Switched reluctance motor fault diagnosis method, system and detection equipment

Abstract

The present application relates to a switched reluctance motor fault diagnosis method, system and detection equipment, including: diagnosing the fault state of a four-phase switched reluctance motor power converter according to a harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state; when the four-phase switched reluctance motor power converter is in a fault state, identifying the fault parameters of the four-phase switched reluctance motor power converter according to a current prediction method, wherein the fault parameters include the fault type and the faulty device. The present application combines the harmonic detection method and the current prediction method to perform fault detection on the switched reluctance motor power converter, which can realize accurate fault diagnosis of a single switch tube, and can obtain more fault information when it is determined that the power converter has a fault, thereby improving the efficiency of fault diagnosis.

Description

Technical Field

[0001] The present application relates to the technical field of switched reluctance motor power converter fault detection, and in particular to a switched reluctance motor fault diagnosis method, system and detection equipment. Background Art

[0002] As a new type of motor, the switched reluctance motor has the advantages of simple structure, high reliability, wide speed regulation range, strong fault tolerance and low manufacturing cost, and is widely used in electric vehicles, household appliances, mechanical textiles, traction drives and other fields. The power converter is the core device of the switched reluctance motor drive system, and the reliability of the power converter is directly related to the operating performance of the entire motor system.

[0003] The power converter is mainly composed of a switch tube, a diode and a phase winding, among which the switch tube is the most important component in the power converter. To ensure the normal operation of the switched reluctance motor, the switch tube needs to be continuously turned on and off according to the system instructions. Frequent switching of the switch state for a long time can easily cause the switch tube to fail, which will cause the motor to not work properly. Therefore, it is necessary to perform fault diagnosis on the switch tube to timely discover, locate and solve the fault.

[0004] Phase current measurement is a common method for fault diagnosis of switched reluctance motor power converters. This measurement method can obtain complete current information when the motor is operating normally, but it cannot obtain complete current information when the switched reluctance motor power converter is operating faultily. Due to the special topological structure of the asymmetric half-bridge power converter, the inability to locate the faulty device for an open circuit fault and the delay in locating the faulty device for a short circuit fault weaken the performance of the traditional phase current measurement method in fault diagnosis and limit its application. Summary of the invention

[0005] Based on this, it is necessary to provide a switched reluctance motor fault diagnosis method, system and detection equipment that can accurately identify the fault state of the switched reluctance motor power converter and effectively locate the fault position in response to the above technical problems.

[0006] In a first aspect, the present application provides a switched reluctance motor fault diagnosis method, comprising:

[0007] Diagnosing the fault state of the four-phase switched reluctance motor power converter according to the harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state;

[0008] When the four-phase switched reluctance motor power converter is in a fault state, fault parameters of the four-phase switched reluctance motor power converter are identified according to a current prediction method, wherein the fault parameters include a fault type and a fault component.

[0009] In one embodiment, the diagnosing the fault state of the four-phase switched reluctance motor power converter according to the harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state includes:

[0010] Acquire a bus current of the four-phase switched reluctance motor power converter, and decompose the bus current to obtain a frequency spectrum of the bus current;

[0011] Calculating the fundamental wave component and the second harmonic component in the spectrum;

[0012] When the amplitude of the fundamental component is greater than a first amplitude threshold and the amplitude of the second harmonic component is greater than a second amplitude threshold, it is determined that the four-phase switched reluctance motor power converter is in a fault state.

[0013] In one embodiment, a current sensor is provided in each phase switch tube assembly of the four-phase switched reluctance motor power converter, each switch tube assembly includes at least two switch tubes and two freewheeling diodes, and the current sensor is used to collect the real-time current of the switch tube assembly;

[0014] The method of identifying the fault parameters of the four-phase switched reluctance motor power converter according to the current prediction method includes:

[0015] Collecting the switch parameters and current parameters of each phase switch tube assembly in turn;

[0016] Predicting a first operating state and a second operating state of the switch tube assembly according to the switch parameter and the current parameter;

[0017] Determine the fault parameters of the switch tube assembly of each phase according to the first operating state and the second operating state;

[0018] The fault parameters of all faulty switch tube assemblies are combined to obtain the fault parameters of the four-phase switched reluctance motor power converter.

