Fault diagnosis device of permanent magnet synchronous motor driving system for electric fuel pump

Abstract

The embodiment of the invention discloses a fault diagnosis device of a permanent magnet synchronous motor driving system for an electric fuel pump, which is arranged in the permanent magnet synchronous motor driving system and comprises a three-phase voltage and current monitoring module connected to the output end of a permanent magnet synchronous motor, the motor rotating speed acquisition module is arranged on a rotor of the permanent magnet synchronous motor; the permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis module, the permanent magnet synchronous motor uniform demagnetization fault diagnosis module, the permanent magnet synchronous motor local demagnetization fault diagnosis module, the inverter single-tube fault diagnosis module and the rotary transformer fault diagnosis module are arranged in the motor controller. The permanent magnet synchronous motor driving system provided with the fault diagnosis device provided by the embodiment of the invention has diagnosis capability, can realize online calculation and is rapid in diagnosis, so that the fault can be found in time, and technical support is provided for further eliminating the fault hidden danger in the subsequent process.

Description

Technical Field

[0001] The present invention relates to the field of fuel control technology, but is not limited to it, and more specifically to motor control technology, computer technology, electronic hardware technology, embedded software technology, fault diagnosis technology, and in particular to a fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump. Background Art

[0002] In recent years, multi-electric / all-electric engines have become an important hot research direction in aviation propulsion technology due to their simplified structure, high power-to-weight ratio, high maintainability and reliability. As one of the key components of the electric fuel system of aircraft engines, the reliability of the control of the electric fuel pump is extremely important.

[0003] The stable operation of the permanent magnet synchronous motor drive system ensures the reliability of the electric fuel pump. If the permanent magnet synchronous motor drive system fails, if effective measures are not taken to diagnose and handle the fault, the electric fuel pump will be out of control, which will cause the engine to be unable to obtain sufficient fuel flow and even cause the engine to stop.

[0004] At present, the diagnosis schemes of permanent magnet synchronous motor drive systems can generally be divided into three categories: model-based diagnosis, signal-based diagnosis and knowledge-based diagnosis. Model-based diagnosis schemes are often only targeted at a single component, sensitive to changes in system parameters, and prone to misjudgment of faults; signal-based diagnosis schemes are more complex to calculate and take longer to diagnose; knowledge-based diagnosis schemes require a large amount of historical data, but the small amount of actual fault data makes the training model less accurate, thus affecting the final diagnosis results. Summary of the invention

[0005] Purpose of the invention: In order to solve the above-mentioned technical problems, an embodiment of the present invention provides a fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump, so as to solve the problems in the existing fault diagnosis schemes of the permanent magnet synchronous motor drive system, that is, the model-based diagnosis scheme is prone to misdiagnosis of faults, the signal-based diagnosis scheme has a long diagnosis time, and the diagnosis accuracy of the knowledge-based diagnosis scheme is greatly affected by the amount of data.

[0006] Technical solution of the present invention: The embodiment of the present invention provides a fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump, wherein the permanent magnet synchronous motor drive system includes a permanent magnet synchronous motor and a motor controller; the fault diagnosis device includes: a three-phase voltage and current monitoring module, a motor speed monitoring module, and a permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis module, a permanent magnet synchronous motor uniform demagnetization fault diagnosis module, a permanent magnet synchronous motor local demagnetization fault diagnosis module, an inverter single-tube fault diagnosis module, and a rotary transformer fault diagnosis module arranged in the motor controller;

[0007] The three-phase voltage and current monitoring module is connected to the output end of the permanent magnet synchronous motor, and is used to monitor the three-phase voltage and three-phase current of the permanent magnet synchronous motor in the electric fuel pump system, and convert the physical quantities of the three-phase voltage and the three-phase current into digital quantities respectively;

[0008] The motor speed acquisition module is installed on the rotor of the permanent magnet synchronous motor, and is used to obtain the real-time speed signal of the permanent magnet synchronous motor in the electric fuel pump system; wherein the motor speed acquisition module includes a resolver, which is used to calculate the real-time speed signal of the permanent magnet synchronous motor by acquiring the resolver sine or resolver cosine orthogonal differential signal;

[0009] The permanent magnet synchronous motor turn-to-turn short-circuit fault diagnosis module is used to calculate the turn-to-turn short-circuit fault characteristic value according to the three-phase voltage and speed signal of the permanent magnet synchronous motor as the basis for turn-to-turn short-circuit diagnosis;

[0010] The permanent magnet synchronous motor uniform demagnetization fault diagnosis module is used to calculate the uniform demagnetization fault characteristic value according to the three-phase voltage, three-phase current and speed signal of the permanent magnet synchronous motor as the basis for uniform demagnetization diagnosis;

[0011] The permanent magnet synchronous motor local demagnetization fault diagnosis module is used to calculate the local demagnetization fault characteristic value according to the three-phase current and speed signal of the permanent magnet synchronous motor as the basis for local demagnetization diagnosis;

[0012] The inverter single-tube fault diagnosis module is used to calculate the inverter single-tube fault characteristic value based on the three-phase current and speed signals of the permanent magnet synchronous motor as the basis for inverter single-tube fault diagnosis;

[0013] The resolver fault diagnosis module is used to calculate the resolver fault characteristic value according to the sine, cosine and quadrature differential signals output by the resolver, which serves as the basis for resolver fault diagnosis.

