An aircraft fuel tank fault diagnosis and processing device and method in an electric fuel system

Abstract

This invention belongs to the field of aero-engine fuel control technology, and discloses a device and method for diagnosing and handling aircraft fuel tank faults in an electric fuel system. The control device includes: a bus voltage and current monitoring module for monitoring the voltage and current of the DC bus in the electric fuel pump system and converting the voltage and current quantities into digital quantities; a motor speed acquisition module for acquiring the real-time speed of the electric fuel pump; a motor torque calculation module for calculating the rotational torque of the electric fuel pump based on the bus voltage, current, and speed, as a basis for fuel tank fault diagnosis; a fuel tank fault diagnosis module for diagnosing whether the aircraft fuel tank has a fault in real time based on the motor speed and torque; and a fuel tank fault handling module for providing action information to the electric fuel pump system after the aircraft fuel tank has a fault, driving the electric fuel pump to operate reliably in the fuel tank fault mode, and preventing a chain reaction of faults in the electric fuel pump system caused by the fuel tank fault.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine fuel pump control technology, and discloses a device and method for diagnosing and handling aircraft fuel tank faults in an electric fuel system. Background Technology

[0002] In recent years, multi-electric / hybrid electric aero-engine technology has sparked a research boom internationally, with researchers conducting studies on its key components to varying degrees. The aero-engine fuel pump control system, with its core architecture based on an electric fuel pump, is one of the key components in the development of multi-electric / hybrid electric engines and is considered by the industry as a major revolution in aero-engine fuel control systems.

[0003] The normal operation of aircraft fuel tanks is essential for the functioning of the aircraft engine fuel control system and is a prerequisite for the reliable operation of the pump control system. When an aircraft fuel tank malfunctions, if effective technical methods are not adopted for fault diagnosis and handling, it will lead to the electric fuel pump drawing in air and the fuel pump wearing out and being damaged; the solenoid valve will be damaged due to insufficient cooling flow, and the fuel tank malfunction will trigger a chain reaction, which will exacerbate the failure of the aircraft engine fuel control system.

[0004] In existing aircraft engines, the fuel tank electrical signal is directly output to the aircraft instrument room. The aircraft engine fuel control system is not connected to the aircraft fuel tank electrical signal, so it cannot diagnose and handle aircraft fuel tank faults. It relies solely on the flight crew to make decisions based on the indication signals in the instrument room, which often leads to damage to the fuel control system due to the flight crew's untimely handling. Summary of the Invention

[0005] The purpose of this invention is to address the deficiencies and shortcomings in the aforementioned background technology by proposing a device and method for diagnosing and handling aircraft fuel tank faults in an electric fuel system. This enables the electric fuel system to diagnose and make decisions regarding aircraft fuel tank system faults, allowing it to take timely and appropriate measures when a fuel tank fault occurs, thereby ensuring the operational safety of the fuel control system, engine, and aircraft, and reducing the failure rate of the fuel control system.

[0006] The technical solution of this invention is as follows:

[0007] An aircraft fuel tank fault diagnosis and handling device in an electric fuel system includes: a bus voltage and current monitoring module, a motor speed acquisition module, a motor torque calculation module, a fuel tank fault diagnosis module, and a fuel tank fault handling module.

[0008] The bus voltage and current monitoring module is used to monitor the voltage and current of the DC bus in the electric fuel pump system and convert the voltage and current into digital quantities.

[0009] The motor speed acquisition module is used to collect the real-time speed of the electric fuel pump;

[0010] The motor torque calculation module is used to calculate the rotational torque of the electric fuel pump based on the bus voltage, current and speed, as a basis for fuel tank fault diagnosis.

[0011] The fuel tank fault diagnosis module is used to diagnose whether the aircraft fuel tank is faulty in real time based on the motor speed and torque.

[0012] The fuel tank failure handling module is used to provide action information to the electric fuel pump system after the aircraft fuel tank fails, drive the electric fuel pump to operate reliably in the fuel tank failure mode, and prevent the electric fuel pump system failure chain reaction caused by the fuel tank failure.

