DSEG system HBSCR fault diagnosis method based on bus current

Abstract

The invention discloses a DSEG system HBSCR fault diagnosis method based on bus current, and relates to the field of H-bridge half-controlled rectifiers. According to the method, a current sensor is additionally arranged on a bus positive electrode between equipotential connecting ends of three left bridge arms and equipotential connecting ends of three right bridge arms in an HBSCR; a current sensor is additionally arranged on a bus positive electrode between equipotential connecting ends of three right bridge arms and a positive electrode of a load resistor, and fault detection is realized by combining the current characteristic combination of a last group of current sampling values before the end position of a working interval of each sector and a first group of current sampling values after the end position of the working interval. The method is simple in implementation mode and small in calculation amount, and makes up the technical vacancy of the industry. And the method is not influenced by rotating speed or load change, is not influenced by a fault occurrence position, and is wide in applicability.

Description

Technical Field

[0001] The present application relates to the field of H-bridge half-controlled rectifiers, and in particular to a DSEG system HBSCR fault diagnosis method based on bus current. Background Art

[0002] Doubly Salient Electromagnetic Generator (DSEG) is widely favored for its advantages such as simple structure, high reliability and strong fault tolerance, especially in the fields of aviation and wind power generation. Compared with the traditional uncontrolled rectifier system, the DSEG system using H-Bridge Semi-Controlled Rectifier (HBSCR) has independent three-phase currents, short commutation process, low iron loss and copper loss. In addition, the H-bridge semi-controlled rectifier system can control the armature current by adjusting the conduction angle of the switch tube to increase the output power of the motor and improve the motor performance, so it has received widespread attention in the academic community.

[0003] However, due to the harsh working environment, HBSCR has become the most prone to failure in the DSEG system. The fault types can be divided into open circuit faults and short circuit faults. Short circuit faults are characterized by fast response and great harm. After the fault, the phase winding will overcurrent, and in severe cases, the system will shut down. Therefore, in practice, it is usually converted into an open circuit fault through a hardware circuit. Open circuit faults can cause large fluctuations in the output voltage and a decrease in the system's load capacity. If not diagnosed in time, secondary faults may occur in the system. Therefore, it is of great significance to conduct research on the open circuit fault diagnosis method of the HBSCR switch tube, but the research and application of HBSCR is still in its infancy. Therefore, there is a lack of relevant methods for diagnosing the open circuit fault of the HBSCR switch tube, and there is a technical gap in the industry. Summary of the invention

[0004] In view of the above problems and technical requirements, this application proposes a DSEG system HBSCR fault diagnosis method based on bus current. The technical solution of this application is as follows:

[0005] A DSEG system HBSCR fault diagnosis method based on bus current, in which each phase armature winding in an electrically excited double-salient-pole generator in the DSEG system is respectively connected to the bridge arm midpoint of the left bridge arm and the bridge arm midpoint of the right bridge arm in the HBSCR, a current sensor CS2 is further provided on the bus positive pole between the equipotential connection ends of the three left bridge arms and the equipotential connection ends of the three right bridge arms in the HBSCR, and a current sensor CS1 is further provided on the bus positive pole between the equipotential connection ends of the three right bridge arms and the positive pole of the load resistor; the DSEG system HBSCR fault diagnosis method includes:

[0006] When in the current sector [θ s ,θ e ] within [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 When the left switch tube and the right switch tube of the current sector are both working normally, it is determined that the left switch tube and the right switch tube of the current sector have an open circuit fault; otherwise, it is determined that the left switch tube and the right switch tube of the current sector have an open circuit fault;

[0007] Among them, i CS1 is the sampling current of current sensor CS1, i CS2 is the sampling current of the current sensor CS2; the working left switch tube of the current sector is the lower bridge arm switch tube located in the left bridge arm connected to one of the phase windings and turned on in the current sector, the working right switch tube of the current sector is the lower bridge arm switch tube located in the right bridge arm connected to one of the phase windings and turned on in the current sector, and the working left switch tube and the working right switch tube of the current sector are in the [θ s ,θ s +θ c ] interval, in the current sector [θ s +θ c ,θ e ] is turned off within the interval; θ c-b is θ s +θ c The electrical angle corresponding to the most recent sampling moment of the two current sensors, θ c-a is θ s +θ c Then the electrical angle corresponding to the most recent sampling moment of the two current sensors.

[0008] A further technical solution is to determine that the working left switch tube of the current sector has an open circuit fault and the working right switch tube of the current sector works normally when the following conditions are detected:

[0009] In the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θc-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour;

[0010] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour;

[0011] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 hour.

