High-bandwidth control of turbofan / turboprop thrust response using embedded motors

Abstract

Systems and methods for high-bandwidth control of thrust response in turbofan or turboprop engines are provided. Such systems and methods include an engine control system that processes rate commands and feedback signals from the engine to generate separate fuel and motor control signals that separately control the engine's fuel and motor dynamics to generate engine dynamics that result in a desired thrust response.

Description

Technical Field

[0001] These teachings generally concern jet engines, and more specifically high-bandwidth control of the thrust response of turbofans or turboprops using embedded motors. Background Technology

[0002] Turbojet engines, such as turbofans and turboprops, typically have thrust control systems that rely on controlling the amount and timing of fuel supplied to the engine. Additionally, these engines are often coupled to an electric motor (e.g., a controllable electric motor / generator) that can provide additional thrust to the engine, transmit power between shafts in a multi-axis engine, and / or generate electricity for use by the engine or other aircraft systems. Efficient thrust control and efficient operation of the electric motors can lead to efficient operation of both the aircraft and the engine. Attached Figure Description

[0003] By providing high-bandwidth control of the thrust response of the turbofan / turboprop using the embedded motor described in the detailed description below, various requirements are at least partially met, particularly when studied in conjunction with the accompanying drawings. A complete and enabling disclosure of all aspects of this description, including its best mode, is set forth in the specification with reference to the accompanying drawings for those skilled in the art, wherein:

[0004] Figure 1 This is a cross-sectional view of a gas turbine engine used in aircraft.

[0005] Figure 2 This is a block diagram of an engine control system based on various embodiments of these teachings;

[0006] Figure 3 This is a block diagram of an engine control system based on various embodiments of these teachings;

[0007] Figure 4 These are schematic diagrams of engine control systems based on various embodiments of these teachings;

[0008] Figure 5 These are schematic diagrams of engine control systems based on various embodiments of these teachings;

[0009] Figure 6 These are schematic diagrams of engine control systems based on various embodiments of these teachings;

[0010] Figure 7 This is a block diagram of an engine control system based on various embodiments of these teachings;

[0011] Figure 8 These are schematic diagrams of engine control systems based on various embodiments of these teachings;

[0012] Figure 9 It is a graph of the thrust rate of a gas turbine engine over time using an engine control system based on various embodiments of these teachings.

[0013] Figure 10 It is a graph of fuel consumption over time for a gas turbine engine employing an engine control system according to various embodiments of these teachings.

[0014] Figure 11 It is a graph of the speed of a gas turbine engine over time using an engine control system based on various embodiments of these teachings;

[0015] Figure 12 It is a graph of the error signal of the engine control system over time according to various embodiments of these teachings; and

[0016] Figure 13 It is a graph of the engine feedback signal of the engine control system according to various embodiments of these teachings.

[0017] The elements in the accompanying drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size and / or relative positioning of some elements may be exaggerated relative to other elements to aid in understanding the various embodiments of this teaching. Furthermore, common but easily understood elements that are useful or necessary in commercially viable embodiments are generally not depicted to facilitate less obstructed observation of these various embodiments of this teaching. Certain actions and / or steps may be described or depicted in a specific sequence of occurrence, and those skilled in the art will understand that such specificity regarding sequence is not actually necessary. Detailed Implementation

[0018] Existing turbofan and turboprop jet engines primarily rely on fuel-based control systems to achieve desired engine thrust and thrust trajectory. However, fuel-based control systems can be slow to respond to errors in the thrust response identified from engine feedback. This slow response, compared to the engine's ideal response, can lead to excessive fuel consumption, sluggish speed response or poor speed maintenance, increased engine wear, and other drawbacks. These are significant challenges in aviation application settings.

[0019] Typically, various aspects of this disclosure can be used in conjunction with engine control systems and related methods that distribute thrust control between fuel controllers and motor controllers to provide tighter control over thrust response, minimize thrust asymmetry through tighter control of acceleration paths, maximize thrust response for specific scenarios, reduce fuel system hardware design margins by meeting thrust bandwidth and disturbance suppression requirements, actively force linear behavior to provide more uniform equipment dynamics, improve synchronization phasing capability, minimize core speed overshoot (particularly exacerbated by icing), reduce transport time through restricted areas (e.g., severe vibration zones), and / or suppress gearbox vibration modes of geared turbofans.

[0020] Unless otherwise specified herein, the terms and expressions used herein have the ordinary technical meanings as attributed to them by those skilled in the art. Unless otherwise expressly stated, the word “or” as used herein should be interpreted as having a disjunctive structure rather than a conjunctive structure. Unless otherwise stated, the terms “connection,” “fixed,” “attached to,” etc., refer both directly to a connection, fixation, or attachment, and indirectly to a connection, fixation, or attachment through one or more intermediate components or features. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include plural references.

[0021] As used herein throughout the specification and claims, approximate language is applied to modify any quantitative expression that may allow variation without altering its essential function. Therefore, values ​​modified by one or more terms such as “about,” “approximate,” and “substantially” are not limited to specified exact values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, approximate language may refer to a margin of 10%.

