CN112034394B - Rectifier open-circuit fault diagnosis method based on current half-wave difference and electronic equipment - Google Patents

Rectifier open-circuit fault diagnosis method based on current half-wave difference and electronic equipment Download PDF

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CN112034394B
CN112034394B CN202011211006.5A CN202011211006A CN112034394B CN 112034394 B CN112034394 B CN 112034394B CN 202011211006 A CN202011211006 A CN 202011211006A CN 112034394 B CN112034394 B CN 112034394B
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open
circuit fault
current
network side
bridge arm
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CN112034394A (en
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伍珣
成庶
于天剑
刘暾
赵俊栋
胡裕松
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Central South University
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/54—Testing for continuity
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
    • G01R19/16571—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/26—Testing of individual semiconductor devices
    • G01R31/2607—Circuits therefor
    • G01R31/2608—Circuits therefor for testing bipolar transistors

Abstract

The invention provides a rectifier open-circuit fault diagnosis method based on current half-wave difference, wherein a rectifier is a single-phase four-quadrant full-bridge rectifier and comprises the following steps: standardizing the network side input current to obtain a standard network side input current; acquiring and storing the standard network side input current of the sampling points in real time, and calculating the difference value between the sum value and the error of the standard network side input current of the kth sampling point and k-n/2 sampling points, wherein n is the number of the sampling points of each current period, and the number of the sampling points of the positive half cycle and the negative half cycle is the same; the number of the stored sampling points is less than or equal to n; and comparing the difference value with a threshold value, and judging the type of the open-circuit fault to be an IGBT open-circuit fault or an anti-parallel diode open-circuit fault. The IGBT open-circuit fault and the anti-parallel diode open-circuit fault are distinguished through the reduction degree of the amplitude of the input current at the network side, fault diagnosis can be performed rapidly and effectively in real time, and good anti-interference performance and robustness are achieved for load change, network side voltage change and carrier change.

Description

Rectifier open-circuit fault diagnosis method based on current half-wave difference and electronic equipment
Technical Field
The invention relates to the technical field of rectifiers, in particular to a single-phase four-quadrant rectifier open-circuit fault diagnosis method based on current half-wave difference and electronic equipment.
Background
The single-phase four-quadrant rectifier is used as a train power supply side converter and is an important component of the whole converter system. By means of a simple hardware structure, the single-phase four-quadrant rectifier can obtain a power factor close to 1, reduce harmonic content, realize bidirectional flow of energy and reduce electromagnetic interference on the external environment. Due to the complexity of control of power electronic devices, misoperation, device aging, environmental interference, mechanical vibration and the like, the single-phase four-quadrant rectifier inevitably has various faults. According to the fault statistics of the past literature, the single-phase four-quadrant rectifier and the PWM inverter occupy higher fault rate, and the fault reasons mainly comprise burning loss of an IGBT internal module, vibration cracking of the IGBT module, line looseness and poor contact. Thus, the fault appears to be primarily an open circuit fault.
For a single-phase four-quadrant rectifier, an IGBT open-circuit fault will result in reduced dc side voltage amplitude, increased ripple, reduced power factor, and distortion of the net side input current. For the whole converter system, the harmonic content on the network side is increased due to the IGBT open circuit fault, and meanwhile, the normal work of the direct-current side load is seriously influenced, so that great potential safety hazard is brought to the whole system. After the single-phase four-quadrant rectifier has an open-circuit fault, corresponding emergency measures need to be taken as soon as possible to avoid the occurrence of secondary faults and reduce unnecessary loss. Therefore, real-time open-circuit fault diagnosis appears to be crucial.
The existing diagnosis method can be realized only by giving a control signal to an interface, and some uncertainty problems can be caused by disassembling or changing the original system.
Disclosure of Invention
In view of this, the present invention provides a rectifier open-circuit fault diagnosis method based on half-wave current difference, so as to solve the problems of complexity and low accuracy of the existing diagnosis method.
Based on the above purpose, the present invention provides a method for diagnosing an open-circuit fault of a rectifier based on a half-wave difference of current, wherein the rectifier is a single-phase four-quadrant full-bridge rectifier, and the method comprises:
standardizing the network side input current to obtain a standard network side input current so as to reduce the influence of the load on the current amplitude of the network side input current;
acquiring and storing the standard network side input current of a sampling point in real time, and calculating the difference value between the sum value and the error of the standard network side input current of the kth sampling point and the kth-n/2 sampling point, wherein n is the number of sampling points of each current period, and the number of sampling points of a positive half cycle is the same as that of sampling points of a negative half cycle; the number of the stored sampling points is less than or equal to n;
and comparing the difference value with a threshold value, and judging the type of the open-circuit fault, wherein the type of the open-circuit fault is an IGBT open-circuit fault or an anti-parallel diode open-circuit fault.
An embodiment of the present invention further provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the method is implemented as described above.
From the above, it can be seen that the method provided by the invention can obtain the residual error only by adding the sampling point acquired at the current moment and the data at the corresponding moment before the half cycle, and then can judge the type of the open-circuit fault as the open-circuit fault of the IGBT or the open-circuit fault of the anti-parallel diode according to the residual error. The method has the advantages of real-time, quick and effective fault diagnosis, and has better anti-interference performance and robustness for load change, network side voltage change and carrier change.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a circuit diagram of a single-phase four-quadrant full bridge rectifier according to an embodiment of the present invention;
FIG. 2 is a flow chart of a method for diagnosing an open-circuit fault of a rectifier based on half-wave current difference according to an embodiment of the present invention;
fig. 3 is a schematic diagnostic flowchart of a rectifier open-circuit fault diagnosis method based on half-wave current difference according to an embodiment of the present invention;
FIG. 4 shows a single-phase four-quadrant rectifier at T according to an embodiment of the present invention1At open circuit faultA circuit diagram of (a);
FIG. 5 shows a single-phase four-quadrant rectifier at T according to an embodiment of the present invention2A circuit diagram at open circuit fault;
FIG. 6 shows a single-phase four-quadrant rectifier at T according to an embodiment of the present invention3A circuit diagram at open circuit fault;
FIG. 7 shows a single-phase four-quadrant rectifier at T according to an embodiment of the present invention4A circuit diagram at open circuit fault;
FIG. 8 is a diagram of a single-phase four-quadrant rectifier in D according to an embodiment of the present invention1A circuit diagram at open circuit fault;
FIG. 9 is a diagram of a single-phase four-quadrant rectifier in D2A circuit diagram at open circuit fault;
FIG. 10 shows a single-phase four-quadrant rectifier in D3A circuit diagram at open circuit fault;
FIG. 11 is a diagram of a single-phase four-quadrant rectifier in D4A circuit diagram at open circuit fault;