[0014] Optionally, in the fault diagnosis device for the permanent magnet synchronous motor drive system for the electric fuel pump as described above, the three-phase voltage and current monitoring module includes: a voltage and current acquisition circuit, a voltage and current active filter circuit, an A / D converter, and an SCI communicator connected in sequence;

[0015] The voltage and current acquisition circuit is used to monitor the three-phase current of the permanent magnet synchronous motor and convert the three-phase current into an analog voltage signal electrically isolated from the current; the voltage and current acquisition circuit comprises: a power supply, a Hall current sensor, an I / V converter, and a voltage follower connected in sequence;

[0016] Wherein, the power supply is used to power the Hall current sensor;

[0017] The Hall current sensor is used to collect the three-phase current signal of the permanent magnet synchronous motor;

[0018] The I / V converter is used to convert the three-phase current signal output by the Hall current sensor into a three-phase voltage signal;

[0019] The voltage follower is used for impedance matching between the I / V converter and the voltage-current active filter circuit;

[0020] The voltage and current active filtering circuit is used to perform low-pass active filtering on the three-phase voltage signal and the three-phase current signal output by the voltage and current acquisition circuit;

[0021] The A / D converter is used to convert the analog quantities of the three-phase voltage signal and the three-phase current signal output after filtering into digital quantities under the control of the motor controller, so as to obtain the three-phase voltage digital signal and the three-phase current digital signal;

[0022] The SCI communicator is used to transmit the three-phase voltage digital signal and the three-phase current digital signal to the motor controller through serial communication.

[0023] Optionally, in the fault diagnosis device for the permanent magnet synchronous motor drive system for the electric fuel pump as described above, the motor speed monitoring module comprises: a rotary transformer, an angular velocity acquisition unit, an A / D converter, and an SCI controller connected in sequence;

[0024] Wherein, the rotary transformer is used to obtain the rotor position angle of the permanent magnet synchronous motor;

[0025] An angular velocity acquisition unit is used to calculate the real-time speed of the motor according to the rotor position angle using its built-in differentiator and filter it through a built-in differential low-pass filter;

[0026] A / D converter, used for converting the output analog signals of rotor position angle and real-time speed into digital angle signals and speed signals of the motor shaft;

[0027] The SCI controller is used to transmit the angle digital signal and the speed digital signal of the motor shaft to the motor controller through serial communication.

[0028] Optionally, in the fault diagnosis device for the permanent magnet synchronous motor drive system for the electric fuel pump as described above, the output end of the permanent magnet synchronous motor is connected to a gear pump, and the gear pump and the permanent magnet synchronous motor drive system constitute the electric fuel pump;

[0029] The permanent magnet synchronous motor turn-to-turn short-circuit fault diagnosis module is used to calculate the negative sequence voltage synthesis vector of the electric fuel pump according to the three-phase voltage and speed signal of the permanent magnet synchronous motor, that is, the turn-to-turn short-circuit fault characteristic value, as the basis for turn-to-turn short-circuit fault diagnosis; the permanent magnet synchronous motor turn-to-turn short-circuit fault diagnosis module includes: a dq axis positive sequence voltage calculation unit, a dq axis negative sequence voltage calculation unit, and a negative sequence voltage synthesis vector calculation unit;

[0030] The dq axis positive sequence voltage calculation unit is used to calculate the three-phase voltage digital signal u output by the three-phase voltage and current acquisition module. a ,u b ,u c And the speed digital signal w output by the motor speed monitoring module m , u in the natural coordinate system a ,u b ,u c The positive sequence voltage is converted to the stationary coordinate system α-β by Clark coordinate transformation for:

[0031]

[0032] Then, the positive sequence voltage in the stationary coordinate system α-β is transformed by Park coordinate transformation. Transformed to the positive sequence voltage of the dq axis of the synchronous rotating coordinate system for:

[0033]

[0034] Among them, θ e is the electrical angular velocity, and is the angle digital signal θ output by the motor speed monitoring module m Multiply by the number of pole pairs n of the permanent magnet synchronous motor p ;

[0035] The dq axis negative sequence voltage calculation unit is based on the phase difference of 2w between the positive and negative sequence voltage vectors. e , used to convert the positive sequence voltage Conversion to negative sequence voltage for:

[0036]

[0037] The calculated negative sequence voltage The sliding filters in the unit are used for filtering respectively;

[0038] The dq axis negative sequence synthesis vector calculation unit is used to calculate the negative sequence voltage after filtering. The calculated turn-to-turn short-circuit fault characteristic value is:

[0039] When it is determined that the characteristic value surges, it is determined that an inter-turn short circuit fault occurs in the permanent magnet synchronous motor.

[0040] Optionally, in the fault diagnosis device for the permanent magnet synchronous motor drive system for the electric fuel pump as described above,

[0041] The permanent magnet synchronous motor uniform demagnetization fault diagnosis module establishes a flux observer of the permanent magnet synchronous motor according to the three-phase voltage, three-phase current and speed signal of the permanent magnet synchronous motor as a basis for uniform demagnetization fault diagnosis; the permanent magnet synchronous motor uniform demagnetization fault diagnosis module comprises: a coordinate transformation unit, a back electromotive force calculation unit, a resistance and inductance estimation unit, a flux observer, and a flux comparator connected in sequence; the coordinate transformation unit is also connected to the back electromotive force calculation unit;

[0042] The coordinate transformation unit is used to transform the three-phase voltage digital signal and the three-phase current digital signal u output by the three-phase voltage and current acquisition module. a ,u b ,u c ,i a ,i b ,i c , and the speed digital signal w output by the motor speed monitoring module m , calculate the voltage and current u in the stationary coordinate system through Clark transformation α ,u β ,i α ,i β , and then calculate the voltage and current u in the dq axis coordinate system through Park transformation d ,u q ,i d ,i q ;

[0043] The resistance and inductance estimation unit is used to add a variable forgetting factor on the basis of the least recursive squares algorithm, and can complete the identification of the stator resistance and stator inductance of the permanent magnet synchronous motor. This estimation method improves the accuracy of parameter estimation;

[0044] The back electromotive force calculation unit is used to calculate the u calculated by the coordinate transformation unit. α ,u β ,i α ,i β The stator resistance R estimated by the resistance estimation unit is used to calculate the back EMF:

[0045]

[0046] Where R is the stator resistance of the permanent magnet synchronous motor;

[0047] The flux observer is used to measure the back EMF through an internal integrator.α ,e β Perform integral calculation to obtain the magnetic flux in the stationary coordinate system After park transformation, the dq axis magnetic flux is obtained The calculated dq axis flux A high-pass filter is used to filter out the DC component and the actual flux linkage of the permanent magnet synchronous motor is calculated as Wherein, Ld is the stator inductance of the permanent magnet synchronous motor output by the resistance and inductance estimation unit;

[0048] The flux comparator is used to compare the actual flux output by the flux observer. With pre-calibrated flux value The absolute value of the difference is used as the fault characteristic value; when it is determined that the characteristic value increases sharply, it is determined that a uniform demagnetization fault occurs in the permanent magnet synchronous motor.