[0022] Referring now to the accompanying drawings, in which the same reference numerals denote the same elements throughout the drawings. Figure 1 This is a cross-sectional view of a gas turbine engine. The gas turbine engine is a high-bypass turbofan jet engine, referred to herein as "turbofan engine 10". Turbofan engine 10 defines an axial direction A (extending parallel to a longitudinal centerline 12 for reference) and a radial direction R. Typically, turbofan engine 10 includes a fan section 14 and a core turbine engine 16 disposed downstream of the fan section 14.

[0023] Figure 1The core turbine engine 16 shown includes a generally tubular outer casing 18 defining an annular inlet 20. The tubular outer casing 18 encloses a compressor section, including a low-pressure (LP) compressor 22 and a high-pressure (HP) compressor 24, in a series flow relationship; a combustion section 26; a turbine section, including a high-pressure (HP) turbine 28 and a low-pressure (LP) turbine 30; and an exhaust nozzle section 32. A high-pressure (HP) spool or bobbin 34 drivesly connects the HP turbine 28 to the HP compressor 24. A low-pressure (LP) spool 36 drivesly connects the LP turbine 30 to the LP compressor 22.

[0024] Fan section 14 may include a variable-pitch fan 38 having a plurality of fan blades 40 spaced apart and coupled to disk 42. As shown, the fan blades 40 extend generally outward from disk 42 along a radial direction R. Each of the fan blades 40 is operatively coupled to a suitable actuating member 44, which is configured to collectively and uniformly change the pitch of the fan blades 40 relative to disk 42. The fan blades 40, disk 42, and actuating member 44 are rotatable together about longitudinal centerline 12 via a low-voltage spool 36 across power gearbox 46. Power gearbox 46 includes a plurality of gears for reducing the rotational speed of LP spool 36 to a more efficient fan speed. It should be understood that additional configurations of fan section 14, such as those employing non-ducted or non-variable-pitch designs, are also possible.

[0025] Still referencing Figure 1 In one embodiment, the disk 42 is covered by a rotatable front hub 48 having an aerodynamic profile to facilitate airflow through the plurality of fan blades 40. Furthermore, the fan section 14 includes an annular fan housing or outer nacelle 50 circumferentially surrounding at least a portion of the variable-pitch fan 38 and / or the core turbine engine 16. It should be understood that the outer nacelle 50 may be configured to be supported relative to the core turbine engine 16 by a plurality of circumferentially spaced outlet guide vanes 52. Additionally, a downstream section 54 of the outer nacelle 50 may extend over an external portion of the core turbine engine 16 to define a bypass airflow passage 56 therebetween.

[0026] During operation of the turbofan engine 10, a volume of air 58 enters the turbofan engine 10 through the associated inlet 60 of the outer nacelle 50 and / or fan section 14. As the volume of air 58 passes through the fan blades 40, a first portion 62 of the air 58 is directed or delivered to the bypass airflow passage 56, as indicated by the arrow, while a second portion 64 of the air 58 is directed or delivered to the LP compressor 22, as indicated by the arrow. The ratio between the first portion 62 and the second portion 64 of the air 58 is commonly referred to as the bypass ratio. The pressure of the second portion 64 of the air 58 then increases as it is delivered through the HP compressor 24 and into the combustion section 26, where it mixes with fuel and is burned to provide combustion gas 66. Subsequently, the combustion gas 66 is delivered through the hot flow path or hot section flow path of the HP turbine 28 and LP turbine 30, where a portion of the thermal and / or kinetic energy is extracted from the combustion gas 66.

[0027] Combustion gas 66 is then conveyed through the injection exhaust nozzle section 32 of the core turbine engine 16 to provide propulsive thrust. Simultaneously, as the first portion 62 of air 58 is conveyed through the bypass airflow passage 56 before being discharged from the fan nozzle exhaust section 76 of the turbofan engine 10, the pressure of the first portion 62 of air 58 increases significantly, also providing propulsive thrust.

[0028] However, it should be understood that Figure 1 The turbofan engine 10 shown is merely an example, and in other embodiments, aspects of this disclosure may be additionally or alternatively applied to any other suitable gas turbine engine. For example, in other embodiments, the turbofan engine 10 may alternatively be any other suitable aviation gas turbine engine, such as a turbojet engine, turboshaft engine, turboprop engine, etc. Additionally, in other embodiments, the turbofan engine 10 may include or may be operatively connected to any other suitable accessory system. Additionally or alternatively, the turbofan engine 10 may not include or may be operatively connected to one or more of the accessory systems discussed above.

