Switched reluctance generator integrated controls

Patent metadata

Field	Value
Publication number	US-9340113-B2
Application number	US-201514596387-A
Country	US
Kind code	B2
Filing date	Jan 14, 2015
Priority date	Dec 23, 2010
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A control system for a generator of an electric drive is provided. The control system may include a converter circuit configured to communicate with one or more phases of a stator of the generator, and a controller in communication with the converter circuit and an engine associated with the electric drive. The controller may be configured to determine an operational state of the electric drive based on at least engine speed, and engage one of a map-lookup control scheme and a fixed-theta off control scheme for operating the generator based on the operational state of the electric drive.

First claim

What is claimed is:

1. A control system for a generator of an electric drive, comprising:
a converter circuit configured to communicate with one or more phases of a stator of the generator; and
a controller in communication with the converter circuit and an engine associated with the electric drive,
the controller being configured to
determine an operational state of the electric drive based on at least engine speed, and
engage one of a map-lookup control scheme and a fixed-theta off control scheme for operating the generator based on the operational state of the electric drive.

2. The control system of claim 1 , wherein the controller is configured to
engage the map-lookup control scheme for operating the generator if the operational state of the electric drive is in a steady state, and
engage the fixed-theta off control scheme for operating the generator if the operational state of the electric drive is in a transient state.

3. The control system of claim 1 , wherein the converter circuit includes at least two switches for communicating electrical current to each phase of the stator of the generator, each switch being selectively enabled by the controller.

4. The control system of claim 1 , wherein the map-lookup control scheme controls one or more phases of the stator of the generator according to at least one of a plurality of preprogrammed control maps stored in the controller.

5. The control system of claim 1 , wherein the fixed-theta off control scheme controls one or more phases of the stator of the generator based at least partially on a closed-loop system configured to monitor common bus voltage.

6. The control system of claim 1 , wherein the controller is configured to determine the operational state of the electric drive additionally based on at least one of a torque command and a rate of change in the engine speed.

7. The control system of claim 1 , wherein the controller is further configured to
determine a mode of operating the generator based on the engine speed,
engage a single pulse mode of operating the generator if the engine speed is relatively high and
engage a current regulation mode of operating the generator if the engine speed is not relatively high.

8. The control system of claim 7 , wherein the controller is further configured to
engage a soft chopping mode if the engine speed is relatively low, and
engage a hard chopping mode if the engine speed is nominal.

9. An adaptive control system for a generator of an electric drive, comprising:
a converter circuit configured to communicate with one or more phases of a stator of the generator; and
a controller in communication with the converter circuit and an engine associated with the electric drive,
the controller being configured to
provide a first signal for operating the generator based on a map-lookup control scheme,
provide a second signal for operating the generator based on a fixed-theta off control scheme,
determine an operational state of the electric drive based on output characteristics of the engine, and
selectively enable one of the first and second signals for controlling the generator based on the operational state of the electric drive.

10. The adaptive control system of claim 9 , wherein the controller is configured to
enable the first signal if the operational state of the electric drive is in a steady state, and
enable the second signal if the operational state of the electric drive is in a transient state.

11. The adaptive control system of claim 9 , wherein the controller is configured to determine the operational state of the electric drive based on output characteristics of the engine which include one or more of engine speed, torque command, and rate of change in the engine speed.

12. The adaptive control system of claim 9 , wherein the controller is further configured to
determine a mode of operating the generator based on engine speed,
engage a single pulse mode of operating the generator if the engine speed is relatively high, and
engage a current regulation mode of operating the generator if the engine speed is not relatively high.

13. A machine, comprising:
an engine;
a generator in communication with the engine;
a converter circuit in communication with the generator; and
a controller in communication with each of the converter circuit and the engine,
the controller being configured to
determine an operational state of the machine based on at least engine speed, and
engage one of a map-lookup control scheme and a fixed-theta off control scheme for operating the generator based on the operational state.

14. The machine of claim 13 , wherein the controller is configured to
engage the map-lookup control scheme for operating the generator if the operational state is in a steady state, and
engage the fixed-theta off control scheme for operating the generator if the operational state is in a transient state.

15. The machine of claim 13 , wherein the converter circuit includes at least two switches for communicating electrical current to each phase of the generator, each switch being selectively enabled by the controller.

16. The machine of claim 13 , wherein the map-lookup control scheme controls one or more phases of the generator according to at least one of a plurality of preprogrammed control maps stored in the controller.

17. The machine of claim 13 , wherein the fixed-theta off control scheme controls one or more phases of the generator based at least partially on a closed-loop system configured to monitor common bus voltage.

18. The machine of claim 13 , wherein the controller is configured to determine the operational state additionally based on at least one of a torque command and a rate of change in the engine speed.

19. The machine of claim 13 , wherein the controller is further configured to
determine a mode of operating the generator based on the engine speed,
engage a single pulse mode of operating the generator if the engine speed is relatively high and
engage a current regulation mode of operating the generator if the engine speed is not relatively high.

20. The machine of claim 13 , wherein the controller is further configured to
engage a soft chopping mode if the engine speed is relatively low, and
engage a hard chopping mode if the engine speed is nominal.

Assignees

• Caterpillar Inc

Inventors

• Wai Jackson
• Le Thuong
• Braun Adam
• Gerdes Jesse
• Siegle James
• Hartman Mark

Classifications

• B60L15/20

  for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed · CPC title

• B60W2300/44

  Tracked vehicles · CPC title

• B60W2050/0075

  Automatic parameter input, automatic initialising or calibrating means · CPC title

• B60W2300/17

  Construction vehicles, e.g. graders, excavators · CPC title

• B60L50/10

  using propulsion power supplied by engine-driven generators, e.g. generators driven by combustion engines · CPC title