A method and device for diagnosing power device faults based on pre-charging conditions

Abstract

The present invention provides a method and apparatus for diagnosing power device faults based on a pre-charging operating condition. The method comprises: after pre-charging begins, counting the maximum and minimum phase currents of each pre-charging branch within each power supply voltage cycle within a set time period; obtaining a first diagnostic current and a second diagnostic current for each pre-charging branch based on the maximum and minimum phase currents of each pre-charging branch within each power supply voltage cycle within the set time period and the corresponding sampled bias current value; obtaining the current type of each pre-charging branch based on the first and second diagnostic currents of each pre-charging branch and a current type identification rule; and obtaining a fault diagnosis result based on the current type of each pre-charging branch and a pre-charging operating condition fault diagnosis comparison table to be queried. The method and apparatus for diagnosing power device faults based on a pre-charging operating condition provided by an embodiment of the present invention can diagnose and locate power device faults based on the pre-charging operating condition.

Description

Technical Field

[0001] The present invention relates to the field of rail transportation technology, and in particular to a method and device for diagnosing power device faults based on a pre-charging operating condition. Background Art

[0002] In the initial state before the rectifier is powered on, the DC-side capacitor is at zero voltage, and the voltage across it is zero. If power is applied at this point, the DC-side capacitor is effectively short-circuited, causing a large inrush current in the main circuit and potentially damaging components. Therefore, a pre-charge resistor is inserted in series with the main circuit to suppress the inrush current on the capacitor. When the voltage across the DC-side capacitor reaches the target value, the main contactor is closed to bypass the pre-charge resistor, completing the pre-charge process.

[0003] In the prior art, fault diagnosis of power devices in rectifiers is typically performed by comparing pulse instructions sent to the power devices with their actual conduction feedback status. This method presupposes that pulse instructions must be sent to the power devices, meaning that the rectifier is in an active operating state. However, during the rectifier's pre-charging process, current is conducted through the anti-parallel freewheeling diodes of the power devices, and the rectifier is not yet activated. Therefore, it is impossible to diagnose the fault status of the power devices during the pre-charging process, and it is even more impossible to effectively protect the rectifier. This poses a risk of causing abnormally high pre-charging currents, which could damage the pre-charging resistors and power devices. Summary of the Invention

[0004] In response to the problems in the prior art, embodiments of the present invention provide a method and apparatus for diagnosing power device faults based on a pre-charging condition, which can at least partially solve the problems in the prior art.

[0005] In a first aspect, the present invention provides a power device fault diagnosis method based on a pre-charging condition, comprising:

[0006] After pre-charging starts, the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within a set time period are counted;

[0007] Obtaining a first diagnostic current and a second diagnostic current for each pre-charging branch based on the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value; wherein the sampled bias current value is obtained in advance;

[0008] Obtaining a current type of each pre-charging branch according to the first diagnostic current and the second diagnostic current of each pre-charging branch and a current type identification rule; wherein the current type identification rule is preset;

[0009] The pre-charging condition fault diagnosis table to be queried is determined according to the number of pre-charging branches, and the fault diagnosis result is obtained according to the current type of each pre-charging branch and the pre-charging condition fault diagnosis comparison table to be queried; wherein the pre-charging condition fault diagnosis comparison table is preset.

[0010] In a second aspect, the present invention provides a power device fault diagnosis device based on a pre-charging operating condition, comprising:

[0011] A statistical unit, configured to count the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within a set time period after pre-charging begins;

[0012] a first obtaining unit, configured to obtain a first diagnostic current and a second diagnostic current for each pre-charging branch based on a maximum value and a minimum value of a phase current of each pre-charging branch in each power supply voltage cycle within the set time period and a corresponding sampled bias current value; wherein the sampled bias current value is obtained in advance;

[0013] an identification unit, configured to obtain a current type of each pre-charging branch according to the first diagnostic current and the second diagnostic current of each pre-charging branch and a current type identification rule; wherein the current type identification rule is preset;

[0014] The diagnostic unit is used to determine the pre-charging condition fault diagnosis table to be queried according to the number of pre-charging branches, and obtain the fault diagnosis result according to the current type of each pre-charging branch and the pre-charging condition fault diagnosis comparison table to be queried; wherein the pre-charging condition fault diagnosis comparison table is preset.

[0015] In a third aspect, the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the power device fault diagnosis method based on the pre-charging condition as described in any of the above embodiments is implemented.

[0016] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the power device fault diagnosis method based on pre-charging conditions described in any of the above embodiments.

[0017] In a fifth aspect, the present invention provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the power device fault diagnosis method based on pre-charging conditions described in any of the above embodiments.

[0018] The power device fault diagnosis method and device based on the pre-charging working condition provided by the embodiment of the present invention, after the pre-charging starts, counts the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within a set time period; obtains the first diagnostic current and the second diagnostic current of each pre-charging branch based on the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value; obtains the current type of each pre-charging branch based on the first diagnostic current and the second diagnostic current of each pre-charging branch and the current type identification rule, determines the pre-charging working condition fault diagnosis table to be queried based on the number of pre-charging branches, and obtains the fault diagnosis result based on the current type of each pre-charging branch and the pre-charging working condition fault diagnosis comparison table to be queried, which can diagnose and locate power device faults based on the pre-charging working condition and effectively protect the diagnosed equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0020] Figure 1 It is a structural diagram of a power device fault diagnosis system based on a pre-charging condition provided by the first embodiment of the present invention.

[0021] Figure 2 FIG. 2 is a schematic structural diagram of a diagnosed device provided in a second embodiment of the present invention.

[0022] Figure 3 FIG. 4 is a schematic structural diagram of a diagnosed device provided in a third embodiment of the present invention.

[0023] Figure 4 It is a flow chart of a power device fault diagnosis method based on a pre-charging condition provided by the fourth embodiment of the present invention.

[0024] Figure 5 It is a flowchart of a power device fault diagnosis method based on a pre-charging condition provided by the fifth embodiment of the present invention.

[0025] Figure 6 It is a flow chart of a power device fault diagnosis method based on a pre-charging condition provided by the sixth embodiment of the present invention.

[0026] Figure 7 4 is a schematic diagram of a flow chart of obtaining a sampled bias current value provided by the seventh embodiment of the present invention.

[0027] Figure 8 4 is a flow chart of a method for diagnosing power device faults based on a pre-charging condition provided in the eighth embodiment of the present invention.

[0028] Figure 9 1 is a schematic diagram of a flow chart of identifying the current type of a pre-charging branch provided by the ninth embodiment of the present invention.

[0029] Figure 10 3 is a schematic structural diagram of a power device fault diagnosis device based on a pre-charging condition provided in the tenth embodiment of the present invention.

[0030] Figure 11 It is a structural diagram of a power device fault diagnosis device based on a pre-charging condition provided by the eleventh embodiment of the present invention.