[0013] Furthermore, the bus voltage and current monitoring module includes: a differential voltage isolation module, a Hall current monitoring module, a voltage and current active filter circuit, a high-precision A / D converter, a voltage digital filter, and a current digital filter;

[0014] The differential voltage isolation module is used to convert the bus voltage of the electric fuel pump into two single-ended analog voltage signals that are at the same frequency as the bus and electrically isolated, and share a common ground with the control low voltage.

[0015] The Hall current monitoring module is used to convert the bus current of the electric fuel pump into an analog voltage signal that is electrically isolated from the bus current.

[0016] The voltage and current active filtering circuit is used to perform low-pass active filtering on the two single-ended analog voltage signals and the analog voltage signal output by the differential voltage isolation module and the Hall current monitoring module. The cutoff frequency is 100Hz, the passband gain is 1, and the stopband attenuation is -40dB. The filtering circuit includes two voltage filters and one current filter.

[0017] The high-precision A / D converter is used to convert two filtered single-ended analog voltage signals and analog voltage signals into two single-ended digital voltage signals and digital voltage signals.

[0018] The voltage digital filter is used to digitally filter digital voltage signals. The filter is a linear Kalman filter, with a Q parameter of 0.96 and an R parameter of 0.06.

[0019] Furthermore, the motor speed acquisition module communicates with the electric fuel pump via a bus to obtain the real-time speed of the electric fuel pump.

[0020] Furthermore, the differential voltage isolation module includes: a bus voltage divider, a voltage follower, and an analog voltage isolator;

[0021] The bus voltage divider consists of n resistors connected in series, where 2 < n < 10. The n resistors connected in series are connected between the positive end and the negative end of the bus. The n1 resistor is connected to the negative end of the bus. The values of the n1 resistor and the n2 resistor satisfy the following conditions: at 80% - 120% of the rated bus voltage, the voltage U1 at the end of the n1 resistor far from the bus is higher than 0.1V and lower than 0.3V, and the voltage U2 at the end of the n2 resistor far from the bus is higher than 0.4V and lower than 0.8V;

[0022] The voltage follower includes a voltage follower one and a voltage follower two. One end of the voltage follower one is connected to the end of the n1 resistor far from the bus, and the other end is connected to the analog voltage isolator; one end of the voltage follower two is connected to the end of the n2 resistor far from the bus, and the other end is connected to the analog voltage isolator;

[0023] The analog voltage isolator includes an analog voltage isolator one and an analog voltage isolator two. The analog voltage isolator one is used to linearly isolate the voltage U1 output by the voltage follower one at a ratio of 1:1;

[0024] The analog voltage isolator one is composed of an analog linear isolator, an isolation power supply, and an RC filter. The voltage U1 output by the voltage follower one first passes through the RC filter, enters the analog linear isolator, and after a 1:1 linear transformation, is output to the voltage - current active filter circuit. The isolation power supply provides DC3000V isolation power supply for both ends of the isolation of the analog linear isolator;

[0025] The analog voltage isolator two is used to linearly isolate the voltage U2 output by the voltage follower two at a ratio of 1:1.

[0026] Furthermore, the Hall current monitoring module includes: a Hall current sensor power supply, a Hall current sensor, an I / V converter, and a voltage follower three.

[0027] The Hall current sensor power supply is used to provide ±15V power supply for the Hall current sensor. The input voltage of the power supply is DC5V, and the output voltage is ±15V;

[0028] The Hall current sensor is used to convert the large current signal on the bus into a small current signal according to a ratio of 1000:1 and output it to the I / V converter;

[0029] The I / V converter is used to convert the small current signal output by the Hall current sensor into a voltage signal; it is composed of two equal - value resistors connected to the output end of the Hall current sensor and the reference end of the Hall current sensor power supply;

[0030] The voltage signal output by the I / V converter is connected to the voltage - current active filter circuit through the voltage follower three.

[0031] Furthermore, the motor torque calculation module includes four units: bus voltage calculation, bus current calculation, electric fuel pump input power calculation, and electric fuel pump rotational torque calculation.

[0032] The bus voltage calculation unit calculates the bus voltage based on the measured values ​​of U1 and U2, as follows:

[0033] Let U2-U1=UΔ, the resistance of the n2 resistors be R2, the total resistance of the n resistors connected in series be R, and the bus voltage U=UΔ / R2*R;

[0034] The bus current calculation unit calculates the bus current as I based on the digital voltage signal output by the high-precision A / D converter, the equivalent resistance of the I / V converter, and the turns ratio of the Hall current sensor.

