Lifing and Performance Optimization Limit Management for Turbine Engine

• US 20140271117A1
• Filed: 12/17/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Application

• Current Assignee: Rolls-Royce Corporation (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce Corporation (Rolls-Royce Holdings Plc)
• Inventors: French, Mat, Armstrong, Michael
• Granted Patent: US 10,284,125 B2
• Time in Patent Office: Days
• US Class Current: 415/1
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F01D 21/12 responsive to temperature
• CPC Class Codes: F01D 21/14 responsive to other specific conditions
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• CPC Class Codes: F02C 9/00 Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants controlling air intakes F02C7/057; controlling turbines F01D; controlling compressors F04D27/00; controlling in general G05
• CPC Class Codes: F05D 2270/06 to match engine to driven device
• CPC Class Codes: F05D 2270/101 Compressor surge or stall
• CPC Class Codes: F05D 2270/11 to prolong engine life
• CPC Class Codes: H02P 2101/30 for aircraft
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator

Abstract

A control for a multi-shaft turbine engine system using electrical machines seeks optimal system performance while accommodating hard and soft component limits. To accommodate the component limits, the control may generate a number of possible operating point options reflecting potential trade-offs in performance, lifting, efficiency, or other objectives.

Claims

1. A control for a turbine engine system including a multi-shaft turbine engine and one or more electrical machines coupled to the shafts, the control comprising:

a constraint analyzer to determine applicable component limits based on current operating conditions of the system, wherein each of the component limits defines an operating region in which, if the component limit is exceeded, the life or safety of the component may be compromised; and

a limit management optimizer to generate a desired operating point and one or more possible operating points for the system based on the current operating conditions, the applicable component limits, and an optimization objective, wherein the one or more possible operating points each represents a functional trade-off involving a reduction in a component function to maintain the component limits, an objective trade-off involving a modification of the optimization objective to maintain the component limits, or a modification of one or more of the component limits.

2. The control of claim 1, wherein the limit management optimizer selects the desired operating point or one of the possible operating points, and communicates a control signal to one or more system controllers for the system to achieve the selected operating point.

3. The control of claim 2, wherein the control signal comprises a power extraction control signal and the control communicates the control signal to a generator control unit configured to control the operation of a generator coupled to one of the shafts of the turbine engine system.

4. The control of claim 1, wherein the component limits comprise one or more soft limits that if exceeded, result in a non-fatal penalty to the operation of the system.

5. The control of claim 1, wherein the component limits comprise one or more hard limits that if exceeded, result in a failure of a component of the system.

6. The control of claim 1, wherein the optimization objective comprises one or more of performance, efficiency, lifing, reliability and stability.

7. The control of claim 1, wherein the limit management optimizer communicates data relating to the desired operating point and the possible operating points to a vehicle manager, and the vehicle manager selects the desired operating point or one of the possible operating points.

8. The control of claim 1, wherein the vehicle manager communicates the selected operating point to the control.

9. The control of claim 1, wherein the constraint analyzer uses a system model to determine the applicable component limits, and the system model comprises data relating to an estimated state of the system.

10. A method for controlling the allocation of power extracted from a plurality of shafts of a turbine engine, the shafts having one or more electrical machines coupled thereto, the method comprising:

analyzing current operating conditions of the turbine engine;

determining a optimization objective, the optimization objective being to maximize one of performance, efficiency, component lifing, reliability, and stability of the turbine engine;

determining a component limit based on the current operating conditions;

determining a desired operating point for the turbine engine based on the current operating conditions and the optimization objective,

determining whether the desired operating point violates the component limit; and

determining one or more possible operating points for the turbine engine, each of the possible operating points representing one of a functional trade-off involving a reduction in the operation of a component of the turbine engine to maintain the component limit, an objective trade-off involving a modification of the optimization objective to maintain the component limit, and a modification of the component limit.

11. The method of claim 10, comprising selecting one of the desired operating point and the one or more possible operating points.

12. The method of claim 10, comprising communicating one or more of the desired operating point and the one or more possible operating points to a vehicle manager.

13. The method of claim 10, comprising receiving data relating to the desired operating point and/or one or more of the possible operating points from a vehicle manager.

14. The method of claim 10, comprising sending a control signal to a controller to control the operation of one or more of the electrical machines, wherein the control signal relates to the desired operating point or one of the possible operating points.

15. A control for a turbine engine system including a multi-shaft turbine engine and one or more electrical machines coupled to the shafts, the control being configured to perform the method of claim 10.

17. A system for controlling the allocation of power between or among electrical machines of a turbine engine, the system comprising:

a low pressure turbine, coupled to the turbine engine via a low pressure shaft;

a high pressure turbine, coupled to the turbine engine via a high pressure shaft;

electrical machines coupled to the low pressure shaft and the high pressure shaft, the electrical machines configured to extract rotational power from the low pressure shaft and the high pressure shaft and output electrical power;

controllers coupled to each of the electrical machines to control the amount of rotational power extracted by the electrical machines; and

a limit management optimizer to, during operation of the turbine engine, adjust the allocation of power extraction between or among the electrical machines to achieve an operating point based on current operating conditions of the turbine engine, an optimization objective for the turbine engine, and a component limit of a component of the system, wherein the system is configured to perform the method of claim 10.

16. A system for controlling the allocation of power between or among electrical machines of a turbine engine, the system comprising:

a low pressure turbine, coupled to the turbine engine via a low pressure shaft;

a high pressure turbine, coupled to the turbine engine via a high pressure shaft;

electrical machines coupled to the low pressure shaft and the high pressure shaft, the electrical machines configured to extract rotational power from the low pressure shaft and the high pressure shaft and output electrical power;

controllers coupled to each of the electrical machines to control the amount of rotational power extracted by the electrical machines; and

a limit management optimizer to, during operation of the turbine engine, adjust the allocation of power extraction between or among the electrical machines to achieve an operating point based on current operating conditions of the turbine engine, an optimization objective for the turbine engine, and a component limit of a component of the system.