[0031] Figure 12 3 is a schematic structural diagram of a power device fault diagnosis device based on a pre-charging condition provided in the twelfth embodiment of the present invention.

[0032] Figure 13 It is a structural diagram of a power device fault diagnosis device based on a pre-charging condition provided in the thirteenth embodiment of the present invention.

[0033] Figure 14 It is a schematic diagram of the physical structure of an electronic device provided by the fourteenth embodiment of the present invention. DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of this application can be combined with each other in any manner.

[0035] Figure 1 FIG. 1 is a schematic structural diagram of a power device fault diagnosis system based on a pre-charging condition provided by a first embodiment of the present invention. Figure 1 As shown, the power device fault diagnosis system based on the pre-charging working condition provided by the embodiment of the present invention includes a power device fault diagnosis device 1, a diagnosed device 2 and a current sensor 3, wherein:

[0036] The diagnosed device 2 includes a pre-charging circuit 21 and a power module 22, and the pre-charging circuit 21 is connected to the power module 22; the pre-charging circuit 21 includes at least one pre-charging branch, each pre-charging branch includes a first contactor, a second contactor and a pre-charging resistor, and the first contactor is connected in series with the pre-charging resistor and then in parallel with the second contactor.

[0037] When the diagnosed device 2 is connected to a single-phase power supply, the pre-charging circuit 21 includes one pre-charging branch; when the diagnosed device 2 is connected to a three-phase power supply, the pre-charging circuit 21 includes two pre-charging branches and / or two pre-charging branches, and each pre-charging branch is connected in parallel.

[0038] The power device fault diagnosis device 1 is connected to each first contactor and each second contactor, receives status feedback signals from each first contactor and each second contactor, and samples the current in each pre-charging branch via a current sensor 3. Each pre-charging branch is provided with a corresponding current sensor 3. The power device fault diagnosis device 1 can control the on / off state of each first contactor and each second contactor and perform fault diagnosis on the power device of the device being diagnosed 2. The power device fault diagnosis device can utilize a microprocessor chip such as a single-chip microcomputer or a DSP.

[0039] Figure 2 FIG. 1 is a schematic structural diagram of a diagnosed device provided by a second embodiment of the present invention. Figure 2 As shown, the diagnosed device 2 is a three-phase pulse width modulation (PWM) rectifier, which includes three pre-charging branches, a rectifier bridge, and a support capacitor C1.

[0040] The first pre-charging branch includes a contactor K1, a pre-charging resistor R1, and a contactor Q1. Contactor K1 is connected in series with the pre-charging resistor R1 and then in parallel with contactor Q1. The second pre-charging branch includes a contactor K2, a pre-charging resistor R2, and a contactor Q2. Contactor K2 is connected in series with the pre-charging resistor R2 and then in parallel with contactor Q2. The third pre-charging branch includes a contactor K3, a pre-charging resistor R3, and a contactor Q3. Contactor K3 is connected in series with the pre-charging resistor R3 and then in parallel with contactor Q3. R1 = R2 = R3 can be set.

[0041] The three-phase PWM rectifier is connected to an external three-phase power supply. The three-phase power supply is connected to the AC side of the three-phase rectifier bridge via contactors Q1, Q2, and Q3. The three-phase currents ia, ib, and ic on the AC side are detected by current sensors. The rectifier bridge includes power devices S1, S2, S3, S4, S5, and S6. The DC side of the rectifier bridge is connected to a support capacitor C1.

[0042] Figure 3 FIG. 1 is a schematic structural diagram of a diagnosed device provided by a third embodiment of the present invention. Figure 3 As shown, the diagnosed device 2 is a single-phase PWM rectifier, which includes a fourth pre-charging branch, a rectifier bridge, and a support capacitor C2.

[0043] The fourth pre-charging branch includes a contactor K4, a pre-charging resistor R4 and a contactor Q4. The contactor K4 is connected in series with the pre-charging resistor R4 and then in parallel with the contactor Q4.

[0044] The single-phase PWM rectifier is connected to an external single-phase power supply, which is then connected to the AC side of the rectifier bridge via contactor Q4. The current is detected by a current sensor. The rectifier bridge includes power devices S7, S8, S9, and S10, and the DC side of the rectifier bridge is connected to a support capacitor C2.

[0045] The following describes a specific implementation process of a power device fault diagnosis method based on a pre-charging condition provided by an embodiment of the present invention, taking a power device fault diagnosis device (hereinafter referred to as the fault diagnosis device) as an example of an execution subject.

[0046] Figure 4 FIG. 4 is a flow chart of a method for diagnosing power device faults based on a pre-charging condition according to a fourth embodiment of the present invention. Figure 4 As shown, the power device fault diagnosis method based on the pre-charging working condition provided by the embodiment of the present invention includes:

[0047] S401, after pre-charging starts, counting the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within a set time period;

[0048] Specifically, after the diagnosed device begins precharging, the fault diagnosis device can detect and obtain the phase current of each precharging branch within each power supply voltage cycle within a set time period through a current sensor, and compare the phase currents of each precharging branch within a single power supply voltage cycle to obtain the maximum and minimum phase currents of each precharging branch within a single power supply voltage cycle. The set time period is a period of time after the start of precharging, and the duration of the set time period is less than the duration of the precharging process.

[0049] For example, if the pre-charging process lasts for more than 5 seconds, the set time period can be set to 0-3 seconds after the pre-charging starts. For a power supply with a power frequency of 50Hz and a power supply voltage cycle of 20 milliseconds, the set time period can be set to an integer multiple of 20 milliseconds.

[0050] S402, obtaining a first diagnostic current and a second diagnostic current for each pre-charging branch based on the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current values; wherein the sampled bias current values ​​are obtained in advance;

[0051] Specifically, the fault diagnosis device can obtain a first diagnostic current and a second diagnostic current for each pre-charging branch based on the maximum and minimum phase currents of each pre-charging branch during each power supply voltage cycle within the set time period and the corresponding sampled bias current value. The sampled bias current value is obtained in advance, and the specific process of sampling the bias current value is described in detail below.

[0052] S403, obtaining a current type of each pre-charging branch according to the first diagnostic current and the second diagnostic current of each pre-charging branch and a current type identification rule; wherein the current type identification rule is preset;

[0053] Specifically, for each pre-charging branch, the fault diagnosis device identifies the current type of the pre-charging branch based on the first diagnostic current and the second diagnostic current of the pre-charging branch and a current type identification rule, thereby obtaining the current type of the pre-charging branch. The current type identification rule is preset.

[0054] S404. Determine the pre-charging condition fault diagnosis table to be queried according to the number of pre-charging branches, and obtain a fault diagnosis result according to the current type of each pre-charging branch and the pre-charging condition fault diagnosis comparison table to be queried; wherein the pre-charging condition fault diagnosis comparison table is preset.

