Fault diagnosis method of HBSCR in DSEG system based on bus current

Abstract

This application discloses a bus current-based fault diagnosis method for a DSEG system HBSCR, which relates to the field of H-bridge half-controlled rectifiers. This method adds a current sensor to 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 in the HBSCR, and adds a current sensor to 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. Fault detection is achieved by combining the current characteristics of the last set of current sampling values ​​before the end of the working interval of each sector and the first set of current sampling values ​​after the end of the working interval. This method is simple to implement and requires little computation, filling a technical gap in the industry. Furthermore, this method is not affected by speed or load changes, nor by the location of the fault, and has wide applicability.

Description

Technical Field

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

[0002] Doubly Salient Electromagnetic Generators (DSEGs) are widely favored for their simple structure, high reliability, and robust fault tolerance, demonstrating significant potential in fields such as aviation and wind power generation. Compared to traditional uncontrolled rectifier systems, DSEG systems employing H-bridge semi-controlled rectifiers (HBSCRs) offer independent three-phase currents, a shorter commutation period, and reduced iron and copper losses. Furthermore, H-bridge semi-controlled rectifier systems can control armature current by adjusting the conduction angle of the switching transistors, thereby increasing motor output power and improving performance. Consequently, these systems have garnered significant attention in academia.

[0003] However, due to the harsh working environment, the HBSCR has become the most prone to failure in the DSEG system. Fault types can be divided into open-circuit faults and short-circuit faults. Short-circuit faults are characterized by fast response and high damage. 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 hardware circuit processing. Open-circuit faults can cause large fluctuations in the output voltage and reduce the system's load capacity. If not diagnosed in time, it may cause secondary faults in the system. Therefore, it is of great significance to conduct research on the diagnosis method of the open-circuit fault of the HBSCR switch tube. However, 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 response to the above-mentioned 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 bus current-based HBSCR fault diagnosis method for a DSEG system is disclosed. In the DSEG system, each phase armature winding in an electrically excited doubly salient-pole generator is connected to the midpoint of a left bridge arm and the midpoint of a right bridge arm in the HBSCR, respectively. A current sensor CS2 is provided 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 in the HBSCR, and a current sensor CS1 is provided 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. 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 , 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 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 phase winding and is turned on in the current sector, and 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 phase winding and is turned on in the current sector, and the working left switch tube and the working right switch tube of the current sector are [θ s ,θ s +θ c ] interval, in the current sector [θ s +θ c ,θ e ] interval is turned off; 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 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 is working normally when it is detected that the following conditions are met:

[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, within 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, within 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 is working normally when it is detected that the following conditions are met:

[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, within 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, within 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, within 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, within 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, within 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, within 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, within 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, within 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, within 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, within 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] This application discloses a bus current-based fault diagnosis method for HBSCRs in a DSEG system. This method only requires the addition of two current sensors to the positive pole of the busbar in a traditional topology. This method can detect faults by combining the current characteristics of the last set of current sampling values ​​before the end of the working interval of each sector with the first set of current sampling values ​​after the end of the working interval. This method is simple to implement and requires little computation, filling a technical gap in the industry. Furthermore, although this method requires the addition of two current sensors, the current sensors are added to the busbar, so there is no need to change the rectifier topology. This makes it 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 the fault, but also locate the faulty switch tube. Moreover, this method is not affected by changes in speed or load, nor is it affected by the location of the fault, and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This 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 an APC control strategy for DSEG system based on HBSCR.

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

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

[0034] Figure 6 is in 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 open circuit fault i 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] Figure 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] Figure 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] Figure 11 is in sector 1, i a In [θ c-b ,θ c-a ]When the inner drop is 0, θ=θ c-b The current loop when .

[0040] Figure 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] Figure 13 is in sector 1, T C2 Single tube open circuit fault and θ F At [0°,θ e ]Interval time i c waveform.

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

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

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

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

[0046] Figure 18 It's T C2 Single tube open circuit fault and θ F In [θ e ,θ c ]Interval time i c waveform.

