Method for starting the hydraulic pump of the power system in aircraft emergency power supply mode

Abstract

This invention provides a method for starting a hydraulic pump in an aircraft's emergency power supply mode. A time-delay relay is provided in the control circuit of the aircraft's transformer rectifier contactor (ETRUC). The method includes: determining that the aircraft has entered emergency mode; in response to determining that the aircraft has entered emergency mode, determining whether the aircraft's airspeed is greater than an unloading threshold; and if the aircraft's airspeed is determined to be greater than the unloading threshold, activating the time-delay relay. During the energizing delay time of the time-delay relay, the ETRUC is disconnected, the aircraft's RAT supplies power only to the AC ESS BUS, and the DC ESS BUS is powered by the battery. After the energizing delay time of the time-delay relay, the ETRUC closes, and both the AC ESS BUS and DC ESS BUS are powered by the RAT. This invention ensures that the electro-hydraulic pump can start normally in emergency mode.

Description

Technical Field

[0001] This invention relates to aircraft, and more specifically, to a method for starting a hydraulic pump in an aircraft's power system under emergency power supply mode. Background Technology

[0002] The RAT (Ram-Air Turbine) is designed for emergency landings when an aircraft loses its main and auxiliary power, thereby improving its survivability. According to airworthiness regulations, the RAT must be able to provide the hydraulic power required for basic main flight control operations and the electrical power required to ensure basic flight and operation of the aircraft.

[0003] When the RAT (Radar Atlas) drives the emergency hydraulic pump, it acts as an emergency hydraulic system, simultaneously driving the hydraulic motor generator (HMDG) connected to the hydraulic system, thus forming both an emergency hydraulic and emergency power source. The A320 uses this mode, i.e., hydraulic mode. When the RAT drives the emergency generator, it acts as an emergency power system, simultaneously driving the electric pump in the hydraulic system, thus forming both an emergency power and emergency hydraulic source. The ARJ21 uses this mode, i.e., electric mode. Most regional jets use electric mode; the A380 also uses this mode, and Bombardier's C Series will also adopt this mode in the future. When the RAT simultaneously drives the emergency generator and the emergency hydraulic pump, it forms both the aircraft's emergency power and hydraulic source. The Boeing 787 uses this mode, i.e., hybrid mode.

[0004] If a civil aircraft's ramjet turbine design employs an electrical-mode variable frequency AC generator (RAT), the RAT provides emergency AC power to the entire aircraft under emergency conditions. The RAT generator frequency depends on airspeed; the higher the airspeed, the higher the generator frequency. High frequencies are detrimental to starting electric hydraulic pumps. In emergency mode, when the RAT starts the electric hydraulic pump, the pump's driving torque is inversely proportional to the power supply frequency. At high power frequencies, the starting torque is low. Combined with low-temperature conditions or a malfunctioning hydraulic reset valve leading to a lack of soft start, there may be a risk of insufficient RAT power supply margin, causing the RAT to disconnect from the grid, the motor to stall, or the hydraulic pump circuit breaker to trip and fail to start.

[0005] When the electric pump is tested using power from an external power vehicle on the ground, the power supply frequency of the ground power vehicle is 400HZ, which is relatively low. Therefore, the hidden faults of the electric hydraulic pump (such as the failure of the hydraulic self-reset valve causing no soft start) cannot be found during the functional test. If the design of the hydraulic pump load end is modified and optimized, and a motor controller is added, the cost and weight will increase significantly.

[0006] Therefore, to ensure the load-carrying capacity of the RAT, the emergency power supply mode will unload important DC loads according to a certain airspeed threshold. Above the threshold, the RAT is released and connected to the grid, at which time important DC loads and electric hydraulic pumps will be directly connected to the grid; below the certain airspeed threshold, to avoid insufficient power supply capacity of the RAT, important DC loads are unloaded, important AC loads are powered only by the RAT generator, and important DC loads are powered by the battery.