[0055] Specifically, the fault diagnosis device can count the number of pre-charging branches based on the pre-charging branches in which the phase current is detected, obtain the number of pre-charging branches, and then determine the pre-charging operating condition fault diagnosis table to be queried based on the number of pre-charging branches. The fault diagnosis device queries the fault type corresponding to the current type from the pre-charging operating condition fault diagnosis comparison table to be queried based on the current type of each pre-charging branch. If the fault type corresponding to the current type is queried, the fault diagnosis result includes the fault type. If the fault type corresponding to the current type is not queried, it indicates that the power device has no fault, and the fault diagnosis result can indicate that there is no fault. If a power device of the diagnosed device is diagnosed to have a fault, such as a short circuit or open circuit fault, the corresponding contactor can be disconnected to protect the diagnosed device and avoid damage to the pre-charging resistor and the power device. Among them, the correspondence between the number of pre-charging branches and the pre-charging operating condition fault diagnosis table is preset.

[0056] For example, for a three-phase PWM rectifier, if three pre-charging branches are used for pre-charging, a pre-charging condition fault diagnosis comparison table can be set as shown in Table 1. By querying Table 1 based on the current type of each pre-charging branch, single-tube fault and dual-tube fault conditions can be obtained. In Table 1, phases A, B, and C each correspond to a pre-charging branch. For example, if the current type of the pre-charging branch corresponding to phase A is 3-, the current type of the pre-charging branch corresponding to phase B is 3+, and the current type of the pre-charging branch corresponding to phase C is 3+, then power device S1 is short-circuited.

[0057] Table 1 Three-phase rectifier three-way pre-charging fault diagnosis comparison table

[0058]

[0059]

[0060] For example, for a three-phase PWM rectifier, if two pre-charging branches are used for pre-charging, a pre-charging condition fault diagnosis comparison table can be set as shown in Table 2. For example, if the current type of the pre-charging branch corresponding to A is 3-type and the current type of the pre-charging branch corresponding to B is 3+type, then power device S1 or S4 is short-circuited.

[0061] Table 2 Three-phase rectifier two-way pre-charging fault diagnosis comparison table

[0062]

[0063] For example, for a single-phase PWM rectifier, a pre-charge condition fault diagnosis comparison table can be set as shown in Table 3. For example, if the current type obtained in the pre-charge branch is 4+, then the power device S8 or S9 is open.

[0064] Table 3 Single-phase rectifier pre-charge fault diagnosis comparison table

[0065]

[0066] The embodiment of the present invention provides a power device fault diagnosis method based on pre-charging conditions. After pre-charging starts, the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within a set time period are counted; the first diagnostic current and the second diagnostic current of each pre-charging branch are obtained according to the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value; the current type of each pre-charging branch is obtained according to the first diagnostic current and the second diagnostic current of each pre-charging branch and the current type identification rule, the pre-charging condition fault diagnosis table to be queried is determined according to the number of pre-charging branches, and the fault diagnosis result is obtained according to the current type of each pre-charging branch and the pre-charging condition fault diagnosis comparison table to be queried. The power device fault can be diagnosed and located based on the pre-charging condition, and the diagnosed equipment can be effectively protected.

[0067] Figure 5 FIG. 5 is a flow chart of a method for diagnosing power device faults based on a pre-charging condition according to a fifth embodiment of the present invention. Figure 5 As shown, based on the above embodiments, further, the step of obtaining the sampled bias current value includes:

[0068] S501. In an initial state, sampling the phase current of each pre-charging branch to obtain a sampled current value of each pre-charging branch;

[0069] Specifically, the fault diagnosis device samples the phase current of each pre-charging branch using a current sensor in an initial state to obtain a sampled current value of each pre-charging branch. The initial state refers to when the fault diagnosis device is powered on and the contactors of each pre-charging branch are disconnected, at which point the phase current of each pre-charging branch should theoretically be zero.

[0070] For a device connected to a single-phase power supply, only the phase current of one pre-charging branch needs to be sampled. For a device connected to a three-phase power supply, the phase currents of two or three pre-charging branches need to be sampled.

[0071] S502 : Based on the sampled current value and sampling period of each pre-charging branch, obtain a sampled bias current value corresponding to each pre-charging branch.

[0072] Specifically, for each pre-charging branch, the fault diagnosis device can obtain the sampled bias current value corresponding to the pre-charging branch based on the sampled current value and sampling period of the pre-charging branch. The sampling period is preset and set according to actual conditions, and is not limited in the embodiments of the present invention.

[0073] Figure 6FIG. 6 is a flow chart of a method for diagnosing power device faults based on a pre-charging condition according to a sixth embodiment of the present invention. Figure 6 As shown, based on the above embodiments, further, obtaining the sampled bias current value corresponding to each pre-charging branch based on the sampled current value and sampling period of each pre-charging branch includes:

[0074] S601, calculating the product of the sampling period and a preset value to obtain a product result, and comparing the product result with the sampling offset removal time;

[0075] Specifically, the fault diagnosis device multiplies the sampling period by a preset value to obtain the product of the sampling period and the preset value, and then compares the product with the sampling offset removal time. The sampling offset removal time is set based on actual conditions, such as 1 second, and is not limited in this embodiment of the present invention. The preset value is set based on actual experience and is not limited in this embodiment of the present invention.

[0076] S602: If it is determined that the sampling offset removal time is greater than the product result, re-sampling the phase current of each pre-charging branch, and accumulating the sampled current value of each pre-charging branch to obtain an accumulated value of the sampled current of each pre-charging branch;

[0077] Specifically, if the fault diagnosis device determines that the sampling offset removal time is greater than the product, it will resample the phase current of each pre-charging branch. The fault diagnosis device also accumulates the sampled current value of each pre-charging branch, that is, calculates the sum of the sampled current value obtained in the current sampling and the accumulated sampled current value after the previous sampling, updates the accumulated sampled current value of each pre-charging branch, and records the number of accumulations. It is understood that when sampling for the first time, the initial value of the accumulated sampled current value is 0.

[0078] S603: If it is determined that the sampling bias removal time is equal to the product result, the result of dividing the accumulated value of the sampling current of each pre-charging branch by the number of accumulations is calculated as the sampling bias current value corresponding to each pre-charging branch.

[0079] Specifically, if the fault diagnosis device determines that the sampling bias removal time is equal to the product, the fault diagnosis device calculates the result of dividing the accumulated sampling current value of each pre-charging branch by the number of accumulations as the sampling bias current value corresponding to each pre-charging branch. The sampling bias current value corresponding to each pre-charging branch is used to correct the phase current of each pre-charging branch after pre-charging begins.