[0029] Now for reference Figure 2A block diagram of an engine control system 100 is shown. The engine control system 100 includes a thrust controller 102 that receives a rate command 104 from an engine (such as a turbofan engine 10) and jointly manages the electric motor (EM) dynamics 106 and fuel dynamics 108 of the turbofan engine 10, such that the engine dynamics 110 of the turbofan engine 10 generates an output thrust rate indicated by the rate command 104. It should be understood that the engine control system 100 can be used with engines having ducted or non-ducted fans. In some embodiments, the rate command 104 may be calculated or generated by the thrust controller 102 based on the thrust currently output by the turbofan engine 10 and the thrust required for new thrust to be output by the turbofan engine 10, received from one or more aircraft control interfaces. The rate command 104 may be calculated based on the specific hardware capabilities of the turbofan engine 10 to avoid stall or other hazardous situations, and may take the form of one or more of thrust, fan, or core velocity trajectories.

[0030] Furthermore, the thrust controller 102 may incorporate feedback 112 for managing motor dynamics 106 and fuel dynamics 108. Feedback 112 is a function of engine dynamics 110, such that it provides the thrust controller 102 with an indication of the current thrust response of the turbofan engine 10. The thrust controller 102 can then modify the control of motor dynamics 106 and fuel dynamics 108 to take into account the current thrust response indicated by feedback 112 and ensure that the turbofan engine 10 achieves the thrust rate indicated by rate command 104. In some embodiments, motor dynamics 106 may operate in a frequency range of kHz to apply torque to the spool of the turbofan engine 10, while the slower-responding fuel dynamics 108 may only operate in a frequency range of approximately less than 10 Hz.

[0031] In normal operation, thrust and electrical load are set, and the engine control system 100 distributes the application of power within the turbofan engine 10 and other systems of the aircraft utilizing the engine control system 100. Then, when acceleration is required, a new ideal thrust rate is calculated and issued as a rate command 104. The engine control system 100 then measures the error between the ideal rate and the actual rate and dually manages motor dynamics 106 and fuel dynamics 108 to manipulate power distribution to minimize the rate error while maintaining the constant total electrical load required by the aircraft. Specifically, in the absence of energy storage devices (batteries, supercapacitors, etc.) in the aircraft, the management of motor dynamics 106 can be limited to power distribution among multiple motors to maintain the required aircraft power (meaning at least two motors are required). However, if energy storage devices are available, the management of motor dynamics 106 is not limited to power distribution and can therefore be operated using a single motor. This additional flexibility provided by energy storage devices improves control. For example, disturbances to fan speed can be suppressed by modulating the low-voltage motor while using energy storage to maintain the aircraft load and thus keep the high-voltage motor constant.

[0032] Turn now Figure 3 A block diagram of a signal distribution embodiment of an engine control system 100 is shown. In this embodiment, Figure 2 The thrust controller 102 may include a signal distribution controller 102A. The signal distribution controller 102A includes a motor controller 200, a fuel controller 202, a signal distributor 204 electrically connected to the fuel controller 202 and the motor controller 200, and a first signal combiner 206. The first signal combiner 206 receives a rate command 104 and subtracts feedback 112 from it to generate an error signal 208. The signal distributor 204 then generates a motor control signal 210 for the motor controller 200 to manage motor dynamics 106 and a fuel control signal 212 for the fuel controller 202 to manage fuel dynamics 108.

[0033] Turn now Figure 4 A schematic diagram of a signal distribution controller 102A integrated with a turbofan engine or turboprop engine (e.g., turbofan engine 10) is shown. Figure 4As shown, the turbofan engine 10 may also include an electric motor physically coupled (e.g., geared) to a spool of the turbofan engine 10 and used to apply positive torque to the spool to generate thrust and negative torque to the spool to generate power. Specifically, the turbofan engine 10 may include a low-voltage motor 300 geared to the LP spool 36 and a high-voltage motor 302 geared to the HP spool 34. It should be understood that additional or fewer motors may be coupled to the LP spool 36 and / or the HP spool 34 and controlled according to the systems and methods described herein. Furthermore, it should be understood that embodiments with additional spools, which also include associated motors operable by the engine control system 100, are contemplated in addition to the LP spool 36 and / or the HP spool 34.

[0034] Furthermore, the engine control system 100 may include a fuel supply system 304 electrically connected to the fuel controller 202 and power electronics 306 electrically connected to the motor controller 200. Additionally, the engine control system 100 may include a selection controller 308 electrically connected to the fuel controller 202, the motor controller 200, and other control system loops 310 of the aircraft. Furthermore, the engine control system 100 may include a motor power management controller 312 that receives power demands 314. In some embodiments, the motor power management controller 312 may be integrated into the motor controller 200. Additionally, feedback 112 may be sent from the fan section 14 to the signal distribution controller 102A and may include data indicating current speed, acceleration, engine pressure ratio, and other similar data.

[0035] In operation, the signal distribution controller 102A can use the first signal combiner 206 to generate an error signal 208 from the rate command 104 and feedback 112, for example, by subtracting feedback 112 from the rate command 104. The signal distributor 204 can then distribute the error signal 208 into the motor control signal 210 and the fuel control signal 212, and transmit these signals to the motor controller 200 and the fuel controller 202, respectively. Next, the fuel controller 202 can generate fuel dynamics 108 by directing the fuel supply system 304 to supply fuel to the combustion zone 26 based on the fuel control signal 212. Similarly, the motor controller 200 can generate motor dynamics 106 by directing the power electronics 306 to drive the low-voltage motor 300 and the high-voltage motor 302 to apply positive or negative torque to the spool of the turbofan engine 10.