[0035] The electric fuel pump input power calculation unit calculates the electric fuel pump input power based on the electric fuel pump bus voltage U and bus current I, P = U * I;

[0036] The electric fuel pump rotational torque calculation unit is used to calculate the rotational torque T of the electric fuel pump based on the input power P of the electric fuel pump and the motor speed n, where T = P * η / n.

[0037] η represents the efficiency at different rotational speeds.

[0038] Furthermore, the fuel tank fault diagnosis module diagnoses whether the aircraft fuel tank is faulty as follows:

[0039] The diagnostic strategy is to obtain the rated torque T corresponding to the motor speed n. N Let D = T / T N ;

[0040] Sample T at a period of 0.01ms, and denote the T corresponding to the first sampling time as T1 and the T corresponding to the second sampling time as T2, and then calculate the first derivative T′ of T;

[0041] The counter c represents the number of times T′ exceeds the limit. When T′ < 0.02, c is incremented; otherwise, c is cleared. When D < 0.6 and c ≥ 5, the aircraft fuel tank is judged to be faulty, and the fault is marked F. fault Set to 1, otherwise F fault Reset to zero.

[0042] Furthermore, the fuel tank fault handling module reports the fault status when the aircraft fuel tank fails, and calculates the expected speed of the electric fuel pump under the fault status.

[0043] When F fault When the flag is set, the fault status is sent to the electric fuel pump system via the RS422 communication interface;

[0044] The method for calculating the expected speed of the electric fuel pump under fault conditions is as follows: Differentiate the first derivative T′ of T again to obtain the second derivative T” of the electric fuel pump's rotational torque, and then obtain the motor speed n corresponding to T” = 0. f

[0045] The expected speed n of the electric fuel pump under fault conditions y 0.8n f The expected speed n of the electric fuel pump under fault conditions. y The command is sent to the electric fuel pump to control it to operate at the desired speed n. y Work.

[0046] A method for diagnosing and handling aircraft fuel tank faults in an electric fuel system, the method being implemented using the aforementioned device, and comprising the following steps:

[0047] Step 1: Obtain the bus voltage, bus current, and electric fuel pump speed of the electric fuel pump;

[0048] Step 2: Calculate the input power of the electric fuel pump based on the bus voltage and bus current;

[0049] Step 3: Calculate the rotational torque of the electric fuel pump based on the input power and the electric fuel pump speed;

[0050] Step 4: Determine if the aircraft fuel tank is faulty based on the rotational torque; if faulty, proceed to Step 5; otherwise, return to Step 1.

[0051] Step 5: Send the fault status to the electric fuel pump system via the bus; calculate the expected speed of the electric fuel pump under the fault status, control the electric fuel pump to work according to the expected speed of the electric fuel pump under the fault status, and return to Step 1.

[0052] The beneficial effects of this invention are:

[0053] 1) A fault diagnosis and handling device for aircraft fuel tanks in an electric fuel system is proposed;

[0054] 2) Through research on the acquisition of electrical signals and fault diagnosis strategies, aircraft fuel tank faults were effectively diagnosed;

[0055] 3) The electric fuel pump speed under fault conditions was calculated using a given algorithm;

[0056] 4) By using dynamic fault diagnosis strategies and calculating the electric fuel pump speed under fault conditions, the safety of the electric fuel pump system is improved, preventing engine fuel control system failures caused by aircraft fuel tank failures. Attached Figure Description

[0057] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings will be described below.

[0058] Figure 1 This is a schematic diagram of a fault diagnosis and treatment device for aircraft fuel tanks in an electric fuel system.

[0059] Figure 2 This is a schematic diagram of the bus voltage and current monitoring module.

[0060] Figure 3 This is a schematic diagram for diagnosing faults in an electric fuel pump. Detailed Implementation

[0061] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0062] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0063] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0064] An aircraft fuel tank fault diagnosis and handling device in an electric fuel system includes: a bus voltage and current monitoring module, a motor speed acquisition module, a motor torque calculation module, a fuel tank fault diagnosis module, and a fuel tank fault handling module.

[0065] The bus voltage and current monitoring module is used to monitor the voltage and current of the DC bus in the electric fuel pump system and convert the voltage and current into digital quantities.

