Turboshaft engine fuel pump current disturbance detection extraction circuit and analysis device

Abstract

The present application relates to the technical fields of turbofan engine fuel system control, in particular to a kind of turbofan engine fuel pump current interference detection extraction circuit and analysis device, the circuit includes voltage follower module and bidirectional threshold detection extraction module;In bidirectional threshold detection extraction module, the positive input end of first operational amplifier is grounded, and the negative input end is connected to the output end of voltage follower module, and the output end of first operational amplifier is respectively connected to the cathode of first diode and the anode of second diode;The anode of first diode is respectively connected to the output end of voltage follower module and the negative input end of second operational amplifier;The cathode of second diode is respectively connected to the output end of voltage follower module and the positive input end of second operational amplifier;The output end of second operational amplifier is connected to the current interference analysis module outside.Such, by hardware circuit, the detection extraction effect of interference current can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of turbofan engine fuel system control, in particular to a turbofan engine fuel pump current interference detection extraction circuit and analysis device. BACKGROUND

[0002] The fuel system of a turbofan engine is responsible for providing a certain flow pressure of fuel to the turbofan engine, thereby generating the power required to drive the rotation of the fan blades of the turbofan engine, thereby providing power for the engine to maintain flight through the high-speed rotation of the fan blades. Among them, the fuel system includes a controller, a fuel pump motor, a fuel pump, and cables and pipelines and other components. The fuel flow output by the fuel pump determines the energy generated by combustion, and the amount of flow directly affects the stability of the engine acceleration and deceleration, and the fuel pump is driven by the fuel pump motor, so the control effect of the fuel pump motor is crucial.

[0003] In the prior art, the turbofan engine fuel pump is usually driven by a permanent magnet synchronous motor, and the control of the fuel pump motor is realized through a vector control algorithm. The performance of the algorithm depends heavily on the accurate and real-time sampling of the three-phase current of the motor. However, in the motor control system (including the above-mentioned controller), the frequent turn-on and turn-off of the power device will generate strong interference signals on the current sampling line, in addition, the external electromagnetic environment will also generate interference signals on the current sensor and its power supply circuit. If these signals are not identified, the motor control effect will be affected, for example, the motor speed will have large fluctuations and oscillations, and even instantaneous overcurrent phenomena will occur, causing the motor to stop or over-speed. These abnormal conditions of the motor speed will seriously affect the speed of the engine and the stability and safety of the entire engine system.

[0004] To this end, the prior art generally sets a digital low-pass filter module in the controller software to filter out the interference in the current signal. However, in the above method, first of all, the processing of the interference signal by software only will be affected by the performance of the analog quantity acquisition interface, and there is a risk of false collection of interference signals; at the same time, software filtering will also be affected by the calculation time of the filter module, causing the delayed output of the filtered current value to the core algorithm module, affecting the control effect; and software filtering will also be limited by the bandwidth and current loop gain, affecting the filtering effect. SUMMARY

[0005] Therefore, the present application aims to provide a turbofan engine fuel pump current interference detection extraction circuit and analysis device to overcome the poor filtering effect in the current control of the turbofan engine fuel pump.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the application provides a turbofan engine fuel pump current interference detection extraction circuit, comprising a detection extraction circuit, the detection extraction circuit comprising: a voltage follower module and a bidirectional threshold detection extraction module;

[0008] The input end of the voltage follower module is connected to the current sampling signal interface of the turbofan engine fuel pump.

[0009] The bidirectional threshold detection extraction module comprises a first operational amplifier, a second operational amplifier, a first diode, a second diode, a first resistor and a second resistor; wherein the positive input end of the first operational amplifier is grounded, the negative input end is connected to the output end of the voltage follower module, and the output end of the first operational amplifier is connected to the cathode of the first diode and the anode of the second diode respectively; the anode of the first diode is connected to the output end of the voltage follower module through the first resistor, and the anode of the first diode is also connected to the negative input end of the second operational amplifier; the cathode of the second diode is connected to the output end of the voltage follower module through the second resistor, and the cathode of the second diode is also connected to the positive input end of the second operational amplifier; and the forward conduction voltage drops of the first diode and the second diode are the same.

