comprising scaling the difference using a gain matrix
G
A
W
=
[
G
Add
G
Adq
G
Aqd
G
A
q
q
]
,
where G Add , G Adq , G Aqd , and G Aqq are anti-windup parameters.
5. The system of claim 4 , wherein the anti-windup parameters are based on cutoff frequencies for d-axis and q-axis of closed-loop current controller.
6. The system of claim 4 , wherein G Aqd and G Adq are set to zero.
7. The system of claim 4 , wherein G Adq is set to zero.
8. The system of claim 4 , wherein G Aqd is set to zero.
9. The system of claim 1 , wherein the modified current command retains a proportion of a direct axis (d-axis) current and a quadrature axis (q-axis) current provided by the commanded voltage.
10. A method for preventing controller windup in an electric motor, the method comprising:
generating, by an anti-windup module, a modified current command based on a difference between a commanded voltage and a limited voltage command determined by subtracting the commanded voltage from the limited voltage command; and
using, by a controller, the modified current command as input to determine a voltage to be applied across the electric motor for torque generation.
11. The method of claim 10 , further comprising:
determining the limited voltage command in response to the commanded voltage exceeding an available voltage of a motor power source, the limited voltage command being applied to the electric motor.
12. The method of claim 10 , wherein the anti-windup module uses an integrator back calculation to generate the modified current command, the integrator back calculation comprising scaling the difference using a gain matrix
G
A
W
=
[
G
Add
G
Adq
G
Aqd
G
A
q
q
]
,
where G Add , G Adq , G Aqd , and G Aqq are anti-windup parameters.
13. The method of claim 12 , wherein the anti-windup parameters are based on cutoff frequencies for d-axis and q-axis of closed-loop current controller.
14. The method of claim 12 , wherein G Adq is set to zero.
15. The method of claim 12 , wherein G Aqd is set to zero.