[0036] Furthermore, in some embodiments, the motor controller 200 may work in conjunction with the motor power management controller 312 to ensure that the low-voltage motor 300 and the high-voltage motor 302 operate primarily in a negative torque mode to generate and supply power to meet the power demand 314. For example, in some embodiments, the motor controller 200 and the motor power management controller 312 may prioritize negative torque mode and power generation over positive torque or thrust generation mode. In these embodiments, the motor controller 200 utilizes residual capacitance from the negative torque application to apply positive torque to the spool of the turbofan engine 10.

[0037] Turn now Figure 5 A schematic diagram of a signal distribution controller 102A is shown. In this embodiment, the fuel control signal 212 may include the low-frequency portion of the error signal 208, and the motor control signal 210 may include the high-frequency portion of the error signal 208. In some embodiments, the high-frequency and low-frequency portions of the error signal 208 may be decoupled from each other spectrally. The signal distributor 204 may include a first filter 400 and a second filter 402, the first filter 400 receiving the error signal 208 and passing through the low-frequency portion of the error signal 208 to generate the fuel control signal 212, and the second filter 402 receiving the error signal 208 and passing through the high-frequency portion of the error signal 208 to generate the motor control signal 210. In some embodiments, the first filter 400 may include a low-pass filter, and the second filter 402 may include a high-pass filter. The low-pass and high-pass filters are designed such that their sum is one. However, in some embodiments, the sum may roll off at a higher frequency to prevent aliasing and eliminate noise. Additionally or alternatively, the second filter 402 may include a bandpass filter that passes through the high-frequency portion of the error signal 208 while also removing high-frequency noise to prevent aliasing. Furthermore, in some embodiments, the signal distributor 204 may include a second signal combiner 404 that combines the output of the second filter 402 with the power demand 314 to generate a motor control signal 210.

[0038] Turn now Figure 6Another schematic diagram of the signal distribution controller 102A is shown. In this embodiment, the fuel control signal 212 and the motor control signal 210 may include an error signal 208, and the signal distributor 204 may directly transmit the error signal 208 to the fuel controller 202 as the fuel control signal 212 and directly transmit the error signal 208 to the motor controller 200 as the motor control signal 210. In these embodiments, the motor controller 200 is configured to process a portion of the error signal 208 having a frequency at least 5 times, and preferably in the range of at least 10-20 times, that of the portion of the error signal processed by the fuel controller 202. Furthermore, in some embodiments, the signal distributor 204 may include a second signal combiner 404 that combines the error signal 208 with the power demand 314 to generate the motor control signal 210.

[0039] It should also be noted that additional embodiments of the signal distribution controller 102A are conceivable, wherein the magnitude of the error signal 208 is used to distribute the error signal 208 into the motor control signal 210 and the fuel control signal 212. However, typically, the signal distribution controller 102A provides improved thrust response than conventional systems by utilizing the low-voltage motor 300 and the high-voltage motor 302 to provide rapid correction of the high-frequency portion of the error signal 208, thereby reducing the error correction burden on the slower-responding fuel controller 202. Specifically, the fuel controller 202 can be configured to correct only the lower-frequency portion of the error signal 208, resulting in significantly improved fuel savings and extended lifespan of the turbofan engine 10.

[0040] Turn now Figure 7 A block diagram of an embodiment of a disturbance observer for an engine control system 100 is shown. In this embodiment, Figure 2 The thrust controller 102 may include a disturbance observer controller 102B. The disturbance observer controller 102B includes a motor controller 200, a fuel controller 202, a first signal combiner 206, a linearized model 500 of fuel dynamics 108 and engine dynamics 110 ideally generated by the fuel controller 202, and a third signal combiner 502. The linearized model 500 can model the ideal operation of the turbofan engine 10 by the fuel controller 202 in response to an error signal 208, which in this embodiment corresponds to the fuel control signal 212. Furthermore, the motor control signal 210 may include a second error signal generated by the third signal combiner 502 by subtracting feedback 112 from the output of the linearized model 500 (e.g., the expected response of the turbofan engine 10 to the fuel controller 202). Various inputs to the linearized model 500 are contemplated, such as the rate command 104, the error signal 208, the feedback 112, and / or the output of the fuel controller 202.

[0041] Turn now Figure 8 A schematic diagram of an embodiment of a disturbance observer controller 102B combined with a turbofan or turboprop engine (e.g., turbofan engine 10) is shown. Figure 8 As shown, the turbofan engine 10 may include a low-voltage motor 300 and a high-voltage motor 302. Furthermore, the engine control system 100 may include a fuel supply system 304 electrically connected to the fuel controller 202, power electronics 306 electrically connected to the motor controller 200, and a selection controller 308 electrically connected to the fuel controller 202, the motor controller 200, and other control system loops 310. Additionally, the linearization model 500 may include a nominal inverse model receiving feedback 112 as input, a third filter 504, and a fourth filter 506. In some embodiments, the third filter 504 and the fourth filter 506 may include the same low-pass or band-pass filter that rejects disturbances below their shared cutoff frequency. Typically, the third filter 504 and the fourth filter 506 may be configured such that the amplitude of the motor control signal 210 remains within the pre-configured control limits of the motor controller 200.