[0049] Optionally, in the fault diagnosis device for the permanent magnet synchronous motor drive system for the electric fuel pump as described above, the permanent magnet synchronous motor local demagnetization fault diagnosis module is used to calculate the current harmonics according to the three-phase current and speed signal of the permanent magnet synchronous motor as the basis for local demagnetization fault diagnosis; the permanent magnet synchronous motor local demagnetization fault diagnosis module includes: a harmonic frequency calculation unit and a harmonic current calculation unit connected to each other;

[0050] The harmonic frequency calculation unit is used to calculate the harmonic frequency of the fault characteristics contained in the magnetic field of the permanent magnet synchronous motor:

[0051]

[0052] In the formula, f dm is the harmonic frequency of the fault characteristic, f c is the fundamental frequency generated by the motor controller, n p is the number of pole pairs of the permanent magnet synchronous motor, k is the harmonic order, which is less than or equal to n p integer;

[0053] The harmonic current calculation unit is used to calculate the harmonic current according to n p The calculated harmonic order k is used to calculate the dq axis current i through coordinate transformation d ,i q , extract i d ,i q The kth harmonic in the current, i d ,i q The kth harmonic of the current is converted into a DC component, which is the current harmonic;

[0054]

[0055] The fault feature needs to be filtered before it can be extracted. The average value filtering method is used, and the local demagnetization fault feature value is calculated as follows: If any k-th current harmonic increases significantly, it is determined that a fault has occurred.

[0056] Optionally, in the fault diagnosis device of the permanent magnet synchronous motor drive system for the electric fuel pump as described above, the inverter single-tube fault diagnosis module is used to obtain the single-tube fault characteristic value of the three-phase current signal according to the three-phase current signal and the speed signal of the permanent magnet synchronous motor; the inverter single-tube fault diagnosis module includes: a Park vector modulus calculation unit, a phase current average value calculation unit, and a phase current average value comparator;

[0057] The Park vector module calculation unit is used to calculate the three-phase current digital signal i output by the three-phase voltage and current acquisition module. a ,i b ,i c , calculate the current i in the stationary coordinate system through Clark transformation α ,i β :

[0058]

[0059] Then calculate the modulus of the Clark vector

[0060] The phase current average value calculation unit is used to calculate each phase current i according to the modulus of the Clark vector. n The average value of (n=a,b,c) is:

[0061]

[0062] The phase current average value comparator is used to compare the difference between the average value of each phase current and the preset threshold μ. It is determined that the lower tube of the corresponding phase is faulty; It is determined that the upper tube of the corresponding phase is faulty.

[0063] Optionally, in the fault diagnosis device for the permanent magnet synchronous motor drive system for the electric fuel pump as described above, the resolver fault diagnosis module includes an amplitude error unit and a phase error unit;

[0064] The amplitude error unit sets a threshold value and compares it with the envelope peak value of the sine-cosine orthogonal differential signal output by the resolver. When the envelope peak value is less than or greater than the threshold value, it can be determined that the resolver signal is lost and the fault cause is a resolver winding fault.

[0065] The phase error unit compares the phase difference β between the excitation signal output by the primary winding of the rotary transformer and the sine-cosine orthogonal differential signal output by the two secondary windings of the rotary transformer with a set threshold range, and determines that a phase lock error occurs if the phase difference exceeds the threshold range.

[0066] Beneficial effects of the invention: An embodiment of the invention provides a fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump. The fault diagnosis device is arranged in the permanent magnet synchronous motor drive system, including: a three-phase voltage and current monitoring module connected to the output end of the permanent magnet synchronous motor, a motor speed acquisition module installed on the rotor of the permanent magnet synchronous motor, and a permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis module, a permanent magnet synchronous motor uniform demagnetization fault diagnosis module, a permanent magnet synchronous motor local demagnetization fault diagnosis module, an inverter single-tube fault diagnosis module, and a rotary transformer fault diagnosis module arranged in a motor controller.

[0067] The above-mentioned fault diagnosis device provided by the embodiment of the present invention is mainly used for fault diagnosis of electric fuel systems, and its main function is to evaluate the reliability of various components of the permanent magnet synchronous motor drive system based on the fault diagnosis function of the intelligent electric fuel pump system. When a fault occurs, the cause of the fault is quickly located through the diagnosis strategy. The diagnosis strategy and method can be implemented through an embedded control system, which is an effective means to improve the reliability of the motor drive system. The permanent magnet synchronous motor drive system equipped with the above-mentioned fault diagnosis device provided by the embodiment of the present invention has diagnostic capabilities, can realize online calculation, and has fast diagnosis, so as to timely discover faults and provide technical support for further eliminating potential fault hazards. The fault diagnosis device provided by the embodiment of the present invention has the following beneficial effects:

[0068] 1) A fault diagnosis device suitable for the permanent magnet synchronous motor drive system in an electric fuel pump is proposed;

[0069] 2) Through the acquisition of various electrical signals in the electric fuel pump and the fault diagnosis strategy, various faults in the permanent magnet synchronous motor drive system are effectively diagnosed;

[0070] 3) The diagnostic objects cover the permanent magnet synchronous motor, inverter and rotary transformer in the permanent magnet synchronous motor drive system, and the diagnostic scope is relatively wide;

[0071] 4) Through various online fault diagnosis strategies, the cause of the permanent magnet synchronous motor drive system failure is quickly located, providing a basis for the implementation of subsequent fault-tolerant measures and ensuring the safety of the electric fuel pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0073] Figure 1 A schematic diagram of the structure of a fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump provided by an embodiment of the present invention;

[0074] Figure 2 A schematic structural diagram of a three-phase voltage and current monitoring module in a fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0075] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0076] The above background technology has explained that the stable operation of the permanent magnet synchronous motor drive system plays an important role in ensuring the reliability of the electric fuel pump; however, the three types of diagnostic schemes currently used for the permanent magnet synchronous motor drive system all have corresponding problems, namely, the model-based diagnostic scheme is prone to misdiagnosis of faults, the signal-based diagnostic scheme has a long diagnostic time, and the diagnostic accuracy of the knowledge-based diagnostic scheme is greatly affected by the amount of data.