FIG. 12 is a diagnostic concept of the diagnostic method of an embodiment of the present invention;
fig. 13 is a flow chart of an open-circuit fault diagnosis of a single-phase four-quadrant rectifier according to an embodiment of the present invention;
FIG. 14 shows the input and output of a single-phase four-quadrant rectifier under normal operating conditions in accordance with an embodiment of the present invention;
FIG. 15 shows an embodiment of the present invention T1The diagnosis process of the single-phase four-quadrant rectifier when the open-circuit fault occurs;
FIG. 16 shows an embodiment of the present invention T2The diagnosis process of the single-phase four-quadrant rectifier when the open-circuit fault occurs;
FIG. 17 shows an embodiment of the present invention T3The diagnosis process of the single-phase four-quadrant rectifier when the open-circuit fault occurs;
FIG. 18 shows a schematic view of a view of an embodiment D of the present invention1The diagnosis process of the single-phase four-quadrant rectifier when the open-circuit fault occurs;
FIG. 19 shows a schematic view of a view of an embodiment D of the present invention2The diagnosis process of the single-phase four-quadrant rectifier when the open-circuit fault occurs;
FIG. 20 shows an embodiment of the present inventionLoad fluctuation time T of single-phase four-quadrant rectifier of embodiment1A process of diagnosing an open circuit fault;
FIG. 21 shows the single-phase four-quadrant rectifier with fluctuating load D1A process of diagnosing an open circuit fault;
FIG. 22 shows the voltage T of the single-phase four-quadrant rectifier during the network side voltage fluctuation according to the embodiment of the present invention1A process of diagnosing an open circuit fault;
FIG. 23 shows voltage fluctuation on the grid side of the single-phase four-quadrant rectifier according to the embodiment of the present invention1A process of diagnosing an open circuit fault;
FIG. 24 shows the single-phase four-quadrant rectifier of the embodiment of the present invention at a carrier frequency of 500Hz and T1D1A process of diagnosing an open circuit fault;
FIG. 25 shows the carrier frequency D of the single-phase four-quadrant rectifier at 500Hz1A process of diagnosing an open circuit fault;
FIG. 26 shows the carrier frequency T of the single-phase four-quadrant rectifier of 2kHz according to an embodiment of the present invention1A process of diagnosing an open circuit fault;
FIG. 27 shows the carrier frequency D of the single-phase four-quadrant rectifier of 2k Hz1A process of diagnosing an open circuit fault;
fig. 28 is a schematic diagram of an electronic device according to an embodiment of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings.
Referring to fig. 1, a circuit diagram of a single-phase four-quadrant full-bridge rectifier according to an embodiment of the invention includes four IGBTs, i.e., T1、T2、T3And T4And also four anti-parallel diodes, i.e. D1、D2、D3And D4. Wherein a power supply is definedu NThe positive and negative poles of the first bridge arm are shown in the figure, and the first bridge arm is close to the positive pole of the power supply; the second bridge arm is far away from the anode of the power supply; the third bridge arm is close to the negative pole of the power supply; the fourth bridge arm is far away from the negative pole of the power supply. Then there is, firstBridge arm IGBT is T1The second bridge arm IGBT is T2And the third bridge arm IGBT is T3The fourth bridge arm IGBT is T4. The first bridge arm anti-parallel diode is open-circuited to D1The second bridge arm anti-parallel diode is D2The third bridge arm anti-parallel diode is D3The fourth bridge arm anti-parallel diode is D4。
The inventor finds that under normal working conditions, the voltage output of the direct current side of the single-phase four-quadrant rectifier is constant in a certain voltage range, and the phase of the input current of the grid side is basically consistent with the voltage of the grid side and changes in a sine wave periodic manner in long-term research work of the single-phase four-quadrant rectifier. Due to the influence of carrier frequency, certain harmonic waves exist in the input current of the network side, and the harmonic wave content is related to the size of the carrier frequency.
The inventors have also observed that the net side input current will always have a half cycle time in the case of an open circuit fault, during which time the current amplitude will be reduced to different extents. The fault signature of the net side input current may be as shown in table 3-1. The inventor thinks that the single-phase four-quadrant rectifier IGBT open-circuit fault and the anti-parallel diode open-circuit fault can be diagnosed according to the distortion interval of the network side input current and the reduction degree of the current amplitude.
The inventor proposes a single-phase four-quadrant rectifier open-circuit fault diagnosis method based on half-wave difference of input current at the grid side, and the diagnosis idea is shown in fig. 12. The method distinguishes the No. 1 bit (or the No. 4 bit) (namely D) by comparing the distortion interval of the input current at the network side1Or D4) And position 2 (or position 3) (i.e. D)2Or D3) The open-circuit fault of the switching tube is distinguished from the open-circuit fault of the IGBT and the open-circuit fault of the anti-parallel diode through the reduction degree of the amplitude of the input current at the network side, and the four types of faults in the table 3-1 can be diagnosed in real time, quickly and effectively.
Referring to fig. 2 and 3, the method for diagnosing an open-circuit fault of a rectifier based on half-wave current difference according to an embodiment of the present invention includes:
s100, carrying out standardization processing on the network side input current to obtain a standard network side input current so as to reduce the influence of the load on the current amplitude of the network side input current;
s200, acquiring and storing the standard network side input current of the sampling points in real time, and calculating the difference value between the sum value and the error of the standard network side input current of the kth sampling point and the kth-n/2 sampling points, wherein n is the number of the sampling points of each current period, and the number of the sampling points of a positive half cycle is the same as that of the sampling points of a negative half cycle; the number of the stored sampling points is less than or equal to n;
and S300, comparing the difference value with a threshold value, and judging the type of the open-circuit fault, wherein the type of the open-circuit fault is an IGBT open-circuit fault or an anti-parallel diode open-circuit fault.
According to the method provided by the embodiment of the invention, the residual error can be obtained only by adding the sampling point acquired at the current moment and the data at the corresponding moment before the half period, and the type of the open-circuit fault can be judged to be the IGBT open-circuit fault or the anti-parallel diode open-circuit fault according to the residual error.
As shown in fig. 13, in step S100, the normalizing the grid-side input current to obtain a standard grid-side input current specifically includes: the normalization process is performed by equation (1). Wherein the content of the first and second substances,i N_Sfor the input current to the standard grid side,i Nfor the input of the current on the network side,i N_RMSthe root mean square effective value of the input current at the network side.
Wherein the root mean square effective value of the grid-side input current is calculated by formula (2) or formula (3). Formula (2) is formula (3) in discrete form. Wherein the content of the first and second substances,Tinputting a current fundamental wave period for a network side;nthe number of sampling points of each period of the current input to the network side is an even number which is larger than zero;i N(k) For input of current to the network sidekAnd (4) sampling points.
Figure 203178DEST_PATH_IMAGE001
（1）；
Figure 168248DEST_PATH_IMAGE002
（2）；
Figure 531096DEST_PATH_IMAGE003
（3）
In this step, the degree of influence of the current amplitude of the obtained standard grid-side input current by factors such as a load can be greatly reduced by the normalization processing of the expressions (1) and (2) or the expressions (1) and (3). Even if the load changes during the diagnostic process,i N_Sthe value of (a) is also substantially free from significant anomalies, thereby improving diagnostic accuracy.