[0012] A further technical solution is to determine that the working right switch tube of the current sector has an open circuit fault and the working left switch tube of the current sector works normally when the following conditions are detected:

[0013] In the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 hour;

[0014] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour;

[0015] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour.

[0016] A further technical solution is to determine that both the working left switch tube and the working right switch tube of the current sector have open circuit faults when the following conditions are detected:

[0017] In the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock;

[0018] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock;

[0019] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour;

[0020] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock;

[0021] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock;

[0022] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠iCS2 hour;

[0023] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour;

[0024] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour;

[0025] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 hour.

[0026] The beneficial technical effects of this application are:

[0027] The present application discloses a DSEG system HBSCR fault diagnosis method based on bus current. This method only needs to add two current sensors to the positive pole of the bus in the traditional topology structure, and can realize fault detection by combining the current characteristic combination of the last group of current sampling values ​​before the end position of the working interval of each sector and the first group of current sampling values ​​after the end position of the working interval. This method is simple to implement and has a small amount of calculation, which fills the technical gap in the industry. Moreover, although this method needs to add two current sensors, the current sensors are added to the bus, so there is no need to change the rectifier topology, which is suitable for integrated modules and easy to promote.

[0028] This fault diagnosis method can be used to diagnose each sector and single-tube open-circuit faults and double-tube open-circuit faults. It can not only diagnose the occurrence of faults, but also locate the faulty switch tubes. This method is not affected by changes in speed or load, and is not affected by the location of the fault, and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is the topology diagram of the traditional HBSCR-based DSEG system.

[0030] Figure 2 This is the topology diagram of the HBSCR-based DSEG system targeted by this application.

[0031] Figure 3 It is the APC control strategy of DSEG system based on HBSCR.

[0032] Figure 4 is in sector 1 [0°,θ c ]Interval phase current waveform.

[0033] Figure 5 is the area within sector 1 [θ c-b ,θ c ] interval current loop.

[0034] Figure 6 is the area within sector 1 [θ c ,θ c-a ] interval current loop.

[0035] Figure 7 is the inner region of sector 1 [0°,θ c ]In the interval T A1 After the open circuit fault a Waveform.

[0036] Figure 8 is the inner region of sector 1 [0°,θ c ]In the interval T A1 After an open circuit fault, in [θ c-b ,θ c-a ] interval ia Waveform.

[0037] Fig. 9 is in sector 1, i a In [θ c-b ,θ c-a ] before it drops to 0, θ = θ c-b The current loop when .

[0038] Fig.10 is in sector 1, i a In [θ c-b ,θ c-a ] before it drops to 0, θ=θ c-a The current loop when .

[0039] Fig.11 is in sector 1, i a In [θ c-b ,θ c-a ] When the internal drop is 0, θ = θ c-b The current loop when .

[0040] Fig.12 is in sector 1, i a In [θ c-b ,θ c-a ] is not 0 when θ=θ c-a The current loop when .

[0041] Fig.13 is in sector 1, T C2 Single tube open circuit fault and θ F At [0°,θ e ]Interval time c waveform.

[0042] Fig.14 is in sector 1, T C2 Single tube open circuit fault and θ F At [0°,θ e ] interval, i c ≠0 [θ c-b ,θ c ] interval current loop.

[0043] Fig.15 is in sector 1, T C2 Single tube open circuit fault and θ F At [0°,θ e ] interval, i c ≠0 [θ c ,θ c-a ] interval current loop.

[0044] Fig.16is in sector 1, T C2 Single tube open circuit fault and θ F At [0°,θ e ] interval, i c = 0 [θ c-b ,θ c ] interval current loop.

[0045] Fig.17 is in sector 1, T C2 Single tube open circuit fault and θ F At [0°,θ e ] interval, i c = 0 [θ c ,θ c-a ] interval current loop.

[0046] Fig.18 It is T C2 Single tube open circuit fault and θ F In [θ e ,θ c ]Interval time c waveform.

[0047] Fig.19 It is T C2 Single tube open circuit fault and θ F In [θ e ,θ c ] interval, i c In [θ c-b ,θ c-a ] rises to 0 when [θ c-b ,θ c-a ] i in the interval c Waveform.

[0048] Fig. 20 is in sector 1, [0°,θ c ]In the interval T A1 T C2 After the double tube is open [θ c-b ,θ c-a ] phase current waveform in the interval.

