Method for detecting pre-charge failure, detection device thereof, and detection system thereof

Abstract

The application provides a pre-charging fault detection method, a detection device thereof and a detection system thereof. The method comprises the following steps: obtaining voltages between two ends of a capacitor at multiple time points to obtain multiple first voltages and determining whether each first voltage is within a first predetermined range within a predetermined time period after pre-charging of a pre-charging circuit; determining that pre-charging is successful in the case that each first voltage is within the first predetermined range; determining that pre-charging fails in the case that each first voltage is not within the first predetermined range, and obtaining voltages between the two ends of the capacitor at multiple time points during the pre-charging process to obtain multiple second voltages; and determining a pre-charging fault type according to whether the multiple second voltages meet a predetermined condition, wherein the pre-charging fault type comprises a short-circuit fault, an open-circuit fault, a resistance-capacitance fault and other faults. The method solves the problem that pre-charging faults cannot be accurately determined in the prior art, thereby causing maintenance difficulties.

Description

Technical Field

[0001] This application relates to the field of AC motor technology, and more specifically, to a method for detecting precharge faults, a device for detecting precharge faults, a computer-readable storage medium, and a system for detecting precharge faults. Background Technology

[0002] like Figure 1 As shown, a pre-charge resistor 51 and a pre-charge relay 61 are typically configured in the circuit. To connect the main circuit, only the pre-charge relay 61 and the second main relay 41 are connected first. Due to the current-limiting effect of the pre-charge resistor 51, a moderate current I will be generated in the circuit. p The voltage U across capacitor 31 c The voltage will slowly increase from the initial voltage U0 to U b U b U is the voltage across DC power supply 11 at time t1. c ≈U b Then, the first main relay 21 is turned on again, and the pre-charge relay 61 is turned off, thus completing the safe power-on.

[0003] However, in harsh environments such as severe vibration, the load-side cable may experience poor plug contact or cable breakage. Sometimes, load failure may even lead to internal circuit breakage. In addition, personnel may occasionally forget to connect the cable after maintenance, all of which will prevent the pre-charging process from being completed, the system from powering on the load, and the abnormal pre-charging circuit will always have current, posing a safety hazard.

[0004] Therefore, there is an urgent need for a method to determine pre-charge faults, which can effectively locate the fault point after the fault occurs, and facilitate fault repair.

[0005] The information disclosed above in the background section is only intended to enhance the understanding of the background art of the art described herein. Therefore, the background art may contain certain information that does not constitute prior art known to those skilled in the art in this country. Summary of the Invention

[0006] The main objective of this application is to provide a method, device, computer-readable storage medium, and system for detecting precharge faults, in order to solve the problem that the inability to accurately determine precharge faults in the prior art leads to maintenance difficulties.

[0007] To achieve the above objectives, according to one aspect of this application, a method for detecting pre-charge faults is provided, applied to a pre-charge circuit, wherein a DC power supply, a first main relay, a capacitor, and a second main relay are sequentially connected to form a closed loop, and the first main relay is connected in parallel with a pre-charge resistor and a pre-charge relay connected in series. The method includes: acquiring the voltage across the capacitor within a predetermined time period after pre-charging in the pre-charge circuit, obtaining multiple first voltages at various times, and determining whether each first voltage is within a first predetermined range; determining that pre-charging is successful if each first voltage is within the first predetermined range; determining that a pre-charge fault has occurred if each first voltage is outside the first predetermined range, and acquiring the voltage across the capacitor at various times during the pre-charging process, obtaining multiple second voltages; determining the type of pre-charge fault based at least on whether the multiple second voltages meet predetermined conditions, wherein the type of pre-charge fault includes short-circuit fault, open-circuit fault, resistor-capacitor fault, and other faults.

[0008] Optionally, the pre-charge fault type is determined based on at least whether a plurality of the second voltages meet predetermined conditions, including: calculating the difference between the second voltages at any two adjacent moments according to the order of pre-charge times to obtain a first dataset; calculating the difference between any two adjacent values ​​in the first dataset to obtain a plurality of first differences; and determining the pre-charge fault type based at least on whether the first differences are within a second predetermined range.