In step S200, as shown in fig. 3, a standard grid-side input current of a sampling point may be collected in real time by a current sensor. And when the sampling points are collected, the standard network side input current of the sampling points is stored in real time. And setting the number of sampling points of each current period as n, wherein n is an even number and is larger than zero. Meanwhile, the number of sampling points of the positive half cycle and the negative half cycle of each current cycle is set to be the same, namelyn/2。
In one or more embodiments of the present invention, after the sampling time is longer than half of the current period from the time of starting sampling, that is, when the number k of the sampling point at the current time is satisfied and k > n/2, the k-th sampling point (that is, the sampling point at the current time) and the k-n/2-th sampling point (that is, the sampling point at the corresponding time before the half of the current period) start to be calculated in real time, and the sum of the currents input at the standard network sides of the two sampling points.
In an embodiment, the calculating the difference between the sum of the standard grid-side input currents and the error specifically includes:
the difference is calculated by equation (4). Wherein the content of the first and second substances,D k the difference value of the sum value and the error of the input current of the standard network side is obtained;i N_S(k) + i N_S(k - nand/2) the sum of the obtained standard network side input currents;i N_S(k) Is as followskInputting current to a standard network side of each sampling point;i N_S(k - n/2) is the followingk-n/2The normal net side input current of each sampling point,e k is an error.
i N_S(k) + i N_S(k - n/2) = D k + e k （4）
e k In order to take a small error, under normal conditions,e k the value of (c) is substantially close to zero. It is understood that equation (5) is generally satisfied for the sampling point at each time instant.
i N_S(k) + i N_S(k + n/2) = e k （5）
In one or more embodiments of the present invention, from the time of starting sampling, when the sampling time is less than or equal to one current period, that is, when the number k of the sampling point at the current time is satisfied, and k is less than or equal to n, the sampling point is directly stored in real time, so that the number of the stored sampling points is less than or equal to n.
And when the sampling time is longer than one current period, namely the number k of the sampling point at the current moment is satisfied, and k is larger than n, deleting the (k-n) th sampling point (namely the sampling point at the corresponding moment before one current period) to enable the number of the stored sampling points to be n all the time.
In one or more embodiments of the present invention, in step S300, the comparing the difference with the threshold value, and determining the type of the open-circuit fault specifically includes:
calculating the root mean square of the difference value according to the difference value;
comparing the root mean square with the threshold, and judging the type of the open-circuit fault to be an IGBT open-circuit fault when the root mean square is larger than a first threshold and smaller than a second threshold; and when the root mean square is larger than a second threshold value, judging that the type of the open-circuit fault is an anti-parallel diode open-circuit fault.
The root mean square of the difference is calculated by equation (6). Wherein the content of the first and second substances,
Figure 629502DEST_PATH_IMAGE004
is the difference valueD k Root mean square (rms).
Figure 52393DEST_PATH_IMAGE005
（6）
It should be noted that the specific values of the first threshold and the second threshold are set and adjusted according to the actual working condition of the single-phase four-quadrant rectifier.
Wherein, when T1In the event of an open-circuit fault, the control states that may be affected areS U = 1，S V= 1 andS U = 1，S Vand = 0. Wherein, the network side inputs currenti NThe effect of the fault is most obvious. When in useS U = 1，S VWhen = 1, VT1The circuit diagram for an open fault is shown in fig. 4. Due to VT1Reason for failure, original meridian T1And D3The formed current loop becomes a loop D3A DC side capacitor, and D2The current loop of (2). At this time, the network side voltage and the inductanceL NAnd energy is released to the direct current side capacitor and the load, and the current amplitude is reduced compared with the normal working condition. When in useS U = 1，S VWhen = 0, due to VT1Reason for failure, original meridian T1And T4The current loop formed becomes via T4And D2The DC side capacitor and the load form a current loop. At this time, the network side voltage is directly applied to the inductorL NAnd at the two ends, the inductor is charged, and the current amplitude is reduced.
Thus, at T1Network side input current during open circuit faulti NThe current amplitude in the negative half cycle is reduced relative to the normal condition.
When T is2In the event of an open-circuit fault, the control states that may be affected areS U = 0，S V= 1 andS U = 0，S Vand = 0. Likewise, the net side inputs currenti NAre greatly affected. When in useS U = 0，S VWhen = 1, T2Electricity under open circuit faultThe road map is shown in fig. 5. Due to T2Reason for failure, original meridian T2And T3The formed current loop becomes a loop D1And T3Forming a current loop. At this time, the DC side capacitor and the load form a current loop, and the inductor is only coupled by the network side voltageL NEnergy charging and currenti NThe charging rate of (2) is obviously reduced. When in useS U = 0，S VWhen = 0, due to T2Reason for failure, original meridian T2And D4The formed current loop becomes a loop D1A DC side capacitor, and D4The current loop of (2). At this time, the network side and the inductanceL NAnd energy is released to the direct current side capacitor and the load, and the current amplitude is reduced compared with the normal working condition.
Thus, T2When an open-circuit fault occurs, the energy of the network side inductor is reduced or even released in the energy charging stage, and the amplitude of the network side input current in the positive half cycle is generally reduced.
When T is3In the event of an open-circuit fault, the control states that may be affected areS U = 1，S V= 1 andS U = 0，S Vand = 1. Net side input currenti NChange of (2) and T2Substantially similar in open circuit fault. When in useS U = 1，S VWhen = 1, T2The circuit diagram for an open fault is shown in fig. 6. Due to T3Reason for failure, original meridian D1And T3The formed current loop becomes a loop D1A DC side capacitor, and D4The current loop of (2). At this time, the network side voltage and the inductanceL NAnd energy is released to the direct current side capacitor and the load, and the current amplitude is reduced compared with the normal working condition. When in useS U = 0，S VWhen = 1, due to T3Reason for failure, original meridian T2And T3The current loop formed becomes via T2And D4The current loop of (2). At this time, the DC side capacitor and the load form a current loop, and the inductor is only coupled by the network side voltageL NEnergy charging and currenti NThe charging rate of (2) is obviously reduced.
Therefore, the net side inductance is at T3And the energy can not be effectively stored in the open circuit fault, so that the amplitude of the input current of the network side in the positive half cycle is reduced generally.
T4In the event of an open-circuit fault, the control states that may be affected areS U = 1，S V= 0 andS U = 0，S Vand = 0. Net side input currenti NChange of (2) and T1Substantially similar in open circuit fault. When in useS U = 1，S VWhen = 0, T4The circuit diagram for an open fault is shown in fig. 7. Due to T4Reason for failure, original meridian T1And T4The current loop formed becomes via T1And D3The current loop of (2). At the moment, the DC side capacitor and the load form a current loop, and the network side voltage is directly applied to the inductorL NAnd at the two ends, the inductor is charged, and the current amplitude is reduced. When in useS U = 0，S VWhen = 0, due to T4Reason for failure, original meridian D2And T4The formed current loop becomes a loop D3A DC side capacitor, and D2The current loop of (2). At this time, the network side voltage and the inductanceL NAnd energy is released to the direct current side capacitor and the load, and the current amplitude is reduced compared with the normal working condition.