[0077] In view of the above problems, the present invention provides a fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump. The fault diagnosis device is arranged in the permanent magnet synchronous motor drive system, so that the system has diagnostic capabilities, can realize online calculation, and diagnose quickly, so as to timely discover faults and provide technical support for further eliminating potential faults. In addition, the technical solution provided in the embodiment of the present invention is applicable to the design of an electric fuel system for an aircraft engine.

[0078] The present invention provides the following specific embodiments which can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0079] Figure 1 A schematic diagram of the structural relationship between the fault diagnosis device for the permanent magnet synchronous motor drive system for the electric fuel pump provided by the embodiment of the present invention and the permanent magnet synchronous motor drive system. Figure 1 As shown, the permanent magnet synchronous motor drive system includes a permanent magnet synchronous motor and a motor controller; the fault diagnosis device provided by the embodiment of the present invention includes: a three-phase voltage and current monitoring module, a motor speed monitoring module, and a permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis module, a permanent magnet synchronous motor uniform demagnetization fault diagnosis module, a permanent magnet synchronous motor local demagnetization fault diagnosis module, an inverter single-tube fault diagnosis module, and a rotary transformer fault diagnosis module arranged in the motor controller.

[0080] like Figure 1 In the circuit structure of the fault diagnosis device and permanent magnet synchronous motor drive system shown, the three-phase voltage and current monitoring module is connected to the output end of the permanent magnet synchronous motor, and is used to monitor the three-phase voltage and three-phase current of the permanent magnet synchronous motor in the electric fuel pump system, and convert the physical quantities of the three-phase voltage and three-phase current into digital quantities respectively.

[0081] The motor speed acquisition module in the embodiment of the present invention is installed on the rotor of the permanent magnet synchronous motor, and is used to obtain the real-time speed signal of the permanent magnet synchronous motor in the electric fuel pump system; the motor speed acquisition module includes a rotary transformer, which is used to calculate the real-time speed signal of the permanent magnet synchronous motor by obtaining the rotary transformer sine or rotary transformer cosine differential signal.

[0082] It should be noted that the motor speed is obtained by calculating the real-time speed signal through the output signal of the rotary transformer as follows:

[0083] The resolver sine and cosine orthogonal differential signals output by the resolver are:

[0084]

[0085] Among them, E is the input amplitude of the primary coil of the rotary transformer, K is the transformation ratio, and n p is the number of pole pairs of the permanent magnet synchronous motor, w is the rotor angular velocity, θ m is the rotor angle. The real-time speed signal of the permanent magnet synchronous motor is obtained by the resolver sine and cosine orthogonal differential signals, and the formula is as follows:

[0086]

[0087] The functions of the modules in the motor controller in the embodiment of the present invention are as follows:

[0088] The permanent magnet synchronous motor turn-to-turn short-circuit fault diagnosis module is used to calculate the turn-to-turn short-circuit fault characteristic value according to the three-phase voltage and speed signal of the permanent magnet synchronous motor as the basis for turn-to-turn short-circuit diagnosis;

[0089] The permanent magnet synchronous motor uniform demagnetization fault diagnosis module is used to calculate the uniform demagnetization fault characteristic value according to the three-phase voltage, three-phase current and speed signal of the permanent magnet synchronous motor as the basis for uniform demagnetization diagnosis;

[0090] The permanent magnet synchronous motor local demagnetization fault diagnosis module is used to calculate the local demagnetization fault characteristic value according to the three-phase current and speed signal of the permanent magnet synchronous motor as the basis for local demagnetization diagnosis;

[0091] The inverter single-tube fault diagnosis module is used to calculate the inverter single-tube fault characteristic value based on the three-phase current and speed signals of the permanent magnet synchronous motor as the basis for inverter single-tube fault diagnosis;

[0092] The resolver fault diagnosis module is used to calculate the resolver fault characteristic value according to the sine, cosine and quadrature differential signals output by the resolver, which serves as the basis for resolver fault diagnosis.

[0093] In one implementation of the embodiment of the present invention, Figure 2 A schematic diagram of the structure of a three-phase voltage and current monitoring module in a fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump provided by an embodiment of the present invention. Figure 2 As shown, the three-phase voltage and current monitoring module includes: a voltage and current acquisition circuit, a voltage and current active filter circuit, an A / D converter and an SCI communicator connected in sequence.

[0094] In this implementation, the voltage and current acquisition circuit is used to monitor the three-phase current of the permanent magnet synchronous motor and convert the three-phase current into an analog voltage signal that is electrically isolated from the current.

[0095] The voltage and current acquisition circuit in this implementation includes: a power supply, a Hall current sensor, an I / V converter, and a voltage follower connected in sequence, such as Figure 2 shown.

[0096] Wherein, the power supply is used to power the Hall current sensor;

[0097] Hall current sensor, used to collect three-phase current signals of permanent magnet synchronous motor;

[0098] An I / V converter is used to convert the three-phase current signal output by the Hall current sensor into a three-phase voltage signal;

[0099] Voltage follower, used for impedance matching between I / V converter and voltage and current active filter circuit;

[0100] The voltage and current active filter circuit is used for performing low-pass active filtering on the three-phase voltage signal and the three-phase current signal output by the voltage and current acquisition circuit.