[0019] In one embodiment, identifying fault parameters of a single-phase switch tube assembly according to a current prediction method includes:

[0020] Acquire a first switch tube signal, a second switch tube signal, and a phase current of a single-phase switch tube assembly, wherein the first switch tube signal is used to indicate a switch state of the first switch tube, and the second switch tube signal is used to indicate a switch state of the second switch tube;

[0021] Calculate a first operating state quantization factor according to the first switch tube signal and the second switch tube signal;

[0022] Calculate a second operating state quantization factor according to the real-time current collected by the current sensor in the single-phase switch tube assembly and the phase current;

[0023] The fault parameter is determined according to the first operating state quantization factor and the second operating state quantization factor.

[0024] In one embodiment, determining the fault parameter according to the first operating state quantization factor and the second operating state quantization factor includes:

[0025] Calculating a difference between the first operating state quantization factor and the second operating state quantization factor;

[0026] If the difference is a first value, it is determined that a first fault occurs in the first switch tube;

[0027] If the difference is a second value, it is determined that a second fault occurs in the first switch tube;

[0028] If the difference is a third value, it is determined that the first fault occurs in the second switch tube;

[0029] If the difference is a fourth value, it is determined that the second switch tube has the second fault.

[0030] In one embodiment, calculating the first operating state quantization factor according to the first switch tube signal and the second switch tube signal includes:

[0031] Calculate the sum of twice the state value of the first switch tube signal and the state value of the second switch tube signal;

[0032] The sum is determined as the first operating state quantization factor.

[0033] In one embodiment, the calculating the second operating state quantization factor according to the real-time current collected by the current sensor in the single-phase switch tube assembly and the phase current includes:

[0034] Dividing four current ranges according to the phase current, wherein each current range corresponds to a factor value;

[0035] A factor value corresponding to the current range to which the real-time current belongs is determined as the second operating state quantization factor.

[0036] In a second aspect, the present application also provides a switched reluctance motor fault diagnosis system, comprising:

[0037] a fault state identification unit, used for diagnosing the fault state of the four-phase switched reluctance motor power converter according to a harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state;

[0038] A fault parameter identification unit is used to identify the fault parameters of the four-phase switched reluctance motor power converter according to a current prediction method when the four-phase switched reluctance motor power converter is in a fault state, wherein the fault parameters include a fault type and a fault device.

[0039] In one embodiment, a current sensor is provided in each phase switch tube assembly of the four-phase switched reluctance motor power converter, each switch tube assembly includes at least two switch tubes and two freewheeling diodes, and the current sensor is used to collect the real-time current of the switch tube assembly;

[0040] A fault parameter identification unit is specifically used to sequentially collect the switch parameters and current parameters of each phase switch tube assembly; predict the first operating state and the second operating state of the switch tube assembly according to the switch parameters and the current parameters; determine the fault parameters of each phase switch tube assembly according to the first operating state and the second operating state; and obtain the fault parameters of the four-phase switched reluctance motor power converter by integrating the fault parameters of all faulty switch tube assemblies.

[0041] In a third aspect, the present application further provides a detection device, including the switched reluctance motor fault diagnosis system described in the second aspect.

[0042] In summary, the present application proposes a switched reluctance motor fault diagnosis method, system and detection equipment, including: diagnosing the fault state of a four-phase switched reluctance motor power converter according to a harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state; when the four-phase switched reluctance motor power converter is in a fault state, identifying the fault parameters of the four-phase switched reluctance motor power converter according to a current prediction method, wherein the fault parameters include the fault type and the faulty device. The present application combines the harmonic detection method and the current prediction method to perform fault detection on the switched reluctance motor power converter, which can realize accurate fault diagnosis of a single switch tube, and can obtain more fault information when it is determined that the power converter has a fault, thereby improving the efficiency of fault diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A circuit diagram of a four-phase switched reluctance motor power converter in one embodiment;

[0044] Figure 2 A circuit diagram of a switch component corresponding to the A-phase winding of a four-phase switched reluctance motor power converter in various switching states in one embodiment;

[0045] Figure 3 A schematic diagram of a circuit of a switch tube assembly in an embodiment when a first switch tube short circuit fault occurs;

[0046] Figure 4 A schematic diagram of a circuit of a switch tube assembly in an embodiment when a second switch tube short circuit fault occurs;