[0009] Optionally, the pre-charge fault type is determined at least based on whether the first difference is within a second predetermined range, including: when each of the first differences is within the second predetermined range, the type of the pre-charge fault is determined to be either a short-circuit fault or an open-circuit fault based on the relationship between each of the second voltages and the first predetermined voltage value at the corresponding time and the second predetermined voltage value at the corresponding time, wherein each of the first predetermined voltage values ​​satisfies a first relationship and each of the second predetermined voltage values ​​satisfies a second relationship, wherein the first relationship is the relationship between the pre-charge time and the voltage at a first operating temperature threshold, and the second relationship is the relationship between the pre-charge time and the voltage at a second operating temperature threshold; when each of the first differences is not within the second predetermined range, the type of the pre-charge fault is determined to be either a resistor-capacitor fault or another fault based on whether each of the first differences is within a corresponding third predetermined range, wherein the maximum value of each of the third predetermined ranges satisfies a third relationship, and the minimum value of each of the third predetermined ranges satisfies a fourth relationship, wherein the third relationship is the relationship between the pre-charge time and the voltage change when the pre-charge resistance and the capacitance are at their maximum values, and the fourth relationship is the relationship between the pre-charge time and the voltage change when the pre-charge resistance and the capacitance are at their minimum values.

[0010] Optionally, when each of the first differences is within the second predetermined range, the type of the pre-charge fault is determined to be either a short-circuit fault or an open-circuit fault based on the relationship between each of the second voltages and the first predetermined voltage value at the corresponding time and the second predetermined voltage value at the corresponding time. This includes: determining the type of the pre-charge fault as a short-circuit fault when each of the second voltages is less than the first predetermined voltage value at the corresponding time; and determining the type of the pre-charge fault as an open-circuit fault when each of the second voltages is greater than the second predetermined voltage value at the corresponding time.

[0011] Optionally, if each of the first differences is not within the second predetermined range, the type of the pre-charge fault is determined to be one of the resistor-capacitor fault and the other fault based on whether each of the first differences is within the corresponding third predetermined range, including: if each of the first differences is not within the third predetermined range at the corresponding time, the type of the pre-charge fault is determined to be the resistor-capacitor fault; if each of the first differences is within the third predetermined range at the corresponding time, the type of the pre-charge fault is determined to be the other fault.

[0012] Optionally, the method further includes: in the case that the precharge fault type is one of the short circuit fault, the open circuit fault, and the resistor-capacitor fault, controlling the precharge circuit to disconnect from the load.

[0013] Optionally, the method further includes: sending corresponding fault information to the load if a pre-charging failure is determined.

[0014] According to another aspect of this application, a pre-charge fault detection device is provided, applied to a pre-charge circuit. In the pre-charge circuit, a DC power supply, a first main relay, a capacitor, and a second main relay are sequentially connected to form a closed loop. The first main relay is connected in parallel with a pre-charge resistor and a pre-charge relay connected in series. The device includes an acquisition unit, a first determination unit, a second determination unit, and a third determination unit. The acquisition unit is used to acquire the voltage across the capacitor within a predetermined time period after pre-charging in the pre-charge circuit, obtaining first voltages at multiple moments, and determining whether each first voltage is within a first predetermined range. The first determination unit is used to determine that pre-charging is successful if each first voltage is within the first predetermined range. The second determination unit is used to determine that a pre-charge fault has occurred if each first voltage is outside the first predetermined range, and acquires the voltage across the capacitor at multiple moments during the pre-charging process, obtaining multiple second voltages. The third determination unit is used to determine the pre-charge fault type based at least on whether the multiple second voltages meet predetermined conditions. The pre-charge fault type includes short-circuit fault, open-circuit fault, resistor-capacitor fault, and other faults.

[0015] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the aforementioned precharge fault detection methods.

[0016] According to another aspect of this application, a precharge fault detection system is provided, including a precharge circuit and a controller, wherein in the precharge circuit, a DC power supply, a first main relay, a capacitor, and a second main relay are sequentially connected to form a closed loop, and the first main relay is connected in parallel with a precharge resistor and a precharge relay connected in series; the controller is communicatively connected to the precharge circuit and is used to execute any of the precharge fault detection methods described above.

[0017] The method for detecting pre-charge faults using the technical solution of this application includes: acquiring the voltage across the capacitor during a predetermined time period after pre-charging in the pre-charging circuit, obtaining multiple first voltages at various times, and determining whether each first voltage is within a first predetermined range; determining that pre-charging is successful if each first voltage is within the first predetermined range; determining that pre-charging has failed if each first voltage is outside the first predetermined range, and acquiring the voltage across the capacitor at multiple times during the pre-charging process to obtain multiple second voltages; and determining the type of pre-charging fault based on at least whether the multiple second voltages meet predetermined conditions, wherein the pre-charging fault types include short-circuit faults, open-circuit faults, resistor-capacitor faults, and other faults. This method determines whether pre-charging is successful by acquiring the first voltage across the capacitor during a predetermined time period after pre-charging in the pre-charging circuit and determining whether each first voltage is within a first predetermined range. If it is outside the first predetermined range, the type of pre-charging fault is determined based on whether the multiple voltages within the pre-charging time meet predetermined conditions, thereby allowing for fault identification and facilitating fault repair. This solves the problem in the prior art where accurate identification of pre-charging faults leads to repair difficulties. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 A schematic diagram of a pre-charging circuit according to an embodiment of this application is shown;