Thus, at T4At open circuit fault, with T1Open circuit fault like, net side input currenti NThe current amplitude in the negative half cycle is reduced relative to the normal condition.
D1The circuit diagram of a single-phase four-quadrant rectifier when an open-circuit fault occurs is shown in fig. 8. If the direction of current flow is negative, i.e. current flows through T1Or D2At this time D1The open circuit does not affect the normal operation of the single-phase four-quadrant rectifier. If the current direction is positive and T2When conducting, the current will pass through T2Inflow rectifier, D1Open circuit faults also do not affect the normal operation of the rectifier. When the current direction is positive and T2When the rectifier is not conducted, the current cannot form a loop through the rectifier. At this time, the currenti NClose to zero, and the net side is accompanied by higher pulse voltage, which causes great impact on other power tubes of the rectifier.
Thus, D1Open circuit fault can result in current flowi NThe current amplitude in the positive half cycle is greatly reduced.
D2The circuit diagram of a single-phase four-quadrant rectifier when an open circuit fault occurs is shown in fig. 9. If the direction of current flow is positive, i.e. current flows through D1Or T2At this time D2The open circuit does not affect the normal operation of the single-phase four-quadrant rectifier. If the current direction is negative and T1When conducting, the current will pass through T1Into the side of the net, D2Open circuit faults also do not affect the normal operation of the rectifier. When the current direction is negative and T1When not conducting, the current cannot form a loop through the rectifieri NClose to zero, a higher pulse voltage is generated on the net side.
Thus, D2Open circuit fault can result in current flowi NThe current amplitude at the negative half cycle is greatly reduced.
D3The circuit diagram of a single-phase four-quadrant rectifier when an open-circuit fault occurs is shown in fig. 10. If the direction of current flow is positive, i.e. current flows through T3Or D4At this time D3The open circuit does not affect the normal operation of the single-phase four-quadrant rectifier. If the current direction is negative and T4When conducting, the current will pass through T4Into single-phase four-quadrant rectifiers, D3Open circuit faults also do not affect the normal operation of the rectifier. When the current direction is negative and T4When not conducting, the current cannot form a loop through the rectifieri NClose to zero, a higher pulse voltage is generated on the net side.
Thus, D3Open circuit fault can result in current flowi NThe current amplitude at the negative half cycle is greatly reduced.
D4The circuit diagram of a single-phase four-quadrant rectifier when an open circuit fault occurs is shown in fig. 11. If the direction of current flow is negative, i.e. current flows through D3Or T4At this time D4Open circuit can not be pairedNormal operation of the phase four-quadrant rectifier is effected. If the current direction is positive and T3When conducting, the current will pass through T3Into the side of the net, D4Open circuit faults also do not affect the normal operation of the rectifier. When the current direction is positive and T3When not conducting, the current cannot form a loop through the rectifieri NClose to zero, a higher pulse voltage is generated on the net side.
Thus, D4Open circuit fault can result in current flowi NThe current amplitude in the positive half cycle is greatly reduced.
The correspondence between the different open circuit fault types and the grid side input current characteristics is shown in table 3-1.
TABLE 3-1 grid side input Current characteristics under different open-Circuit Fault conditions
Figure 236250DEST_PATH_IMAGE006
Through the specific steps, the magnitude relation between the root mean square and the first threshold and the magnitude relation between the root mean square and the second threshold are compared, and the IGBT open-circuit fault and the anti-parallel diode open-circuit fault can be quickly distinguished.
In another embodiment of the present invention, in step S300, the comparing the difference value with the threshold value, and the determining the type of the open-circuit fault specifically includes:
s311, respectively calculating the root mean square and the average value of the difference values according to the difference values;
s312, calculating a product of the root mean square of the difference and the average of the difference;
s313, judging the type of the open-circuit fault according to the threshold interval to which the product belongs, wherein the type of the open-circuit fault comprises a first bridge arm IGBT fault or a fourth bridge arm IGBT fault, a second bridge arm IGBT fault or a third bridge arm IGBT fault, a first bridge arm anti-parallel diode open-circuit fault or a fourth bridge arm anti-parallel diode open-circuit fault or a second bridge arm anti-parallel diode open-circuit fault or a third bridge arm anti-parallel diode open-circuit fault; the first bridge arm is close to the anode of a power supply; the second bridge arm is far away from the anode of the power supply; the third bridge arm is close to the negative pole of the power supply; and the fourth bridge arm is far away from the negative pole of the power supply.
In step S311, the root mean square of the difference is calculated by the above equation (6), and the specific content is as described above, which is not described herein again. The average value of the difference is calculated by the above equation (7) to determine the positive and negative of the difference. Wherein the content of the first and second substances,D AVEis the difference valueD k Average value of (a). By the equation (6), the positive and negative of the difference can be accurately determined.
Figure 668368DEST_PATH_IMAGE007
（7） S = D RMS·D AVE （8）
In step S312, the product of the root mean square of the difference and the average value of the difference may be calculated by equation (8). Wherein the content of the first and second substances,Sfor said product, the product may be used as a diagnostic signal.D RMSThe root mean square of the difference can be specifically calculated by the aforementioned formula (6),D AVEthe average value of the difference can be specifically calculated by the aforementioned formula (7), which is not described herein again.
In one or more embodiments of the present invention, in step S313, the determining, according to the threshold interval to which the product belongs, the type of the open-circuit fault specifically includes:
when the product belongs to a first threshold interval, judging that the first bridge arm IGBT fault or the fourth bridge arm IGBT fault exists, wherein the first threshold interval is larger than a first threshold and smaller than a second threshold;
when the product belongs to a second threshold interval, judging that the second bridge arm IGBT fault or the third bridge arm IGBT fault exists, wherein the second threshold interval is a negative value which is larger than a second threshold and smaller than a first threshold;
when the product belongs to a third threshold interval, judging that the first bridge arm anti-parallel diode open-circuit fault or the fourth bridge arm anti-parallel diode open-circuit fault exists, wherein the third threshold interval is a negative value smaller than a second threshold;
and when the product belongs to a fourth threshold interval, judging that the second bridge arm anti-parallel diode is in an open-circuit fault or the third bridge arm anti-parallel diode is in an open-circuit fault, wherein the fourth threshold interval is larger than the second threshold.
That is, the correspondence relationship between the threshold region to which the product belongs and the type of the specific open fault may be as shown in table 3-2. Wherein the content of the first and second substances,D th_lowis a first threshold value for the first time period,D th_highis the second threshold.
TABLE 3-2 SINGLE-PHASE FOUR-QUADRATORY RECTIFIER OPEN CIRCUIT FAULT DIAGNOSIS
Figure 621281DEST_PATH_IMAGE008
By calculating the product of the root mean square of the difference value and the average value of the difference value, the specific fault type of the IGBT open-circuit fault or the anti-parallel diode open-circuit fault can be more accurately judged.