[0047] Figure 5 A schematic diagram of a circuit of a switch tube assembly in an embodiment when a first switch tube open circuit failure occurs;

[0048] Figure 6 A schematic diagram of a circuit of a switch tube assembly in an embodiment when a second switch tube open circuit failure occurs;

[0049] Figure 7 A schematic diagram of a reconstruction circuit of a four-phase switched reluctance motor power converter in one embodiment;

[0050] Figure 8 A schematic diagram of a flow chart of a switched reluctance motor fault diagnosis method in one embodiment;

[0051] Fig. 9 Schematic diagram of a harmonic detection method in one embodiment;

[0052] Fig.10 is a flow chart of a current prediction method in one embodiment;

[0053] Fig.11 is a flow chart of a current prediction method in another embodiment;

[0054] Fig.12 is a structural block diagram of a switched reluctance motor fault diagnosis system in one embodiment;

[0055] Fig.13 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0056] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0058] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0059] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0060] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least a portion of an element” means a part or all of an element.

[0061] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0062] like Figure 1 As shown, a four-phase switched reluctance motor asymmetric half-bridge power converter main circuit is provided, including a DC power supply 、Filter capacitor and a four-phase switch tube assembly, wherein the four-phase switch tube assembly includes a first switch tube assembly, a second switch tube assembly, a third switch tube assembly and a fourth switch tube assembly, and a filter capacitor Each phase switch tube assembly is connected in parallel to the DC power supply The positive terminal and the negative terminal of the switch tube assembly include at least two switch tubes and two freewheeling diodes.

[0063] Taking the first switch tube assembly corresponding to the A-phase winding as an example, the first switch tube assembly includes a chopper tube , Position conduction tube , upper freewheeling diode and the lower freewheeling diode Among them, the chopper tube of phase A One end of the DC power supply The positive terminal of the chopper tube is connected to The other end is electrically connected to one end of the A phase winding, and the position conduction tube One end of the DC power supply The negative end of the position conduction tube S2 is electrically connected to the other end of the A phase winding, and the upper freewheeling diode One end and DC power supply Positive terminal connected to the freewheeling diode The other end is electrically connected to the other end of the A phase winding, and the lower freewheeling diode One end and DC power supply Negative terminal electrical connection, lower freewheeling diode The other end is electrically connected to one end of the A-phase winding.

[0064] Need to know, such as Figure 1 As shown, the internal circuit connection method of the second switch tube assembly, the third switch tube assembly and the fourth switch tube assembly is similar to the circuit connection method of the first switch tube assembly corresponding to the A-phase winding, and will not be repeated here.

[0065] In this embodiment, winding A, winding B, winding C and winding D are three-phase windings. , , , , , , , For the freewheeling diode. , , , , , , , The control device of each switching tube can adjust the working mode of the power converter.

[0066] In a specific embodiment, according to the relationship between the switch state of the switch tube and the driving signal, the switch state of each switch tube can be defined as:

[0067]

[0068] in, is the switch state of the switch tube. Taking the first switch tube component corresponding to the A-phase winding as an example, the first switch tube component includes four switch states, namely and ( )、 and ( )、 and ( )、 and ( ).

[0069] like Figure 2 As shown, the current flow paths in the power converter circuit under the four switching states are: and In the case of and the lower freewheeling diode , the circuit is in a negative voltage demagnetization state. and In the case of and the lower freewheeling diode , the circuit is in the freewheeling state under zero voltage. and In the case of and the upper freewheeling diode , the circuit is in the zero voltage freewheeling state. and In the case of And the lower switch , the circuit is in the positive voltage excitation state.

[0070] In this embodiment, the corresponding relationship between the branch current of each element and the state of each switch tube in the four switching states is shown in Table 1 below:

[0071] Table 1

[0072]

[0073] in, Indicates components The branch current, Indicates components The branch current, Indicates components The branch current, Indicates components The branch current, is the phase current of phase A winding.