[0007] Furthermore, due to limitations in industrial product capabilities, heavy-duty circuit breakers may exhibit mismatch issues, such as a mismatch between the ACMP (Electro-hydraulic Pump) circuit breaker and the L / R interconnection circuit breaker on the AC ESS BUS (Important AC Busbar). When the aircraft is under normal power supply, if the ACMP power supply line is powered by the AC ESS BUS, due to limitations in circuit breaker types, the start-up of the ACMP may cause the L / R interconnection circuit breaker on the AC ESS BUS to trip. If a large-capacity circuit breaker is selected, it may fail to provide protection. Therefore, when the aircraft is under normal power supply, the ACMP power supply line should not be connected to the AC ESS BUS. Summary of the Invention

[0008] This summary is provided to introduce, in a simplified form, some concepts that will be further described in the following detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0009] In view of the deficiencies in the prior art described above, the object of the present invention is to provide a method for starting the hydraulic pump of the power system in the emergency power supply mode of an aircraft, so as to ensure the starting of the electric hydraulic pump in the emergency mode.

[0010] According to one aspect of the invention, a method for starting a hydraulic pump in an aircraft power system under emergency power supply mode is provided, wherein a time-delay relay is provided on the control circuit of the aircraft's transformer rectifier contactor (ETRUC). The method may include: determining that the aircraft has entered an emergency mode; in response to determining that the aircraft has entered an emergency mode, determining whether the aircraft's airspeed is greater than an unloading threshold; and if the aircraft's airspeed is determined to be greater than the unloading threshold, activating the time-delay relay, wherein during the energizing delay time of the time-delay relay, the ETRUC is disconnected, the aircraft's ram air turbine (RAT) supplies power only to the critical AC busbar (AC ESS BUS) and the critical DC busbar (DC ESS BUS) is powered by the battery, and wherein after the energizing delay time of the time-delay relay, the ETRUC is closed, and both the AC ESS BUS and the DC ESS BUS are powered by the RAT.

[0011] In one embodiment of the invention, if it is determined that the airspeed of the aircraft is not greater than the unloading threshold, the ETRUC is disconnected, the RAT supplies power only to the AC ESS BUS and the battery supplies power only to the DC ESS BUS.

[0012] In one embodiment of the invention, determining that the aircraft has entered emergency mode includes using the auxiliary contacts of the generator contactor to determine that the aircraft has entered emergency mode.

[0013] In one embodiment of the present invention, the coil control signal of the time delay relay can be triggered using an emergency mode signal.

[0014] In one embodiment of the invention, the energizing delay time of the time delay relay is set according to the time required for successful startup of the electric hydraulic pump.

[0015] In one embodiment of the present invention, the unloading threshold can be determined based on the characteristics of the RAT itself, and can be, for example, 170 sections, 150 sections, or less than 150 sections.

[0016] In one embodiment of the invention, the method may further include: in response to determining that the aircraft has entered an emergency mode, connecting an electro-hydraulic pump to a critical AC busbar of the aircraft.

[0017] In one embodiment of the invention, connecting an electro-hydraulic pump to a critical AC busbar of an aircraft may include switching the electro-hydraulic pump from the main AC busbar to the critical AC busbar by interlocking a first contactor of the electro-hydraulic pump connected to the main AC busbar with a second contactor of the electro-hydraulic pump connected to the critical AC busbar.

[0018] According to another aspect of the invention, an apparatus is provided for starting a hydraulic pump in an aircraft power system under emergency power supply mode, wherein a time-delay relay is provided on the control loop circuit of the aircraft's transformer rectifier contactor (ETRUC). The apparatus may include: a memory; and one or more processors coupled to the memory, the processors being configured to: determine that the aircraft has entered emergency mode; in response to determining that the aircraft has entered emergency mode, determine whether the aircraft's airspeed is greater than an unloading threshold; and if the aircraft's airspeed is determined to be greater than the unloading threshold, activate the time-delay relay, wherein during the energizing delay time of the time-delay relay, the ETRUC is disconnected, the aircraft's ram air turbine RAT supplies power only to the critical AC bus AC ESS BUS and the critical DC bus DC ESS BUS is powered by a battery, and wherein after the energizing delay time of the time-delay relay, the ETRUC is closed, and both the AC ESS BUS and DC ESS BUS are powered by the RAT.