In another embodiment of the present invention, in step S313, the comparing the difference with the threshold value, and the determining the type of the open-circuit fault specifically includes:
calculating the average value of the difference values according to the difference values;
and comparing the magnitude relation between the root mean square and a first threshold and a second threshold, and the magnitude between the average value and zero, and judging the specific open-circuit fault type.
The specific judgment is as follows: when the root mean square is larger than a first threshold value and smaller than a second threshold value and the average value is larger than zero, judging that the first bridge arm IGBT fault or the fourth bridge arm IGBT fault occurs; when the root mean square is larger than a first threshold value and smaller than a second threshold value and the average value is smaller than zero, judging that the second bridge arm IGBT fault or the third bridge arm IGBT fault occurs; when the root mean square is larger than a second threshold value and the average value is larger than zero, judging that the second bridge arm anti-parallel diode open-circuit fault or the third bridge arm anti-parallel diode open-circuit fault occurs; and when the root mean square is larger than a second threshold value and the average value is smaller than zero, judging that the first bridge arm anti-parallel diode open-circuit fault or the fourth bridge arm anti-parallel diode open-circuit fault occurs.
Note that for similarity to T1And T4Because the network side voltage and current after the fault and the fault characteristics of the direct current side voltage basically have no obvious difference, the fault identification of the two switching tubes can be realized only by a control signal or a mode of additionally installing an additional sensor. However, making changes to the system in practice creates a series of liability allocation problems that are difficult to deal with effectively. Therefore, the way of performing diagnosis by controlling signals or adding additional sensors is not an effective solution.
According to the rectifier open-circuit fault diagnosis method based on the current half-wave difference, provided by the embodiment of the invention, fault diagnosis can be completed only by acquiring a current signal from an existing current sensor, so that the cost can be greatly saved. Meanwhile, two types of open-circuit fault diagnosis can be realized only through the signal of the sensor: the IGBT and the anti-parallel diode can diagnose the bridge arm where the specific IGBT fault and the anti-parallel diode open-circuit fault are located. By designing an algorithm, namely, firstly carrying out standardization processing on the network side input current, then sampling, calculating the sum of the k-th sampling point and the standard network side input current of the k-n/2-th sampling point, then calculating the difference between the sum and a preset error, calculating the product of the average value of the difference and the root mean square, and obtaining a specific diagnosis result according to the threshold interval of the product, the method ensures that the load change, the network side voltage change and the carrier change can not influence the final diagnosis result, thereby being applicable to a complex working environment. In conclusion, the method has the characteristics of low cost, large diagnosis range and stability.
Examples of the experiments
And simulating the IGBT open-circuit fault and the anti-parallel diode open-circuit fault of the single-phase four-quadrant rectifier to verify the diagnosis method. The main experimental parameters are shown in tables 3-3. In the experiment, the open-circuit fault of the IGBT is simulated by closing the control signal, and the open-circuit fault of the anti-parallel diode is simulated by connecting the controllable switch in series at one side of the anti-parallel diode and controlling the switch to be turned off.
The diagnostic method comprises the following steps:
and (3) standardizing the network side input current through the formulas (1) and (3) to obtain the standard network side input current.
The standard network side input current of sampling points is collected in real time through a current sensor, the number of the sampling points in each current period is n, and the positive half cycle and the negative half cycle are bothn/2. And when the sampling points are collected, the standard network side input current of the sampling points is stored in real time. When the number k of the sampling point at the current moment meets the requirement that k is larger than n/2, calculating the difference value between the sum value of the input current of the standard network side of the kth sampling point and the kth-n/2 sampling point and the error by the formula (4) ((D k ) (ii) a When the number k of the sampling points at the current moment is satisfied, and k is less than or equal to n, the sampling points are directly stored in real time, so that the number of the stored sampling points is less than or equal to n.
The root mean square and the mean of the difference are calculated by equations (6) and (7), respectively, and S (i.e., a diagnostic signal) is calculated by equation (8).
And judging the specific type of the open-circuit fault according to the value of S: when S belongs to a first threshold interval (0,1), judging that the first bridge arm IGBT is in fault (T)1Fault) or fourth leg IGBT fault (T)4Failure);
when S belongs to a second threshold interval (-1,0), judging that the second bridge arm IGBT is in fault (T)2Fault) or third arm IGBT fault (T)3Failure);
when S belongs to a third threshold range (-infinity, -1), it is determined that the first bridge arm antiparallel diode is in an open-circuit fault (D)1Fault) or open fault of the fourth leg anti-parallel diode (D)4Failure);
when S belongs to a fourth threshold range (1, + ∞), it is determined that the second arm antiparallel diode is open-circuited (D)2Fault) or third arm antiparallel diode open circuit fault (D)3Failure).
Tables 3-3 Main Experimental parameters
Figure 215073DEST_PATH_IMAGE009
1) Validity detection of fault diagnosis method
Under normal operation, the grid-side input voltage, the grid-side input current, and the output voltage of the single-phase four-quadrant rectifier are shown in fig. 14. Due to the low carrier frequency, the input current at the network side fluctuates in a sawtooth shape and a small amplitude. The output voltage of the direct current side is basically stabilized at about 600V.
When T is1The diagnostic process for a single-phase four-quadrant rectifier in the event of an open-circuit fault is shown in fig. 15. The diagnostic method is as described above. The sequence of the input current on the grid side, the voltage on the dc side and the diagnostic signal is shown in fig. 15. T is1Open circuit fault occurs int AThe time of day. Diagnosing signals before open circuit fault occursSThe substantially irregular square wave is alternating positive and negative with an amplitude of about 0.2. This occurs because the half-wave difference of the input current on the grid side is small under normal conditions, and the sum of the corresponding sampling points is basically floated around zero value, so that the sum of the sampling points is zeroD AVEAlso varies between 1 and-1, resulting in a diagnostic signalSWith irregular square wave variations. When T is1After the open circuit fault occurs, the amplitude of the input current of the network side in the negative half cycle is reduced compared with the amplitude in the normal condition, and the amplitude in the positive half cycle is basically unchanged; the output voltage of the direct current side is in a descending trend. At this point, it is clearly observed that the value of the diagnostic signal S rises gradually and that after approximately one fundamental period of time the diagnostic signal S has passedSFinally, a stable value is reached, about 0.8, which is greater than the first threshold value 0.5 and less than the second threshold value 1, and T is diagnosed1(or T)4) And (4) generating an open-circuit fault, wherein the diagnosis result is consistent with the actual fault type. Thus, the method of embodiments of the present invention enables diagnosis of T1(or T)4) An open circuit fault occurs.