[0074] According to Table 1 above, the following current calculation formula can be obtained:

[0075]

[0076] In this embodiment, when a single-tube fault occurs in the switch tube assembly corresponding to the A-phase winding, the current flow path will generate two different types of fault current flow paths based on the switch state of another normal switch tube. The current flow path after the upper switch tube short circuit fault occurs in the switch tube assembly corresponding to the A-phase winding is as follows: Figure 3 The current flow path after the switch tube short circuit fault occurs in the switch tube component corresponding to the A phase winding is as follows Figure 4 The current flow path after the upper switch tube of the switch tube component corresponding to the A phase winding opens is as follows: Figure 5 The current flow path after the switch tube component corresponding to the A phase winding has an open circuit fault is as follows: Figure 6 shown.

[0077] In this embodiment, if Figure 7 As shown, current sensors are provided at the winding of each switch tube assembly of the four-phase power converter circuit and on the busbar section of the DC power supply, namely, current sensor LEMA, current sensor LEMB, current sensor LEMC, current sensor LEMD and current sensor LEMZ. The real-time current at the corresponding position can be collected by each current sensor to assist the detection equipment in fault diagnosis.

[0078] In one embodiment, Figure 8 As shown, a switched reluctance motor fault diagnosis method is provided, which is used to detect Figure 7 Taking the single-tube fault of the power converter circuit corresponding to the A-phase winding in the example as an example, the following steps are included:

[0079] S801, diagnose the fault state of the four-phase switched reluctance motor power converter according to the harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state.

[0080] S802, when the four-phase switched reluctance motor power converter is in a fault state, identifying fault parameters of the four-phase switched reluctance motor power converter according to a current prediction method, wherein the fault parameters include a fault type and a faulty device.

[0081] In this embodiment, the actual circuit of the four-phase switched reluctance motor power converter can be as follows: Figure 7 As shown, various circuit structures of the four-phase switched reluctance motor power converter are not described here one by one.

[0082] In this embodiment, by performing Fourier transform on the phase currents of the four-phase switched reluctance motor, it can be seen that the four-phase 8 / 6 switched reluctance motor has symmetry in spatial structure and power-on time. The subharmonic components cancel each other out, and the amplitude of these subharmonic components in the bus current is very small. The subharmonic components (DC components when k=0) overlap with each other, and the amplitudes of these subharmonic components in the bus current are large.

[0083] This embodiment uses the amplitude of the bus current fundamental component and the amplitude of the second harmonic component as fault characteristic quantities, and implements the diagnosis of the fault state of the four-phase switched reluctance motor power converter based on the harmonic detection method, which can more accurately determine whether there is a single-tube fault in the power converter.

[0084] It is determined that the four-phase switched reluctance motor power converter is in a faulty state, indicating that a single-tube fault exists in the four-phase switched reluctance motor power converter. At this time, further identifying the fault parameters of the four-phase switched reluctance motor power converter based on the current prediction method can accurately identify the fault type and accurately locate the faulty device. In the fault diagnosis process, more specific fault information can be obtained to solve the fault problem of the power converter.

[0085] In one embodiment, if Fig. 9 As shown, the fault state of the four-phase switched reluctance motor power converter is diagnosed according to the harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state, including:

[0086] S901, obtaining a bus current of a four-phase switched reluctance motor power converter, and decomposing the bus current to obtain a frequency spectrum of the bus current.

[0087] S902, calculating the fundamental wave component and the second harmonic component in the frequency spectrum.

[0088] S903: When the amplitude of the fundamental component is greater than the first amplitude threshold and the amplitude of the second harmonic component is greater than the second amplitude threshold, determine that the four-phase switched reluctance motor power converter is in a fault state.

[0089] In this embodiment, by performing Fourier transform on the bus current of the switched reluctance motor, the frequency spectrum of the bus current can be decomposed, and then the amplitudes of the fundamental component and the second harmonic component of the bus current can be effectively calculated from the frequency spectrum. Finally, the formula for judging whether the four-phase switched reluctance motor power converter is in a fault state is:

[0090]

[0091] in, and are the amplitudes of the fundamental component and the second harmonic component of the bus current, and are the setting thresholds for the amplitudes of the bus current fundamental component and the second harmonic component respectively. In this embodiment, the first amplitude threshold is , the second amplitude threshold is .