[0049] Fig.21 yes Fig. 20 In case (a) [θ c-b ,θ c-a ] interval current loop.

[0050] Fig. 22 yes Fig. 20 In case (b) θ = θ c-b The current loop when .

[0051] Fig.23yes Fig. 20 In case (d), θ = θ c-b The current loop when .

[0052] Fig.24 yes Fig. 20 In case (e), θ = θ c-b The current loop when .

[0053] Fig.25 In the non-working interval of sector 1, T A1 When a single tube fails a waveform. DETAILED DESCRIPTION

[0054] The specific implementation of the present application is further described below in conjunction with the accompanying drawings.

[0055] The present application discloses a DSEG system HBSCR fault diagnosis method based on bus current. The method performs open circuit fault diagnosis on the switch tube in the HBSCR in the DSEG system. The conventional DSEG system topology using HBSCR is as follows: Figure 1 As shown, in the DSEG system, each phase armature winding in the electrically excited double-pole generator is connected to the midpoint of the left bridge arm and the midpoint of the right bridge arm in the HBSCR respectively. Each bridge arm in the HBSCR includes an upper bridge arm diode and a lower bridge arm switch tube. The cathode of the upper bridge arm diode is connected to the positive pole of the busbar, the anode of the upper bridge arm diode is connected to the collector of the lower bridge arm switch tube and is connected to the armature winding as the midpoint of the bridge arm. The emitter of the lower bridge arm switch tube is connected to the negative pole of the busbar, and the lower bridge arm switch tube is also anti-parallel connected with a diode. Figure 1 As shown, for any M-phase armature winding, M = A, B, C represent the three-phase armature winding of the electrically excited double-pole generator. The upper bridge arm diode of the left bridge arm connected to the M-phase armature winding is D M1 , the lower bridge arm switch tube is T M1 , the lower bridge arm switch tube T M1 The anti-parallel diode is denoted as D M2 The upper bridge arm diode of the right bridge arm connected to the M-phase armature winding is D M3 , the lower bridge arm switch tube is T M2 , the lower bridge arm switch tube T M2 The anti-parallel diode is denoted as D M4 The positive pole of the busbar of HBSCR is connected to the positive pole of the load resistor R, the negative pole of the busbar is connected to the negative pole of the load resistor R, and a filter capacitor C is also connected between the positive pole of the busbar and the negative pole of the busbar. o is the output voltage.

[0056] This application adds current sensor CS1 and current sensor CS2 on the basis of this topology. This application targets the DSEG system topology using HBSCR such as Figure 2 As shown, the cathodes of the upper bridge arm diodes in the three left bridge arms in the HBSCR are connected to form an equipotential connection terminal, and the cathodes of the upper bridge arm diodes in the three right bridge arms are connected to form an equipotential connection terminal. The current sensor CS2 is set on the positive pole of the busbar between the equipotential connection terminals of the three left bridge arms and the equipotential connection terminals of the three right bridge arms, and the positive pole of the busbar between the equipotential connection terminals of the left bridge arm and the equipotential connection terminals of the right bridge arm passes from the P pole to the N pole of the current sensor CS2. The current sensor CS1 is set on the positive pole of the busbar between the equipotential connection terminals of the three right bridge arms and the positive pole of the load resistor R, and the positive pole of the busbar between the equipotential connection terminals of the three right bridge arms and the load resistor R passes from the P pole to the N pole of the current sensor CS1, and the current sensor takes the P pole pointing to the N pole as the positive direction of the current.

[0057] The fault diagnosis method of this application is based on the angular position control (APC) strategy of the classic DSEG system, please refer to Figure 3 The control strategy shown. p = a, b, c represent the A, B, C phase armature windings of the electrically excited double-pole generator respectively, i p is the phase current, L p is the armature winding self-inductance, L pf is the mutual inductance between the armature winding and the field winding, e pf is the excitation back EMF, and θ is the rotor position angle. The DSEG system takes 0°~360° as a control cycle and is equally divided into three sectors. The electrical angle range covered by each sector can be recorded as [θ s ,θ e ], specifically including sector 1 covering 0°~120°, sector 2 covering 120°~240° and sector 3 covering 240°~360°. In each sector, two lower bridge arm switches are turned on and the conduction angle of the switch is θ c , that is, each sector has two lower bridge arm switches in the current sector [θ s ,θ s +θ c ] interval, in the current sector [θ s +θ c ,θ e ] is turned off within the range.