Simulation T2The diagnostic process for a single-phase four-quadrant rectifier in the event of an open-circuit fault is shown in fig. 16. Similarly, at T2Diagnosing signals before an open circuit fault occursSIrregular square wave change is achieved; at T2After an open circuit fault occurs, the dc side voltage decreases,diagnostic signalSChanges and tends to a stable value after one fundamental period. And T1The difference of open circuit faults is that the input current of the network side is distorted in the positive half cycle, the current amplitude is reduced, and the input current is kept normal in the negative half cycle; diagnostic signalSThe value after the trend to be stable is just equal to T1The values in the case of an open circuit fault are reversed, approximately-0.8, a negative value greater than the second threshold value of-1.0 and less than the first threshold value of-0.5, and a diagnosis of T is made2(or T)3) And (4) generating an open-circuit fault, wherein the diagnosis result is consistent with the actual fault type. Thus, the method of embodiments of the present invention enables diagnosis of T2(or T)3) An open circuit fault occurs.
FIG. 17 shows T3And (3) a diagnosis process of the single-phase four-quadrant rectifier when an open-circuit fault occurs. It can be seen that T is slightly different from the DC-side voltage after the fault, except for the net-side input current3Open circuit fault condition and diagnostic result and T2The open circuit condition and the diagnosis result thereof are substantially the same.
FIGS. 18 and 19 show D, respectively1Open circuit fault and D2And (3) a diagnosis process of the single-phase four-quadrant rectifier during open-circuit fault. It can be seen thatt AAfter that time, the net side input current is significantly distorted in the positive half cycle (or negative half cycle) due to the anti-parallel diode open fault. Compared with the IGBT open-circuit fault, the anti-parallel diode open-circuit fault enables the grid side input current to be more seriously lost in the positive half cycle (or the negative half cycle), and the voltage drop amplitude of the direct current side is higher. Accordingly, the half-wave difference of the net side input current is more obvious,D RMSthe value is also relatively higher. D1Open fault diagnostic signalSGradually decreases and eventually stabilizes to less than-1, follows a negative value less than a second threshold value of 1, and is diagnosed as D1(or D)4) Open circuit failure. When D is present2In case of open-circuit fault, based on the diagnosis signalSGradually rises and finally stabilizes to be greater than 1, meets a second threshold value of 1, and is diagnosed as D2(or D)3) And (4) open-circuit faults, wherein the diagnosis result is the same as the actual fault type. Therefore, the method provided by the embodiment of the invention can effectively carry out two anti-parallel connectionAnd diagnosing the pole tube open circuit fault.
Therefore, the single-phase four-quadrant rectifier open-circuit fault diagnosis method based on the half-wave difference of the input current at the network side can effectively diagnose T1(or T)4) Open circuit fault, T2(or T)3) Open circuit failure, D1(or D)4) Open circuit failure, and D2(or D)3) Open circuit failure.
2) Robust detection of fault diagnosis method during load fluctuation
When the load on the DC side changes and T1The diagnostic process for a single-phase four-quadrant rectifier in the event of an open-circuit fault is shown in fig. 20. In thatt AAt this time, the load change causes a slight increase in the dc-side voltage, and the net-side input current is slightly affected. From diagnostic signalsSIt is seen that the value is stabilized within. + -. 0.2. I.e. load variations under normal conditions do not cause any misdiagnosis. During transient after load change, i.e. before the dc-side voltage has not stabilized, T is set1Open circuit failure. It can be seen that, for the reasons of failure, thet BAfter the moment, the negative half cycle of the input current of the network side is distorted, and the positive half cycle is kept normal; the dc side voltage starts to drop. Diagnostic signalSGradually rises and finally stabilizes at about 0.8, and is diagnosed as T1(or T)4) The type of open-circuit fault is T1And (5) the consistency is achieved.
When the load on the DC side changes and D1The diagnostic process for a single-phase four-quadrant rectifier in the event of an open-circuit fault is shown in fig. 21. Similarly, load variations under normal conditions do not cause misdiagnosis. When the anti-parallel diode open circuit fault occurs shortly after the load change, the diagnosis method of the embodiment of the invention can still accurately respond. Diagnostic signalSThe output value of (D) stabilized around-1.2, indicated as D1(or D)4) Open circuit fault of type D from the actual open circuit fault1And (5) the consistency is achieved.
Therefore, the single-phase four-quadrant rectifier open-circuit fault diagnosis method based on the half-wave difference of the input current at the grid side has better robustness for load change.
3) Robust detection of fault diagnosis method during network side voltage fluctuation
FIG. 22 shows the voltage T of the single-phase four-quadrant rectifier during the network side voltage fluctuation1And (4) a diagnosis process of the open-circuit fault. The network side voltages are given in turn in the figureu NNet side input currenti NOutput voltage of DC sideU dAnd fault diagnosis signalS. In order to achieve a better visual effect, the amplitude of the net side input current is adjusted appropriately in the figure. In the experiment, the voltage amplitude is adjusted to gradually reduce the voltage on the network side. During the process of reducing the voltage of the network side, the amplitude of the input current of the network side is slowly reduced. Nevertheless, the diagnostic signal does not show a misdiagnosis phenomenon, and the value thereof is still stabilized within ± 0.2, i.e. within the first threshold interval (0, 1). In thatt ATime of day, T1An open circuit fault occurs. The negative half cycle of the net side input current is distorted while the positive half cycle remains normal. Diagnostic signalSThe value of (A) gradually increases and finally stabilizes at about 0.8, and the diagnosis result is T1(or T)4) Open circuit fault, with actual T1The open circuit fault coincides.
FIG. 23 shows the voltage fluctuation on the grid side of the single-phase four-quadrant rectifier D1And (4) a diagnosis process of the open-circuit fault. Likewise, the network-side voltage fluctuations do not cause malfunction of the diagnostic method before a fault occurs. When D is present1After an open-circuit fault occurs, the positive half cycle of the input current of the network side is distorted and kept normal in the negative half cycle, the diagnosis signal is changed and stabilized at about-1.1, and the diagnosis result is D1(or D)4) Open circuit fault, with actual T1The open circuit fault coincides.
Therefore, when the network side voltage mode fluctuates, the open-circuit fault diagnosis method provided by the embodiment of the invention has better robustness.
4) Robust detection of fault diagnosis method during carrier frequency change
When the carrier frequency of the single-phase four-quadrant rectifier is reduced, the input current of the grid side is relatively lowLarge ripple, the harmonic content is relatively higher. FIG. 24 shows T at 500Hz carrier frequency of a single-phase four-quadrant rectifier1And (4) a diagnosis process of the open-circuit fault. The waveform quality of the net side input current is significantly degraded compared to fig. 15. Especially, in the negative half cycle after the open circuit fault, the distortion of the input current on the network side is more serious. Even so, the diagnostic signal remains within ± 0.2 until failure; until the open circuit fault occurs, the output value of the diagnosis signal rises and stabilizes at about 0.8, and the diagnosis result is indicated as T1(or T)4) Open circuit fault, with actual T1The open circuit fault coincides.
FIG. 25 shows D when the carrier frequency of the single-phase four-quadrant rectifier is 500Hz1And (4) a diagnosis process of the open-circuit fault. Likewise, the net side input current exhibits a pronounced saw-tooth shape. After an open circuit fault occurs, the current approaches zero for the positive half cycle and remains substantially normal for the negative half cycle. Diagnostic signal fromt AThe moment of time begins to change and finally tends to-1.1, and the diagnosis result is indicated as D1(or D)4) Open circuit fault, with actual D1The open circuit fault coincides.