[0092] In summary, this embodiment obtains the bus current of the four-phase switched reluctance motor power converter, calculates the amplitude of the fundamental component and the second harmonic component of the bus current, and compares the magnitude relationship between the amplitude and the amplitude threshold, so as to accurately complete the confirmation of the single-tube fault state of the power converter, and can greatly improve the diagnostic efficiency of the single-tube fault of the power converter. In addition, this embodiment further detects the fault parameters based on the current prediction method only after determining that the power converter has a single-tube fault, so as to avoid performing complex diagnostic procedures for a good power converter and wasting detection resources.

[0093] In one embodiment, if Fig.10 As shown, a current sensor is provided in each phase switch tube assembly of the four-phase switched reluctance motor power converter, and each switch tube assembly includes at least two switch tubes and two freewheeling diodes. The current sensor is used to collect the real-time current of the switch tube assembly.

[0094] Identify fault parameters of a four-phase switched reluctance motor power converter based on current prediction method, including:

[0095] S1001, sequentially collecting the switch parameters and current parameters of the switch tube components of each phase.

[0096] In this embodiment, the switch parameter includes switch state signals of the first switch and the second switch in the corresponding switch tube assembly, for example The drive signal and Drive signal.

[0097] The current parameters include the real-time current and phase current collected by the current sensor.

[0098] S1002, predicting a first operating state and a second operating state of the switch tube assembly according to the switch parameters and the current parameters.

[0099] In this embodiment, the first operating state is used to refer to the operating state of the switch tube component in the corresponding switch state. The second operating state is used to refer to the equivalent operating state of the power converter after a fault occurs.

[0100] S1003, determining the fault parameters of the switch tube assembly of each phase according to the first operating state and the second operating state.

[0101] In this embodiment, based on the first operating state and the second operating state of each phase switch tube assembly, it is determined whether each phase switch tube assembly has a fault, and the fault type and fault position are located, thereby identifying all fault parameters in the four-phase power converter.

[0102] S1004, synthesizing the fault parameters of all faulty switch tube assemblies to obtain the fault parameters of the four-phase switched reluctance motor power converter.

[0103] In one embodiment, if Fig.11 As shown, taking the switch tube assembly corresponding to the A-phase winding as an example, the fault parameters of the single-phase switch tube assembly are identified according to the current prediction method, including:

[0104] S1101, obtaining a first switch tube signal, a second switch tube signal and a phase current of a single-phase switch tube assembly, wherein the first switch tube signal is used to indicate a switching state of the first switch tube, and the second switch tube signal is used to indicate a switching state of the second switch tube.

[0105] S1102, calculating a first operating state quantization factor according to the first switch tube signal and the second switch tube signal.

[0106] S1103, calculating a second operating state quantization factor according to the real-time current and phase current collected by the current sensor in the single-phase switch tube assembly.

[0107] S1104: Determine a fault parameter according to the first operating state quantization factor and the second operating state quantization factor.

[0108] In this embodiment, the first switch tube is a chopper tube. , the second switch tube is a position conduction tube The first switch tube may be referred to as an upper switch tube, and the second switch tube may be referred to as a lower switch tube. The specific types of the first switch tube and the second switch tube may be adaptively replaced according to the needs of the actual application scenario.

[0109] The first switch tube signal is used to indicate The switch state value is 0 or 1. The second switch tube signal is used to refer to The switch state value is 0 or 1. A first operation state quantification factor P is defined to quantify and predict the real-time operation state of the switch tube assembly. A second operation state quantification factor Q is defined to quantify the equivalent operation state after the fault occurs.

[0110] In a specific embodiment, the processing formula for determining the first operating state quantization factor P according to the first switch signal and the second switch tube signal is:

[0111]

[0112] That is, the four switching states of the switch tube assembly corresponding to the A-phase winding can be directly determined according to the first switch signal and the second switch tube signal.

[0113] In one embodiment, calculating the first operating state quantization factor according to the first switch tube signal and the second switch tube signal includes:

[0114] Calculate the sum of twice the state value of the first switch tube signal and the state value of the second switch tube signal;

[0115] The sum is determined as a first operating state quantization factor.

[0116] In this embodiment, based on the corresponding relationship of the first operating state quantization factor, a simplified calculation formula of the first operating state quantization factor can be obtained: .

[0117] In this embodiment, the real-time current collected by the current sensor It can be expressed by the current of each branch as:

[0118]

[0119] in, is the real-time current, is the phase current of phase A winding, For switch tube The current, For switch tube of current.