[0042] In operation, the disturbance observer controller 102B can generate an error signal 208 from the rate command 104 and feedback 112 using the first signal combiner 206. The disturbance observer controller 102B can then pass the error signal 208 to the fuel controller 202 as a fuel control signal 212, and generate a motor control signal 210 from the error signal 208 and the output of the linearization model 500. Specifically, the disturbance observer controller 102B can generate the motor control signal 210 by processing the feedback 112, which is the nominal inverse of the linearization model 500, to generate the expected response of the turbofan engine 10, and subtract the error signal 208 transmitted through the third filter 504 from the expected response transmitted through the fourth filter 506. Next, the fuel controller 202 can generate fuel dynamics 108 by directing the fuel supply system 304 to supply fuel to the combustion section 26 based on the fuel control signal 212. Similarly, the motor controller 200 can generate motor dynamics 106 by directing the power electronics 306 to drive the low-voltage motor 300 and the high-voltage motor 302 to apply positive or negative torque to the spool of the turbofan engine 10. Furthermore, as described herein, at least... Figure 4-6 In more detail, the engine control system 100 can receive a power demand 314 fed to the motor controller 200 or in combination with the motor control signal 210, such that the motor controller 200 operates the low-voltage motor 300 and the high-voltage motor 302 to ensure that sufficient power is generated to meet the power demand 314.

[0043] In various embodiments of the linearized model 500 deployed by the disturbance observer controller 102B, the disturbance observer controller 102B provides an improved thrust response superior to conventional systems by utilizing the low-voltage motor 300 and the high-voltage motor 302 to correct the portion of the error signal 208 within the pre-configured control authority of the motor controller 200. The corrected portion of the error signal, in turn, drives the actual responses of the fuel controller 202, the fuel supply system 304, and the corresponding engine dynamics 110 toward the expected idealized response of the linearized model 500. This configuration simplifies engine design by eliminating many high-bandwidth errors, making engine performance closer to the predictions of the linearized model 500. In some embodiments, the disturbance observer controller 102B can eliminate high-bandwidth errors between approximately 5% and approximately 30%.

[0044] It should be understood that, although the engine control system 100 is in Figure 4-6 and Figure 8 Chinese combination Figure 1 The turbofan engine 10 is schematically shown, but the functionality of the engine control system 100 is not limited to the specific configuration of the turbofan engine 10. Instead, various embodiments of the engine control system 100 shown and described herein are configured to operate in conjunction with various turbofan engines and / or turboprop engines, including feedback outputs similar to feedback 112 and controllable motors similar to low-voltage motor 300 and high-voltage motor 302.

[0045] The common advantages of the various embodiments of the engine control system 100 described herein can be found regarding… Figure 9-13 The graph shown further illustrates this. Specifically, Figure 9-13 The graphs shown illustrate examples of various response characteristics of a turbofan engine (e.g., turbofan engine 10) during the thrust rise phase when controlled by an embodiment of the engine control system 100 described herein. The thrust rise phase corresponds to the transition period between the initial steady-state velocity and thrust of the engine controlled by the engine control system 100 at time T0 and the new desired steady-state velocity or thrust at time T1. The specific slope and shape of the thrust between time T0 and time T1 correspond to the thrust rate of the aircraft during this time period.

[0046] first, Figure 9 This is a time-varying graph comparing the target thrust rate 600 of the engine controlled by the engine control system 100, the conventional fuel control thrust rate 602 of the turbofan engine, and the high bandwidth (BW) control thrust rate 604 of the turbofan engine resulting from the use of the engine control system 100 described herein. Figure 9As shown, the conventional fuel control thrust rate 602 can oscillate more severely around the target thrust rate 600 compared to the high BW control thrust rate 604 generated by the engine control system 100 described herein. Reduction in oscillation can significantly improve wear, fuel efficiency, and other significant improvements described herein in turbofan engines. For example, as... Figure 10 As shown, conventional fuel usage 606 over time can rapidly increase to and significantly exceed the amount of fuel required to maintain steady-state speed or thrust after time T1 during the ascent phase. However, during the same ascent phase, high-BW controlled fuel usage 608 over time can produce a gradual increase in fuel until a new steady-state fuel quantity is reached. The more gradual ascent can be attributed to the use of the low-voltage motor 300 and the high-voltage motor 302 to supplement the thrust applied from the fuel controller 202 and the fuel supply system 304.

