Turbofan engine fuel pump current interference detection extraction circuit and analysis device

Abstract

The invention relates to the technical field of turbofan engine fuel system control, in particular to a turbofan engine fuel pump current interference detection and extraction circuit and analysis device, the circuit comprises a voltage following module and a bidirectional threshold detection and extraction module; in the bidirectional threshold detection and extraction module, the positive input end of a first operational amplifier is grounded, the negative input end of the first operational amplifier is connected with the output end of a voltage following module, and the output end of the first operational amplifier is connected with the cathode of a first diode and the anode of a second diode. The anode of the first diode is respectively connected with the output end of the voltage following module and the negative input end of the second operational amplifier; the cathode of the second diode is respectively connected with the output end of the voltage following module and the positive input end of the second operational amplifier; and the output end of the second operational amplifier is connected with an external current interference analysis module. Therefore, through the hardware circuit, the detection and extraction effect of the interference current can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of turbofan engine fuel system control technology, specifically to a turbofan engine fuel pump current interference detection and extraction circuit and analysis device. Background Technology

[0002] The fuel system of a turbofan engine is responsible for supplying fuel at a certain flow rate and pressure to generate the power needed to drive the engine blades to rotate. This high-speed rotation of the blades provides the engine with the power to maintain flight. The fuel system includes components such as a controller, fuel pump motor, fuel pump, and cables and piping. The fuel flow rate output by the fuel pump determines the energy produced by combustion, and the flow rate directly affects the stability of the engine's acceleration and deceleration. Since the fuel pump is driven by a fuel pump motor, the control effect of the fuel pump motor is crucial.

[0003] In existing technologies, turbofan engine fuel pumps are typically driven by permanent magnet synchronous motors, with vector control algorithms used to control the motor. The performance of these algorithms heavily relies on accurate, real-time sampling of the motor's three-phase current. However, in motor control systems (including the aforementioned controller), frequent switching on and off of power devices generates strong interference signals on the current sampling circuit. Furthermore, external electromagnetic environments also generate interference signals on the current sensors and their power supply circuits. Failure to identify and address these interference signals will affect the motor control performance, causing significant fluctuations and oscillations in motor speed, or even instantaneous overcurrent, leading to motor shutdown or over-speeding. These abnormal motor speeds, in turn, severely impact engine speed, affecting the stability and safety of the entire engine system.

[0004] To address this, existing technologies typically employ a digital low-pass filter module within the controller software to filter out interference in the current signal. However, this method is problematic because, firstly, relying solely on software to process interference signals is susceptible to the performance limitations of the analog signal acquisition interface, posing a risk of erroneous acquisition of interference signals; secondly, software filtering is also affected by the calculation time of the filter module, causing a delay in the output of the filtered current value to the core algorithm module, thus impacting control performance; and thirdly, software filtering is limited by bandwidth and current loop gain, further affecting its effectiveness. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a detection and extraction circuit and analysis device for current interference in turbofan engine fuel pumps, so as to overcome the problem of poor filtering effect in the current control of turbofan engine fuel pumps.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, this application provides a detection and extraction circuit for current interference in a turbofan engine fuel pump, including a detection and extraction circuit, which includes a voltage follower module and a bidirectional threshold detection and extraction module. The input terminal of the voltage follower module is connected to the current sampling signal interface of the turbofan engine fuel pump. The bidirectional threshold detection and extraction module includes a first operational amplifier, a second operational amplifier, a first diode, a second diode, a first resistor, and a second resistor. The positive input terminal of the first operational amplifier is grounded, and its negative input terminal is connected to the output terminal of the voltage follower module. The output terminal of the first operational amplifier is connected to the cathode of the first diode and the anode of the second diode. The anode of the first diode is connected to the output terminal of the voltage follower module through the first resistor, and is also connected to the negative input terminal of the second operational amplifier. The cathode of the second diode is connected to the output terminal of the voltage follower module through the second resistor, and is also connected to the positive input terminal of the second operational amplifier. Furthermore, the forward voltage drops of the first diode and the second diode are the same. The output of the second operational amplifier is connected to an external current interference analysis module.

[0007] Furthermore, in some embodiments of this application, the voltage follower module includes a third operational amplifier; The positive input terminal of the third operational amplifier is connected to the current sampling signal interface of the turbofan engine fuel pump as the input terminal of the voltage follower module, and the output terminal of the third operational amplifier is the output terminal of the voltage follower module.

[0008] Furthermore, in some embodiments of this application, a third resistor, a fourth resistor, and a first capacitor are also provided between the positive input terminal of the third operational amplifier and the current sampling signal interface of the turbofan engine fuel pump. The first end of the third resistor is connected to the current sampling signal interface of the turbofan engine fuel pump, and the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the first capacitor, and the positive input terminal of the third operational amplifier, respectively; the second ends of the fourth resistor and the first capacitor are both grounded.