[0101] In addition, the A / D converter in this implementation is used to convert the analog quantities of the three-phase voltage signal and the three-phase current signal output after filtering into digital quantities under the control of the motor controller, thereby obtaining a three-phase voltage digital signal and a three-phase current digital signal.

[0102] The SCI communicator is used to transmit three-phase voltage digital signals and three-phase current digital signals to the motor controller via serial communication.

[0103] In an implementation of the embodiment of the present invention, the motor speed monitoring module includes: a rotary transformer, an angular velocity acquisition unit, an A / D converter, and an SCI controller connected in sequence.

[0104] In this implementation, the rotary transformer is used to obtain the rotor position angle of the permanent magnet synchronous motor;

[0105] The angular velocity acquisition unit is used to calculate the real-time speed (i.e., angular velocity) of the motor according to the rotor position angle using its built-in differentiator, and filter it through a built-in differential low-pass filter;

[0106] A / D converter, used for converting the output analog signals of rotor position angle and real-time speed into digital angle signals and speed signals of the motor shaft;

[0107] The SCI controller is used to transmit the angle digital signal and the speed digital signal of the motor shaft to the motor controller through serial communication.

[0108] In one implementation of the embodiment of the present invention, Figure 1 As shown, the output end of the permanent magnet synchronous motor is connected to the gear pump, and the gear pump and the permanent magnet synchronous motor drive system constitute an electric fuel pump.

[0109] In this implementation, the permanent magnet synchronous motor turn-to-turn short-circuit fault diagnosis module is used to calculate the negative sequence voltage synthesis vector of the electric fuel pump based on the three-phase voltage and speed signal of the permanent magnet synchronous motor, that is, the turn-to-turn short-circuit fault characteristic value, which serves as the basis for turn-to-turn short-circuit fault diagnosis.

[0110] In one implementation of this implementation, the permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis module includes: a dq axis positive sequence voltage calculation unit, a dq axis negative sequence voltage calculation unit, and a negative sequence voltage synthesis vector calculation unit.

[0111] Among them, the dq axis positive sequence voltage calculation unit is used to calculate the three-phase voltage digital signal u output by the three-phase voltage and current acquisition module a ,u b ,u c And the speed digital signal w output by the motor speed monitoring module m , u in the natural coordinate system a ,u b ,u c The positive sequence voltage is converted to the stationary coordinate system α-β by Clark coordinate transformation for:

[0112]

[0113] Then, the positive sequence voltage in the stationary coordinate system α-β is transformed by Park coordinate transformation. Transformed to the positive sequence voltage of the dq axis of the synchronous rotating coordinate system for:

[0114]

[0115] Among them, θ e is the electrical angular velocity, and is the angle digital signal θ output by the motor speed monitoring module m Multiply by the number of pole pairs n of the permanent magnet synchronous motor p ;

[0116] The dq axis negative sequence voltage calculation unit is based on the phase difference of 2w between the positive and negative sequence voltage vectors. e , used to convert the positive sequence voltage Conversion to negative sequence voltage for:

[0117]

[0118] It should be noted that the calculated positive sequence voltage and negative sequence voltage Neither is a smooth curve, so the calculated negative sequence voltage needs to be The sliding filters in the units are used for filtering respectively; the sliding window of the sliding filter in the embodiment of the present invention is, for example, 50.

[0119] The dq axis negative sequence synthesis vector calculation unit is used to calculate the negative sequence voltage after filtering. The calculated turn-to-turn short-circuit fault characteristic value is: Since the fault characteristic value will increase from 0 after the fault occurs; when it is judged that the characteristic value increases sharply, it can be determined that a turn-to-turn short circuit fault occurs in the permanent magnet synchronous motor.

[0120] In one implementation of an embodiment of the present invention, a specific implementation scheme of a uniform demagnetization fault diagnosis module for a permanent magnet synchronous motor is provided. The uniform demagnetization fault diagnosis module for a permanent magnet synchronous motor establishes a flux observer of the permanent magnet synchronous motor according to the three-phase voltage, three-phase current and speed signal of the permanent magnet synchronous motor as a basis for uniform demagnetization fault diagnosis. The uniform demagnetization fault diagnosis module for a permanent magnet synchronous motor in the implementation scheme includes: a coordinate transformation unit, a back-electromotive force calculation unit, a resistance and inductance estimation unit, a flux observer and a flux comparator connected in sequence; the coordinate transformation unit is also connected to the back-electromotive force calculation unit; the functions of the above components are described as follows:

[0121] The coordinate transformation unit is used to convert the three-phase voltage digital signal and the three-phase current digital signal u output by the three-phase voltage and current acquisition module a ,u b ,u c ,i a ,i b ,i c , and the speed digital signal w output by the motor speed monitoring module m , calculate the voltage and current u in the stationary coordinate system through Clark transformationα ,u β ,i α ,i β , and then calculate the voltage and current u in the dq axis coordinate system through Park transformation d ,u q ,i d ,i q .

[0122] The resistance and inductance estimation unit is used to add a variable forgetting factor based on the least recursive squares algorithm, and can complete the identification of the stator resistance and stator inductance of the permanent magnet synchronous motor. This estimation method improves the accuracy of parameter estimation.

[0123] The back electromotive force calculation unit is used to calculate the u calculated by the coordinate transformation unit. α ,u β ,i α ,i β The stator resistance R estimated by the resistance estimation unit is used to calculate the back EMF:

[0124]

[0125] Where R is the stator resistance of the permanent magnet synchronous motor.

[0126] The flux observer is used to measure the back EMF through an internal integrator. α ,e β Perform integral calculation to obtain the magnetic flux in the stationary coordinate system After park transformation, the dq axis magnetic flux is obtained The calculated dq axis flux A high-pass filter is used to filter out the DC component and the actual flux linkage of the permanent magnet synchronous motor is calculated as Among them, L d It is the stator inductance of the permanent magnet synchronous motor output by the resistance and inductance estimation unit.