[0019] According to another aspect of the invention, a non-transient computer-readable medium is provided for storing a computer program that performs the method of the invention when executed by a processor.

[0020] By adopting the technical solution provided by this invention, the performance of high-frequency low-temperature cold-start hydraulic pumps can be significantly improved, thereby ensuring the normal start-up of electric hydraulic pumps in emergency mode.

[0021] These and other features and advantages will become apparent from the following detailed description and with reference to the accompanying drawings. It should be understood that the foregoing general description and the following detailed description are illustrative only and do not limit the scope of the claims. Attached Figure Description

[0022] To gain a more detailed understanding of the manner in which the features of the present invention are described above, reference can be made to various embodiments to provide a more specific description of the above-briefly summarized aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain typical aspects of the invention and should not be considered as limiting its scope, as this description may allow for other equivalent and effective aspects.

[0023] Figure 1 A schematic block diagram of a system for starting a hydraulic pump in an aircraft power supply system under emergency power supply mode, according to an embodiment of the present invention, is described.

[0024] Figure 2 A flowchart illustrating a method for starting a hydraulic pump in an aircraft power system under emergency power supply mode, according to an embodiment of the present invention, is provided.

[0025] Figure 3 A general hardware device for performing the method of the present invention according to an embodiment of the present invention has been described. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings, and its features will become further apparent in the following specific description.

[0027] The critical DC load capacity of regional jets accounts for approximately 30% of the total capacity. In high-speed, high-frequency power supply scenarios, temporarily unloading this load can significantly ensure the starting of the electro-hydraulic pump (ACMP) and effectively improve the performance of the high-frequency, low-temperature cold-start EMP. Therefore, this invention proposes adding a time-delay relay to the transformer-rectifier contactor (ETRUC) control circuit. After the RAT is released and connected to the grid, priority is given to ensuring the ACMP starts. After successful ACMP startup, the transformer-rectifier outputs power to the critical DC load circuit after a delay. Furthermore, preferably, the switching function is achieved through contactor interlocking, ensuring that the ACMP switches from the main AC busbar to the critical AC busbar, thus resolving the circuit breaker mismatch problem.

[0028] Figure 1 A schematic block diagram of a system 100 for starting a hydraulic pump in an aircraft power system under emergency power supply mode, according to an embodiment of the present invention, is provided. It should be noted that... Figure 1 For illustrative purposes only; the scope of this invention is not limited to this. Figure 1 The system 100 is described in the middle. In one embodiment, at least a portion of the structure of the system 100 may be integrated into a distribution panel box.

[0029] For example, when an aircraft loses both its main and auxiliary power, it can enter emergency mode and generate an emergency mode signal accordingly to instruct the aircraft to enter emergency mode. In one embodiment, the emergency mode signal can be generated by an emergency control device that determines whether the aircraft has lost power or electricity based on various collected signals (e.g., engine signals, generator signals, etc.), thereby generating the corresponding emergency mode signal. In one embodiment, known generator contactor auxiliary contacts can be used to determine that the aircraft has entered emergency mode (e.g., based on a logical AND or OR operation of signals from multiple generator contactor auxiliary contacts).

[0030] When the aircraft enters emergency mode, the RAT generator 110 starts working, and the RAT generator contactor 115 closes upon triggering the emergency mode signal. At this time, the RAT generator contactor 115 can be connected to the three-phase critical AC busbar (three-phase AC ESSBUS) 165.

[0031] The three-phase critical AC busbar 165 can be further connected to the circuit breaker 190, which in turn is connected to the second ACMP contactor 175. Additionally, the main AC busbar 170 can be connected to the circuit breaker 195, which in turn is connected to the first ACMP contactor 180. After the aircraft enters emergency mode, the interlocking of the first ACMP contactor 180 and the second ACMP contactor 175 (e.g., as...) Figure 1The connection method shown allows ACMP 185 to switch from the main AC busbar 170 to the three-phase critical AC busbar (three-phase AC ESS BUS) 165, thus resolving the circuit breaker mismatch problem. Afterward, ACMP 185 is powered by the three-phase critical AC busbar (three-phase AC ESS BUS) 165.