[0080] The following takes the process of obtaining the sampled bias current value of a pre-charge branch as an example to illustrate the process of obtaining the sampled bias current value. Figure 7 shown.

[0081] The first step is to perform current sampling. In the initial state, the fault diagnosis device samples the phase current of the pre-charging branch through the current sensor to obtain the sampled current value ix of the pre-charging branch.

[0082] Step 2: Compare the product result with the sampling offset removal time. The fault diagnosis device calculates the product of the sampling period Tc and the preset value K, obtaining the product result p = KTc. The product result p is compared with the sampling offset removal time T1. If the product result p is less than the sampling offset removal time T1, the process proceeds to step 3. If the product result p is equal to the sampling offset removal time T1, the process proceeds to step 4.

[0083] Step 3: Calculate the cumulative value of the sampled current. The fault diagnosis device calculates the cumulative value of the sampled current ix_sum = ix_sum + ix, and records the number of accumulations k = k + 1. The initial value of ix_sum is 0, and the initial value of k is 0. Then, return to the first step and resample the phase current of the pre-charge branch.

[0084] Step 4: Calculate the sampled bias current value. The fault diagnosis device calculates the sampled bias current value ix_dc=ix_sum / k.

[0085] Figure 8 FIG. 8 is a flow chart of a method for diagnosing power device faults based on a pre-charging condition according to an eighth embodiment of the present invention. Figure 8 As shown, based on the above embodiments, further, obtaining the first diagnostic current and the second diagnostic current of each pre-charging branch according to the maximum value and the minimum value of the phase current of each pre-charging branch during the power supply voltage cycle and the corresponding sampled bias current value includes:

[0086] S801: Perform sampling bias removal on the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle using the sampled bias current values ​​corresponding to each pre-charging branch, to obtain a first intermediate value and a second intermediate value of each pre-charging branch in each power supply voltage cycle; wherein the first intermediate value of each pre-charging branch in each power supply voltage cycle is greater than the second intermediate value;

[0087] Specifically, for each pre-charging branch, the fault diagnosis device calculates the maximum value of the phase current of the pre-charging branch in each power supply voltage cycle minus the difference of the sampled bias current values ​​to obtain a first intermediate value of the pre-charging branch in each power supply voltage cycle, and calculates the minimum value of the phase current of the pre-charging branch in each power supply voltage cycle minus the difference of the sampled bias current values ​​to obtain a second intermediate value of the pre-charging branch in each power supply voltage cycle. The first intermediate value of the pre-charging branch in each power supply voltage cycle is greater than the second intermediate value of the pre-charging branch in each power supply voltage cycle.

[0088] For example, the fault diagnosis device obtains a sample bias current value corresponding to a pre-charge branch as I x_dc The maximum phase current of the pre-charge branch obtained by statistics in a certain power supply voltage cycle is I max The minimum phase current of the pre-charging branch in a certain power supply voltage cycle is I min The first intermediate value I1 of the pre-charge branch in the power supply voltage cycle is I max -I x_dc , the second intermediate value I2 of the pre-charge branch in the power supply voltage cycle = I min -I x_dc .

[0089] S802. Calculate the average value of the sum of the absolute value of the first intermediate value and the absolute value of the second intermediate value of each pre-charging branch in each power supply voltage cycle within the set time period as the first diagnostic current of each pre-charging branch, and calculate the average value of the difference between the absolute value of the first intermediate value and the absolute value of the second intermediate value of each pre-charging branch in each power supply voltage cycle within the set time period as the second diagnostic current of each pre-charging branch.

[0090] Specifically, for each pre-charging branch, the fault diagnosis device calculates an average value of the sum of the absolute value of the first intermediate value and the absolute value of the second intermediate value of the pre-charging branch in each power supply voltage cycle within the set time period as the first diagnostic current of the pre-charging branch. The fault diagnosis device calculates an average value of the difference between the absolute value of the first intermediate value and the absolute value of the second intermediate value of the pre-charging branch in each power supply voltage cycle within the set time period as the second diagnostic current of each pre-charging branch.

[0091] For example, the fault diagnosis device obtains the first intermediate value I of the pre-charge branch in the i-th power supply voltage cycle within the set time period. i1 and the second intermediate value I i2 The first diagnostic current of the pre-charge branch The second diagnostic current of the pre-charging branch Wherein, i is a positive integer and i is less than or equal to n, and n is the number of power supply voltage cycles included in the set time period.

[0092] On the basis of the above embodiments, the current type identification rule further includes:

[0093] If it is determined that the first diagnostic current of the pre-charging branch is greater than the corresponding first threshold, then comparing the second diagnostic current of the pre-charging branch with a second threshold; wherein the first threshold is equal to the product of the pre-charging maximum current threshold and a first set value;

[0094] If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the first type; if it is determined that the second diagnostic current of the pre-charging branch is less than the inverse of the second threshold, the current type of the pre-charging branch is the second type; otherwise, the current type of the pre-charging branch is the third type;

[0095] If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to the corresponding first threshold and the first diagnostic current of the pre-charging branch is greater than a third threshold, then comparing the second diagnostic current of the pre-charging branch with a second threshold; wherein the third threshold is equal to the product of the pre-charging maximum current threshold and a second set value, and the second set value is less than the first set value;

[0096] If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the fourth type; otherwise, the current type of the pre-charging branch is the fifth type;

[0097] If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to the third threshold and the first diagnostic current of the pre-charging branch is greater than the second threshold, comparing the second diagnostic current of the pre-charging branch with the second threshold;

[0098] If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the sixth type; if it is determined that the second diagnostic current of the pre-charging branch is less than the opposite of the second threshold, the current type of the pre-charging branch is the seventh type; otherwise, the current type of the pre-charging branch is the eighth type;

[0099] If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to the corresponding first threshold, the first diagnostic current of the pre-charging branch is less than or equal to the third threshold and the first diagnostic current of the pre-charging branch is less than or equal to the second threshold, then the current type of the pre-charging branch is the ninth type.

[0100] Specifically, the fault diagnosis device compares the first diagnostic current of the pre-charging branch with a corresponding first threshold value. If the first diagnostic current is greater than the corresponding first threshold value, the second diagnostic current of the pre-charging branch is compared with a second threshold value. If the second diagnostic current is greater than the second threshold value, the current type of the pre-charging branch can be determined to be the first type and can be marked as type 2+. If the second diagnostic current is less than the opposite of the second threshold value, the current type of the pre-charging branch can be determined to be the second type and can be marked as type 2-. In the remaining case, that is, if the second diagnostic current is greater than or equal to the opposite of the second threshold value and less than or equal to the second threshold value, the current type of the pre-charging branch can be determined to be the second type and can be marked as type 2.