[0020] Figure 2 A flowchart of a precharge failure detection method according to an embodiment of this application is shown;

[0021] Figure 3A graph showing the pre-charge success rate according to one embodiment of this application is shown;

[0022] Figure 4 A graph illustrating a short-circuit fault according to an embodiment of this application is shown;

[0023] Figure 5 A graph of an open-circuit fault according to an embodiment of this application is shown;

[0024] Figure 6 A graph illustrating resistor-capacitor failure according to an embodiment of this application is shown.

[0025] Figure 7 A flowchart of a precharge failure detection device according to an embodiment of this application is shown;

[0026] Figure 8 A logic diagram of a precharge fault detection method according to an embodiment of this application is shown.

[0027] The above figures include the following reference numerals:

[0028] 11. DC power supply; 21. First main relay; 31. Capacitor; 41. Second main relay; 51. Pre-charge resistor; 61. Pre-charge relay; 71. Load. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be an intermediate element present. Furthermore, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element via a third element.

[0033] As mentioned in the background section, the prior art cannot accurately determine the problem of precharge failure leading to maintenance difficulties. In order to solve the above problem, in a typical embodiment of this application, a method for detecting precharge failure, a device for detecting precharge failure, a computer-readable storage medium, and a system for detecting precharge failure are provided.

[0034] According to embodiments of this application, a method for detecting precharge faults is provided, applied to a precharge circuit, such as... Figure 1 As shown, in the pre-charging circuit, the DC power supply 11, the first main relay 21, the capacitor 31 and the second main relay 41 are connected in sequence to form a closed loop. The first main relay 21 is connected in parallel with the pre-charging resistor 51 and the pre-charging relay 61 connected in series.

[0035] Figure 2 This is a flowchart of a precharge fault detection method according to an embodiment of this application. Figure 2 As shown, the method includes the following steps:

[0036] Step S101: During a predetermined time period after the pre-charging circuit is pre-charged, the voltage across the capacitor is obtained to obtain first voltages at multiple times, and it is determined whether each of the first voltages is within a first predetermined range.

[0037] Step S102: If each of the aforementioned first voltages is within the aforementioned first predetermined range, pre-charging is confirmed to be successful;

[0038] Step S103: If each of the first voltages is not within the first predetermined range, it is determined that a pre-charging failure has occurred, and the voltages across the capacitors at multiple moments during the pre-charging process are obtained to obtain multiple second voltages.

[0039] Step S104: Determine the pre-charge fault type based on whether at least a plurality of the aforementioned second voltages meet predetermined conditions. The aforementioned pre-charge fault types include short circuit faults, open circuit faults, resistor-capacitor faults, and other faults.

[0040] The aforementioned method for detecting pre-charge faults includes: acquiring the voltage across the capacitor during a predetermined time period after pre-charging in the pre-charging circuit, obtaining multiple first voltages at various moments, and determining whether each of the first voltages is within a first predetermined range; if each of the first voltages is within the first predetermined range, determining that pre-charging is successful; if each of the first voltages is outside the first predetermined range, determining that a pre-charging fault has occurred, and acquiring the voltage across the capacitor at multiple moments during the pre-charging process, obtaining multiple second voltages; and determining the type of pre-charging fault based on at least whether the multiple second voltages meet predetermined conditions, wherein the pre-charging fault types include short-circuit faults, open-circuit faults, resistor-capacitor faults, and other faults. This method determines whether pre-charging is successful by acquiring the first voltage across the capacitor during a predetermined time period after pre-charging in the pre-charging circuit and determining whether each first voltage is within a first predetermined range. If it is outside the first predetermined range, the type of pre-charging fault is determined based on whether the multiple voltages within the pre-charging time meet predetermined conditions, thereby identifying the cause of the fault, facilitating fault repair, and solving the problem of difficulty in repair caused by the inability to accurately determine pre-charging faults in the prior art.