[0032] On the other hand, after entering emergency mode, the activation of the time delay relay 145 can be determined based on whether the aircraft's airspeed exceeds the unloading threshold. In one embodiment, the time delay relay 145 can be configured in the transformer rectifier contactor (ETRUC) control circuit. The coil control signal of the time delay relay 145 can be triggered using an emergency mode signal. In one example, the energizing delay time of the time delay relay can be set based on the time required for successful ACMP startup. The unloading threshold can be set based on the characteristics of the RAT equipment itself, testing, experience, or other suitable means. In one example, the unloading threshold can be 170 knots, 150 knots, or less than 150 knots. Of course, the unloading threshold can also be any other suitable value.

[0033] In one embodiment, airspeed switch 140 can close if the aircraft's airspeed exceeds the unloading threshold. MOS transistor 150 can be connected to time-delay relay 145 and ETRUC control relay 135. In one example, after the aircraft enters emergency mode, all contactor auxiliary contacts (e.g., LGC AUX, AGC AUX, RGC AUX, EPR AUX) open, preventing MOS transistor 150 from conducting. Therefore, time-delay relay 145 can only operate if the aircraft enters emergency mode and the airspeed exceeds the unloading threshold. For example, when airspeed switch 140 closes, the control coil of ETRUC control relay 135 is energized, causing time-delay relay 145 to energize. However, during the energizing delay period of time-delay relay 145, time-delay relay 145 is open, thus ETRUC control relay 135 is also open, and ETRUC switches 130 and 125 are also off. At this time, the transformer rectifier 120, which is connected to the three-phase critical AC busbar 165, is not connected to the critical DC busbar (DC ESS BUS) 155. More precisely, the critical DC busbar 155 is currently powered by the battery 160. After the energizing delay time of the time-delay relay 145, the time-delay relay 145 closes, the ETRUC control relay 135 closes, the ETRUC switch 130 closes, and the ETRUC 125 closes, thereby connecting the transformer rectifier 120 to the critical DC busbar (DC ESS BUS) 155, which is then also powered by the RAT.

[0034] In one embodiment, if the aircraft's airspeed does not exceed the unloading threshold, the airspeed switch 140 can be disconnected. In this case, ETRUC 125 is always disconnected, and the critical DC ESS BUS 155 is powered by a battery.

[0035] use Figure 1 The narration system 100 offers the following advantages:

[0036] 1. The performance of high-frequency, low-temperature, cold-start hydraulic pumps can be improved by using time-delay relays.

[0037] 2. The circuit breaker matching problem has been solved, and the ACMP restart problem in non-emergency power supply mode has been overcome.

[0038] Figure 2 A flowchart illustrating a method 200 for starting a hydraulic pump in an aircraft power system under emergency power supply mode, according to an embodiment of the present invention, is provided. In one embodiment, method 200 may be performed by... Figure 3 The hardware device 300, or any suitable device, can be used to perform the explanation.

[0039] In block 210, method 200 may include: determining that the aircraft has entered emergency mode. In one embodiment, this can be determined by utilizing auxiliary contacts of a generator contactor. In another embodiment, this can be determined by acquiring various sensor signals and performing logical processing using these sensor signals.

[0040] In box 220, method 200 may include: in response to determining that the aircraft has entered emergency mode, determining whether the aircraft's airspeed is greater than an unloading threshold. In one embodiment, the aircraft's airspeed may be obtained using sensors or computational methods known in the art. The unloading threshold may be determined based on the characteristics of the RAT device itself and may be, for example, 170 knots, 150 knots, less than 150 knots, or any other suitable value.

[0041] In box 230, method 200 may include: if it is determined that the aircraft's airspeed is greater than an unloading threshold, then triggering a time-delay relay (e.g., Figure 1 The time-delay relay 145 operates, wherein during the energizing delay time of the time-delay relay, the ETRUC (e.g., ETRUC 125) is disconnected, the aircraft's ram air turbine (RAT) supplies power only to the critical AC bus (AC ESS BUS) and the critical DC bus (DC ESS BUS) is powered by the battery, and wherein after the energizing delay time of the time-delay relay, the ETRUC closes, and both the AC ESS BUS and the DC ESS BUS are powered by the RAT.