[0120] That is, the real-time current collected by the current sensor The upper and lower switch tubes of the switch tube assembly corresponding to the A phase winding , The corresponding relationship of the switch state is:

[0121]

[0122] in, For switch tube Switch state value, For switch tube The switch status value.

[0123] Current sensor current in the four working states corresponding to the switch tube The corresponding relationship between the phase current is:

[0124]

[0125] From the above correspondence, it can be seen that when a short circuit fault occurs, the winding current will increase, and the equivalent operating state after the fault will jump to a state with a large footmark value. When an open circuit fault occurs, the winding current will decrease, and the equivalent operating state after the fault will jump to a state with a small footmark value.

[0126] In one embodiment, calculating the second operation state quantification factor according to the real-time current and phase current collected by the current sensor in the single-phase switch tube assembly includes:

[0127] Four current ranges are divided according to the phase current, wherein each current range corresponds to a factor value;

[0128] A factor value corresponding to the current range to which the real-time current belongs is determined as a second operating state quantization factor.

[0129] In this embodiment, the current sensor current From the corresponding relationship between the real-time current and the phase current, it can be known that there is a definite quantitative relationship between the real-time current actually detected by the current sensor and the phase current in the four operating states of ST0, ST1, ST2, and ST3.

[0130] This embodiment can achieve the following by limiting the scope. and Accurately determine the equivalent operating state of the power converter when a fault occurs. The relationship between the quantization factors corresponding to the equivalent state of the fault phase is as follows:

[0131]

[0132] Among them, Q is the second operating state quantization factor, and the four values ​​of Q, 0, 1, 2, and 3, correspond to the four switching states of phase A respectively.

[0133] In actual application, the four current ranges divided according to the phase current can be adaptively divided according to the needs of the actual application scenario. The multiple relationship defined above is only used for example description and is not specifically limited. This embodiment quantifies the range around the ideal relationship between the current sensor current and the predicted phase current under four operating conditions, and can accurately infer the equivalent operating state after the fault.

[0134] Finally, determining the fault parameter according to the first operation state quantization factor and the second operation state quantization factor includes:

[0135] Calculating a difference between a first operating state quantization factor and a second operating state quantization factor;

[0136] If the difference is a first value, it is determined that a first fault occurs in the first switch tube;

[0137] If the difference is a second value, it is determined that a second fault occurs in the first switch tube;

[0138] If the difference is a third value, it is determined that a first fault occurs in the second switch tube;

[0139] If the difference is a fourth value, it is determined that a second fault occurs in the second switch tube.

[0140] In this embodiment, the first value is -2, the second value is 2, the third value is -1, the fourth value is 1, the first fault is a short circuit fault, and the second fault is an open circuit fault.

[0141] The corresponding relationship between the prediction of fault parameters based on the P and Q quantization factors is:

[0142]

[0143] Based on the above formula, it can be known that when the A-phase upper switch tube short-circuit fault occurs in the switched reluctance motor power converter, the trigger signal equivalent to the upper switch tube is high level, which is equivalent to the upper switch tube being turned on under normal circumstances. will jump to , will jump to ,correspond The diagnosis result is that the switch tube A short circuit fault has occurred.

[0144] When the A-phase lower switch tube of the switched reluctance motor power converter is short-circuited, the trigger signal equivalent to the lower switch tube is high level, which is equivalent to the lower switch tube being turned on under normal circumstances. will jump to , will jump to ,correspond The diagnosis result is that the switch tube A short circuit fault has occurred.

[0145] When the upper switch tube of phase A of the switched reluctance motor power converter fails, the trigger signal of the upper switch tube is low level, which is equivalent to the lower switch tube being disconnected under normal circumstances. will jump to , will jump to ,correspond The diagnosis result is that the switch tube An open circuit fault has occurred.

[0146] When the A-phase lower switch tube of the switched reluctance motor power converter fails, the trigger signal equivalent to the lower switch tube is low level, which is equivalent to the lower switch tube being disconnected under normal circumstances. will jump to , will jump to ,correspond The diagnosis result is that the switch tube An open circuit fault has occurred.