[0041] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0042] In practical applications, AC motors are widely used in various industries. However, in situations where only DC power is available, a motor controller is needed to convert the DC power into AC power to supply the AC motor. For example... Figure 1The diagram shows the pre-charging circuit of the load. When the DC power supply 11 is connected to the load 71, if the pre-charging resistor 51 and the pre-charging relay 61 are not configured, the circuit will be similar to a short circuit at the moment the first main relay 21 is turned on. This is because the capacitor 31 has the characteristic of passing AC and blocking DC, resulting in a large current in the circuit. This can easily damage the capacitor 31 and the first main relay 21, causing the system to fail. With the pre-charging resistor and pre-charging relay configured, in harsh environments such as severe vibration, the load-side cable may experience poor contact at the plug or the cable may break. Sometimes, the load may fail, causing an internal open circuit. Or, the cable may be forgotten to be connected after maintenance. If the load-side plug is turned on again due to vibration or the load-side circuit is manually turned on, the uncharged load will be connected to the circuit, resulting in a large instantaneous current, which can easily damage the load and the relay. The DC input cable of the load often experiences insulation wear, short circuits, or near-short circuits due to certain contact resistance. There is also the possibility of an internal short circuit in the load. In this case, the pre-charging work cannot be completed, the system cannot power on the load, and there is always current in this abnormal pre-charging circuit, posing a safety hazard. Therefore, timely fault diagnosis enables prompt action to be taken, facilitating fault repair and ensuring the normal operation of the pre-charging circuit.

[0043] Specifically, other faults may be caused by factors such as sampling accuracy. The relationship between pre-charge time and voltage differs depending on whether the resistance and capacitance are at their maximum and minimum. If the voltage within the predetermined time period after pre-charge is within the first predetermined range, it indicates successful pre-charge. Figure 3 The graph shown is a curve showing the relationship between precharge time and voltage. The shaded area enclosed by the curves for the minimum resistance and capacitance, the maximum resistance and capacitance, the upper voltage limit, and the lower voltage limit represents the area where precharge was successful.

[0044] In order to determine the type of pre-charge failure, in another embodiment of this application, the pre-charge failure type is determined based on at least whether a plurality of the aforementioned second voltages meet predetermined conditions, including: calculating the difference between the aforementioned second voltages at any two adjacent moments according to the order of pre-charge time to obtain a first dataset; calculating the difference between any two adjacent values ​​in the aforementioned first dataset to obtain a plurality of first differences; and determining the pre-charge failure type based at least on whether the aforementioned first differences are within a second predetermined range.

[0045] Specifically, the second predetermined range can be -1% to 1%, and whether the first difference is within the second predetermined range means whether the voltage changes within two adjacent cycles.

[0046] In another embodiment of this application, determining the pre-charge fault type based at least on whether the first difference is within a second predetermined range includes: when each of the first differences is within the second predetermined range, determining the type of the pre-charge fault as either a short-circuit fault or an open-circuit fault based on the relationship between each of the second voltages and the corresponding first predetermined voltage value and the corresponding second predetermined voltage value, wherein each of the first predetermined voltage values ​​satisfies a first relationship, and each of the second predetermined voltage values ​​satisfies a second relationship, wherein the first relationship is the relationship between the pre-charge time and the voltage at a first operating temperature threshold, and the second relationship is the relationship at a second operating temperature threshold. The relationship between the precharge time and the voltage is defined as follows: If each of the first differences is not within the second predetermined range, the type of precharge fault is determined to be either a resistor-capacitor fault or another fault, based on whether each of the first differences is within the corresponding third predetermined range. The maximum value of each of the third predetermined ranges satisfies a third relationship, and the minimum value of each of the third predetermined ranges satisfies a fourth relationship. The third relationship is the relationship between the precharge time and the voltage change when the precharge resistance and capacitance are at their maximum values, and the fourth relationship is the relationship between the precharge time and the voltage change when the precharge resistance and capacitance are at their minimum values. By considering the relationship between the second voltage and the corresponding first predetermined voltage value and the corresponding second predetermined voltage value, as well as whether the first difference is within the corresponding third predetermined range, the type of precharge fault can be determined more accurately.

[0047] In another embodiment of this application, to determine whether the pre-charge fault is a short circuit fault or an open circuit fault, when each of the first differences is within the second predetermined range, the type of the pre-charge fault is determined to be either a short circuit fault or an open circuit fault based on the relationship between each of the second voltages and the first predetermined voltage value and the second predetermined voltage value at the corresponding time. This includes: determining the type of the pre-charge fault as a short circuit fault when each of the second voltages is less than the first predetermined voltage value at the corresponding time; and determining the type of the pre-charge fault as an open circuit fault when each of the second voltages is greater than the second predetermined voltage value at the corresponding time.

