Four quadrant voltage limiter for rotor flux oriented machine control

Patent metadata

Field	Value
Publication number	US-9935573-B2
Application number	US-201514888263-A
Country	US
Kind code	B2
Filing date	Feb 26, 2015
Priority date	Feb 28, 2014
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

Methods, systems and computer readable storage devices for a four quadrant voltage limiter that limits a commanded phase voltage to within a volt second capability of an inverter by maintaining a rotor flux and folding back a torque under both motoring and regeneration torque commands. In one embodiment: (a) in a motoring operation, an upper limit for a q-axis voltage is enforced; and (b) in a regeneration operation a lower limit for the q-axis voltage is enforced.

First claim

What is claimed is:

1. A computer processor-implemented four quadrant voltage limiter method that limits a commanded phase voltage to within a volt second capability of an inverter, the four quadrant voltage limiter computer processor-implemented method comprising:
enforcing by a computer processor an upper limit for a q-axis voltage in a motoring operation, under a condition where the inverter is unable to generate a requested torque;
enforcing by the computer processor a lower limit for the q-axis voltage in a regeneration operation, the lower limit being below a nominal value necessary to maintain flux; and
outputting a command by the computer processor to the inverter to enforce the upper limit and the lower limit for the q-axis voltage to limit the commanded phase voltage to within a volt second capability of the inverter.

2. The method of claim 1 , wherein the commanded phase voltage is limited to within the volt second capability of the inverter by maintaining a rotor flux and folding back a torque under both motoring and regeneration torque commands.

3. The method of claim 1 , wherein, in the motoring operation, the upper limit is a remaining inverter capability when a d-axis voltage is allowed to take on any value that the inverter can produce.

4. The method of claim 1 , wherein, in the regeneration operation, a d-axis voltage is allowed to take on any value that the inverter can produce.

5. The method of claim 1 , wherein: the motoring operation has a speed selected from the group of: (a) positive speed; and (b) negative speed; and the regeneration operation has a speed selected from the group of: (a) positive speed; and (b) negative speed.

6. The method of claim 1 , wherein the motoring operation and the regeneration operation are used in a vehicle.

7. A four quadrant voltage limiter system that limits a commanded phase voltage to within a volt second capability of an inverter, the four quadrant voltage limiter system comprising:
a processor; and
a memory storing computer readable instructions that, when executed by the processor, implement:
a first enforcing unit for enforcing, in a motoring operation, an upper limit for a q-axis voltage under a condition where the inverter is unable to generate a requested torque; and
a second enforcing unit for enforcing, in a regeneration operation, a lower limit for the q-axis voltage, the lower limit being below a nominal value necessary to maintain flux,
wherein enforcing the upper limit and the lower limit for the q-axis voltage limits the commanded phase voltage to within a volt second capability of the inverter.

8. The system of claim 7 , wherein the commanded phase voltage is limited to within the volt second capability of the inverter by maintaining a rotor flux and folding back a torque under both motoring and regeneration torque commands.

9. The system of claim 7 , wherein, in the motoring operation, the upper limit is a remaining inverter capability when a d-axis voltage is allowed to take on any value that the inverter can produce.

10. The system of claim 7 , wherein, in the regeneration operation, a d-axis voltage is allowed to take on any value that the inverter can produce.

11. The system of claim 7 , wherein:
the motoring operation has a speed selected from the group of: (a) positive speed; and
(b) negative speed; and
the regeneration operation has a speed selected from the group of: (a) positive speed;
and (b) negative speed.

12. The system of claim 7 , wherein the motoring operation and the regeneration operation are used in a vehicle.

13. A computer readable storage device including a computer program for four quadrant voltage limiting that limits a commanded phase voltage to within a volt second capability of an inverter, the computer program including instructions for:
in a motoring operation, enforcing an upper limit for a q-axis voltage under a condition where the inverter is unable to generate a requested torque; and
in a regeneration operation, enforcing a lower limit for the q-axis voltage, the lower limit being below a nominal value necessary to maintain flux,
wherein enforcing the upper limit and the lower limit for the q-axis voltage limits the commanded phase voltage to within a volt second capability of the inverter.

14. The computer readable storage device of claim 13 , wherein the commanded phase voltage is limited to within the volt second capability of the inverter by maintaining a rotor flux and folding back a torque under both motoring and regeneration torque commands.

15. The computer readable storage device of claim 13 , wherein, in the motoring operation, the upper limit is a remaining inverter capability when a d-axis voltage is allowed to take on any value that the inverter can produce.

16. The computer readable storage device of claim 13 , wherein, in the regeneration operation, a d-axis voltage is allowed to take on any value that the inverter can produce.

17. The computer readable storage device of claim 13 , wherein:
the motoring operation has a speed selected from the group of: (a) positive speed; and
(b) negative speed; and
the regeneration operation has a speed selected from the group of: (a) positive speed;
and (b) negative speed.

Assignees

• Bae Sys Controls Inc

Inventors

• Vovos Robert J
• Lyons Arthur P

Classifications

• H02P3/18

  for stopping or slowing an AC motor · CPC title

• H02P21/141 Primary

  Flux estimation · CPC title

• H02P23/06

  Controlling the motor in four quadrants · CPC title

• H02P2207/03

  Double rotor motors or generators, i.e. electromagnetic transmissions having double rotor with motor and generator functions, e.g. for electrical variable transmission · CPC title

• B60K1/02

  comprising more than one electric motor · CPC title