[0058] The lower bridge arm switch tubes that are turned on in different sectors are different, but one of the lower bridge arm switch tubes that are turned on in each sector is located in the left bridge arm connected to one of the phase windings, and the other lower bridge arm switch tube is located in the right bridge arm connected to the other phase winding. For the sake of convenience in distinction, this application defines the lower bridge arm switch tube that is turned on in a sector and is located in the left bridge arm connected to one of the phase windings as the working left switch tube of the sector, and defines the lower bridge arm switch tube that is turned on in a sector and is located in the right bridge arm connected to one of the phase windings as the working right switch tube of the sector. Then, each sector has its own corresponding working left switch tube and working right switch tube. Please combine Figure 3 It can be seen from the control strategy that sector 1 corresponds to the working left switch tube T A1 And the working right switch tube T C2 , sector 2 corresponds to the working left switch tube T B1 And the working right switch tube T A2 , sector 3 corresponds to the working left switch tube T C1 And the working right switch tube T B2 .

[0059] The following is an analysis of the working left switch tube T using sector 1 as an example: A1 And the working right switch tube T C2 The specific analysis of normal operation and failure is as follows:

[0060] 1. Working left switch tube T A1 And the working right switch tube T C2 All working properly

[0061] Depend on Figure 3 It can be seen that according to the switch tube T A1 and T C2 Whether to participate in the work, sector 1 can be subdivided into the working interval [0°,θ c ] and non-working interval [θ c ,120°]. The following analyzes the characteristics of the sensor current in the two intervals. b and i c The commutation situation, [0°,θ c The phase current waveforms of the interval are as follows: Figure 4 The five situations shown are: Figure 4 where θ1 is the value of i in sector 1 b and i c The electrical angle at which commutation ends.

[0062] During the operation of the DSEG system, the current values ​​of the current sensor CS1 and the current sensor CS2 are sampled at a predetermined frequency. c-b is θ s +θ cThe electrical angle corresponding to the most recent sampling moment of the two current sensors, θ c-a is θ s +θ c The electrical angle corresponding to the latest sampling moment of the two current sensors. In sector 1, θ s = 0°, so θ c-b is θ c The electrical angle at the previous sampling moment, θ c-a is θ c The electrical angle at the next sampling moment.

[0063] Depend on Figure 4 It can be seen that in the above five cases, in [θ c-b ,θ c ]There are i in the interval a >0、i b =0 and i c <0, the current loop is the same as Figure 5 As shown, in this case, the current values ​​of current sensor CS1 and current sensor CS2 are:

[0064] i CS1 =i CS2 =0 (1)

[0065] For [θ c ,θ c-a ] interval, at this time T A1 and T C2 The armature winding is turned off, and the diode is used to generate the original positive A-phase current and negative C-phase current of the armature winding. The current loop is as follows: Figure 6 As shown. At this time, in [θ c ,θ c-a ]The interval sensor measurements are:

[0066]

[0067] 2. Working left switch tube T A1 And the working right switch tube T C2 At least one switch has an open circuit fault, and θ is defined F is the electrical angle at which the switch tube has an open circuit fault. The switch tube open circuit fault can be divided into a working interval fault and a non-working interval fault. The following will analyze the single tube and double tube faults in the working interval and non-working interval in detail.

[0068] 1. Failure in the working area

[0069] (1) Working left switch tube T A1 Single tube failure

[0070] The three phases of the DSEG system based on HBSCR are independent, so TA1 Open circuit fault b and i c The waveform is still Figure 4 As shown, T A1 In case of an open circuit fault, only phase A needs to be analyzed.

[0071] T A1 After the circuit is opened, the current loop is A4 →A phase winding→T A1 →D A4 ” is transformed into “load R→D A4 →A phase winding→D A1 →Load R", the following equation can be written according to the current loop:

[0072] e a -i a r=u o (3)

[0073] In the formula, e a is the induced potential of phase A winding, r is the internal resistance of armature winding, and the current change rate corresponding to formula (3) is:

[0074]

[0075] In the formula, e ar is the A phase magnetic resistance back EMF, due to i a r is relatively small compared to other quantities, so it can be ignored. Then equation (5) can be simplified as:

[0076]

[0077] According to formula (5), we can find that Depends on af 、e ar and u o The relationship between the three, u o >0, therefore, e af +e ar -u o The amplitude can be positive or negative, so that after the fault Existence Figure 7 The three situations shown include Figure 7 As shown in (a) like Figure 7 As shown in (b) and Smaller, such as Figure 7 As shown in (c) and Larger. and When it is larger, [θ F ,θ c ]Interval i a The reason why it drops to 0 and remains at 0 is as follows: a When it just drops to 0, e ar is 0, and substituting it into formula (5), we can see that e af o , that is, the excitation back EMF is less than the output voltage. At this time, phase A cannot provide energy to the load, so i a Keep it at 0.