When the carrier frequency of the single-phase four-quadrant rectifier rises, the ripple of the input current at the grid side is reduced, and the harmonic content is relatively reduced. At this time, the current waveform is closer to a sine wave, and the error of the diagnostic method is relatively smaller. FIG. 26 shows the carrier frequency T of a single-phase four-quadrant rectifier at 2kHz1And (4) a diagnosis process of the open-circuit fault. It can be seen that normally raising the carrier frequency does not cause misdiagnosis. When T is1When an open-circuit fault occurs, the output value of the diagnosis signal begins to rise and finally stabilizes at about 0.6, and the diagnosis result is indicated as T1(or T)4) Open circuit fault, with actual T1The open circuit fault coincides.
FIG. 27 shows the carrier frequency of a single-phase four-quadrant rectifier at 2kHz, D1And (4) a diagnosis process of the open-circuit fault. Similarly, carrier frequency rise is not paired with D1The open-circuit fault diagnosis of (1) has an influence, the diagnosis signal is finally stabilized at about-1.2, and the diagnosis result is indicated as D1(or D)4) Open circuit fault, with actual D1Open circuitThe failure is consistent.
Therefore, the diagnosis method provided by the embodiment of the invention has better robustness no matter the carrier frequency of the single-phase four-quadrant rectifier rises or falls.
Through the above experimental examples, it can be seen that the diagnosis method of the embodiment of the present invention has the following effects:
1. can effectively diagnose T1(or T)4) Open circuit fault, T2(or T)3) Open circuit failure, D1(or D)4) Open circuit failure, and D2(or D)3) Open circuit failure;
2. the method has better robustness to load fluctuation, and the diagnosis result is not influenced by load change;
3. the method has better robustness to the voltage fluctuation of the network side, and the diagnosis result is not influenced by the voltage change of the network side;
4. the method has better robustness to carrier wave change, and the diagnosis result is not influenced by the carrier wave change.
The method for diagnosing the open-circuit fault of the single-phase four-quadrant rectifier based on the half-wave difference of the input current at the grid side is accurate and effective, and has better immunity and robustness to load change, grid-side voltage change and carrier change.
It should be noted that the method of one or more embodiments of the present disclosure may be performed by a single device, such as a computer or server. The method of the embodiment can also be applied to a distributed scene and completed by the mutual cooperation of a plurality of devices. In such a distributed scenario, one of the devices may perform only one or more steps of the method of one or more embodiments of the present disclosure, and the devices may interact with each other to complete the method.
It should be noted that the above description describes certain embodiments of the present disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.
Based on the same inventive concept, corresponding to any of the above-mentioned embodiments, one or more embodiments of the present specification further provide an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the program, the rectifier open-circuit fault diagnosis method based on half-wave current difference according to any of the above-mentioned embodiments is implemented.
Fig. 28 is a schematic diagram illustrating a more specific hardware structure of an electronic device according to this embodiment, where the electronic device may include: a processor 1010, a memory 1020, an input/output interface 1030, a communication interface 1040, and a bus 1050. Wherein the processor 1010, memory 1020, input/output interface 1030, and communication interface 1040 are communicatively coupled to each other within the device via bus 1050.
The processor 1010 may be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an Application Specific Integrated Circuit (ASIC), or one or more Integrated circuits, and is configured to execute related programs to implement the technical solutions provided in the embodiments of the present disclosure.
The Memory 1020 may be implemented in the form of a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, or the like. The memory 1020 may store an operating system and other application programs, and when the technical solution provided by the embodiments of the present specification is implemented by software or firmware, the relevant program codes are stored in the memory 1020 and called to be executed by the processor 1010.
The input/output interface 1030 is used for connecting an input/output module to input and output information. The i/o module may be configured as a component in a device (not shown) or may be external to the device to provide a corresponding function. The input devices may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output devices may include a display, a speaker, a vibrator, an indicator light, etc.
The communication interface 1040 is used for connecting a communication module (not shown in the drawings) to implement communication interaction between the present apparatus and other apparatuses. The communication module can realize communication in a wired mode (such as USB, network cable and the like) and also can realize communication in a wireless mode (such as mobile network, WIFI, Bluetooth and the like).
Bus 1050 includes a path that transfers information between various components of the device, such as processor 1010, memory 1020, input/output interface 1030, and communication interface 1040.
It should be noted that although the above-mentioned device only shows the processor 1010, the memory 1020, the input/output interface 1030, the communication interface 1040 and the bus 1050, in a specific implementation, the device may also include other components necessary for normal operation. In addition, those skilled in the art will appreciate that the above-described apparatus may also include only those components necessary to implement the embodiments of the present description, and not necessarily all of the components shown in the figures.
The electronic device of the above embodiment is used to implement the corresponding method for diagnosing the open-circuit fault of the rectifier based on the half-wave difference of the current in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiment, which are not described herein again.
Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the idea of the invention, also features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.
The embodiments of the invention are intended to embrace all such alternatives, modifications and variances that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, substitutions, improvements and the like that may be made without departing from the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims (8)

1. A rectifier open-circuit fault diagnosis method based on current half-wave difference is disclosed, wherein the rectifier is a single-phase four-quadrant full-bridge rectifier, and the method is characterized by comprising the following steps:
standardizing the network side input current to obtain a standard network side input current so as to reduce the influence of the load on the current amplitude of the network side input current;
acquiring and storing the standard network side input current of a sampling point in real time, and calculating the difference value between the sum value and the error of the standard network side input current of the kth sampling point and the kth-n/2 sampling point, wherein n is the number of sampling points of each current period, and the number of sampling points of a positive half cycle is the same as that of sampling points of a negative half cycle; the number of the stored sampling points is less than or equal to n;
comparing the difference value with a threshold value, and judging the type of the open-circuit fault, wherein the type of the open-circuit fault is an IGBT open-circuit fault or an anti-parallel diode open-circuit fault;
the calculating the difference between the sum of the input current of the standard network side of the kth sampling point and the input current of the kth-n/2 sampling point and the error specifically comprises the following steps:
passing through typei N_S(k) + i N_S(k - n/2) = D k + e k Calculating the difference; wherein the content of the first and second substances,D k the difference value of the sum value and the error of the input current of the standard network side is obtained;i N_S(k) + i N_S(k - nand/2) the sum of the obtained standard network side input currents;i N_S(k) Is as followskInputting current to a standard network side of each sampling point;i N_S(k - n/2) is the followingk-n/2The normal net side input current of each sampling point,e k in order to be an error, the error is,e k the value of (c) is substantially close to zero.
2. The method for diagnosing the open-circuit fault of the rectifier based on the half-wave current difference as claimed in claim 1, wherein the step of normalizing the grid-side input current to obtain the standard grid-side input current specifically comprises:
passing through type
Figure DEST_PATH_IMAGE001
The normalization process is performed, wherein,i N_Sfor the input current to the standard grid side,i Nfor the input of the current on the network side,i N_RMSthe root mean square effective value of the input current at the network side.