[0101] The fault diagnosis device compares the first diagnostic current of the pre-charging branch with corresponding first and third thresholds. If the first diagnostic current of the pre-charging branch is less than or equal to the corresponding first threshold and the first diagnostic current of the pre-charging branch is greater than the corresponding third threshold, the second diagnostic current of the pre-charging branch is compared with the second threshold. If the second diagnostic current is greater than the second threshold, the current type of the pre-charging branch can be determined to be the fourth type and can be marked as type 3+. Otherwise, that is, the second diagnostic current is less than or equal to the second threshold, the current type of the pre-charging branch can be determined to be the fifth type and can be marked as type 3-.

[0102] The fault diagnosis device compares the first diagnostic current of the pre-charging branch with the corresponding third threshold and the second threshold. If the first diagnostic current is less than or equal to the corresponding third threshold and the first diagnostic current is greater than the second threshold, the second diagnostic current of the pre-charging branch is compared with the second threshold. If the second diagnostic current is greater than the second threshold, the current type of the pre-charging branch can be determined to be the sixth type, which can be marked as type 4+; if the second diagnostic current is less than the opposite of the second threshold, the current type of the pre-charging branch can be determined to be the seventh type, which can be marked as type 4-; in the remaining case, that is, the second diagnostic current is greater than or equal to the opposite of the second threshold and less than or equal to the second threshold, the current type of the pre-charging branch can be determined to be the eighth type, which can be marked as type 1.

[0103] The fault diagnosis device compares the first diagnostic current of the pre-charging branch with a second threshold value. If the first diagnostic current is less than or equal to the second threshold value, it can be determined that the current type of the pre-charging branch is the ninth type, which can be marked as type 0, and type 0 means that the current is always 0.

[0104] The first threshold is equal to the product of the pre-charge maximum current threshold and the first set value; the third threshold is equal to the product of the pre-charge maximum current threshold and the second set value, and the second set value is less than the first set value; since the second set value is less than the first set value, it can be determined that the third threshold is less than the first threshold. The second threshold value is smaller and is used to determine whether the current is close to 0. Pre-charge maximum current threshold I t =U m / R,U m is the amplitude of the power supply phase voltage. For a single-phase powered device, R is the resistance of the pre-charging resistor in the device. For a three-phase powered device, R is the maximum value of each pre-charging resistor in the device.

[0105] The first set value, the second set value, and the second threshold are set based on actual experience and are not limited in the embodiment of the present invention. For example, the first set value is 1.9, the second set value is 1.2, and the second threshold is 5A.

[0106] The following takes the identification process of the current type of a pre-charging branch as an example to illustrate the identification process of the current type of the pre-charging branch. Figure 9 shown.

[0107] The first step is to obtain the maximum and minimum current values ​​within each power supply voltage cycle. After the diagnosed device begins precharging, the fault diagnosis device can use a current sensor to detect and obtain the phase current of the precharging branch within each power supply voltage cycle within a set time period. By comparing the phase currents of the precharging branch within each power supply voltage cycle, the maximum and minimum phase currents of the precharging branch within each power supply voltage cycle can be obtained. If the set time period includes n power supply voltage cycles, the maximum and minimum phase currents of the precharging branch within n power supply voltage cycles can be obtained.

[0108] Step 2: Obtain the first diagnostic current and the second diagnostic current. The fault diagnosis device obtains the sampled bias current value I corresponding to the pre-charge branch. x_dc The maximum current value I of the pre-charge branch in each power supply voltage cycle max Perform sampling bias removal to obtain the first intermediate value I1=I of the pre-charge branch in each power supply voltage cycle. max -I x_dc And through the sampling bias current value I corresponding to the pre-charge branch x_dc The minimum current value I of the precharge branch in each power supply voltage cycle min Perform sampling bias removal to obtain the second intermediate value I2=I of the pre-charge branch in each power supply voltage cycle min -I x_dcThere are n power supply voltage cycles in the set time period, and the first intermediate value and the second intermediate value of the pre-charge branch in the i-th power supply voltage cycle are respectively recorded as I i1 and I i2 , then the first diagnostic current of the pre-charge branch Second diagnostic current of the pre-charging branch

[0109] Step 3: Determine whether the first diagnostic current is greater than the first threshold. x1 Compared with the first threshold value Y1, if I x1 Greater than Y1, then go to step 4; if I x1 Not greater than Y1, then go to step 6.

[0110] Step 4: Determine whether the second diagnostic current is greater than the second threshold. x2 Compare with the second threshold value Y2, if I x2 Greater than Y2, then go to step 11 and obtain the current type as 2+ type; if I x2 Not greater than Y2, then go to step 5.

[0111] Step 5: Determine whether the second diagnostic current is less than the inverse of the second threshold value. x2 Compare with the opposite number of the second threshold -Y2, ​​if I x2 If it is less than -Y2, ​​then go to step 11 and obtain the current type as 2-type; otherwise, go to step 11 and obtain the current type as 2-type.

[0112] Step 6: Determine whether the first diagnostic current is greater than the third threshold. x1 Compare with the third threshold value Y3, if I x1 Greater than Y3, then go to step 7; if I x1 Not greater than Y3, then go to step 8.

[0113] Step 7: Determine whether the second diagnostic current is greater than the second threshold. x2 Compare with the second threshold value Y2, if I x2 Greater than Y2, then go to step 11 and obtain the current type as 3+ type; if I x2 Not greater than Y2, then go to step 11 and obtain the current type as 3-type.

[0114] Step 8: Determine whether the first diagnostic current is greater than the second threshold. x1 Compare with the second threshold value Y2, if Ix1 Greater than Y2, then go to step 9; if I x1 If it is not greater than Y2, then go to step 11 and obtain the current type as type 0.

[0115] Step 9: Determine whether the second diagnostic current is greater than the second threshold. x2 Compare with the second threshold value Y2, if I x2 Greater than Y2, then go to step 11 and obtain the current type as 4+ type; if I x2 Not greater than Y2, then go to step 10.

[0116] Step 10: Determine whether the second diagnostic current is less than the inverse of the second threshold value. x2 Compare with the opposite number of the second threshold -Y2, ​​if I x2 If it is less than -Y2, ​​then go to step 11 and obtain the current type as 4-type; otherwise, go to step 11 and obtain the current type as 1-type.

[0117] Step 11: Obtaining the current type. The fault diagnosis device receives the trigger information from the fourth step and obtains a current type of 2+; receives the trigger information from the "yes" branch in the fifth step and obtains a current type of 2-; receives the trigger information from the "no" branch in the fifth step and obtains a current type of 2; receives the trigger information from the "yes" branch in the seventh step and obtains a current type of 3+; receives the trigger information from the "no" branch in the seventh step and obtains a current type of 3-; receives the trigger information from the ninth step and obtains a current type of 4+; receives the trigger information from the "yes" branch in the tenth step and obtains a current type of 4-; receives the trigger information from the "no" branch in the tenth step and obtains a current type of 1; receives the trigger information from the eighth step and obtains a current type of 0.