[0127] The flux comparator is used to measure the actual flux output by the flux observer. With pre-calibrated flux value The absolute value of the difference is used as the fault characteristic value; when a uniform demagnetization fault occurs, the fault characteristic value increases rapidly; that is, when it is determined that the characteristic value increases sharply, it is determined that a uniform demagnetization fault occurs in the permanent magnet synchronous motor.

[0128] In one implementation of an embodiment of the present invention, a specific implementation scheme of a local demagnetization fault diagnosis module of a permanent magnet synchronous motor is provided. The local demagnetization fault diagnosis module of a permanent magnet synchronous motor is used to calculate current harmonics based on the three-phase current and speed signals of the permanent magnet synchronous motor as a basis for local demagnetization fault diagnosis. The local demagnetization fault diagnosis module of a permanent magnet synchronous motor in this implementation scheme includes: a harmonic frequency calculation unit and a harmonic current calculation unit connected to each other. The implementation functions of the above-mentioned units are described as follows:

[0129] The harmonic frequency calculation unit is used to calculate the harmonic frequency of the fault characteristics contained in the magnetic field of the permanent magnet synchronous motor as follows:

[0130]

[0131] In the formula, f dm is the harmonic frequency of the fault characteristic, f c is the fundamental frequency generated by the motor controller, n p is the number of pole pairs of the permanent magnet synchronous motor, k is the harmonic order, which is less than or equal to n p The harmonic frequency calculation unit is based on the harmonic frequency calculation formula to obtain k.

[0132] Harmonic current calculation unit, used to calculate the harmonic current according to n p The calculated harmonic order k is used to calculate the dq axis current i through coordinate transformation d ,i q , extract i d ,i q The kth harmonic in the current, i d ,i q The kth harmonic of the current is converted into a DC component, which is the current harmonic;

[0133]

[0134] The fault feature needs to be filtered before it can be extracted. The average value filtering method is used, and the local demagnetization fault feature value is calculated as follows: If any k-th current harmonic increases significantly, it is determined that a fault has occurred.

[0135] In one implementation of an embodiment of the present invention, a specific implementation scheme of an inverter single-tube fault diagnosis module is provided. The inverter single-tube fault diagnosis module is used to obtain a single-tube fault characteristic value of a three-phase current signal based on a three-phase current signal and a speed signal of a permanent magnet synchronous motor. The inverter single-tube fault diagnosis module in this implementation includes: a Park vector modulus calculation unit, a phase current average value calculation unit, and a phase current average value comparator. The implementation functions of the above-mentioned components are described as follows:

[0136] The module calculation unit of the Park vector is used to calculate the three-phase current digital signal i output by the three-phase voltage and current acquisition module. a ,i b ,i c , calculate the current i in the stationary coordinate system through Clark transformation α ,i β :

[0137]

[0138] Then calculate the modulus of the Clark vector

[0139] Phase current average calculation unit, used to calculate each phase current i according to the modulus of the Clark vector n The average value of (n=a,b,c) is:

[0140]

[0141] Phase current average value comparator, since the average value of each phase current in a cycle is 0, when a single tube fault occurs, the average value of each phase current surges, and a threshold μ is set. Therefore, the phase current average value comparator is used to compare the difference between the average value of each phase current and the preset threshold μ. It is determined that the lower tube of the corresponding phase is faulty; It is determined that the upper tube of the corresponding phase is faulty.

[0142] In an implementation of an embodiment of the present invention, a specific implementation scheme of a rotary transformer fault diagnosis module is provided, and the rotary transformer fault diagnosis module includes an amplitude error unit and a phase error unit.

[0143] The amplitude error unit in this implementation compares the envelope peak value of the sine-cosine orthogonal differential signal output by the resolver by setting a threshold value. When the envelope peak value is less than or greater than the threshold value, it can be determined that the resolver signal is lost and the cause of the fault is a resolver winding fault.

[0144] The phase error unit in this implementation compares the phase difference β between the excitation signal output by the primary winding of the rotary transformer and the sine-cosine orthogonal differential signal output by the two secondary windings of the rotary transformer with a set threshold range, and determines that a phase lock error occurs if the phase difference exceeds the threshold range.

[0145] An embodiment of the present invention provides a fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump. The fault diagnosis device is arranged in the permanent magnet synchronous motor drive system, and includes: a three-phase voltage and current monitoring module connected to the output end of the permanent magnet synchronous motor, a motor speed acquisition module installed on the rotor of the permanent magnet synchronous motor, and a permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis module, a permanent magnet synchronous motor uniform demagnetization fault diagnosis module, a permanent magnet synchronous motor local demagnetization fault diagnosis module, an inverter single-tube fault diagnosis module, and a rotary transformer fault diagnosis module arranged in a motor controller.

[0146] The above-mentioned fault diagnosis device provided by the embodiment of the present invention is mainly used for fault diagnosis of electric fuel systems, and its main function is to evaluate the reliability of various components of the permanent magnet synchronous motor drive system based on the fault diagnosis function of the intelligent electric fuel pump system. When a fault occurs, the cause of the fault is quickly located through the diagnosis strategy. The diagnosis strategy and method can be implemented through an embedded control system, which is an effective means to improve the reliability of the motor drive system. The permanent magnet synchronous motor drive system equipped with the above-mentioned fault diagnosis device provided by the embodiment of the present invention has diagnostic capabilities, can realize online calculation, and has fast diagnosis, so as to timely discover faults and provide technical support for further eliminating potential fault hazards. The fault diagnosis device provided by the embodiment of the present invention has the following beneficial effects:

[0147] 1) A fault diagnosis device suitable for the permanent magnet synchronous motor drive system in an electric fuel pump is proposed;

[0148] 2) Through the acquisition of various electrical signals in the electric fuel pump and the fault diagnosis strategy, various faults in the permanent magnet synchronous motor drive system are effectively diagnosed;

[0149] 3) The diagnostic objects cover the permanent magnet synchronous motor, inverter and rotary transformer in the permanent magnet synchronous motor drive system, and the diagnostic scope is relatively wide;

[0150] 4) Through various online fault diagnosis strategies, the cause of the permanent magnet synchronous motor drive system failure is quickly located, providing a basis for the implementation of subsequent fault-tolerant measures and ensuring the safety of the electric fuel pump.