[0010] The output end of the second operational amplifier is connected to an external current interference analysis module.

[0011] Further, in some embodiments of the application, the voltage follower module comprises a third operational amplifier;

[0012] The positive input end of the third operational amplifier is connected to the current sampling signal interface of the turbofan engine fuel pump as the input end of the voltage follower module, and the output end of the third operational amplifier is the output end of the voltage follower module.

[0013] Further, in some embodiments of the application, a third resistor, a fourth resistor and a first capacitor are further arranged between the positive input end of the third operational amplifier and the current sampling signal interface of the turbofan engine fuel pump;

[0014] Wherein, the first end of the third resistor is connected to the current sampling signal interface of the turbofan engine fuel pump, 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 end of the third operational amplifier respectively; the second ends of the fourth resistor and the first capacitor are both grounded.

[0015] Further, in some embodiments of the application, the forward conduction voltage drops of the first diode and the second diode are 0.7V.

[0016] Further, in some embodiments of the application, an amplification filtering circuit is further included, and the output end of the second operational amplifier is connected to the current interference analysis module through the amplification filtering circuit.

[0017] In a second aspect, the application provides a turbofan engine fuel pump current interference detection extraction analysis device, characterized in that, comprising the turbofan engine fuel pump current interference detection extraction circuit and the current interference analysis module as described above;

[0018] The output end of the second operational amplifier of the turbofan engine fuel pump current interference detection extraction circuit is connected to the input end of the current interference analysis module.

[0019] Further, in some embodiments of the application, the current interference analysis module is a digital processor.

[0020] The application relates to the technical field of turbofan engine fuel system control, in particular to a turbofan engine fuel pump current interference detection extraction circuit and analysis device. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the accompanying drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the application, and other accompanying drawings can be obtained by those skilled in the art without creative effort on the basis of these accompanying drawings.

[0022] Figure 1 Fig. 1 is a module schematic diagram of the turbofan engine fuel pump current interference detection extraction circuit provided by the embodiment of the application.

[0023] Figure 2 Fig. 2 is a schematic diagram of the detection extraction circuit in the turbofan engine fuel pump current interference detection extraction circuit provided by the embodiment of the application.

[0024] Figure 3 Fig. 3 is a schematic diagram of the amplification filtering circuit in the turbofan engine fuel pump current interference detection extraction circuit provided by the embodiment of the application. DETAILED DESCRIPTION

[0025] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0026] Figure 1 is a module schematic diagram of the turbofan engine fuel pump current interference detection extraction circuit provided by the embodiment of the present application, please refer to Figure 1 The turbofan engine fuel pump current interference detection extraction circuit of the embodiment comprises a detection extraction circuit.

[0027] Specifically, the detection extraction circuit comprises a voltage follower module and a bidirectional threshold detection extraction module. The input end of the voltage follower module is connected with the current sampling signal interface of the turbofan engine fuel pump. The bidirectional threshold detection extraction module comprises a first operational amplifier, a second operational amplifier, a first diode, a second diode, a first resistor and a second resistor. The positive input end of the first operational amplifier is grounded, and the negative input end is connected with the output end of the voltage follower module. The output end of the first operational amplifier is connected with the cathode of the first diode and the anode of the second diode. The anode of the first diode is connected with the output end of the voltage follower module through the first resistor, and the anode of the first diode is also connected with the negative input end of the second operational amplifier. The cathode of the second diode is connected with the output end of the voltage follower module through the second resistor, and the cathode of the second diode is also connected with the positive input end of the second operational amplifier. The output end of the second operational amplifier is connected with an external current interference analysis module.

[0028] It can be understood that the negative input end of the bidirectional threshold detection extraction module is connected with the output end 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 the structure, the signal of the current sampling signal interface of the turbofan engine fuel pump is transmitted to the negative input end of the first operational amplifier in the bidirectional threshold detection extraction module through the voltage follower module.