[0047] Figure 19 It's 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] Figure 20 is in sector 1, [0°,θ c ]In the interval T A1 T C2 After the double tube is opened [θ c-b ,θ c-a ]phase current waveform in the interval.

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

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

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

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

[0053] Figure 25 In the non-working interval of sector 1, T A1 When a single tube open circuit fault occurs a waveform. DETAILED DESCRIPTION

[0054] The specific implementation of this application will be further described below with reference to the accompanying drawings.

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

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

[0057] The fault diagnosis method of this application is based on the classic DSEG system Angular Position Control (APC) strategy, please refer to Figure 3 The control strategy shown in the figure is as follows. p = a, b, c represent the armature windings of phases A, B, and C of the electrically excited doubly salient generator, 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 electromotive force, and θ is the rotor position angle. The DSEG system takes 0° to 360° as a control cycle and is 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° to 120°, sector 2 covering 120° to 240°, and sector 3 covering 240° to 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, 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 analysis takes sector 1 as an example to analyze the working left switch tube T 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 normally

[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 sensor current characteristics in the two intervals in turn. b and i c The commutation situation, [0°,θ c ] The phase current waveforms of the interval are as follows Figure 4 The five cases 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, [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 Turn off, and the diode is used to generate freewheeling power for the original positive phase A current and negative phase C current of the armature winding. The current loop is as follows: Figure 6 As shown. At this time, in [θ c ,θ c-a ]Interval sensor measurement values ​​are:

[0066]

[0067] 2. Working left switch tube T A1 And the working right switch tube T C2 There is at least one open circuit fault in the switch tube, define θ F is the electrical angle at which an open-circuit fault occurs in the switching tube. Switching tube open-circuit faults can be categorized as operating range faults and non-operating range faults. The following details single-tube and dual-tube faults in the operating and non-operating ranges.

[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 open circuit fault, only phase A needs to be analyzed.

[0071] T A1 After the circuit is opened, the current loop is connected by "D 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 based on the current loop:

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

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

[0074]

[0075] Where, e ar is the A-phase magnetoresistance back electromotive force, due to i a r is relatively small compared to other quantities, so it can be ignored. Then formula (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, so 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 large, [θ F ,θ c ]Interval i a The reason why it remains at 0 after falling to 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] Combine Figure 7 i a The waveform shows that in [θ c-b ,θ c-a ] The three-phase current waveforms in the interval have 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 Figure 9 As shown, the sensor measurement value is the same as formula (1), that is, there is no obvious fault feature. c-a The current loop is as follows Figure 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 Figure 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 formula (7), which is different from formula (1) in the normal state. ​

[0086] θ=θ c-a When the current loop is Figure 10 As shown, the sensor measurement value at this time is the same as formula (6), and different from formula (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 Figure 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 Figure 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 is i in sector 1 c The electrical angle at which 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 the fault occurs in these two intervals is analyzed respectively below.

[0091] ①θ F At [0°,θ e ] interval

[0092] [0°,θ e ]Interval i c In commutation, 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] Where, e cc is the self-inductance induced potential of phase C, and its value is when i c The commutation ends when θ=θ e When c is 0, and substituting it into formula (8) we can get u c =e cf Therefore, if Figure 13 As shown, according to e cf with u o The size relationship, 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 Figure 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 Figure 13 Therefore, the following analyses [θ c-b ,θ c-a ]Interval i c ≠0 and i c =0 these two cases.

[0095] a)i c ≠0

[0096] θ=θ c-b When the current loop is Figure 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 Figure 15 As shown, the sensor measurement value at this time is the same as formula (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 Figure 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 Figure 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. The following equation can be written based on the current loop:

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

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

[0107]

[0108] Where, e cr is the C phase magnetoresistance back electromotive force, due to i c r is relatively small compared to other quantities and can therefore be ignored. Then formula (10) can be simplified to:

[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 Figure 18The three situations shown are as follows: Figure 18 As shown in (a) Figure 18 As shown in (b) and Smaller, Figure 18 As shown in (c) and Larger. and When it is large, [θ F ,θ c ]Interval i c It will rise to 0 and remain at 0 for the following reasons: c When it just rises to 0, e cr is 0, and it is substituted into formula (11) to know that -e cf o , Phase C cannot provide energy to the load, i c Keep it at 0.