[0047] Secondly, similar to fuel response, when using engine control system 100 as described herein, the speed of the aircraft and / or engine spool can increase more smoothly with the rise phase. For example, as Figure 11 As shown, a conventional fuel control speed 610 may be more erratic and exceed the final target speed during the ramp-up phase, while conversely, a high BW control speed 612 can smoothly increase to the final target speed with minimal or negligible overshoot. This smoother speed increase reduces engine wear and generally provides a more predictable response to the engine controlled by system 100.

[0048] Finally, turn Figure 12 and Figure 13 This illustrates the overall response of the engine controlled by the engine control system 100. Firstly, Figure 12 The EM control error portion 614 of the error signal 208 over time and the fuel control error portion 616 of the error signal 208 over time are shown. For example... Figure 12 As shown, the EM control error portion 614 increases rapidly at the beginning of the rise phase, but is quickly corrected by the engine control system 100 managing the motor dynamics 106. Meanwhile, the fuel control error portion 616 follows a slower, gentler rise-fall path before reaching the final target speed and steady-state conditions. A gentler path is more suitable for fuel systems with slower responses. Separating the EM control error portion 614 and the fuel control error portion 616, as described herein, can produce... Figure 13 The thrust response over time is shown in 618. (As shown) Figure 13As shown, when using engine control system 100, the thrust response 618 can rise rapidly and smoothly to the final thrust 620, with only minimal overshoot near time T1, compared to systems employing conventional fuel-based control systems. The thrust response 618 from engine control system 100 represents a more tightly controlled thrust response, minimizes thrust asymmetry using a more tightly controlled acceleration path, improves synchronization phasing capability, minimizes core velocity overshoot, reduces transit time through forbidden zones, suppresses gearbox vibration modes, maximizes the thrust response of military engines, and / or many other advantages described herein compared to systems employing conventional fuel-based control systems.

[0049] It should also be understood that the various embodiments of the engine control system 100 described herein are also operable to control and suppress high-frequency or other variations in the thrust output of a controlled engine operating under steady-state thrust conditions. In some of these embodiments, once a new steady-state thrust is achieved, the engine control system 100 can set the rate command 104 to zero. From there, the thrust controller 102 can operate EM dynamics 106 and fuel dynamics 106 to maintain steady-state thrust while correcting for and suppressing any high-frequency or other variations.

[0050] Further aspects of this disclosure are provided by the subject matter of the following clauses:

[0051] 1. An engine control system comprising a fuel controller that directs fuel supply to a turbine engine based on a fuel control signal; a motor controller that directs one or more motors to apply positive torque to the turbine engine based on a motor control signal; and a signal distributor electrically connected to the fuel controller and the motor controller, generating the fuel control signal and the motor control signal from an error signal.

[0052] 2. The engine control system according to any of the preceding clauses further includes a signal combiner electrically connected to the signal distributor, wherein the signal combiner receives a feedback signal and a rate command from the turbine engine, and wherein the signal combiner generates the error signal by subtracting the feedback signal from the rate command.

[0053] 3. The engine control system according to any of the preceding clauses, wherein the fuel control signal includes a low-frequency portion of the error signal, and the motor control signal includes a high-frequency portion of the error signal.

[0054] 4. The engine control system according to any of the preceding clauses, wherein the signal distributor comprises: a first filter that receives the error signal and uses the low-frequency portion of the error signal to generate the fuel control signal; and a second filter that receives the error signal and uses the high-frequency portion of the error signal to generate the motor control signal.

[0055] 5. The engine control system according to any of the preceding clauses, wherein the first filter is a low-pass filter and the second filter is a high-pass filter.

[0056] 6. The engine control system according to any of the preceding clauses, wherein the signal distributor directly transmits the error signal to the fuel controller as the fuel control signal, and directly transmits the error signal to the motor controller as the motor control signal.

[0057] 7. The engine control system according to any of the preceding clauses, wherein the motor controller is configured to process the error signal at a frequency at least five times that of a portion of the error signal processed by the fuel controller.

[0058] 8. An engine control system according to any of the preceding clauses, wherein the motor controller receives a power demand, and wherein the motor controller directs the one or more motors to apply negative torque to the turbine engine to generate sufficient power to meet the power demand.

[0059] 9. An engine control system according to any of the preceding clauses, wherein the motor controller utilizes the remaining capacitor from which the negative torque is applied to apply the positive torque to the turbine engine.

[0060] 10. An engine control system, comprising: a fuel controller that directs fuel supply to a turbine engine based on a first error signal; a motor controller that directs one or more motors to apply positive torque to the turbine engine based on a motor control signal; and a disturbance observer electrically connected to the motor controller, wherein the disturbance observer generates a second error signal for the expected response of the turbine engine to the fuel controller, and wherein the disturbance observer generates the motor control signal from the second error signal.

[0061] 11. The engine control system according to any of the preceding clauses, wherein the disturbance observer receives a feedback signal from the turbine engine and generates the second error signal by subtracting the feedback signal from the expected response.

[0062] 12. An engine control system according to any of the preceding clauses, wherein the disturbance observer generates the expected response by processing the first error signal through a linearized model of the operation of the turbine engine by the fuel controller.