[0078] Combination Figure 7 i a The waveform shows that in [θ c-b ,θ c-a ] The three-phase current waveform in the interval has the following three situations: a) i a In [θ c-b ,θ c-a ] before it drops to 0, the current waveform is as follows Figure 8 As shown in (a) in .

[0079] In this case, θ = θ c-b The current loop is as follows Fig. 9 As shown, the sensor measurement value is the same as formula (1), that is, there is no obvious fault feature. θ=θ c-a The current loop is as follows Fig.10 As shown, the sensor measurements are as follows:

[0080]

[0081] Since equation (6) is different from equation (2) in the normal state, by combining θ=θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0082] b)i a In [θ c-b ,θ c-a ] drops to 0, the current waveform is as follows Figure 8 As shown in (b) in .

[0083] In this case, θ = θ c-b When the current loop is Fig.11 As shown, the sensor measurements are:

[0084] i CS1 =i CS2 =i a >0 (7)

[0085] At this time, the sensor measurement value is equation (7), which is different from equation (1) in the normal state. ​

[0086] θ=θ c-a When the current loop is Fig.10 As shown, the sensor measurement value at this time is the same as equation (6) and different from equation (3) in the normal state.

[0087] Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection. c)i a In [θ c-b ,θ c-a ] is not 0, the current waveform is as follows Figure 8 As shown in (c) in .

[0088] In this case, θ = θ c-b When the current loop is Fig.11 As shown, the sensor measurement value is the same as equation (7), which is different from equation (1) in normal conditions. c-a When the current loop is Fig.12 As shown, the sensor measurement value is the same as the normal state equation (2). Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0089] (2) Working right switch tube T C2 Single tube failure

[0090] The three phases of the DSEG system based on HBSCR are independent, so T C2 Open circuit fault a and i b The waveform is still Figure 4 As shown, T C2 In case of open circuit fault, only phase C needs to be analyzed. Define θ e i in sector 1 c The electrical angle at which the commutation ends, then the working interval T C2 The open circuit may occur at [0°,θ e ] interval or [θ e ,θ c ] interval, the sensor current after faults occur in these two intervals is analyzed separately below.

[0091] ①θ F At [0°,θ e ]Interval

[0092] [0°,θ e ]Interval i c In the phase change, the current loop is: load R→D C4 →C phase winding→D C1 →Load R, at this time T C2D C4 Reverse clamp, T C2 The fault does not affect the current loop in this section. The voltage at the phase C terminal u c The expression is as follows:

[0093]

[0094] In the formula, e cc is the self-inductance induced potential of phase C, and its value is when i c The commutation ends, i.e. θ = θ e When c is 0, and substituting it into formula (8) yields u c =e cf Therefore, if Fig.13 As shown, according to e cf with u o The size relationship of i c After the commutation is completed, the working state of phase C has the following two possibilities: cf |>u o When the C phase generates electricity in an uncontrolled rectifier mode, i c ≠0, such as Fig.13 As shown in (a) in the figure. When |e cf | o When the C phase winding cannot provide energy to the load, i c =0, such as Fig.13 Therefore, the following will analyze [θ c-b ,θ c-a ]Interval i c ≠0 and i c =0 these two situations.

[0095] a)i c ≠0

[0096] θ=θ c-b When the current loop is Fig.14 As shown, the sensor measurement value is the same as equation (6), which is different from equation (1) in the normal state.

[0097] θ=θ c-a When the current loop is Fig.15 As shown, the sensor measurement value at this time is the same as equation (2) in the normal state.

[0098] Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0099] b)i c =0

[0100] ​θ=θ c-b When the current loop is Fig.16 As shown, the sensor measurement value is the same as equation (1) in the normal state.

[0101] θ=θ c-a When the current loop is Fig.17 As shown, the sensor measurement value is the same as equation (7), which is different from equation (2) in the normal state.