[0111] Combine Figure 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, no further details will be given, and 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, Figure 19 As shown. θ=θ c-b The current loop is as follows Figure 14 As shown, the sensor measurement value is the same as equation (6), which is different from equation (1) in normal state. c-a When the current loop is Figure 17 As shown, the sensor measurement value is the same as formula (7), which is different from formula (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 the open circuit fault, [θ c-b ,θ c-a ]Interval phase current waveform is as follows Figure 20 The following are 9 situations that are analyzed in detail.

[0115] a) Figure 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 Figure 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), so by combining θ = θ c-b and θ = θ c-a The sensor current characteristics at this time can realize fault detection.

[0117] b) Figure 20 T under (b) A1 T C2 Open circuit fault analysis

[0118] θ=θ c-b The current loop is as follows Figure 22 As shown, the sensor measurement value is the same as formula (6). θ=θ c-a The current loop is as follows Figure 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 state. 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) Figure 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 Figure 22 As shown, the sensor measurement value is the same as that of formula (6), which is different from the sensor current characteristics under 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.

[0122] d) Figure 20 T under (d) A1 T C2 Open circuit fault analysis

[0123] θ=θ c-b The current loop is as follows Figure 23 As shown, the sensor measurement value is the same as formula (7). θ=θ c-a The current loop is as follows Figure 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) Figure 20 T under (e) A1 T C2 Open circuit fault analysis

[0125] θ=θ c-b The current loop is as follows Figure 24 As shown, the sensor measurement value is the same as formula (2). θ=θ c-a The current loop is as follows Figure 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) Figure 20 T under (f) A1 T C2 Open circuit fault analysis

[0127] θ=θ c-bThe current loop is as follows Figure 24 As shown, the sensor measurement value is the same as formula (2). θ=θ c-a The current loop is as follows Figure 22 As shown, the sensor measurement value is the same as formula (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) Figure 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 Figure 23 As shown, the sensor measurement value is the same as formula (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) Figure 20 T under (h) A1 T C2 Open circuit fault analysis

[0131] θ=θ c-b The current loop is as follows Figure 24 As shown, the sensor measurement value is the same as formula (2). θ=θ c-a The current loop is as follows Figure 23 As shown, the sensor measurement value is the same as formula (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) Figure 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 Figure 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 [θ c-b ,θ c-a ] interval to perform fault detection. A1 Open circuit fault, T C2 Open circuit fault and T A1 T C2 Analyze open circuit faults.