[0066] The motor speed acquisition module is used to acquire the real-time speed of the motor from the electric fuel pump system;

[0067] The motor torque calculation module is used to calculate the rotational torque of the electric fuel pump based on physical quantities such as bus voltage, current and speed, as a basis for fuel tank fault diagnosis.

[0068] The fuel tank fault diagnosis module is used to diagnose whether the aircraft fuel tank is faulty in real time based on signals such as motor speed and torque, combined with fault diagnosis strategies.

[0069] The fuel tank failure handling module is used to provide action information to the electric fuel pump system after the aircraft fuel tank fails, drive the electric fuel pump to operate reliably in the fuel tank failure mode, and prevent the electric fuel pump system failure chain reaction caused by the fuel tank failure.

[0070] The electric fuel pump is a high-low voltage coupled system with strong common-mode interference. The bus voltage monitoring uses a differential circuit, and the current sensor is an electrically isolated device using a single-ended circuit. The bus voltage and current monitoring module includes a differential voltage isolation module, a Hall current monitoring module, a voltage and current active filtering circuit, a high-precision A / D converter, a voltage digital filter, and a current digital filter.

[0071] The differential voltage isolation module is used to convert the bus voltage of the electric fuel pump into two single-ended analog voltage signals that are isolated from the bus voltage and share a common reference with the control low voltage; it includes a bus voltage divider, a voltage follower, and an analog voltage isolator.

[0072] The bus voltage divider consists of five resistors connected in series. One end of resistor n1 is connected to the negative terminal of the bus voltage, one end of resistor n2 is connected to the other end of resistor n1, and the other end of resistor n2 is connected to the remaining resistors. The resistance of resistor n1 is set to 12.7KΩ, the resistance of resistor n2 is set to 39KΩ, and the total circuit resistance is 27MΩ. This satisfies the condition that under a bus voltage of 216V to 324V, the voltage at the other end of resistor n1 is higher than 0.1V and lower than 0.3V, and the voltage at the other end of resistor n2 is higher than 0.4V and lower than 0.8V.

[0073] The voltage follower includes voltage follower 1 and voltage follower 2. Voltage follower 1 is used to follow U1 and perform impedance matching with the bus voltage divider and subsequent circuits. Voltage follower 2 has a similar function, and the voltage signal output by the voltage follower is connected to the analog voltage isolator.

[0074] The analog voltage isolator is used for linear isolation and preliminary filtering of differential voltage signals, including analog voltage isolator one and analog voltage isolator two. The voltage U1 output by the voltage follower first passes through an RC filter (cutoff frequency 100Hz) to suppress high-frequency interference components in the signal, and then passes through a 1:1 linear isolator ADUM4190 for electrical isolation to prevent common-mode interference at the high-voltage end from coupling to the low-voltage end through distributed capacitance and distributed inductance. Finally, the signal is filtered again by an active filter circuit.

[0075] The function and composition of analog voltage isolator 2 are the same as those of analog voltage isolator 1.

[0076] The Hall current monitoring module is used to convert the current flowing through the bus into an analog voltage signal that is electrically isolated from the bus current and is in phase and frequency; it includes a Hall current sensor power supply, a Hall current sensor, an I / V converter, and a voltage follower.

[0077] The Hall current sensor is powered by ±15V, provided by a dedicated power module.

[0078] The Hall current sensor is used to convert a large current signal on the bus into a small current signal through a through-hole mounting with a transformation ratio of 1000:1, and output it to the I / V converter.

[0079] The I / V converter is used to convert the small current signal output by the Hall sensor into a voltage signal; it consists of two equivalent resistors connected between the output terminal of the Hall sensor and ground. The two equivalent resistors can compensate for the temperature drift coefficient of a single resistor, reducing the sensitivity of the I / V converter to temperature.

[0080] The voltage follower, used for impedance matching between the I / V converter and the voltage-current active filter circuit, is composed of an operational amplifier whose inverting input is directly connected to the output.

[0081] The voltage and current active filtering circuit is used to perform low-pass active filtering on the voltage signals output by the differential voltage isolation module and the Hall current monitoring module. It consists of an operational amplifier LT1631 and resistors and capacitors. By adjusting the resistor and capacitor parameters, it can meet the requirements of 100Hz bandwidth, 0dB passband gain, and -40dB stopband attenuation. The isolation power supply provides DC 3000V isolated power to both ends of the analog linear isolator.