[0147] In summary, this embodiment provides a method for diagnosing a single switch tube fault of a four-phase switched reluctance motor power converter. By integrating the harmonic detection method and the current prediction method, and combining the setting of the current sensor structure, the online fault diagnosis of the single switch tube of the four-phase switched reluctance motor power converter can be accurately completed. The difference between the first operating state quantization factor and the second operating state quantization factor is used as the basis for judging the fault type, that is, the analog quantity is processed by digitization and quantization factors, which greatly improves the diagnostic reliability and robustness for power converter circuit fault problems.

[0148] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0149] Based on the same inventive concept, the embodiment of the present application also provides a switched reluctance motor fault diagnosis system for implementing the switched reluctance motor fault diagnosis method involved above. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more switched reluctance motor fault diagnosis system embodiments provided below can refer to the limitations of the switched reluctance motor fault diagnosis method above, and will not be repeated here.

[0150] In one embodiment, Fig.12 As shown, a switched reluctance motor fault diagnosis system 1200 is provided, comprising: a fault state identification unit 1210 and a fault parameter identification unit 1220, wherein:

[0151] A fault state identification unit 1210 is used to diagnose the fault state of the four-phase switched reluctance motor power converter according to a harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state;

[0152] The fault parameter identification unit 1220 is used to identify the fault parameters of the four-phase switched reluctance motor power converter according to the current prediction method when the four-phase switched reluctance motor power converter is in a fault state, wherein the fault parameters include the fault type and the fault device.

[0153] In one of the embodiments, the fault state identification unit 1210 is specifically used to obtain the bus current of the four-phase switched reluctance motor power converter, and decompose the bus current to obtain the frequency spectrum of the bus current; calculate the fundamental component and the second harmonic component in the frequency spectrum; when the amplitude of the fundamental component is greater than the first amplitude threshold and the amplitude of the second harmonic component is greater than the second amplitude threshold, determine that the four-phase switched reluctance motor power converter is in a fault state.

[0154] In one embodiment, a current sensor is provided in each phase switch tube assembly of the four-phase switched reluctance motor power converter, each switch tube assembly includes at least two switch tubes and two freewheeling diodes, and the current sensor is used to collect the real-time current of the switch tube assembly;

[0155] The fault parameter identification unit 1220 is specifically used to collect the switch parameters and current parameters of each phase switch tube assembly in sequence; predict the first operating state and the second operating state of the switch tube assembly according to the switch parameters and the current parameters; determine the fault parameters of each phase switch tube assembly according to the first operating state and the second operating state; and obtain the fault parameters of the four-phase switched reluctance motor power converter by integrating the fault parameters of all faulty switch tube assemblies.

[0156] The fault parameter identification unit 1220 is specifically used to obtain the first switch tube signal, the second switch tube signal and the phase current of the single-phase switch tube assembly, wherein the first switch tube signal is used to indicate the switching state of the first switch tube, and the second switch tube signal is used to indicate the switching state of the second switch tube; calculate the first operating state quantization factor according to the first switch tube signal and the second switch tube signal; calculate the second operating state quantization factor according to the real-time current and phase current collected by the current sensor in the single-phase switch tube assembly; determine the fault parameter according to the first operating state quantization factor and the second operating state quantization factor.

[0157] Each unit in the above-mentioned switched reluctance motor fault diagnosis system can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned units can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above-mentioned units.

[0158] In one embodiment, a detection device is provided, including a computer device and the switched reluctance motor fault diagnosis system in the above system embodiment.

[0159] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Fig.13 As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a switched reluctance motor fault diagnosis method is implemented. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0160] Those skilled in the art will understand that Fig.13 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0161] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the switched reluctance motor fault diagnosis method in the aforementioned method embodiment is implemented.

[0162] In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the fault diagnosis method in the aforementioned method embodiment is implemented. In one embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the switched reluctance motor fault diagnosis method in the aforementioned method embodiment is implemented.

[0163] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0164] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0165] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A switched reluctance motor fault diagnosis method, characterized in that: include: Diagnosing the fault state of the four-phase switched reluctance motor power converter according to the harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state; When the four-phase switched reluctance motor power converter is in a fault state, fault parameters of the four-phase switched reluctance motor power converter are identified according to a current prediction method, wherein the fault parameters include a fault type and a fault component.

