Switched reluctance generator integrated controls

• US 8,975,878 B2
• Filed: 12/23/2010
• Issued: 03/10/2015
• Est. Priority Date: 12/23/2010
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Wai, Jackson, Le, Thuong, Braun, Adam, Gerdes, Jesse, Siegle, James, Hartman, Mark
• Primary Examiner(s): Ramirez, Julio Gonzalez
• Application Number:
  US12/977,973
• Publication Number:
  US 20120161723A1
• Time in Patent Office: 1,538 Days
• Field of Search: 322/29, 322/44, 322/20, 700/287, 700/290
• US Class Current: 322/44
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 50/10 using propulsion power supplied by engine-driven generators, e.g. generators driven by combustion engines
• CPC Class Codes: B60L 50/13 using AC generators and AC motors
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 2050/0075 Automatic parameter input, automatic initialising or calibrating means
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 2300/44 Tracked vehicles
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: F02B 63/042 Rotating electric generators
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y10S 903/902 Prime movers comprising electrical and internal combustion motors

Abstract

A method of controlling a generator (110) of an electric drive (104) associated with an engine (102) is provided. The method may determine an operational state of the electric drive (104) based on a speed of the engine (102), and selectively engage one of a map-lookup control scheme (150) and a fixed-theta off control scheme (152) for operating the generator (110) based on the operational state of the electric drive (104).

Claims

1. A method of controlling a generator of an electric drive associated with an engine, the method comprising the steps of:

determining a mode of operating the generator based on a speed of the engine;

engaging a single pulse mode of operating the generator if the engine speed is relatively high;

engaging a current regulation mode of operating the generator if the engine speed is not relatively high;

providing a first signal for operating the generator based on a map-lookup control scheme;

providing a second signal for operating the generator based on a fixed-theta off control scheme;

determining an operational state of the electric drive based on output characteristics of the engine; and

selectively enabling one of the first and second signals for controlling the generator based on the detected operational state of the electric drive.

2. The method of claim 1, wherein the first signal is enabled if the operational state of the electric drive is in a steady state and the second signal is enabled if the operational state of the electric drive is in a transient state.

3. The method of claim 1, wherein the operational characteristics of the engine include one or more of engine speed, a torque command and a rate of change in engine speed.

4. The method of claim 1 further providing a third signal for operating the generator based on a map-lookup control scheme.

5. The method of claim 4 further enabling the third signal for controlling the generator if the current regulation mode is engaged.

6. The method of claim 1, wherein a soft chopping mode is engaged if the engine speed is relatively low.

7. The method of claim 1, wherein a hard chopping mode is engaged if the engine speed is nominal.

8. The method of claim 1, wherein the map-lookup control scheme is configured to control one or more phases of a stator of the generator according to at least one of a plurality of preprogrammed control maps.

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