[0102] Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0103] ②θ F In [θ e ,θ c ]Interval

[0104] T C2 After a fault occurs in this section, the current loop is: load R→D C2 →C phase winding→D C3 → Load R. According to the current loop, the following equation can be written:

[0105] e c -i c r=-u o (9)

[0106] In the formula, e c is the induced potential of the C-phase winding, and the current change rate corresponding to equation (9) is:

[0107]

[0108] In the formula, e cr is the C phase magnetoresistance back EMF, due to i c r is relatively small compared to other quantities, so it can be ignored. Then formula (10) can be simplified as:

[0109]

[0110] From the above formula, we can get: Depends on cf 、e cr and u o The relationship between the three, u o >0, so e cf +e cr -u o The amplitude can be positive or negative, making In [θ F ,θ c ] The interval exists as Fig.18The three situations shown are as follows: Fig.18 As shown in (a) Fig.18 As shown in (b) and Smaller, Fig.18 As shown in (c) and Larger. and When [θ F ,θ c ]Interval i c will rise to 0 and remain at 0 for the following reasons: c When it just rises to 0, e cr is 0, and substituting it into formula (11), we can see that -e cf o , phase C cannot provide energy to the load, i c Keep it at 0.

[0111] Combination Fig.18 It can be seen that in [θ c-b ,θ c-a ] There are three situations in the interval: 1)i c In [θ c-b ,θ c-a ] rose to 0.2)i c In [θ c-b ,θ c-a ] rises to 0.3)i c In [θ c-b ,θ c-a ] is not 0. Among them, the analysis of cases 1) and 3) is the same as θ F At [0°,θ e ] interval, and will not be repeated here. The following will analyze situation 2).

[0112] i c In [θ c-b ,θ c-a ]When the C phase current waveform rises to 0, Fig.19 As shown. θ=θ c-b The current loop is as follows Fig.14 As shown, the sensor measurement value is the same as equation (6), which is different from equation (1) in the normal state. θ=θ c-a When the current loop is Fig.17 As shown, the sensor measurement value is the same as equation (7), which is different from equation (2) in the normal state. Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0113] ​(3) Working left switch tube T A1 And the working right switch tube T C2 Double pipe failure

[0114] Since the three-phase currents are independent, T A1 T C2 Open circuit fault a and i c The situation can be regarded as T A1 Open circuit fault a and T C2 Open circuit fault c Combining the analysis of (1) and (2), we can get T A1 T C2 After an open circuit fault, c-b ,θ c-a The phase current waveform of the interval is as follows Fig. 20 The 9 situations shown are analyzed in detail below.

[0115] a) Fig. 20 T under (a) A1 T C2 Open Circuit Fault Analysis

[0116] θ=θ c-b and θ = θ c-a The current loop is as follows Fig.21 As shown, the sensor measurement value is the same as formula (1). θ = θ c-a The current characteristics of the sensor are different from those in the normal state (2). Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0117] b) Fig. 20 T under (b) A1 T C2 Open Circuit Fault Analysis

[0118] θ=θ c-b The current loop is as follows Fig. 22 As shown, the sensor measurement value is the same as equation (6). θ = θ c-a The current loop is as follows Fig.21 As shown, the sensor measurement value is the same as formula (1).

[0119] θ=θ c-b and θ = θ c-a The current characteristics of the sensor are different from those in normal conditions. Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0120] c) Fig. 20 T under (c) A1 T C2 Open Circuit Fault Analysis

[0121] θ=θ c-b and θ = θ c-a The current loop is as follows Fig. 22 As shown, the sensor measurement value is the same as formula (6), which is different from the sensor current characteristics in normal state. Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0122] d) Fig. 20 T under (d) A1 T C2 Open Circuit Fault Analysis

[0123] θ=θ c-b The current loop is as follows Fig.23 As shown, the sensor measurement value is the same as equation (7). θ = θ c-a The current loop is as follows Fig.21 As shown, the sensor measurement value is the same as formula (1). θ = θ c-b and θ = θ c-a The sensor current characteristics at this time are different from those at normal time. Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0124] e) Fig. 20 T under (e) A1 T C2 Open Circuit Fault Analysis

[0125] θ=θ c-b The current loop is as follows Fig.24 As shown, the sensor measurement value is the same as equation (2). θ = θ c-a The current loop is as follows Fig.21 As shown, the sensor measurement value is the same as formula (1). θ = θ c-b and θ = θ c-a The sensor current characteristics at this time are different from those at normal time. Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0126] f) Fig. 20 T under (f) A1 T C2 Open Circuit Fault Analysis

[0127] θ=θ c-bThe current loop is as follows Fig.24 As shown, the sensor measurement value is the same as equation (2). θ = θ c-a The current loop is as follows Fig. 22 As shown, the sensor measurement value is the same as equation (6). θ = θ c-b and θ = θ c-a The sensor current characteristics at this time are different from those at normal time. Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0128] g) Fig. 20 T under (g) A1 T C2 Open Circuit Fault Analysis