[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 phase A generates electricity in an uncontrolled rectifier mode, i a ≠0, such as Figure 25 As shown in (a) in the figure. When e af o When the A phase winding cannot provide energy to the load, i a =0, such as Figure 25 These two situations are respectively related to Figure 8 (c) and Figure 8 The analysis of the situation corresponding to (a) in the preceding text 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, similarly, 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), it can be found that i a and i c After 0, and The absolute values ​​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, Phase A and phase C are both operated in uncontrolled rectification mode, i a and i c Both are not 0. These two cases are respectively related to Figure 20 (a) and Figure 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 tube 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 will not be described in detail. 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 be used to 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 It is the working left switch of the current sector, T R It is the working right switch of the current sector. L 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 is working 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, within 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, within 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 is working 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, within 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, within 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, within 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, within 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, within 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, within 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, within 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, within 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, within 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, within 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 description 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 variations directly derived or imagined 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 scope of protection 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 of the electrically excited doubly salient generator is connected to the midpoint of the left bridge arm and the midpoint of the right bridge arm of the HBSCR. A current sensor CS2 is provided 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 of the HBSCR. A current sensor CS1 is provided 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. The DSEG system takes 0° to 360° as a control cycle and is equally divided into three sectors. The electrical angle interval covered by each sector is recorded as [ i s ,i e ], in each sector, two lower bridge arm switches are turned on and the conduction angle of the switch tube is i c , each sector has two lower bridge arm switches in the current sector [ i s , i s + i c ] interval, in the current sector [ i s + i c , i e ] is turned off within the interval; The DSEG system HBSCR fault diagnosis method includes: When in the current sector [ i s ,i e [ within ] i c-b ,i s +θ c ]Interval detected i CS1 = i CS2 =0, and in [ i s +θ c ,i 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 an open circuit fault; in, 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 is turned on in the current sector, and 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 is 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 [ i s ,i s +θ c ] interval, in the current sector [ i s +θ c ,i e ] is turned off within the interval; i c-b yes i s +θ c The electrical angle corresponding to the most recent sampling moment of the two current sensors, i c-a yes i s +θ c The electrical angle corresponding to the most recent sampling moment of the two current sensors; When the following conditions are detected, it is determined that the left switch tube of the current sector has an open circuit fault and the right switch tube of the current sector is working normally: i c-b ,i s +θ c ]Interval detected i CS1 = i CS2 =0, and in [ i s + i c ,i c-a ]Interval detected i CS1 >0, i CS2 =0 and i CS1 ≠ i CS2 When; or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 >0 and i CS1 = i CS2 , and in [ i s +θ c ,i c-a ]Interval detected i CS1 >0, i CS2 =0 and i CS1 ≠ i CS2 When; or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 >0 and i CS1 = i CS2 , and in [ i s +θ c ,i c-a ]Interval detected i CS1 >0, i CS2 >0 and i CS1 ≠ i CS2 hour; 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 is working normally: i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 =0 and i CS1 ≠ i CS2 , and in [ i s +θ c ,i c-a ]Interval detected i CS1 >0, i CS2 >0 and i CS1 ≠ i CS2 When; or, in the current sector [ i c-b ,i s + i c ]Interval detected i CS1 = i CS2 =0, and in [ i s +θ c ,i c-a ]Interval detected i CS1 >0, i CS2 >0 and i CS1 = i CS2 When; or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 =0 and i CS1 ≠ i CS2 , and in [ i s +θ c ,i c-a ]Interval detected i CS1 >0, i CS2 >0 and i CS1 = i CS2 hour.

2. The DSEG system HBSCR fault diagnosis method according to claim 1, characterized in that: When the following conditions are detected, determine whether the current sector’s working left switch tube and working right switch tube are present open circuit fault: In the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 = i CS2 =0, and in [ i s +θ c ,i c-a ]Interval detected i CS1 = i CS2 =0; Or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 =0 and i CS1 ≠ i CS2 , and in [ i s +θ c , i c-a ]Interval detected i CS1 = i CS2 =0; Or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 =0 and i CS1 ≠ i CS2 , and in [ i s +θ c , i c-a ]Interval detected i CS1 >0, i CS2 =0 and i CS1 ≠ i CS2 hour; Or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 >0 and i CS1 = i CS2 , and in [ i s +θ c , i c-a ]Interval detected i CS1 = i CS2 =0; Or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 >0 and i CS1 ≠ i CS2 , and in [ i s +θ c , i c-a ]Interval detected i CS1 = i CS2 =0; Or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 >0 and i CS1 ≠ i CS2 , and in [ i s +θ c , i c-a ]Interval detected i CS1 >0, i CS2 =0 and i CS1 ≠ i CS2 hour; Or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 >0 and i CS1 = i CS2 , and in [ i s +θ c , i c-a ]Interval detected i CS1 >0, i CS2 >0 and i CS1 = i CS2 hour; Or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 >0 and i CS1 ≠ i CS2 , and in [ i s +θ c , i c-a ]Interval detected i CS1 >0, i CS2 >0 and i CS1 = i CS2 hour; Or, in the current sector [ i c-b ,i s +θ c ]Interval detected i CS1 >0, i CS2 >0 and i CS1 ≠ i CS2 , and in [ i s +θ c , i c-a ]Interval detected i CS1 >0, i CS2 >0 and i CS1 ≠ i CS2 hour.

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