[0042] In box 240, method 200 may include: if it is determined that the aircraft airspeed is not greater than the unloading threshold, then disconnect the ETRUC, the RAT supplies power only to the AC ESS BUS and the battery supplies power only to the DC ESS BUS.

[0043] In one embodiment, method 200 may further include: in response to determining that the aircraft has entered an emergency mode, connecting an electro-hydraulic pump to a critical AC busbar of the aircraft, wherein connecting the electro-hydraulic pump to the critical AC busbar of the aircraft may include: switching the electro-hydraulic pump from the primary AC busbar to the critical AC busbar by utilizing an interlock between a first contactor of the electro-hydraulic pump connected to the primary AC busbar and a second contactor of the electro-hydraulic pump connected to the critical AC busbar.

[0044] Figure 3 A general hardware device 300 for performing the method of the present invention according to exemplary embodiments of the present disclosure is described.

[0045] Reference Figure 3 Hardware device 300 will now be described, which is an example of a hardware device applicable to various aspects of this disclosure. Hardware device 300 can be any machine configured to perform processing and / or computation, and can be, but is not limited to, a workstation, server, desktop computer, laptop computer, tablet computer, personal digital assistant, smartphone, airborne device, or any combination thereof.

[0046] Hardware device 300 may include elements that can be connected to or communicate with bus 302 via one or more interfaces. For example, hardware device 300 may include bus 302, one or more processors 304, one or more input devices 306, and one or more output devices 308. The one or more processors 304 may be any type of processor and may include, but are not limited to, one or more general-purpose processors and / or one or more dedicated processors (such as specialized processing chips). Input devices 306 may be any type of device that can input information into the hardware device and may include, but are not limited to, a mouse, keyboard, touchscreen, microphone, and / or remote control. Output devices 308 may be any type of device that can present information and may include, but are not limited to, a monitor, speaker, video / audio output terminal, vibrator, and / or printer. Hardware device 300 may also include or be connected to a non-transient storage device 310. The non-transient storage device 310 may be any storage device that is non-transient and capable of data storage, and may include, but is not limited to, disk drives, optical storage devices, solid-state storage, floppy disks, hard disks, magnetic tapes or any other magnetic media, optical discs or any other optical media, ROM (read-only memory), RAM (random access memory), cache memory and / or any other memory chip or memory cartridge, and / or any other medium from which a computer can read data, instructions, and / or code. The non-transient storage device 310 may be separable from an interface. The non-transient storage device 310 may have data / instructions / code for implementing the methods and steps described above. Hardware device 300 may also include a communication device 312. The communication device 312 may be any type of device or system capable of communicating with external devices and / or networks, and may include, but is not limited to, modems, network interface cards, infrared communication devices, and devices such as Bluetooth. TM Wireless communication devices and / or chipsets such as devices, 1302.11 devices, WiFi devices, WiMax devices, cellular communication facilities, etc.

[0047] Bus 302 may include, but is not limited to, Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.

[0048] Hardware device 300 may also include working memory 314, which may be any type of working memory that can store instructions and / or data useful for the operation of processor 304, and may include, but is not limited to, random access memory and / or read-only memory devices.

[0049] Software elements may reside in working memory 314, including but not limited to operating system 316, one or more application programs 318, drivers, and / or other data and code. Instructions for performing the methods and steps described above may be included in one or more application programs 318. Executable code or source code of the instructions of the software elements may be stored in a non-transitory computer-readable storage medium (such as storage device 310 described above) and may be read into working memory 314 by compilation and / or installation. Executable code or source code of the instructions of the software elements may also be downloaded from a remote location.

[0050] From the above embodiments, those skilled in the art will clearly understand that this disclosure can be implemented by software with the necessary hardware, or by hardware, firmware, etc. Based on this understanding, embodiments of this disclosure can be implemented in part as software. The computer software can be stored on a readable storage medium such as a computer's floppy disk, hard disk, optical disk, or flash memory. The computer software includes a series of instructions to cause a computer (e.g., a personal computer, service station, or network terminal) to perform a method or a portion thereof according to a corresponding embodiment of this disclosure.