[0063] 13. An engine control system according to any of the preceding clauses, wherein the disturbance observer generates the second error signal by: the fuel controller processing a feedback signal from the turbine engine through an inverse linearization model of the turbine engine's operation to generate the expected response; and subtracting the first error signal from the expected response.

[0064] 14. The engine control system according to any one of the preceding clauses, wherein the disturbance observer generates the second error signal by: the fuel controller processing a feedback signal from the turbine engine through an inverse linearization model of the turbine engine's operation to generate the expected response; and subtracting the first error signal transmitted through the first filter from the expected response transmitted through the second filter.

[0065] 15. An engine control system according to any of the preceding clauses, wherein the motor controller receives a power demand, and wherein the motor controller directs the one or more motors to apply negative torque to the turbine engine to generate sufficient power to meet the power demand.

[0066] 16. An engine control system according to any of the preceding clauses, wherein the motor controller utilizes the residual capacitor from which the negative torque is applied to apply the positive torque to the turbine engine.

[0067] 17. A method for controlling engine thrust, the method comprising: receiving a rate command; receiving a feedback signal from a turbine engine; generating a fuel control signal and a motor control signal from the rate command and the feedback signal; transmitting the fuel control signal to a fuel controller of the turbine engine; transmitting the motor control signal to a motor controller; directing fuel supply to the turbine engine based on the fuel control signal via the fuel control signal; and directing a motor to apply positive torque to the turbine engine based on the motor control signal via the motor control signal.

[0068] 18. A method for controlling engine thrust, the method comprising: generating a fuel control signal and a motor control signal from a rate command and a feedback signal from a turbine engine; directing fuel supply to the turbine engine based on the fuel control signal via a fuel controller of the turbine engine; and directing a motor to apply positive torque to the turbine engine based on the motor control signal via a motor controller of the motor engine.

[0069] 19. The method according to any of the preceding clauses, further comprising generating the fuel control signal and the motor control signal from the rate command and the feedback signal by: subtracting the feedback signal from the rate command to generate an error signal; directly transmitting the error signal to the fuel controller as the fuel control signal; and directly transmitting the error signal to the motor controller as the motor control signal.

[0070] 20. The method according to any of the preceding clauses, further comprising generating the fuel control signal and the motor control signal from the rate command and the feedback signal by: subtracting the feedback signal from the rate command to generate an error signal; filtering the error signal into a low-frequency component and a high-frequency component; passing the low-frequency component to the fuel controller as the fuel control signal; and passing the high-frequency component to the motor controller as the motor control signal.

[0071] 21. The method according to any of the preceding clauses, further comprising generating the fuel control signal and the motor control signal from the rate command and the feedback signal by: subtracting the feedback signal from the rate command to generate a first error signal; transmitting the first error signal to the fuel controller as the fuel control signal; processing the feedback signal by the fuel controller through an inverse linearization model of the operation of the turbine engine to generate a desired response; subtracting the first error signal transmitted through a first filter from the desired response transmitted through a second filter to generate a second error signal; and transmitting the second error signal to the motor controller as the motor control signal.

[0072] 22. The method or engine control system according to any of the preceding clauses, wherein the one or more motors are physically geared to one or more spools of the turbofan engine.

[0073] 23. The method or engine control system according to any of the preceding clauses, wherein the one or more motors include a low-voltage motor driven to a low-voltage spool of the turbofan engine and a high-voltage motor driven to a high-voltage spool of the turbofan engine.

[0074] 24. The method or engine control system according to any of the preceding clauses, wherein the rate command is generated by the thrust controller based on the thrust currently output by the turbofan engine and the new thrust required to be output by the turbofan engine, and the new thrust required is received from one or more aircraft control interfaces.

[0075] 25. The method or engine control system according to any of the preceding clauses, wherein the rate command is calculated based on the specific hardware capabilities of the turbofan engine to avoid stall or other dangerous situations.

[0076] 26. The method or engine control system according to any of the preceding clauses, wherein the rate command takes the form of one or more of thrust, fan, or core velocity trajectory.

[0077] 27. The method or engine control system according to any of the preceding clauses, wherein the motor controller operates in the kHz frequency range to apply torque to the spool of the turbofan engine, and wherein the fuel controller operates in the frequency range of approximately less than 10 Hz.

[0078] 28. The method or engine control system according to any of the preceding clauses, wherein the motor controller and the fuel controller manage the power distribution between the one or more motors in order to minimize the error signal while maintaining the required constant total electrical load.

[0079] 29. The method or engine control system according to any of the preceding clauses, wherein the motor controller and the fuel controller manage the power distribution between the one or more motors and the energy storage device in order to minimize the error signal while maintaining the required constant total electrical load.

[0080] 30. The method or engine control system according to any of the preceding clauses, wherein the first filter and the second filter are configured to have a unity sum.

[0081] 31. The method or engine control system according to any of the preceding clauses, wherein the motor controller is configured to process the error signal at a frequency at least five times that of a portion of the error signal processed by the fuel controller.