[0009] Furthermore, in some embodiments of this application, the forward voltage drop of the first diode and the second diode is 0.7V.

[0010] Furthermore, in some embodiments of this application, an amplification and filtering circuit is also included, wherein the output terminal of the second operational amplifier is connected to the current interference analysis module through the amplification and filtering circuit.

[0011] Secondly, this application provides a turbofan engine fuel pump current interference detection, extraction and analysis device, characterized in that it includes the turbofan engine fuel pump current interference detection and extraction circuit and current interference analysis module as described above. The output of the second operational amplifier in the turbofan engine fuel pump current interference detection and extraction circuit is connected to the input of the current interference analysis module.

[0012] Furthermore, in some embodiments of this application, the current interference analysis module is a digital processor.

[0013] This invention relates to the field of turbofan engine fuel system control technology, specifically to a turbofan engine fuel pump current interference detection and extraction circuit and analysis device. The circuit includes a voltage follower module and a bidirectional threshold detection and extraction module. In the bidirectional threshold detection and extraction module, the positive input terminal of a first operational amplifier is grounded, and the negative input terminal is connected to the output terminal of the voltage follower module. The output terminal of the first operational amplifier is connected to the cathode of a first diode and the anode of a second diode. The anode of the first diode is connected to the output terminal of the voltage follower module and the negative input terminal of the second operational amplifier. The cathode of the second diode is connected to the output terminal of the voltage follower module and the positive input terminal of the second operational amplifier. The output terminal of the second operational amplifier is connected to an external current interference analysis module. Thus, through this hardware circuit, the detection and extraction effect of interference current can be effectively improved. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a turbofan engine fuel pump current interference detection and extraction circuit provided in an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the detection and extraction circuit in the turbofan engine fuel pump current interference detection and extraction circuit provided in an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the amplification and filtering circuit in the turbofan engine fuel pump current interference detection and extraction circuit provided in an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0019] Figure 1 This is a schematic diagram of a module of the turbofan engine fuel pump current interference detection and extraction circuit provided in an embodiment of the present invention. Please refer to [link / reference]. Figure 1 The turbofan engine fuel pump current interference detection and extraction circuit in this embodiment includes a detection and extraction circuit.

[0020] Specifically, the detection and extraction circuit includes a voltage follower module and a bidirectional threshold detection and extraction module. The input of the voltage follower module is connected to the current sampling signal interface of the turbofan engine fuel pump. The bidirectional threshold detection and extraction module includes a first operational amplifier, a second operational amplifier, a first diode, a second diode, a first resistor, and a second resistor. The positive input of the first operational amplifier is grounded, and its negative input is connected to the output of the voltage follower module. The output of the first operational amplifier is connected to the cathode of the first diode and the anode of the second diode. The anode of the first diode is connected to the output of the voltage follower module through the first resistor, and it is also connected to the negative input of the second operational amplifier. The cathode of the second diode is connected to the output of the voltage follower module through the second resistor, and it is also connected to the positive input of the second operational amplifier. The output of the second operational amplifier is connected to an external current interference analysis module.

[0021] It is understandable that the negative input of the bidirectional threshold detection and extraction module is connected to the output of the voltage follower module, so as to connect the current sampling signal interface of the turbofan engine fuel pump through the voltage follower module. Through this structure, the signal of the current sampling signal interface of the turbofan engine fuel pump is transmitted to the negative input of the first operational amplifier in the bidirectional threshold detection and extraction module via the voltage follower module.

[0022] Because of the presence of the first operational amplifier and other basic circuit components that ensure its operation (such as resistors controlling the amplification factor, which are existing technologies and can be configured according to requirements, and will not be elaborated here), when the voltage signal (i.e., the voltage at the output of the voltage follower module, hereinafter referred to as the input voltage) is positive and its value is greater than the forward conduction voltage drop of the first diode, the first diode will be in the conducting state. The voltage at the anode of the first diode is the sum of the voltage at the output of the first operational amplifier and the voltage drop of the first diode. Since the output of the first operational amplifier is a negative input voltage, the voltage at the anode of the first diode is the difference between the voltage drop of the first diode and the input voltage. Meanwhile, the second diode will be in the cutoff state, and the voltage at the cathode of the second diode is the input voltage. At this time, the negative input terminal of the second operational amplifier is the difference between the voltage drop of the first diode and the input voltage, and the positive input terminal is the input voltage.