3. The method of claim 2, wherein the rms effective value of the grid-side input current is passed
Figure DEST_PATH_IMAGE002
Or formula
Figure DEST_PATH_IMAGE003
Calculating; wherein the content of the first and second substances,Tinputting a current fundamental wave period for a network side;nthe number of sampling points of each period of the current input to the network side is an even number which is larger than zero;i N(k) For input of current to the network sidekAnd (4) sampling points.
4. The rectifier open-circuit fault diagnosis method based on half-wave current difference as claimed in claim 1, wherein the comparing the difference value with a threshold value to determine the type of open-circuit fault specifically comprises:
calculating the root mean square of the difference value according to the difference value;
comparing the root mean square with the threshold, and judging the type of the open-circuit fault to be an IGBT open-circuit fault when the root mean square is larger than a first threshold and smaller than a second threshold; and when the root mean square is larger than a second threshold value, judging that the type of the open-circuit fault is an anti-parallel diode open-circuit fault.
5. The rectifier open-circuit fault diagnosis method based on half-wave current difference as claimed in claim 1, wherein the comparing the difference value with a threshold value to determine the type of open-circuit fault specifically comprises:
respectively calculating the root mean square and the average value of the difference values according to the difference values;
calculating a product of a root mean square of the difference and an average of the difference;
judging the type of the open-circuit fault according to the threshold interval to which the product belongs, wherein the type of the open-circuit fault comprises one of a first bridge arm IGBT fault or a fourth bridge arm IGBT fault, a second bridge arm IGBT fault or a third bridge arm IGBT fault, a first bridge arm anti-parallel diode open-circuit fault or a fourth bridge arm anti-parallel diode open-circuit fault, and a second bridge arm anti-parallel diode open-circuit fault or a third bridge arm anti-parallel diode open-circuit fault; the first bridge arm is close to the anode of a power supply; the second bridge arm is far away from the anode of the power supply; the third bridge arm is close to the negative pole of the power supply; the fourth bridge arm is far away from the negative pole of the power supply;
wherein the product is represented byS = D RMS·D AVEAnd (c) calculating, wherein,Sfor the purpose of said product, the product is,D RMSroot mean square of said difference, by
Figure DEST_PATH_IMAGE004
Calculating;D AVEis the average value of the difference, by
Figure DEST_PATH_IMAGE005
And (4) calculating.
6. The rectifier open-circuit fault diagnosis method based on half-wave current difference as claimed in claim 5, wherein the determining the type of the open-circuit fault according to the threshold interval to which the product belongs specifically comprises:
when the product belongs to a first threshold interval, judging that the first bridge arm IGBT fault or the fourth bridge arm IGBT fault exists, wherein the first threshold interval is larger than a first threshold and smaller than a second threshold;
when the product belongs to a second threshold interval, judging that the second bridge arm IGBT fault or the third bridge arm IGBT fault exists, wherein the second threshold interval is a negative value which is larger than a second threshold and smaller than a first threshold;
when the product belongs to a third threshold interval, judging that the first bridge arm anti-parallel diode open-circuit fault or the fourth bridge arm anti-parallel diode open-circuit fault exists, wherein the third threshold interval is a negative value smaller than a second threshold;
and when the product belongs to a fourth threshold interval, judging that the second bridge arm anti-parallel diode is in an open-circuit fault or the third bridge arm anti-parallel diode is in an open-circuit fault, wherein the fourth threshold interval is larger than the second threshold.
7. The rectifier open-circuit fault diagnosis method based on half-wave current difference as claimed in claim 1, wherein the storing the number of sampling points less than or equal to n specifically comprises:
and when the number of the sampling points at the current moment is more than n, deleting the k-n sampling points to ensure that the number of the stored sampling points is equal to n.
8. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the method according to any of claims 1 to 7 when executing the program.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113376496B (en) * 2021-05-21 2022-04-05 南京航空航天大学 Self-coupling transformer rectifier diode fault diagnosis method based on Hausdorff distance
CN113589127A (en) * 2021-08-02 2021-11-02 科大国创新能科技有限公司 Power tube fault detection method and cascade power tube fault detection method
CN114236374B (en) * 2021-12-13 2023-11-14 中国矿业大学 Real-time diagnosis method for open-circuit fault of rectifier
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CN117554810B (en) * 2024-01-10 2024-03-19 南京师范大学 Fault diagnosis method for aviation three-stage starting/generator rotating rectifier

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004080865A (en) * 2002-08-12 2004-03-11 Nissan Motor Co Ltd Failure diagnostic circuit for semiconductor
WO2009085438A1 (en) * 2007-12-21 2009-07-09 General Electric Company Method and device for preventing damage to a semiconductor switch circuit during a failure
CN102053210A (en) * 2010-11-11 2011-05-11 哈尔滨工业大学 IGBT stuck-open fault diagnosis method for three-phase inverter bridge of frequency converter
CN102565662A (en) * 2012-03-15 2012-07-11 株洲变流技术国家工程研究中心有限公司 State detection device for high-potential thyristor
CN104166083A (en) * 2014-08-14 2014-11-26 北京天诚同创电气有限公司 Fault detection method and device for IGBT (insulated gate bipolar transistor) reverse parallel diode
CN109738778A (en) * 2019-01-29 2019-05-10 中南大学 Inverter open circuit diagnostic method, device, terminal device and computer-readable medium
CN110907859A (en) * 2019-11-28 2020-03-24 广西电网有限责任公司南宁供电局 Open-circuit fault diagnosis method for voltage source type inverter in UPS system

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004080865A (en) * 2002-08-12 2004-03-11 Nissan Motor Co Ltd Failure diagnostic circuit for semiconductor
WO2009085438A1 (en) * 2007-12-21 2009-07-09 General Electric Company Method and device for preventing damage to a semiconductor switch circuit during a failure
CN102053210A (en) * 2010-11-11 2011-05-11 哈尔滨工业大学 IGBT stuck-open fault diagnosis method for three-phase inverter bridge of frequency converter
CN102565662A (en) * 2012-03-15 2012-07-11 株洲变流技术国家工程研究中心有限公司 State detection device for high-potential thyristor
CN104166083A (en) * 2014-08-14 2014-11-26 北京天诚同创电气有限公司 Fault detection method and device for IGBT (insulated gate bipolar transistor) reverse parallel diode
CN109738778A (en) * 2019-01-29 2019-05-10 中南大学 Inverter open circuit diagnostic method, device, terminal device and computer-readable medium
CN110907859A (en) * 2019-11-28 2020-03-24 广西电网有限责任公司南宁供电局 Open-circuit fault diagnosis method for voltage source type inverter in UPS system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
无刷直流电机驱动系统逆变器的开路故障诊断;王强 等;《中国电机工程学报》;20130825;第33卷(第24期);第114-120页 *

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