[0051] Throughout the specification, references to "an example" or "one example" have been made, meaning that a specific feature, structure, or characteristic is included in at least one example. Therefore, the use of such phrases may involve more than one example. Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more examples.

[0052] However, those skilled in the art will recognize that these examples can be practiced without one or more specific details, or with other methods, resources, materials, etc. In other instances, well-known structures, resources, or operations have not been shown or described in detail to avoid obscuring aspects of these examples.

[0053] Although examples and applications have been explained and described, it should be understood that these examples are not limited to the precise configurations and resources described above. Various modifications, alterations, and variations that will be obvious to those skilled in the art can be made to the arrangement, operation, and details of the methods and systems disclosed herein without departing from the scope of the claimed examples.

Claims

1. A method for starting a hydraulic pump in an aircraft power system under emergency power supply mode, wherein a time-delay relay is provided in the control circuit of the aircraft's transformer rectifier contactor (ETRUC), the method comprising: Confirm that the aircraft has entered emergency mode; In response to determining that the aircraft has entered emergency mode, determine whether the airspeed of the aircraft is greater than the unloading threshold; as well as If it is determined that the airspeed of the aircraft is greater than the unloading threshold, the time-delay relay is activated, wherein during the energizing delay time of the time-delay relay, the ETRUC is disconnected, the aircraft's ram air turbine RAT supplies power only to the critical AC bus ESS BUS and the critical DC bus ESS BUS is powered by the battery, and wherein after the energizing delay time of the time-delay relay, the ETRUC is closed, and both the AC ESS BUS and the DC ESS BUS are powered by the RAT.

2. The method of claim 1, wherein if it is determined that the airspeed of the aircraft is not greater than the unloading threshold, the ETRUC is disconnected, the RAT supplies power only to the AC ESS BUS and the battery supplies power only to the DC ESS BUS.

3. The method of claim 1, wherein determining that the aircraft has entered emergency mode includes using a generator contactor auxiliary contact to determine that the aircraft has entered emergency mode.

4. The method of claim 1, wherein the coil control signal of the time delay relay is triggered using an emergency mode signal.

5. The method of claim 1, wherein the energizing delay time of the time delay relay is set according to the time required for successful startup of the electric hydraulic pump.

6. The method of claim 1, wherein the unloading threshold is determined based on the characteristics of the RAT itself.

7. The method of claim 1, further comprising: In response to determining that the aircraft has entered emergency mode, an electro-hydraulic pump is connected to a critical AC busbar of the aircraft.

8. The method of claim 7, wherein connecting the electro-hydraulic pump to a critical AC busbar of the aircraft comprises: The switching of the electric hydraulic pump from the main AC busbar to the important AC busbar is achieved by interlocking the first contactor of the electric hydraulic pump connected to the main AC busbar and the second contactor of the electric hydraulic pump connected to the important AC busbar.

9. A device for starting a hydraulic pump in an aircraft's emergency power supply mode, wherein a time-delay relay is provided in the control circuit of the aircraft's transformer rectifier contactor (ETRUC), the device comprising: Memory; as well as One or more processors coupled to the memory, the one or more processors being configured to: Confirm that the aircraft has entered emergency mode; In response to determining that the aircraft has entered emergency mode, determine whether the airspeed of the aircraft is greater than the unloading threshold; as well as If it is determined that the airspeed of the aircraft is greater than the unloading threshold, the time-delay relay is activated, wherein during the energizing delay time of the time-delay relay, the ETRUC is disconnected, the aircraft's ram air turbine RAT supplies power only to the critical AC bus ESS BUS and the critical DC bus ESS BUS is powered by the battery, and wherein after the energizing delay time of the time-delay relay, the ETRUC is closed, and both the AC ESS BUS and the DC ESS BUS are powered by the RAT.

10. A non-transient computer-readable medium storing a computer program that, when executed by a processor, performs the method as described in any one of claims 1-8.

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