[0082] The high-precision A / D converter is used to convert the analog signals output by the voltage U1, U2 and the Hall current monitoring module into digital quantities under the control of the microprocessor.

[0083] The voltage digital filter is used to digitally filter the digital quantity after the bus current is converted, so as to eliminate the measurement noise introduced by the A / D converter. The filter is a linear Kalman filter, where the Q parameter is 0.96 and the R parameter is 0.06.

[0084] The motor speed acquisition module is used to obtain the motor speed of the device and the electric fuel pump through bus communication. It includes RS422 communication circuit, SCI controller, and communication protocol.

[0085] The RS422 communication circuit is used to convert the TTL signal output by the SCI controller into a full-duplex differential signal conforming to the RS422 standard.

[0086] The SCI controller is used to receive and send asynchronous serial data. Its main control parameters include baud rate, data format, and transmission and reception control.

[0087] The communication protocol is Modbus-RTU, where the device is the master and the electric fuel pump system is the slave. Communication is conducted in a master-slave call mode with the slave responding. The baud rate is 115200bps and the communication period is 10ms.

[0088] The motor torque calculation module calculates the rotational torque of the electric fuel pump based on the bus voltage, current, speed, and efficiency, serving as the basis for fuel tank fault diagnosis. This includes bus voltage calculation, bus current calculation, electric fuel pump input power calculation, and electric fuel pump rotational torque calculation.

[0089] The bus voltage calculation is used to calculate the bus voltage based on the measured values ​​of U1 and U2. Let U2-U1=UΔ, the resistance of resistor n2 be R2, the total resistance of the series circuit of the bus voltage divider be R, and the bus voltage U=UΔ / R2*R.

[0090] The bus current calculation is used to calculate the bus current of the electric fuel pump system based on the digital quantity output by the high-precision A / D converter. The process is: I = (3300 * Dc) / (4096 * Rc); where Dc is the digital quantity output by the A / D converter, Rc is the equivalent resistance of the I / V converter, the A / D bit is 12 bits, and the reference voltage is 3.3V.

[0091] The electric fuel pump input power calculation is used to calculate the electric fuel pump input power based on the electric fuel pump bus voltage U and bus current I, P = U * I;

[0092] The electric fuel pump rotational torque calculation is used to calculate the rotational torque T of the electric fuel pump based on the input power P of the electric fuel pump and the motor speed n. The calculation method is as follows: establish an efficiency table corresponding to different speeds of the electric fuel pump in the microprocessor, where η is the efficiency of the electric fuel pump, then T = P * η / n.

[0093] The fuel tank fault diagnosis module determines whether the aircraft fuel tank is faulty based on the electric fuel pump's rotational torque T and employs a fault diagnosis strategy. The diagnosis method involves storing the rated torque T corresponding to each rotational speed in the microprocessor. N Let D = T / T N This is the ratio of the current torque to the rated torque; combined with... Figure 3 The torque change during the fault is sampled at a period of 0.01 ms. The T corresponding to the first sampling time is denoted as T1, and the T corresponding to the second sampling time as T2. The first derivative T′ of T is then calculated. A counter c represents the number of times T′ exceeds the limit. When the torque slope change is very small, i.e., T′ < 0.02, c is incremented; otherwise, c is cleared. When both conditions D < 0.6 and c > 4 are met simultaneously, it indicates a fuel tank fault, and the fault is marked F. fault Set, otherwise F fault Reset to zero.

[0094] The fuel tank fault handling module includes fault status reporting and electric fuel pump speed calculation under fault conditions.

[0095] The fault status reporting is used when F fault When the flag is set, the aircraft fuel tank fault status indication byte in the Modbus-RTU communication protocol is set by software, and the fault status is sent to the electric fuel pump system through the RS422 communication interface.

[0096] The calculation of the electric fuel pump speed under fault conditions is used to calculate the given speed of the electric fuel pump under aircraft fuel tank failure conditions, preventing fuel control system malfunctions. The calculation method for the electric fuel pump speed is as follows: differentiate T′ again to obtain the second derivative T″ of the electric fuel pump's rotational torque. If T″ = 0, it is assumed that the torque fluctuation is very small and the slope is stable, and the corresponding electric fuel pump speed is n. f Then 0.8n f The expected speed for an electric fuel pump.