[0029] Because of the first operational amplifier and other basic circuit devices (such as resistance for controlling amplification, which is prior art and can be set according to requirements, and will not be described here) that ensure the operation of the amplifier, when the voltage signal (i.e. the voltage at the output end of the voltage follower module, hereinafter referred to as the input voltage) is positive and the value is greater than the forward conduction voltage drop of the first diode, the first diode will be in a conducting state, and the voltage at the anode of the first diode will be the sum of the voltage at the output end of the first operational amplifier and the voltage drop of the first diode. Because the output of the first operational amplifier is the 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. In addition, the second diode will be in a cut-off state, and the voltage at the cathode of the second diode will be the input voltage. At this time, the negative input end of the second operational amplifier is the difference between the voltage drop of the first diode and the input voltage, and the positive input end is the input voltage.

[0030] When the voltage signal is negative and the absolute value is greater than the forward conduction voltage drop of the second diode, the second diode will be in a conducting state, and the voltage at the cathode of the second diode will be the difference between the voltage at the output end of the first operational amplifier and the voltage drop of the first diode. Because 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. In addition, the first diode will be in a cut-off state, and the voltage at the anode of the first diode will be the opposite of the input voltage. At this time, the negative input end of the second operational amplifier is the opposite of the input voltage, and the positive input end is the difference between the opposite of the input voltage and the voltage drop of the second diode.

[0031] In this way, when the absolute value of the input voltage is the same, the second operational amplifier can output the same signal to complete positive and negative pulse detection and extraction, and convert positive and negative pulses into positive square waves.

[0032] It can be understood that when the absolute value of the input voltage is between the forward conduction voltage drops of the first diode and the second diode, neither the first diode nor the second diode is conducting, and the second operational amplifier has no output.

[0033] Further, in some embodiments of the present application, the voltage follower module comprises 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. In addition, a third resistor, a fourth resistor and a first capacitor are arranged 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, 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, and the second ends of the fourth resistor and the first capacitor are grounded.

[0034] In some embodiments of the present application, the forward conduction voltage drop of the first diode and the second diode is 0.7V, Figure 2 is a schematic diagram of the detection extraction circuit provided by the turbofan engine fuel pump current interference detection extraction circuit, and the working principle of the circuit will be introduced in detail with specific numerical values in combination with Figure 2 circuit structure, as shown in Figure 2

[0035] For the convenience of description, the output terminal of the voltage follower module in the detection extraction circuit shown in Figure 2 is defined as TP0 node, the anode of the first diode D1 is defined as TP1 node, the cathode of the second diode D2 is defined as TP2 node, and the output terminal of the bidirectional threshold detection extraction module, i.e. the output terminal of the second operational amplifier U2, is defined as TP3 node. In Figure 2 , J1 is the current sampling signal interface of the turbofan engine fuel pump, and the signal collected from the current sampling signal interface of the turbofan engine fuel pump enters the third operational amplifier U3 after being divided by the third resistor R3 and the fourth resistor R4, so as to pass through the input impedance of the first operational amplifier. In this embodiment, the model of the first operational amplifier U1, the second operational amplifier U2 and the third operational amplifier U3 can be AD8001, and the model of the first diode D1 and the second diode D2 can be 1N4148W.

[0036] At this time, when the voltage Vin of the TP0 node is greater than zero a, and a is greater than 0.7V, the first diode D1 is in the on state, and the output U3out of the first operational amplifier U1 is-a; since the diode D1 itself has a voltage drop of 0.7V, the voltage of the TP1 node is-a+0.7V; at this time, the second diode D2 is in the off state, and the voltage of the TP2 node is a; when the amplification of the second operational amplifier U2 is 2, the voltage of the output TP3 point of the second operational amplifier U2 is specifically:

[0037] ​[a-(0.7-a)]*2=4a-1.4V.

[0038] When the voltage Vin of the TP0 node is -a, and a is less than 0.7V, the second diode D2 is in the conducting state, the output U3out of the first operational amplifier U1 is a, and since the second diode D2 itself has a 0.7V voltage drop, the potential of the TP2 node is a-0.7V; at this time, the first diode D1 is in the cut-off state, and the voltage of the TP2 node is -a; the output voltage of the TP3 point is specifically:

[0039] [(a-0.7)-(-a)]*2=4a-1.4V.