[0151] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump, characterized in that: The permanent magnet synchronous motor drive system includes a permanent magnet synchronous motor and a motor controller; the fault diagnosis device includes: a three-phase voltage and current monitoring module, a motor speed monitoring module, and a permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis module, a permanent magnet synchronous motor uniform demagnetization fault diagnosis module, a permanent magnet synchronous motor local demagnetization fault diagnosis module, an inverter single-tube fault diagnosis module, and a rotary transformer fault diagnosis module arranged in the motor controller; The three-phase voltage and current monitoring module is connected to the output end of the permanent magnet synchronous motor, and is used to monitor the three-phase voltage and three-phase current of the permanent magnet synchronous motor in the electric fuel pump system, and convert the physical quantities of the three-phase voltage and the three-phase current into digital quantities respectively; The motor speed acquisition module is installed on the rotor of the permanent magnet synchronous motor, and is used to obtain the real-time speed signal of the permanent magnet synchronous motor in the electric fuel pump system; wherein the motor speed acquisition module includes a resolver, which is used to calculate the real-time speed signal of the permanent magnet synchronous motor by obtaining the resolver sine or resolver cosine orthogonal differential signal; The permanent magnet synchronous motor turn-to-turn short-circuit fault diagnosis module is used to calculate the turn-to-turn short-circuit fault characteristic value according to the three-phase voltage and speed signal of the permanent magnet synchronous motor as the basis for turn-to-turn short-circuit diagnosis; The permanent magnet synchronous motor uniform demagnetization fault diagnosis module is used to calculate the uniform demagnetization fault characteristic value according to the three-phase voltage, three-phase current and speed signal of the permanent magnet synchronous motor as the basis for uniform demagnetization diagnosis; The permanent magnet synchronous motor local demagnetization fault diagnosis module is used to calculate the local demagnetization fault characteristic value according to the three-phase current and speed signal of the permanent magnet synchronous motor as the basis for local demagnetization diagnosis; The inverter single-tube fault diagnosis module is used to calculate the inverter single-tube fault characteristic value based on the three-phase current and speed signals of the permanent magnet synchronous motor as the basis for inverter single-tube fault diagnosis; The resolver fault diagnosis module is used to calculate the resolver fault characteristic value according to the sine, cosine and quadrature differential signals output by the resolver, which serves as the basis for resolver fault diagnosis.

2. The fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump according to claim 1, characterized in that: The three-phase voltage and current monitoring module includes: a voltage and current acquisition circuit, a voltage and current active filter circuit, an A / D converter, and an SCI communicator connected in sequence; The voltage and current acquisition circuit is used to monitor the three-phase current of the permanent magnet synchronous motor and convert the three-phase current into an analog voltage signal electrically isolated from the current; the voltage and current acquisition circuit includes: a power supply, a Hall current sensor, an I / V converter, and a voltage follower connected in sequence; Wherein, the power supply is used to power the Hall current sensor; The Hall current sensor is used to collect the three-phase current signal of the permanent magnet synchronous motor; The I / V converter is used to convert the three-phase current signal output by the Hall current sensor into a three-phase voltage signal; The voltage follower is used for impedance matching between the I / V converter and the voltage-current active filter circuit; The voltage and current active filtering circuit is used to perform low-pass active filtering on the three-phase voltage signal and the three-phase current signal output by the voltage and current acquisition circuit; The A / D converter is used to convert the analog quantities of the three-phase voltage signal and the three-phase current signal output after filtering into digital quantities under the control of the motor controller, so as to obtain the three-phase voltage digital signal and the three-phase current digital signal; The SCI communicator is used to transmit the three-phase voltage digital signal and the three-phase current digital signal to the motor controller through serial communication.

3. The fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump according to claim 1, characterized in that: The motor speed monitoring module includes: a rotary transformer, an angular velocity acquisition unit, an A / D converter, and an SCI controller connected in sequence; Wherein, the rotary transformer is used to obtain the rotor position angle of the permanent magnet synchronous motor; An angular velocity acquisition unit is used to calculate the real-time speed of the motor according to the rotor position angle using its built-in differentiator and filter it through a built-in differential low-pass filter; A / D converter, used for converting the output analog signals of rotor position angle and real-time speed into digital angle signals and speed signals of the motor shaft; The SCI controller is used to transmit the angle digital signal and the speed digital signal of the motor shaft to the motor controller through serial communication.

4. The fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump according to claim 3, characterized in that: The output end of the permanent magnet synchronous motor is connected to a gear pump, and the gear pump and the permanent magnet synchronous motor drive system constitute an electric fuel pump; The permanent magnet synchronous motor turn-to-turn short-circuit fault diagnosis module is used to calculate the negative sequence voltage synthesis vector of the electric fuel pump according to the three-phase voltage and speed signal of the permanent magnet synchronous motor, that is, the turn-to-turn short-circuit fault characteristic value, as the basis for turn-to-turn short-circuit fault diagnosis; The permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis module includes: a dq axis positive sequence voltage calculation unit, a dq axis negative sequence voltage calculation unit, and a negative sequence voltage synthesis vector calculation unit; The dq axis positive sequence voltage calculation unit is used to calculate the three-phase voltage digital signal u output by the three-phase voltage and current acquisition module. a ,u b ,u c And the speed digital signal w output by the motor speed monitoring module m , u in the natural coordinate system a ,u b ,u c The positive sequence voltage is converted to the stationary coordinate system α-β by Clark coordinate transformation for: Then, the positive sequence voltage in the stationary coordinate system α-β is transformed by Park coordinate transformation. Transformed to the positive sequence voltage of the dq axis of the synchronous rotating coordinate system for: Among them, θ e is the electrical angular velocity, and is the angle digital signal θ output by the motor speed monitoring module m Multiply by the number of pole pairs n of the permanent magnet synchronous motor p ; The dq axis negative sequence voltage calculation unit is based on the phase difference of 2w between the positive and negative sequence voltage vectors. e , used to convert the positive sequence voltage Conversion to negative sequence voltage for: The calculated negative sequence voltage The sliding filters in the unit are used for filtering respectively; The dq axis negative sequence synthesis vector calculation unit is used to calculate the negative sequence voltage after filtering. The calculated turn-to-turn short-circuit fault characteristic value is: When it is determined that the characteristic value surges, it is determined that an inter-turn short circuit fault occurs in the permanent magnet synchronous motor.