[0048] In practical applications, if the voltages at times t0, t1, t2, and t3 are obtained, the aforementioned first predetermined voltage value can be the minimum voltage of the capacitor at each time, and the aforementioned first operating temperature threshold can be the maximum operating temperature. When the load is short-circuited, the load voltage will always remain at a low level. Figure 4 As shown, it can be seen that within any two adjacent periods t0~t1, t1~t2, and t2~t3, the voltage of the capacitor remains unchanged, and the voltages collected at times t1, t2, and t3 are less than the minimum voltage value K at the corresponding times. 1min K2min K 3min The formula for the minimum voltage across the capacitor at times t1, t2, and t3 is:

[0049]

[0050] Among them, K 1min / 2min / 3min Let t be the minimum voltage across the capacitor at times t1, t2, and t3. 1 / 2 / 3 : t1, t2, t3 are the times, R is the pre-charge resistance value, x R For the accuracy of the pre-charge resistor, 'a' is the temperature coefficient of the pre-charge resistor, and 'T' is the temperature coefficient of the pre-charge resistor. max The maximum operating temperature is given by C, where C is the capacitance and x is the capacitance. C For capacitor accuracy.

[0051] Furthermore, the aforementioned second predetermined voltage value can be the maximum voltage of the capacitor at any given time, and the aforementioned second operating temperature threshold can be the minimum operating temperature. When the load is open-circuited or has high resistance, the load voltage will always remain at a high level. Figure 5 As shown, it can also be seen that within any two adjacent periods of t0~t1, t1~t2, and t2~t3, the voltage of the capacitor remains unchanged. However, the voltages collected at times t1, t2, and t3 are greater than the maximum voltage K of the capacitor at the corresponding times. 1max K 2max K 3max The formula for the maximum voltage across the capacitor at times t1, t2, and t3 is:

[0052]

[0053] Among them, K 1max / 2max / 3max Let t be the maximum voltage across the capacitor at times t1, t2, and t3. 1 / 2 / 3 : t1, t2, t3 are the times, R is the pre-charge resistance value, x R For the accuracy of the pre-charge resistor, 'a' is the temperature coefficient of the pre-charge resistor, and 'T' is the temperature coefficient of the pre-charge resistor. min The minimum operating temperature is given, C is the capacitance, and x is the value. C For capacitor accuracy.

[0054] In another embodiment of this application, when each of the aforementioned first differences is not within the aforementioned second predetermined range, the type of the pre-charge fault is determined to be either a resistor-capacitor fault or one of the aforementioned other faults based on whether each of the aforementioned first differences is within the corresponding third predetermined range. This includes: determining the type of the pre-charge fault as a resistor-capacitor fault when none of the aforementioned first differences are within the third predetermined range at the corresponding time; and determining the type of the pre-charge fault as one of the aforementioned other faults when all of the aforementioned first differences are within the third predetermined range at the corresponding time. When each of the aforementioned first differences is not within the second predetermined range, the type of the pre-charge fault—whether it is a resistor-capacitor fault or another fault—can be clearly determined based on whether each of the aforementioned first differences is within the corresponding third predetermined range.

[0055] Specifically, when the resistance and capacitance exceed their accuracy range, the rate of rise of the pre-charge resistance will exceed its theoretical range. To eliminate the influence of sampling accuracy, the judgment method uses the difference in capacitor voltage at two adjacent time points. When the resistance and capacitance are theoretically at their minimum, the voltage difference ΔK of the capacitor is... x@RCmin The calculation is as follows:

[0056] When the resistance and capacitance are theoretically at their minimum, the difference in voltage across the capacitor between two adjacent time points is ΔK. x@RCmin =K x@RCmin -K x-1@RCmin When the resistance and capacitance are at their theoretical maximum, the voltage difference ΔK across the capacitor is... x@RCmax The calculation is as follows:

[0057] When the resistance and capacitance are theoretically at their maximum, the difference in voltage across the capacitor between two adjacent time points is ΔK. x@RCmax =K x@RCmax -K x-1@RCmax , where ΔK x@RCmin When the resistance and capacitance are at their minimum, at time t x-1 ~t x The change in voltage across the capacitor at time K x@RCmin When the resistance and capacitance are at their minimum, at time t x The voltage across the capacitor at time ΔK x@RCmax When the resistance and capacitance are at their maximum, at time t x-1 ~t x The change in voltage across the capacitor at time K x@RCmax When the resistance and capacitance are at their maximum, at time t x The voltage across the capacitor at time t 1 / 2 / 3 : t1, t2, t3 are the times, R is the pre-charge resistance value, x R For the accuracy of the pre-charge resistor, 'a' is the temperature coefficient of the pre-charge resistor, and 'T' is the temperature coefficient of the pre-charge resistor.max The maximum operating temperature is given by C, where C is the capacitance and x is the capacitance. C For capacitor accuracy, x k This refers to the voltage sampling accuracy. If the pre-charge is normal, at t... x-1 ~t x Within a given time period, the voltage of the capacitor collected should be within ΔK. x@RCmin ~ΔK x@RCmax If the value is outside the specified range, it indicates an abnormality in the pre-charging circuit resistor and capacitor. Figure 6 As shown, at t x-1 ~t x Within a given time period, the voltage across the capacitor is greater than ΔK. x@RCmax And the voltage of the capacitor collected is less than ΔK x@RCmin The curve.

[0058] In order to prevent damage to resistors, capacitors and other devices, in another embodiment of this application, the above method further includes: controlling the pre-charge circuit to disconnect from the load when the pre-charge fault type is one of the above short circuit fault, the above open circuit fault and the above resistor and capacitor fault.

[0059] In practical applications, short circuit faults, resistor and capacitor faults can damage resistors, capacitors and other components and pose safety risks, so power-on is not allowed. Other faults, however, do not damage resistors, capacitors and other components, so power-on is allowed. This allows for adaptive adjustments for faults that do not affect safety.

[0060] In another embodiment of this application, the method further includes: sending corresponding fault information to the load when a pre-charging failure is determined. Timely transmission of fault information upon occurrence of a fault allows maintenance personnel to promptly determine the fault type and implement different handling methods for different faults, ensuring normal operation without compromising safety. Furthermore, fault reporting after occurrence effectively locates the fault point, facilitating fault repair.

[0061] This application also provides a pre-charge fault detection device, applied to a pre-charge circuit, such as... Figure 1 As shown, in the aforementioned pre-charge circuit, the DC power supply 11, the first main relay 21, the capacitor 31, and the second main relay 41 are sequentially connected to form a closed loop. The first main relay 21 is connected in parallel with the pre-charge resistor 51 and the pre-charge relay 61, which are connected in series. It should be noted that the pre-charge fault detection device of this application embodiment can be used to execute the pre-charge fault detection method provided in this application embodiment. The pre-charge fault detection device provided in this application embodiment is described below.

[0062] Figure 7This is a schematic diagram of a precharge fault detection device according to an embodiment of this application. Figure 7 As shown, the device includes an acquisition unit 10, a first determination unit 20, a second determination unit 30, and a third determination unit 40. The acquisition unit 10 acquires the voltage across the capacitor within a predetermined time period after precharging in the precharging circuit, obtaining first voltages at multiple moments, and determines whether each first voltage is within a first predetermined range. The first determination unit 20 determines that precharging is successful if each first voltage is within the first predetermined range. The second determination unit 30 determines that a precharging failure has occurred if each first voltage is outside the first predetermined range, and acquires the voltage across the capacitor at multiple moments during precharging to obtain multiple second voltages. The third determination unit 40 determines the precharging failure type based at least on whether the multiple second voltages meet predetermined conditions. The precharging failure types include short-circuit faults, open-circuit faults, resistor-capacitor faults, and other faults.

[0063] The aforementioned pre-charge fault detection device, through the acquisition unit, acquires the voltage across the capacitor within a predetermined time period after pre-charging in the pre-charging circuit, obtaining multiple first voltages at various moments, and determines whether each of the first voltages is within a first predetermined range. If the first voltages are within the first predetermined range, the first determination unit determines that pre-charging is successful. If the first voltages are outside the first predetermined range, the second determination unit determines that a pre-charging fault has occurred, and acquires multiple second voltages at various moments during the pre-charging process. The third determination unit determines the type of pre-charging fault, including short-circuit faults, open-circuit faults, resistor-capacitor faults, and other faults, based at least on whether the multiple second voltages meet predetermined conditions. This device determines whether pre-charging is successful by acquiring the first voltages across the capacitor within a predetermined time period after pre-charging in the pre-charging circuit and determining whether each first voltage is within a predetermined range. If it is outside the first predetermined range, the device determines the type of pre-charging fault based on whether the multiple voltages within the pre-charging time meet predetermined conditions, thereby identifying the cause of the fault, facilitating fault repair, and solving the problem of difficult repair caused by the inability to accurately determine pre-charging faults in the prior art.