[0097] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A device for diagnosing and handling aircraft fuel tank faults in an electric fuel system, characterized in that, The device includes: a bus voltage and current monitoring module, a motor speed acquisition module, a motor torque calculation module, a fuel tank fault diagnosis module, and a fuel tank fault handling module; The bus voltage and current monitoring module is used to monitor the voltage and current of the DC bus in the electric fuel pump system, and convert the voltage and current physical quantities into digital quantities; The motor speed acquisition module is used to collect the real-time speed of the electric fuel pump; The motor torque calculation module is used to calculate the rotational torque of the electric fuel pump based on the bus voltage, current, and speed, as the basis for fuel tank fault diagnosis; The fuel tank fault diagnosis module is used to diagnose in real time whether the aircraft fuel tank has a fault based on the motor speed and torque; The fuel tank fault handling module is used to give action information to the electric fuel pump system after a fault occurs in the aircraft fuel tank, drive the electric fuel pump to operate reliably in the fuel tank fault mode, and prevent the fault chain reaction of the electric fuel pump system caused by the fuel tank fault; The bus voltage and current monitoring module includes: The differential voltage isolation module is used to convert the bus voltage of the electric fuel pump into two single-ended analog voltage signals that are of the same frequency as the bus, electrically isolated, and share the same ground with the control weak electricity; The Hall current monitoring module is used to convert the bus current of the electric fuel pump into an analog voltage signal that is electrically isolated from the bus current; The voltage and current active filter circuit is used to perform low-pass active filtering on the two single-ended analog voltage signals and the analog voltage signal output by the differential voltage isolation module and the Hall current monitoring module; The high-precision A / D converter is used to convert the two filtered single-ended analog voltage signals and the analog voltage signal into two single-ended digital voltage signals and the digital voltage signal; The voltage digital filter is used to perform digital filtering on the digital voltage signal, and the filter is a linear Kalman filter.

2. The aircraft fuel tank fault diagnosis and handling device in the electric fuel system according to claim 1, wherein The cut-off frequency of the voltage and current active filter circuit is 100Hz, the passband gain is 1, the stopband attenuation is -40dB, and the filter circuit includes 2 voltage filters and 1 current filter; The Q parameter of the voltage digital filter is 0.96 and the R parameter is 0.

06.

3. The aircraft fuel tank fault diagnosis and handling device in the electric fuel system according to claim 1, characterized in that, The motor speed acquisition module communicates with the electric fuel pump through a bus to obtain the real-time speed of the electric fuel pump.

4. The aircraft fuel tank fault diagnosis and handling device in the electric fuel system according to claim 2, characterized in that, The differential voltage isolation module includes: a bus voltage divider, a voltage follower, and an analog voltage isolator; The bus voltage divider is composed of n resistors connected in series, 2 < n < 10. The n resistors connected in series are connected between the positive end and the negative end of the bus. The n1 resistor is connected to the negative end of the bus. The values of the n1 resistor and the n2 resistor satisfy the following conditions: at 80% - 120% of the rated bus voltage, the voltage U1 at the end of the n1 resistor far from the bus is higher than 0.1v and lower than 0.3v, and the voltage U2 at the end of the n2 resistor far from the bus is higher than ​ The analog voltage isolator includes analog voltage isolator one and analog voltage isolator two. Analog voltage isolator one is used to linearly isolate the voltage U1 output by voltage follower one in a 1:1 ratio. The analog voltage isolator consists of an analog linear isolator, an isolation power supply, and an RC filter. The voltage U1 output by the voltage follower first passes through the RC filter and enters the analog linear isolator. After a 1:1 linear transformation, it is output to the voltage and current active filter circuit. The isolation power supply provides DC 3000V isolation power to the isolation terminals of the analog linear isolator. Analog voltage isolator 2 is used to linearly isolate the voltage U2 output by voltage follower 2 in a 1:1 ratio.