[0082] 32. The method or engine control system according to any of the preceding clauses, wherein the first filter is a bandpass filter.

[0083] 33. The method or engine control system according to any of the preceding clauses, wherein the second filter is a bandpass filter.

[0084] 34. The method or engine control system according to any of the preceding clauses, wherein the first filter and the second filter are identical bandpass filters that reject disturbances below the shared cutoff frequency.

[0085] 34. The method or engine control system according to any of the preceding clauses, wherein the first filter and the second filter are configured to keep the amplitude of the motor control signal within a pre-configured control authority of the motor controller.

[0086] 35. The method or engine control system according to any of the preceding clauses, wherein the disturbance observer eliminates a higher bandwidth error between about 5% and about 30%.

[0087] Those skilled in the art will recognize that various modifications, alterations, and combinations can be made to the above embodiments without departing from the scope of the invention, and such modifications, alterations, and combinations should be considered within the scope of the concept of the invention.

Claims

1. An engine control system characterized by comprising: Comprising: a fuel controller directing fuel to a turbine engine based on a first error signal; an electric machine controller directing one or more electric machines to apply positive torque to the turbine engine based on an electric machine control signal; and a disturbance observer electrically coupled to the electric machine controller, wherein the disturbance observer generates a second error signal for an expected response of the turbine engine to the fuel controller, and wherein the disturbance observer generates the electric machine control signal from the second error signal, wherein the disturbance observer receives a feedback signal from the turbine engine and a rate command and generates the first error signal by subtracting the feedback signal from the rate command.

2. The engine control system according to claim 1, characterized by, wherein the disturbance observer generates the second error signal by subtracting the feedback signal from the expected response.

3. The engine control system of claim 1, wherein wherein the disturbance observer generates the expected response by processing the first error signal through a linearized model of operation of the turbine engine by the fuel controller.

4. The engine control system of claim 1, wherein wherein the disturbance observer generates the second error signal by: processing the feedback signal from the turbine engine through an inverse linearized model of operation of the turbine engine by the fuel controller to generate the expected response; and subtracting the first error signal from the expected response.

5. The engine control system of claim 1, wherein wherein the disturbance observer generates the second error signal by: processing the feedback signal from the turbine engine through an inverse linearized model of operation of the turbine engine by the fuel controller to generate the expected response; and subtracting the first error signal from the expected response sent through a second filter. wherein the electric machine controller receives an electric power demand and wherein the electric machine controller directs the one or more electric machines to apply negative torque to the turbine engine to generate sufficient electric power to meet the electric power demand.

6. The engine control system of claim 1, wherein wherein the electric machine controller utilizes residual capacitance from applying the negative torque to apply the positive torque to the turbine engine.

7. The engine control system of claim 6, wherein wherein the one or more electric machines are physically geared to one or more spools of the turbine engine.

8. The engine control system of claim 1, wherein wherein the one or more electric machines comprise a low pressure electric machine geared to a low pressure spool of the turbine engine and a high pressure electric machine geared to a high pressure spool of the turbine engine.

9. The engine control system of claim 1, wherein wherein the disturbance observer eliminates higher bandwidth errors between 5% and 30%.

10. The engine control system of claim 1, wherein wherein the electric machine controller and the fuel controller manage power distribution between the one or more electric machines in order to minimize the first error signal while maintaining a constant total electrical load required.

11. The engine control system of claim 1, wherein wherein the electric machine controller and the fuel controller manage power distribution between the one or more electric machines and an energy storage device in order to minimize the first error signal while maintaining a constant total electrical load required.

12. The engine control system of claim 1, wherein, The method comprising:

13. A method for controlling engine thrust, characterized by, generating a fuel control signal and an electric machine control signal from a rate command and a feedback signal from a turbine engine by: ​ subtracting the feedback signal from the rate command to generate a first error signal; passing the first error signal to a fuel controller of the turbine engine as the fuel control signal; processing the feedback signal by the fuel controller through an inverse linearized model of operation of the turbine engine to generate an expected response; subtracting the first error signal sent through a first filter from the expected response sent through a second filter to generate a second error signal; and passing the second error signal to an electric machine controller as the electric machine control signal; based on the fuel control signal, directing fuel supply to the turbine engine via the fuel control signal sent to the fuel controller of the turbine engine; and based on the electric machine control signal, directing an electric machine to apply positive torque to the turbine engine via the electric machine control signal sent to the electric machine controller.

14. The method of claim 13, wherein, wherein the rate command is generated from a current thrust output by the turbine engine and a new demanded thrust to be output by the turbine engine, the new demanded thrust received from one or more aircraft control interfaces.

15. The method of claim 13, wherein, wherein the rate command is calculated based on one or more of a thrust, fan or core speed trajectory of the turbine engine to avoid stalling.

16. The method of claim 13, wherein, wherein the rate command takes the form of one or more of a thrust, fan or core speed trajectory.

17. The method of claim 13, wherein, wherein the electric machine is physically geared to one or more spools of the turbine engine.

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