[0118] The power device fault diagnosis method based on pre-charge conditions provided by the embodiments of the present invention diagnoses and locates power device faults based on pre-charge conditions, without requiring the device being diagnosed to be active. This overcomes the shortcomings of existing diagnostic techniques, which rely on pulse instructions and feedback from the device's actual conduction state. Furthermore, a power device fault state can cause abnormal pre-charge currents, which can subsequently burn out the pre-charge resistor. The present invention can rapidly diagnose power device faults and promptly implement effective protective measures, preventing damage to the device while simultaneously directing the fault to safety.

[0119] Figure 10 FIG. 1 is a schematic structural diagram of a power device fault diagnosis device based on a pre-charging condition according to a tenth embodiment of the present invention. Figure 10As shown, the power device fault diagnosis device based on the pre-charging working condition provided by the embodiment of the present invention includes a statistical unit 1001, a first obtaining unit 1002, an identification unit 1003 and a diagnosis unit 1004, wherein:

[0120] The statistical unit 1001 is used to count the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within a set time period after pre-charging starts; the first obtaining unit 1002 is used to obtain the first diagnostic current and the second diagnostic current of each pre-charging branch based on the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampling bias current value; wherein the sampling bias current value is obtained in advance; the identification unit 1003 is used to obtain the current type of each pre-charging branch based on the first diagnostic current and the second diagnostic current of each pre-charging branch and the current type identification rule; wherein the current type identification rule is preset; the diagnostic unit 1004 is used to determine the pre-charging operating condition fault diagnosis table to be queried according to the number of pre-charging branches, and obtain the fault diagnosis result according to the current type of each pre-charging branch and the pre-charging operating condition fault diagnosis comparison table to be queried; wherein the pre-charging operating condition fault diagnosis comparison table is preset.

[0121] Specifically, after the pre-charging of the diagnosed device begins, the statistical unit 1001 can detect the phase current of each pre-charging branch in each power supply voltage cycle within a set time period through a current sensor, and compare the phase currents of each pre-charging branch within a single power supply voltage cycle to obtain the maximum and minimum phase currents of each pre-charging branch within a single power supply voltage cycle. The set time period is a time period after the start of pre-charging, and the duration of the set time period is less than the duration of the pre-charging process.

[0122] The first obtaining unit 1002 can obtain the first diagnostic current and the second diagnostic current of each pre-charging branch according to the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value.

[0123] For each pre-charging branch, the identification unit 1003 identifies the current type of the pre-charging branch based on the first diagnostic current and the second diagnostic current of the pre-charging branch and the current type identification rule, thereby obtaining the current type of the pre-charging branch. The current type identification rule is preset.

[0124] The diagnostic unit 1004 can count the number of pre-charging branches based on the pre-charging branches in which the phase current is detected, obtain the number of pre-charging branches, and then determine the pre-charging operating condition fault diagnosis table to be queried based on the number of pre-charging branches. The diagnostic unit 1004 queries the fault type corresponding to the current type from the pre-charging operating condition fault diagnosis comparison table to be queried based on the current type of each pre-charging branch. If the fault type corresponding to the current type is queried, the fault diagnosis result includes the fault type. If the fault type corresponding to the current type is not queried, it indicates that the power device has no fault, and the fault diagnosis result can indicate that there is no fault. If a power device of the diagnosed device is diagnosed to have a fault, such as a short circuit or open circuit fault, the corresponding contactor can be disconnected to protect the diagnosed device and avoid damaging the pre-charging resistor and the power device. Among them, the correspondence between the number of pre-charging branches and the pre-charging operating condition fault diagnosis table is preset.

[0125] The power device fault diagnosis device based on the pre-charging working condition provided by the embodiment of the present invention counts the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within a set time period after pre-charging starts; obtains the first diagnostic current and the second diagnostic current of each pre-charging branch based on the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value; obtains the current type of each pre-charging branch based on the first diagnostic current and the second diagnostic current of each pre-charging branch and the current type identification rule, determines the pre-charging working condition fault diagnosis table to be queried based on the number of pre-charging branches, and obtains the fault diagnosis result based on the current type of each pre-charging branch and the pre-charging working condition fault diagnosis comparison table to be queried, which can diagnose and locate power device faults based on the pre-charging working condition and effectively protect the diagnosed equipment.

[0126] Figure 11 FIG. 1 is a schematic structural diagram of a power device fault diagnosis device based on a pre-charging condition according to an eleventh embodiment of the present invention. Figure 11 As shown, based on the above embodiments, further, the power device fault diagnosis device based on the pre-charging working condition provided by the embodiment of the present invention further includes a sampling unit 1005 and a second obtaining unit 1006, wherein:

[0127] The sampling unit 1005 is used to sample the phase current of each pre-charging branch in the initial state to obtain the sampled current value of each pre-charging branch; the second obtaining unit 1006 is used to obtain the sampled bias current value corresponding to each pre-charging branch based on the sampled current value of each pre-charging branch and the sampling period.

[0128] Figure 12FIG. 1 is a schematic structural diagram of a power device fault diagnosis device based on a pre-charging condition provided by the twelfth embodiment of the present invention. Figure 12 As shown, based on the above embodiments, the second obtaining unit 1006 further includes a calculating subunit 10061, a first judging subunit 10062 and a second judging subunit 10063, wherein:

[0129] The calculation subunit 10061 is used to calculate the product of the sampling period and the preset value, obtain the product result, and compare the product result with the sampling bias removal time; the first judgment subunit 10062 is used to, after judging that the sampling bias removal time is greater than the product result, re-sample the phase current of each pre-charging branch, and accumulate the sampled current value of each pre-charging branch to obtain the sampled current accumulated value of each pre-charging branch; the second judgment subunit 10063 is used to, after judging that the sampling bias removal time is equal to the product result, calculate the result of dividing the sampled current accumulated value of each pre-charging branch by the number of accumulations, as the sampling bias current value corresponding to each pre-charging branch.

[0130] Figure 13 FIG. 13 is a schematic structural diagram of a power device fault diagnosis device based on a pre-charging condition provided by the thirteenth embodiment of the present invention. Figure 13 As shown, based on the above embodiments, the first obtaining unit 1002 further includes a sampling bias removal subunit 10021 and a calculation subunit 10022, wherein:

[0131] The sampling bias removal subunit 10021 is used to perform sampling bias removal on the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle through the sampling bias current value corresponding to each pre-charging branch, and obtain the first intermediate value and the second intermediate value of each pre-charging branch in each power supply voltage cycle; wherein, the first intermediate value of each pre-charging branch in each power supply voltage cycle is greater than the second intermediate value; the calculation subunit 10022 is used to calculate the average value of the sum of the absolute value of the first intermediate value and the absolute value of the second intermediate value of each pre-charging branch in each power supply voltage cycle within the set time period as the first diagnostic current of each pre-charging branch, and calculate the average value of the difference between the absolute value of the first intermediate value and the absolute value of the second intermediate value of each pre-charging branch in each power supply voltage cycle within the set time period as the second diagnostic current of each pre-charging branch.