[0023] When the voltage signal is negative and its absolute value is greater than the forward voltage drop of the second diode, the second diode will be in the conducting state. The voltage at the cathode of the second diode is the difference between the voltage at the output of the first operational amplifier and the voltage drop of the first diode. Since the output of the first operational amplifier is the opposite of the input voltage (i.e., positive), the potential at the cathode of the second diode is the difference between the opposite of the input voltage and the voltage drop of the second diode. Conversely, when the first diode is in the cutoff state, the voltage at the anode of the first diode is the opposite of the input voltage. At this time, the negative input terminal of the second operational amplifier is the opposite of the input voltage, and the positive input terminal is the difference between the opposite of the input voltage and the voltage drop of the second diode.

[0024] Thus, when the absolute values ​​of the input voltages are the same, the second operational amplifier can output the same signal to complete the detection and extraction of positive and negative pulses, converting the positive and negative pulses into positive square waves.

[0025] It is understandable that when the absolute value of the input voltage is between the forward voltage drops of the first diode and the second diode, neither the first diode nor the second diode will conduct, and the second operational amplifier will have no output.

[0026] Furthermore, in some embodiments of this application, the voltage follower module includes a third operational amplifier; the positive input terminal of the third operational amplifier serves as the input terminal of the voltage follower module and is connected to the current sampling signal interface of the turbofan engine fuel pump, and the output terminal of the third operational amplifier serves as the output terminal of the voltage follower module. A third resistor, a fourth resistor, and a first capacitor are also provided between the positive input terminal of the third operational amplifier and the current sampling signal interface of the turbofan engine fuel pump; wherein, the first end of the third resistor is connected to the current sampling signal interface of the turbofan engine fuel pump, and the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the first capacitor, and the positive input terminal of the third operational amplifier; the second ends of the fourth resistor and the first capacitor are both grounded.

[0027] In some embodiments of this application, the forward voltage drop of the first diode and the second diode is 0.7V. Figure 2 This is a schematic diagram of the detection and extraction circuit in the turbofan engine fuel pump current interference detection and extraction circuit provided in an embodiment of the present invention. The following is in conjunction with... Figure 2 The circuit structure is described, and the working principle of the circuit is explained in detail with specific numerical values, such as... Figure 2 As shown: For ease of narration, Figure 2 In the detection and extraction circuit shown, the output terminal of the voltage follower module is defined as node TP0, the anode of the first diode D1 is defined as node TP1, the cathode of the second diode D2 is defined as node TP2, and the output terminal of the bidirectional threshold detection and extraction module, i.e., the output terminal of the second operational amplifier U2, is defined as node TP3. Figure 2 In this embodiment, J1 is the current sampling signal interface of the turbofan engine fuel pump. The signal collected from the current sampling signal interface of the turbofan engine fuel pump is divided by the third resistor R3 and the fourth resistor R4, and then enters the third operational amplifier U3 to improve the input impedance through the first operational amplifier. Furthermore, in this embodiment, the first operational amplifier U1, the second operational amplifier U2, and the third operational amplifier U3 can be of model AD8001, and the first diode D1 and the second diode D2 can be of model 1N4148W.

[0028] At this time, when the voltage Vin at node TP0 is greater than zero and a is greater than 0.7V, the first diode D1 is in the conducting state, and the output U3out of the first operational amplifier U1 is -a; since diode D1 itself has a voltage drop of 0.7V, the voltage at node TP1 is -a+0.7V; at this time, the second diode D2 is in the cutoff state, and the voltage at node TP2 is a; with the amplification factor of the second operational amplifier U2 being 2, the specific voltage at the output TP3 point of the second operational amplifier U2 is: [a-(0.7-a)]*2=4a-1.4V.

[0029] When the voltage Vin at node TP0 is -a, and a is less than 0.7V, the second diode D2 is in the conducting state, and the output U3out of the first operational amplifier U1 is a. Since the second diode D2 itself has a voltage drop of 0.7V, the potential at node TP2 is a-0.7V. At this time, the first diode D1 is in the cutoff state, and the voltage at node TP2 is -a. The specific output voltage at point TP3 is as follows: [(a-0.7)-(-a)]*2=4a-1.4V.

[0030] When the voltage Vin at node TP0 is between 0.7V and -0.7V, neither the first diode D1 nor the second diode D2 conducts, and TP3 has no voltage output.

[0031] Thus, the positive and negative pulses are detected and extracted through the above circuit, and the positive and negative pulses are converted into positive square waves.