[0129] θ=θ c-b and θ = θ c-a The current loop is as follows Fig.23 As shown, the sensor measurement value is the same as equation (7). θ = θ c-b and θ = θ c-a The sensor current characteristics at this time are different from those at normal time. Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0130] h) Fig. 20 T under (h) A1 T C2 Open Circuit Fault Analysis

[0131] θ=θ c-b The current loop is as follows Fig.24 As shown, the sensor measurement value is the same as equation (2). θ = θ c-a The current loop is as follows Fig.23 As shown, the sensor measurement value is the same as equation (7). θ = θ c-b and θ = θ c-a The sensor current characteristics at this time are different from those at normal time. Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0132] i) Fig. 20 T under (i) A1 T C2 Open Circuit Fault Analysis

[0133] θ=θ c-b and θ = θ c-a The current loop is as follows Fig.24 As shown, the sensor measurement value is the same as formula (2), θ = θ c-bThe sensor current characteristics at this time are different from those of the normal state (1). Therefore, by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0134] 2. Non-working interval failure

[0135] Since the switch tube does not work in the non-working interval, an open circuit fault occurs at this time, and there is no fault feature. It is necessary to c-b ,θ c-a ] interval for fault detection. A1 Open circuit fault, T C2 Open circuit fault and T A1 T C2 Analyze open circuit fault.

[0136] (1) Working left switch tube T A1 Single tube failure

[0137] When the next electrical angle cycle θ = 0°, i a =0, at this time is approximately 0 and can be ignored. It can be simplified to:

[0138]

[0139] According to e af with u o There are two possibilities for the relationship between the size of e: af >u o When the A phase generates electricity in an uncontrolled rectifier mode, i a ≠0, such as Fig.25 As shown in (a) in the figure. af o When the A phase winding cannot provide energy to the load, i a =0, such as Fig.25 These two situations are respectively related to Figure 8 (c) and Figure 8 The analysis of the situation corresponding to (a) in FIG. 1 is the same, so it will not be repeated here.

[0140] (2) Working right switch tube T C2 Single tube failure

[0141] θ=θ e When c =0, and e can be ignored. cr , replace the formula (11) Simplified to:

[0142] ​

[0143] According to e cf with u o There are two possibilities for the relationship between the size of |e cf |>u o When the C phase generates electricity in an uncontrolled rectifier mode, i c ≠0. when|e cf | o When the C phase winding cannot provide energy to the load, i c = 0. The analysis of these two cases and [0°,θ e ]Interval T C2 The analysis of open circuit fault is the same and will not be repeated here.

[0144] (3) Working left switch tube T A1 And the working right switch tube T C2 Double pipe failure

[0145] In formula (13), e cf =-e af According to formula (12) and formula (13), we can find that i a and i c After 0, and The absolute values ​​of are equal and the signs are opposite. Therefore, when e af o That is |e cf | o When phase A and phase C cannot provide energy to the load, i a and i c All remain at 0. af >u o That is |e cf |>u o hour, Both phase A and phase C operate in uncontrolled rectification mode. a and i c Both are not 0. These two cases are respectively related to Fig. 20 (a) and Fig. 20 The situation corresponding to (i) in the above is the same, so I will not repeat it here.

[0146] In summary, in the above cases, T A1 Single tube open circuit, T C2 Single open circuit and T A1 T C2 The fault detection characteristics of the two tubes when they are open are different, so the ... c-b and θ = θ c-a The sensor current characteristics at T A1 and T​​​C2 Single and double tube fault detection.

[0147] Since the three sectors are symmetrical, the impact of the failure of the left and right switch tubes in the other two sectors can be obtained by analogy, and no further explanation is given. In summary, during the operation of the DSEG system, according to the two currents in each sector [θ c-b ,θ s +θ c ] interval and [θ s +θ c ,θ c-a ] The combined current characteristics of the interval can realize fault diagnosis. Based on the analysis of the above sector 1, the open circuit fault detection characteristic table in any sector can be obtained:

[0148]

[0149]

[0150] Among them, T L is the working left switch of the current sector, T R It is the working right switch of the current sector. L It is the working left switch tube T of the current sector L Phase current of the connected armature winding, i R It is the working right switch tube T of the current sector R Phase current of the connected armature winding:

[0151] In sector 1, T L =T A1 , T R =T C2 ,i L =i a ,i R =i c .

[0152] In sector 2, T L =T B1 , T R =T A2 ,i L =i b ,i R =i a .