[0132] On the basis of the above embodiments, the current type identification rule further includes:

[0133] If it is determined that the first diagnostic current of the pre-charging branch is greater than the corresponding first threshold, then comparing the second diagnostic current of the pre-charging branch with a second threshold; wherein the first threshold is equal to the product of the pre-charging maximum current threshold and a first set value;

[0134] If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the first type; if it is determined that the second diagnostic current of the pre-charging branch is less than the inverse of the second threshold, the current type of the pre-charging branch is the second type; otherwise, the current type of the pre-charging branch is the third type;

[0135] If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to a corresponding first threshold and the first diagnostic current of the pre-charging branch is greater than a corresponding third threshold, then comparing the second diagnostic current of the pre-charging branch with a second threshold; wherein the third threshold is equal to the product of the pre-charging maximum current threshold and a second set value, and the second set value is less than the first set value;

[0136] If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the fourth type; otherwise, the current type of the pre-charging branch is the fifth type;

[0137] If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to the corresponding third threshold and the first diagnostic current of the pre-charging branch is greater than the second threshold, then comparing the second diagnostic current of the pre-charging branch with the second threshold;

[0138] If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the sixth type; if it is determined that the second diagnostic current of the pre-charging branch is less than the opposite of the second threshold, the current type of the pre-charging branch is the seventh type; otherwise, the current type of the pre-charging branch is the eighth type;

[0139] If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to the second threshold, the current type of the pre-charging branch is the ninth type.

[0140] The embodiments of the apparatus provided in the embodiments of the present invention can be specifically used to execute the processing flow of the above-mentioned method embodiments. Its functions are not described in detail here, and reference can be made to the detailed description of the above-mentioned method embodiments.

[0141] Figure 14 FIG. 1 is a schematic diagram of the physical structure of an electronic device provided in the fourteenth embodiment of the present invention. Figure 14As shown, the electronic device may include: a processor (processor) 1401, a communication interface (Communications Interface) 1402, a memory (memory) 1403 and a communication bus 1404, wherein the processor 1401, the communication interface 1402, and the memory 1403 communicate with each other through the communication bus 1404. The processor 1401 can call the logic instructions in the memory 1403 to execute the following method: after pre-charging starts, the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within a set time period are counted; based on the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampling bias current value, the first diagnostic current and the second diagnostic current of each pre-charging branch are obtained; wherein the sampling bias current value is obtained in advance; based on the first diagnostic current and the second diagnostic current of each pre-charging branch and the current type identification rule, the current type of each pre-charging branch is obtained; wherein the current type identification rule is preset; determine the pre-charging operating condition fault diagnosis table to be queried according to the number of pre-charging branches, and obtain the fault diagnosis result according to the current type of each pre-charging branch and the pre-charging operating condition fault diagnosis comparison table to be queried; wherein the pre-charging operating condition fault diagnosis comparison table is preset.

[0142] In addition, the logic instructions in the above-mentioned memory 1403 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0143] This embodiment discloses a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can perform the methods provided by the above-mentioned method embodiments, for example, including: after pre-charging begins, counting the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within a set time period; obtaining a first diagnostic current and a second diagnostic current for each pre-charging branch based on the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value; wherein the sampled bias current value is obtained in advance; obtaining a current type of each pre-charging branch based on the first and second diagnostic currents of each pre-charging branch and a current type identification rule; wherein the current type identification rule is preset; determining a pre-charging operating condition fault diagnosis table to be queried based on the number of pre-charging branches, and obtaining a fault diagnosis result based on the current type of each pre-charging branch and the pre-charging operating condition fault diagnosis comparison table to be queried; wherein the pre-charging operating condition fault diagnosis comparison table is preset.

[0144] This embodiment provides a computer-readable storage medium, which stores a computer program, and the computer program enables the computer to execute the methods provided by the above-mentioned method embodiments, for example, including: after pre-charging starts, counting the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within a set time period; obtaining a first diagnostic current and a second diagnostic current of each pre-charging branch based on the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value; wherein the sampled bias current value is obtained in advance; obtaining the current type of each pre-charging branch based on the first diagnostic current and the second diagnostic current of each pre-charging branch and a current type identification rule; wherein the current type identification rule is preset; determining the pre-charging operating condition fault diagnosis table to be queried based on the number of pre-charging branches, and obtaining a fault diagnosis result based on the current type of each pre-charging branch and the pre-charging operating condition fault diagnosis comparison table to be queried; wherein the pre-charging operating condition fault diagnosis comparison table is preset.

[0145] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0146] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0147] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0148] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0149] Throughout this specification, reference to terms such as "one embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0150] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for diagnosing power device faults based on pre-charging conditions, characterized in that: include: After pre-charging starts, the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within a set time period are counted; According to the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value, a first diagnostic current and a second diagnostic current of each pre-charging branch are obtained; wherein the result of dividing the accumulated value of the sampled current of each pre-charging branch by the number of accumulations is calculated as the sampled bias current value corresponding to each pre-charging branch; Obtaining a current type of each pre-charging branch according to the first diagnostic current and the second diagnostic current of each pre-charging branch and a current type identification rule; wherein the current type identification rule is preset; Determining a pre-charging operating condition fault diagnosis table to be queried according to the number of pre-charging branches, and obtaining a fault diagnosis result according to the current type of each pre-charging branch and the pre-charging operating condition fault diagnosis comparison table to be queried; wherein the pre-charging operating condition fault diagnosis comparison table is preset; Wherein, obtaining the first diagnostic current and the second diagnostic current of each pre-charging branch according to the maximum value and the minimum value of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value includes: performing sampling bias removal on the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle using the sampled bias current value corresponding to each pre-charging branch, thereby obtaining a first intermediate value and a second intermediate value of each pre-charging branch in each power supply voltage cycle; wherein the first intermediate value of each pre-charging branch in each power supply voltage cycle is greater than the second intermediate value; The average value of the sum of the absolute value of the first intermediate value and the absolute value of the second intermediate value of each pre-charging branch in each power supply voltage cycle within the set time period is calculated as the first diagnostic current of each pre-charging branch, and the average value of the difference between the absolute value of the first intermediate value and the absolute value of the second intermediate value of each pre-charging branch in each power supply voltage cycle within the set time period is calculated as the second diagnostic current of each pre-charging branch.