5. The fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump according to claim 3, characterized in that: The permanent magnet synchronous motor uniform demagnetization fault diagnosis module establishes a flux observer of the permanent magnet synchronous motor according to the three-phase voltage, three-phase current and speed signal of the permanent magnet synchronous motor as a basis for uniform demagnetization fault diagnosis; the permanent magnet synchronous motor uniform demagnetization fault diagnosis module comprises: a coordinate transformation unit, a back electromotive force calculation unit, a resistance and inductance estimation unit, a flux observer, and a flux comparator connected in sequence; the coordinate transformation unit is also connected to the back electromotive force calculation unit; The coordinate transformation unit is used to transform the three-phase voltage digital signal and the three-phase current digital signal u output by the three-phase voltage and current acquisition module. a ,u b ,u c ,i a ,i b ,i c , and the speed digital signal w output by the motor speed monitoring module m , calculate the voltage and current u in the stationary coordinate system through Clark transformation α ,u β ,i α ,i β , and then calculate the voltage and current u in the dq axis coordinate system through Park transformation d ,u q ,i d ,i q ; The resistance and inductance estimation unit is used to add a variable forgetting factor on the basis of the least recursive squares algorithm, and can complete the identification of the stator resistance and stator inductance of the permanent magnet synchronous motor. This estimation method improves the accuracy of parameter estimation; The back electromotive force calculation unit is used to calculate the u calculated by the coordinate transformation unit. α ,u β ,i α ,i β The stator resistance R estimated by the resistance estimation unit is used to calculate the back EMF: Where R is the stator resistance of the permanent magnet synchronous motor; The flux observer is used to measure the back EMF through an internal integrator. α ,e β Perform integral calculation to obtain the magnetic flux in the stationary coordinate system After park transformation, the dq axis magnetic flux is obtained The calculated dq-axis flux A high-pass filter is used to filter out the DC component and the actual flux linkage of the permanent magnet synchronous motor is calculated as Wherein, Ld is the stator inductance of the permanent magnet synchronous motor output by the resistance and inductance estimation unit; The flux comparator is used to compare the actual flux output by the flux observer. With pre-calibrated flux value The absolute value of the difference is used as the fault characteristic value; when it is determined that the characteristic value increases sharply, it is determined that a uniform demagnetization fault occurs in the permanent magnet synchronous motor.

6. The fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump according to claim 3, characterized in that: The permanent magnet synchronous motor local demagnetization fault diagnosis module is used to calculate the current harmonics according to the three-phase current and speed signal of the permanent magnet synchronous motor as the basis for local demagnetization fault diagnosis; the permanent magnet synchronous motor local demagnetization fault diagnosis module includes: a harmonic frequency calculation unit and a harmonic current calculation unit connected to each other; The harmonic frequency calculation unit is used to calculate the harmonic frequency of the fault characteristics contained in the magnetic field of the permanent magnet synchronous motor: In the formula, f dm is the harmonic frequency of the fault characteristic, f c is the fundamental frequency generated by the motor controller, n p is the number of pole pairs of the permanent magnet synchronous motor, k is the harmonic order, which is less than or equal to n p integer; The harmonic current calculation unit is used to calculate the harmonic current according to n p The calculated harmonic order k is used to calculate the dq axis current i through coordinate transformation d ,i q , extract i d ,i q The kth harmonic in the current, i d ,i q The kth harmonic of the current is converted into a DC component, which is the current harmonic; The fault feature needs to be filtered before it can be extracted. The average value filtering method is used, and the local demagnetization fault feature value is calculated as follows: If any k-th current harmonic increases significantly, it is determined that a fault has occurred.

7. The fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump according to claim 3, characterized in that: The inverter single-tube fault diagnosis module is used to obtain a single-tube fault characteristic value of the three-phase current signal according to the three-phase current signal and the speed signal of the permanent magnet synchronous motor; The inverter single-tube fault diagnosis module includes: a Park vector modulus calculation unit, a phase current average value calculation unit, and a phase current average value comparator; The Park vector module calculation unit is used to calculate the three-phase current digital signal i output by the three-phase voltage and current acquisition module. a ,i b ,i c , calculate the current i in the stationary coordinate system through Clark transformation α ,i β : Then calculate the modulus of the Clark vector The phase current average value calculation unit is used to calculate each phase current i according to the modulus of the Clark vector. n The average value of (n=a,b,c) is: The phase current average value comparator is used to compare the difference between the average value of each phase current and the preset threshold μ. It is determined that the lower tube of the corresponding phase is faulty; It is determined that the upper tube of the corresponding phase is faulty.

8. The fault diagnosis device for a permanent magnet synchronous motor drive system for an electric fuel pump according to any one of claims 1 to 7, characterized in that: The rotary transformer fault diagnosis module includes an amplitude error unit and a phase error unit; The amplitude error unit sets a threshold value and compares it with the envelope peak value of the sine-cosine orthogonal differential signal output by the resolver. When the envelope peak value is less than or greater than the threshold value, it can be determined that the resolver signal is lost and the fault cause is a resolver winding fault. The phase error unit compares the phase difference β between the excitation signal output by the primary winding of the rotary transformer and the sine-cosine orthogonal differential signal output by the two secondary windings of the rotary transformer with a set threshold range, and determines that a phase lock error occurs if the phase difference exceeds the threshold range.

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