[0064] Specifically, other faults may be caused by factors such as sampling accuracy. The relationship between pre-charge time and voltage differs depending on whether the resistance and capacitance are at their maximum and minimum. If the voltage within the predetermined time period after pre-charge is within the first predetermined range, it indicates successful pre-charge. Figure 3 As shown, the shaded area represents the region where pre-charging was successful.

[0065] In another embodiment of this application, to determine the type of pre-charge failure, the third determining unit includes a first calculation subunit, a second calculation subunit, and a determining subunit. The first calculation subunit is used to calculate the difference between the second voltage at any two adjacent moments according to the order of pre-charge time to obtain a first dataset. The second calculation subunit is used to calculate the difference between any two adjacent values ​​in the first dataset to obtain a plurality of first differences. The first determining subunit is used to determine the type of pre-charge failure at least based on whether the first differences are within a second predetermined range.

[0066] Specifically, the second predetermined range can be -1% to 1%, and whether the first difference is within the second predetermined range means whether the voltage changes within two adjacent cycles.

[0067] In another embodiment of this application, the determining module includes a first determining module and a second determining module. The first determining module is used to determine, when each of the first differences is within the second predetermined range, the type of the pre-charge fault is either a short-circuit fault or an open-circuit fault based on the relationship between each of the second voltages and the corresponding first predetermined voltage value and the corresponding second predetermined voltage value. Each of the first predetermined voltage values ​​satisfies a first relationship, and each of the second predetermined voltage values ​​satisfies a second relationship. The first relationship is the relationship between the pre-charge time and the voltage at a first operating temperature threshold, and the second relationship is the relationship between the pre-charge time and the voltage at a second operating temperature threshold. The relationship between charging time and the aforementioned voltage; the second determining module is used to determine the type of the pre-charge fault as one of a resistor-capacitor fault and other faults, based on whether each of the aforementioned first differences is within the corresponding third predetermined range, when the aforementioned first differences are not within the aforementioned second predetermined range. The maximum value of each of the aforementioned third predetermined ranges satisfies a third relationship, and the minimum value of each of the aforementioned third predetermined ranges satisfies a fourth relationship. The third relationship is the relationship between the pre-charge time and the voltage change when the aforementioned pre-charge resistor and the aforementioned capacitor are at their maximum values, and the fourth relationship is the relationship between the pre-charge time and the voltage change when the aforementioned pre-charge resistor and the aforementioned capacitor are at their minimum values. By using the relationship between the second voltage and the corresponding first predetermined voltage value and the corresponding second predetermined voltage value, as well as whether the aforementioned first differences are within the corresponding third predetermined range, the type of pre-charge fault can be determined more accurately.

[0068] In order to determine whether the pre-charge fault is a short circuit fault or an open circuit fault, in another embodiment of this application, the first determining module includes a first determining submodule and a second determining submodule. The first determining submodule is used to determine the type of the pre-charge fault as a short circuit fault when all the second voltages are less than the first predetermined voltage value at the corresponding time. The second determining submodule is used to determine the type of the pre-charge fault as an open circuit fault when all the second voltages are greater than the second predetermined voltage value at the corresponding time.

[0069] In practical applications, if the voltages at times t0, t1, t2, and t3 are obtained, the aforementioned first predetermined voltage value can be the minimum voltage of the capacitor at each time, and the aforementioned first operating temperature threshold can be the maximum operating temperature. When the load is short-circuited, the load voltage will always remain at a low level. Figure 4 As shown, it can be seen that within any two adjacent periods t0~t1, t1~t2, and t2~t3, the voltage of the capacitor remains unchanged, and the voltages collected at times t1, t2, and t3 are less than the minimum voltage value K at the corresponding times. 1min K 2min K 3min The formula for the minimum voltage across the capacitor at times t1, t2, and t3 is:

[0070]

[0071] Among them, K 1min / 2min / 3min Let t be the minimum voltage across the capacitor at times t1, t2, and t3. 1 / 2 / 3 : t1, t2, t3 are the times, R is the pre-charge resistance value, x R For the accuracy of the pre-charge resistor, 'a' is the temperature coefficient of the pre-charge resistor, and 'T' is the temperature coefficient of the pre-charge resistor. max The maximum operating temperature is given by C, where C is the capacitance and x is the capacitance. C For capacitor accuracy.