2. The method according to claim 1, characterized in that The step of obtaining the sampled bias current value includes: In an initial state, the phase current of each pre-charging branch is sampled to obtain a sampled current value of each pre-charging branch; Based on the sampled current value and sampling period of each pre-charging branch, a sampled bias current value corresponding to each pre-charging branch is obtained.

3. The method according to claim 2, characterized in that The step of obtaining a sampled bias current value corresponding to each pre-charging branch based on the sampled current value and the sampling period of each pre-charging branch includes: Calculating the product of the sampling period and a preset value to obtain a product result, and comparing the product result with the sampling offset removal time; If it is determined that the sampling offset removal time is greater than the product result, re-sampling the phase current of each pre-charging branch, and accumulating the sampled current value of each pre-charging branch to obtain the sampled current accumulated value of each pre-charging branch; If it is determined that the sampling bias removal time is equal to the product result, the result of dividing the accumulated sampling current value of each pre-charging branch by the number of accumulations is calculated as the sampling bias current value corresponding to each pre-charging branch.

4. The method according to any one of claims 1 to 3, characterized in that The current type identification rules include: If it is determined that the first diagnostic current of the pre-charging branch is greater than the corresponding first threshold, then comparing the second diagnostic current of the pre-charging branch with a second threshold; wherein the first threshold is equal to the product of the pre-charging maximum current threshold and a first set value; If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the first type; if it is determined that the second diagnostic current of the pre-charging branch is less than the inverse of the second threshold, the current type of the pre-charging branch is the second type; otherwise, the current type of the pre-charging branch is the third type; If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to a corresponding first threshold and the first diagnostic current of the pre-charging branch is greater than a corresponding third threshold, then comparing the second diagnostic current of the pre-charging branch with a second threshold; wherein the third threshold is equal to the product of the pre-charging maximum current threshold and a second set value, and the second set value is less than the first set value; If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the fourth type; otherwise, the current type of the pre-charging branch is the fifth type; If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to the corresponding third threshold and the first diagnostic current of the pre-charging branch is greater than the second threshold, then comparing the second diagnostic current of the pre-charging branch with the second threshold; If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the sixth type; if it is determined that the second diagnostic current of the pre-charging branch is less than the opposite of the second threshold, the current type of the pre-charging branch is the seventh type; otherwise, the current type of the pre-charging branch is the eighth type; If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to the second threshold, the current type of the pre-charging branch is the ninth type.

5. A power device fault diagnosis device based on pre-charging working condition, characterized in that: include: A statistical unit, configured to count the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle within a set time period after pre-charging begins; a first obtaining unit, configured to obtain a first diagnostic current and a second diagnostic current for each pre-charging branch based on the maximum and minimum values ​​of the phase current of each pre-charging branch in each power supply voltage cycle within the set time period and the corresponding sampled bias current value; wherein the result of dividing the accumulated value of the sampled current of each pre-charging branch by the number of accumulations is calculated as the sampled bias current value corresponding to each pre-charging branch; an identification unit, configured to obtain a current type of each pre-charging branch according to the first diagnostic current and the second diagnostic current of each pre-charging branch and a current type identification rule; wherein the current type identification rule is preset; a diagnostic unit, configured to determine a pre-charging condition fault diagnosis table to be queried based on the number of pre-charging branches, and obtain a fault diagnosis result based on the current type of each pre-charging branch and the pre-charging condition fault diagnosis comparison table to be queried; wherein the pre-charging condition fault diagnosis comparison table is preset; Wherein, the first obtaining unit includes: a sampling bias removal subunit, configured to perform sampling bias removal on the maximum and minimum phase currents of each pre-charging branch in each power supply voltage cycle using the sampling bias current value corresponding to each pre-charging branch, thereby obtaining a first intermediate value and a second intermediate value of each pre-charging branch in each power supply voltage cycle; wherein the first intermediate value of each pre-charging branch in each power supply voltage cycle is greater than the second intermediate value; The calculation subunit is used to calculate the average value of the sum of the absolute value of the first intermediate value and the absolute value of the second intermediate value of each pre-charging branch in each power supply voltage cycle within the set time period as the first diagnostic current of each pre-charging branch, and calculate the average value of the difference between the absolute value of the first intermediate value and the absolute value of the second intermediate value of each pre-charging branch in each power supply voltage cycle within the set time period as the second diagnostic current of each pre-charging branch.

6. The device according to claim 5, characterized in that Also includes: A sampling unit, configured to sample the phase current of each pre-charging branch in an initial state to obtain a sampled current value of each pre-charging branch; The second obtaining unit is configured to obtain a sampled bias current value corresponding to each pre-charging branch based on the sampled current value and the sampling period of each pre-charging branch.

7. The device according to claim 6, characterized in that The second obtaining unit includes: a calculation subunit, configured to calculate a product of a sampling period and a preset value, obtain a product result, and compare the product result with a sampling offset removal time; a first judging subunit, configured to, after determining that the sampling offset removal time is greater than the multiplication result, resample the phase current of each pre-charging branch and accumulate the sampled current values ​​of each pre-charging branch to obtain an accumulated sampled current value of each pre-charging branch; The second judgment subunit is used to calculate the result of dividing the accumulated sampling current value of each pre-charging branch by the number of accumulations after judging that the sampling bias removal time is equal to the product result, as the sampling bias current value corresponding to each pre-charging branch.

8. The device according to any one of claims 5 to 7, characterized in that The current type identification rules include: If it is determined that the first diagnostic current of the pre-charging branch is greater than the corresponding first threshold, then comparing the second diagnostic current of the pre-charging branch with a second threshold; wherein the first threshold is equal to the product of the pre-charging maximum current threshold and a first set value; If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the first type; if it is determined that the second diagnostic current of the pre-charging branch is less than the inverse of the second threshold, the current type of the pre-charging branch is the second type; otherwise, the current type of the pre-charging branch is the third type; If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to a corresponding first threshold and the first diagnostic current of the pre-charging branch is greater than a corresponding third threshold, then comparing the second diagnostic current of the pre-charging branch with a second threshold; wherein the third threshold is equal to the product of the pre-charging maximum current threshold and a second set value, and the second set value is less than the first set value; If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the fourth type; otherwise, the current type of the pre-charging branch is the fifth type; If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to the corresponding third threshold and the first diagnostic current of the pre-charging branch is greater than the second threshold, then comparing the second diagnostic current of the pre-charging branch with the second threshold; If it is determined that the second diagnostic current of the pre-charging branch is greater than the second threshold, the current type of the pre-charging branch is the sixth type; if it is determined that the second diagnostic current of the pre-charging branch is less than the opposite of the second threshold, the current type of the pre-charging branch is the seventh type; otherwise, the current type of the pre-charging branch is the eighth type; If it is determined that the first diagnostic current of the pre-charging branch is less than or equal to the second threshold, the current type of the pre-charging branch is the ninth type.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

11. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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