2. The method according to claim 1, characterized in that: The method of diagnosing the fault state of the four-phase switched reluctance motor power converter according to the harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state includes: Acquire a bus current of the four-phase switched reluctance motor power converter, and decompose the bus current to obtain a frequency spectrum of the bus current; Calculating the fundamental wave component and the second harmonic component in the spectrum; When the amplitude of the fundamental component is greater than a first amplitude threshold and the amplitude of the second harmonic component is greater than a second amplitude threshold, it is determined that the four-phase switched reluctance motor power converter is in a fault state.

3. The method according to claim 1, characterized in that A current sensor is provided in each phase switch tube assembly of the four-phase switched reluctance motor power converter, each switch tube assembly includes at least two switch tubes and two freewheeling diodes, and the current sensor is used to collect the real-time current of the switch tube assembly; The method of identifying the fault parameters of the four-phase switched reluctance motor power converter according to the current prediction method includes: Collecting the switch parameters and current parameters of each phase switch tube assembly in turn; Predicting a first operating state and a second operating state of the switch tube assembly according to the switch parameter and the current parameter; Determine the fault parameters of the switch tube assembly of each phase according to the first operating state and the second operating state; The fault parameters of all faulty switch tube assemblies are combined to obtain the fault parameters of the four-phase switched reluctance motor power converter.

4. The method according to claim 3, characterized in that Identify fault parameters of single-phase switch tube components based on current prediction method, including: Acquire a first switch tube signal, a second switch tube signal, and a phase current of a single-phase switch tube assembly, wherein the first switch tube signal is used to indicate a switch state of the first switch tube, and the second switch tube signal is used to indicate a switch state of the second switch tube; Calculate a first operating state quantization factor according to the first switch tube signal and the second switch tube signal; Calculate a second operating state quantization factor according to the real-time current collected by the current sensor in the single-phase switch tube assembly and the phase current; The fault parameter is determined according to the first operating state quantization factor and the second operating state quantization factor.

5. The method according to claim 4, characterized in that The determining the fault parameter according to the first operating state quantization factor and the second operating state quantization factor includes: Calculating a difference between the first operating state quantization factor and the second operating state quantization factor; If the difference is a first value, it is determined that a first fault occurs in the first switch tube; If the difference is a second value, it is determined that a second fault occurs in the first switch tube; If the difference is a third value, it is determined that the first fault occurs in the second switch tube; If the difference is a fourth value, it is determined that the second switch tube has the second fault.

6. The method according to claim 4, characterized in that The calculating the first operation state quantization factor according to the first switch tube signal and the second switch tube signal includes: Calculate the sum of twice the state value of the first switch tube signal and the state value of the second switch tube signal; The sum is determined as the first operating state quantization factor.

7. The method according to claim 4, characterized in that The calculating of the second operation state quantization factor according to the real-time current collected by the current sensor in the single-phase switch tube assembly and the phase current comprises: Dividing four current ranges according to the phase current, wherein each current range corresponds to a factor value; A factor value corresponding to the current range to which the real-time current belongs is determined as the second operating state quantization factor.

8. A switched reluctance motor fault diagnosis system, characterized in that: include: a fault state identification unit, used for diagnosing the fault state of the four-phase switched reluctance motor power converter according to a harmonic detection method to determine whether the four-phase switched reluctance motor power converter is in a fault state; A fault parameter identification unit is used to identify the fault parameters of the four-phase switched reluctance motor power converter according to a current prediction method when the four-phase switched reluctance motor power converter is in a fault state, wherein the fault parameters include a fault type and a fault device.

9. The system according to claim 8, characterized in that A current sensor is provided in each phase switch tube assembly of the four-phase switched reluctance motor power converter, each switch tube assembly includes at least two switch tubes and two freewheeling diodes, and the current sensor is used to collect the real-time current of the switch tube assembly; A fault parameter identification unit is specifically used to sequentially collect the switch parameters and current parameters of each phase switch tube assembly; predict the first operating state and the second operating state of the switch tube assembly according to the switch parameters and the current parameters; determine the fault parameters of each phase switch tube assembly according to the first operating state and the second operating state; and obtain the fault parameters of the four-phase switched reluctance motor power converter by integrating the fault parameters of all faulty switch tube assemblies.

10. A detection device, characterized in that: Including the switched reluctance motor fault diagnosis system as described in claim 8 or 9.

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