[0040] When the voltage Vin of the TP0 node is between 0.7V and -0.7V, the first diode D1 and the second diode D2 are both not conducting, and the TP3 has no voltage output.

[0041] In this way, the positive and negative pulse detection extraction is completed through the above-mentioned circuit, and the positive and negative pulse is converted into a positive square wave.

[0042] Further, in some embodiments of the present application, the turbofan engine fuel pump current interference detection extraction circuit further comprises an amplification filtering circuit, Figure 3 which is a schematic diagram of the amplification filtering circuit in the turbofan engine fuel pump current interference detection extraction circuit provided by the embodiments of the present application, as Figure 3 shown:

[0043] In the embodiments of the present application, the input end of the amplification filtering circuit is connected to the output end (shown by TP3) of the bidirectional threshold detection extraction module, and after the positive and negative pulse interference is converted into a positive square wave circuit by the bidirectional threshold detection extraction module, the square wave circuit is amplified by the amplification filtering circuit to convert it into a positive square wave signal recognizable by the current interference analysis module such as a digital processor, so as to provide it to the digital processor for processing. Among them, the amplification filtering circuit can be provided with an operational amplifier (such as U4 in Figure 3 and basic circuit devices such as R6 and R7 to ensure its amplification function), and also includes a filtering capacitor. It should be noted that the settings of this part and other resistor and capacitor devices in the above-mentioned Figure 2 are all conventional technical means in the art, which can be adjusted according to the actual situation such as the type of digital processor, and can be understood by referring to the prior art, and will not be described here.

[0044] The turbofan engine fuel pump current interference detection extraction circuit provided by the application can extract the interference analog signal injected in the current signal, which is not easy to collect, as a pulse signal which is easy to identify, has clear rising and falling edges, and is independent of the signal.

[0045] Based on the same inventive concept, the application further provides a turbofan engine fuel pump current interference detection extraction analysis device, which comprises the turbofan engine fuel pump current interference detection extraction circuit and the current interference analysis module mentioned in the above embodiments; wherein the output end of the second operational amplifier of the turbofan engine fuel pump current interference detection extraction circuit is connected to the input end of the current interference analysis module. The current interference analysis module mentioned in the above embodiments can be a digital processor.

[0046] It can be understood that the same or similar parts in the above embodiments can be mutually referred to, and the content not described in detail in some embodiments can be referred to the same or similar content in other embodiments.

[0047] It should be noted that, in the description of the application, the terms "first", "second", etc. are only used for the purpose of description and should not be understood as indicating or implying relative importance. In addition, in the description of the application, unless otherwise specified, the meaning of "a plurality of" is at least two.

[0048] Any process or method descriptions in flow charts or described elsewhere herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for performing specific logic functions or steps in the process, and the various embodiments of the application include additional implementations in which the functions described with or without specific reference to successive steps of the processes are performed at least partially contemporaneously, or in reverse order, or are performed substantially concurrently with one another, or are performed individually, or with priority, or are combined with other operations and methods.

[0049] It should be understood that the parts of the application can be realized by hardware, software, firmware or their combination. In the above embodiments, the plurality of steps or methods can be realized by software or firmware stored in the memory and executed by the appropriate instruction execution system. For example, if realized by hardware, and as in another embodiment, it can be realized by any one or their combination of the following technologies known in the art: discrete logic circuit with logic gate circuit for implementing logic function on data signal, application specific integrated circuit with appropriate combination logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA) and the like.

[0050] Those skilled in the art can understand that all or part of the steps of the method carried out by the above-mentioned embodiments can be instructed by a program to the relevant hardware, and the program can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0051] In addition, each functional unit in each embodiment of the present application can be integrated into one processing module, or each unit can exist physically independently, or two or more units can be integrated into one module. The integrated module can be realized in the form of hardware or in the form of a software functional module. When the integrated module is realized in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer readable storage medium.

[0052] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0053] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0054] Although the embodiments of the present application have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the present application. Those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments within the scope of the present application.

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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