[0032] Furthermore, in some embodiments of this application, the turbofan engine fuel pump current interference detection and extraction circuit further includes an amplification and filtering circuit. Figure 3 This is a schematic diagram of the amplification and filtering circuit in the turbofan engine fuel pump current interference detection and extraction circuit provided in an embodiment of the present invention, as shown below. Figure 3 As shown: In this embodiment, the input of the amplification and filtering circuit is connected to the output of the bidirectional threshold detection and extraction module (shown as TP3). After the bidirectional threshold detection and extraction module converts the positive and negative pulse interference into a positive square wave circuit, the amplification and filtering circuit amplifies the square wave circuit to convert it into a positive square wave signal that can be recognized by the current interference analysis module, such as a digital processor, for processing by the digital processor. The amplification and filtering circuit may include an operational amplifier (such as...). Figure 3 This includes U4 and the basic circuit components that ensure its amplification function, such as R6 and R7, as well as filter capacitors. It should be noted that this part, along with the aforementioned... Figure 2 The placement of other resistors and capacitors is a conventional technique in this field and can be adjusted according to the actual situation, such as the type of digital processor. You can refer to the existing technology for understanding, and it will not be elaborated here.

[0033] The turbofan engine fuel pump current interference detection and extraction circuit provided in this application can extract interference analog signals injected into the current signal, which are originally difficult to collect, into easily identifiable, distinct rise and fall edges, and independent pulse signals. Furthermore, the detection and extraction results can be used to improve the control precision of the turbofan engine fuel system through motor control algorithms.

[0034] Based on the same inventive concept, this application also provides a turbofan engine fuel pump current interference detection, extraction, and analysis device, including a turbofan engine fuel pump current interference detection and extraction circuit and a current interference analysis module as mentioned in the above embodiments; wherein, the output terminal of the second operational amplifier of the turbofan engine fuel pump current interference detection and extraction circuit is connected to the input terminal of the current interference analysis module. Furthermore, the current interference analysis module mentioned in the above embodiments can specifically be a digital processor.

[0035] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0036] It should be noted that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means at least two.

[0037] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0038] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0039] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0040] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0041] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0042] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A circuit for detecting and extracting interference from the fuel pump current of a turbofan engine, characterized in that, The circuit includes a detection and extraction circuit, which comprises a voltage follower module and a bidirectional threshold detection and extraction module. The input terminal of the voltage follower module is connected to the current sampling signal interface of the turbofan engine fuel pump. The bidirectional threshold detection and extraction module includes a first operational amplifier, a second operational amplifier, a first diode, a second diode, a first resistor, and a second resistor. The positive input terminal of the first operational amplifier is grounded, and its negative input terminal is connected to the output terminal of the voltage follower module. The output terminal of the first operational amplifier is connected to the cathode of the first diode and the anode of the second diode. The anode of the first diode is connected to the output terminal of the voltage follower module through the first resistor, and is also connected to the negative input terminal of the second operational amplifier. The cathode of the second diode is connected to the output terminal of the voltage follower module through the second resistor, and is also connected to the positive input terminal of the second operational amplifier. Furthermore, the forward voltage drops of the first diode and the second diode are the same. The output of the second operational amplifier is connected to an external current interference analysis module.

2. The turbofan engine fuel pump current interference detection and extraction circuit according to claim 1, characterized in that, The voltage follower module includes a third operational amplifier; The positive input terminal of the third operational amplifier is connected to the current sampling signal interface of the turbofan engine fuel pump as the input terminal of the voltage follower module, and the output terminal of the third operational amplifier is the output terminal of the voltage follower module.

3. The turbofan engine fuel pump current interference detection and extraction circuit according to claim 2, characterized in that, A third resistor, a fourth resistor, and a first capacitor are also provided between the positive input terminal of the third operational amplifier and the current sampling signal interface of the turbofan engine fuel pump. The first end of the third resistor is connected to the current sampling signal interface of the turbofan engine fuel pump, and the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the first capacitor, and the positive input terminal of the third operational amplifier, respectively; the second ends of the fourth resistor and the first capacitor are both grounded.

4. The turbofan engine fuel pump current interference detection and extraction circuit according to claim 1, characterized in that, The forward voltage drop of the first diode and the second diode is 0.7V.

5. The turbofan engine fuel pump current interference detection and extraction circuit according to claim 1, characterized in that, It also includes an amplification and filtering circuit, and the output of the second operational amplifier is connected to the current interference analysis module through the amplification and filtering circuit.

6. A device for detecting, extracting, and analyzing interference in the fuel pump of a turbofan engine, characterized in that, Includes the turbofan engine fuel pump current interference detection and extraction circuit and current interference analysis module as described in any one of claims 1-5; The output of the second operational amplifier in the turbofan engine fuel pump current interference detection and extraction circuit is connected to the input of the current interference analysis module.

7. The turbofan engine fuel pump current interference detection, extraction, and analysis device according to claim 6, characterized in that, The current interference analysis module is a digital processor.

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