5. The aircraft fuel tank fault diagnosis and handling device in the electric fuel system according to claim 4, characterized in that, The Hall current monitoring module includes: a Hall current sensor power supply, a Hall current sensor, an I / V converter, and a voltage follower. The power supply for the Hall current sensor is used to provide ±15V power to the Hall current sensor. The power input voltage is DC5V and the output voltage is ±15V. The Hall current sensor is used to convert the large current signal on the bus into a small current signal according to a transformation ratio of 1000:1, and output it to the I / V converter. The I / V converter is used to convert the small current signal output by the Hall current sensor into a voltage signal; it consists of two equal resistors connected to the output terminal of the Hall current sensor and the reference terminal of the power supply of the Hall current sensor. The voltage signal output by the I / V converter is connected to the voltage and current active filter circuit through the voltage follower.

6. The aircraft fuel tank fault diagnosis and handling device in the electric fuel system according to claim 5, characterized in that, The motor torque calculation module includes a bus voltage calculation unit, a bus current calculation unit, an electric fuel pump input power calculation unit, and an electric fuel pump rotational torque calculation unit. The bus voltage calculation unit calculates the bus voltage based on the measured values ​​of U1 and U2, as follows: Let U2 - U1 = UΔ, the resistance of resistor n2 be R2, the total resistance of n resistors connected in series be R, and the bus voltage U = UΔ / R2 * R; The bus current calculation unit calculates the bus current as I based on the digital voltage signal output by the high-precision A / D converter, the equivalent resistance of the I / V converter, and the turns ratio of the Hall current sensor. The electric fuel pump input power calculation unit calculates the electric fuel pump input power based on the electric fuel pump bus voltage U and bus current I, P=U*I; The electric fuel pump rotational torque calculation unit is used to calculate the rotational torque T of the electric fuel pump based on the input power P of the electric fuel pump and the motor speed n, where T = P * η / n. η represents the efficiency at different rotational speeds.

7. The aircraft fuel tank fault diagnosis and handling device in the electric fuel system according to claim 6, characterized in that, The fuel tank fault diagnosis module diagnoses whether an aircraft fuel tank is faulty as follows: The diagnostic strategy is to obtain the rated torque T corresponding to the motor speed n. N Let D = T / T N ; Sample T at a period of 0.01ms, and denote the T corresponding to the first sampling time as T1 and the T corresponding to the second sampling time as T2, and then calculate the first derivative T′ of T; The counter c represents the number of times T′ exceeds the limit. When T′ < 0.02, c is incremented; otherwise, c is cleared. When D < 0.6 and c ≥ 5, the aircraft fuel tank is judged to be faulty, and the fault is marked F. fault Set to 1, otherwise F fault Reset to zero.

8. The aircraft fuel tank fault diagnosis and handling device in the electric fuel system according to claim 7, characterized in that, The fuel tank failure handling module reports the failure status when the aircraft fuel tank fails, and calculates the expected speed of the electric fuel pump under the failure status. When F fault When the flag is set, the fault status is sent to the electric fuel pump system via the RS422 communication interface; The method for calculating the expected speed of the electric fuel pump under fault conditions is as follows: Differentiate the first derivative T′ of T again to obtain the second derivative T” of the electric fuel pump's rotational torque, and then obtain the motor speed n corresponding to T”=0. f The expected speed n of the electric fuel pump under fault conditions y 0.8n f The expected speed n of the electric fuel pump under fault conditions. y The command is sent to the electric fuel pump to control it to operate at the desired speed n. y Work.

9. A method for diagnosing and handling faults in aircraft fuel tanks in an electric fuel system, characterized in that: The method is implemented using the apparatus according to any one of claims 1-8, characterized in that the method comprises the following steps: Step 1: Obtain the bus voltage, bus current, and electric fuel pump speed of the electric fuel pump; Step 2: Calculate the input power of the electric fuel pump based on the bus voltage and bus current; Step 3: Calculate the rotational torque of the electric fuel pump based on the input power and the electric fuel pump speed; Step 4: Determine if the aircraft fuel tank is faulty based on the rotational torque; if faulty, proceed to Step 5; otherwise, return to Step 1. Step 5: Send the fault status to the electric fuel pump system via the bus; calculate the expected speed of the electric fuel pump under the fault status, control the electric fuel pump to work according to the expected speed of the electric fuel pump under the fault status, and return to Step 1.

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