[0153] In sector 3, T L =T C1 , T R =T B2 ,i L =i c ,i R =i b.

[0154] Based on the above analysis and the obtained open circuit fault detection characteristic table, the DSEG system HBSCR fault diagnosis method of the present application includes:

[0155] During the operation of the DSEG system, the current value i of the current sensor CS1 is collected. CS1 and the current value i of the current sensor CS2 CS2 , when in the current sector [θ s ,θ e ] within [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 When , it is determined that the working left switch tube and the working right switch tube of the current sector are both working normally, otherwise it is determined that the working left switch tube and the working right switch tube of the current sector have open circuit faults.

[0156] Furthermore, the fault diagnosis method of the present application can also realize specific fault location, including three situations:

[0157] (1) When the following conditions are detected, it is determined that the working left switch tube of the current sector has an open circuit fault and the working right switch tube of the current sector works normally:

[0158] In the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour.

[0159] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θs +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour.

[0160] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 hour.

[0161] (2) When the following conditions are detected, it is determined that the working right switch tube of the current sector has an open circuit fault and the working left switch tube of the current sector works normally:

[0162] In the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 hour.

[0163] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour.

[0164] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour.

[0165] (3) When the following conditions are detected, it is determined that both the working left switch tube and the working right switch tube of the current sector have open circuit faults:

[0166] In the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock.

[0167] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock.

[0168] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and iCS1 ≠i CS2 hour.

[0169] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock.

[0170] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock.

[0171] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour.

[0172] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、iCS2 >0 and i CS1 =i CS2 hour.

[0173] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour.

[0174] Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 hour.

[0175] The above is only a preferred embodiment of the present application, and the present application is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present application should be considered to be included in the protection scope of the present application.

Claims

1. A DSEG system HBSCR fault diagnosis method based on bus current, characterized in that: In the DSEG system, each phase armature winding in the electrically excited double-salient-pole generator is respectively connected to the midpoint of the left bridge arm and the midpoint of the right bridge arm in the HBSCR, and a current sensor CS2 is also provided on the positive pole of the busbar between the equipotential connection ends of the three left bridge arms and the equipotential connection ends of the three right bridge arms in the HBSCR, and a current sensor CS1 is also provided on the positive pole of the busbar between the equipotential connection ends of the three right bridge arms and the positive pole of the load resistor; the DSEG system HBSCR fault diagnosis method includes: When in the current sector [θ s ,θ e ] within [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 When the left switch tube and the right switch tube of the current sector are both working normally, it is determined that the left switch tube and the right switch tube of the current sector have an open circuit fault; otherwise, it is determined that the left switch tube and the right switch tube of the current sector have an open circuit fault; Among them, i CS1 is the sampling current of current sensor CS1, i CS2 is the sampling current of the current sensor CS2; the working left switch tube of the current sector is the lower bridge arm switch tube located in the left bridge arm connected to one of the phase windings and turned on in the current sector, the working right switch tube of the current sector is the lower bridge arm switch tube located in the right bridge arm connected to one of the phase windings and turned on in the current sector, and the working left switch tube and the working right switch tube of the current sector are in the [θ s ,θ s +θ c ] interval, in the current sector [θ s +θ c ,θ e ] is turned off within the interval; θ c-b is θ s +θ c The electrical angle corresponding to the most recent sampling moment of the two current sensors, θ c-a is θ s +θ c Then the electrical angle corresponding to the most recent sampling moment of the two current sensors.

2. The DSEG system HBSCR fault diagnosis method according to claim 1, characterized in that: When the following conditions are detected, it is determined that the working left switch tube of the current sector has an open circuit fault and the working right switch tube of the current sector works normally: In the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 hour.

3. The DSEG system HBSCR fault diagnosis method according to claim 1, characterized in that: When the following conditions are detected, it is determined that the working right switch tube of the current sector has an open circuit fault and the working left switch tube of the current sector works normally: In the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 hour; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour.

4. The DSEG system HBSCR fault diagnosis method according to claim 1, characterized in that: When the following conditions are met, it is determined that both the working left switch tube and the working right switch tube of the current sector have open circuit faults: In the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 =i CS2 = 0, and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 =i CS2 =0 o'clock; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 =0 and i CS1 ≠i CS2 hour; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 =i CS2 hour; Or, in the current sector [θ c-b ,θ s +θ c ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 , and in [θ s +θ c ,θ c-a ] interval detected i CS1 >0、i CS2 >0 and i CS1 ≠i CS2 hour.

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