[0072] Furthermore, the aforementioned second predetermined voltage value can be the maximum voltage of the capacitor at any given time, and the aforementioned second operating temperature threshold can be the minimum operating temperature. When the load is open-circuited or has high resistance, the load voltage will always remain at a high level. Figure 5 As shown, it can also be seen that within any two adjacent periods of t0~t1, t1~t2, and t2~t3, the voltage of the capacitor remains unchanged. However, the voltages collected at times t1, t2, and t3 are greater than the maximum voltage K of the capacitor at the corresponding times. 1max K 2max K 3max The formula for the maximum voltage across the capacitor at times t1, t2, and t3 is:

[0073]

[0074] Among them, K 1max / 2max / 3max Let t be the maximum voltage across the capacitor at times t1, t2, and t3. 1 / 2 / 3 : t1, t2, t3 are the times, R is the pre-charge resistance value, x R For the accuracy of the pre-charge resistor, 'a' is the temperature coefficient of the pre-charge resistor, and 'T' is the temperature coefficient of the pre-charge resistor. min The minimum operating temperature is given, C is the capacitance, and x is the value. C For capacitor accuracy.

[0075] In another embodiment of this application, when each of the aforementioned first differences is not within the aforementioned second predetermined range, the type of the pre-charge fault is determined to be either a resistor-capacitor fault or one of the aforementioned other faults based on whether each of the aforementioned first differences is within the corresponding third predetermined range. This includes: determining the type of the pre-charge fault as a resistor-capacitor fault when none of the aforementioned first differences are within the third predetermined range at the corresponding time; and determining the type of the pre-charge fault as one of the aforementioned other faults when all of the aforementioned first differences are within the third predetermined range at the corresponding time. When each of the aforementioned first differences is not within the second predetermined range, the type of the pre-charge fault—whether it is a resistor-capacitor fault or another fault—can be clearly determined based on whether each of the aforementioned first differences is within the corresponding third predetermined range.

[0076] Specifically, when the resistance and capacitance exceed their accuracy range, the rate of rise of the pre-charge resistance will exceed its theoretical range. To eliminate the influence of sampling accuracy, the judgment method uses the difference in capacitor voltage at two adjacent time points. When the resistance and capacitance are theoretically at their minimum, the voltage difference ΔK of the capacitor is... x@RCmin The calculation is as follows:

[0077] When the resistance and capacitance are theoretically at their minimum, the difference in voltage across the capacitor between two adjacent time points is ΔK. x@RCmin =K x@RCmin -K x-1@RCmin When the resistance and capacitance are at their theoretical maximum, the voltage difference ΔK across the capacitor is... x@RCmax The calculation is as follows:

[0078] When the resistance and capacitance are theoretically at their maximum, the difference in voltage across the capacitor between two adjacent time points is ΔK. x@RCmax =K x@RCmax -K x-1@RCmax , where ΔK x@RCmin When the resistance and capacitance are at their minimum, at time t x-1 ~t x The change in voltage across the capacitor at time K x@RCmin When the resistance and capacitance are at their minimum, at time t xThe voltage across the capacitor at time ΔK x@RCmax When the resistance and capacitance are at their maximum, at time t x-1 ~t x The change in voltage across the capacitor at time K x@RCmax When the resistance and capacitance are at their maximum, at time t x The voltage across the capacitor at time t 1 / 2 / 3 : t1, t2, t3 are the times, R is the pre-charge resistance value, x R For the accuracy of the pre-charge resistor, 'a' is the temperature coefficient of the pre-charge resistor, and 'T' is the temperature coefficient of the pre-charge resistor. max The maximum operating temperature is given by C, where C is the capacitance and x is the capacitance. C For capacitor accuracy, x k This refers to the voltage sampling accuracy. If the pre-charge is normal, at t... x-1 ~t x Within a given time period, the voltage of the capacitor collected should be within ΔK. x@RCmin ~ΔK x@RCmax If the value is outside the specified range, it indicates an abnormality in the pre-charging circuit resistor and capacitor. Figure 6 As shown, at t x-1 ~t x Within a given time period, the voltage across the capacitor is greater than ΔK. x@RCmax And the voltage of the capacitor collected is less than ΔK x@RCmin The curve.

[0079] In order to prevent damage to resistors, capacitors and other devices, in another embodiment of this application, the above-mentioned device further includes a processing unit, which is used to control the pre-charge circuit to disconnect from the load when the pre-charge fault type is one of the above-mentioned short circuit fault, the above-mentioned open circuit fault and the above-mentioned resistor and capacitor fault.

[0080] In practical applications, short circuit faults, resistor and capacitor faults can damage resistors, capacitors and other components and pose safety risks, so power-on is not allowed. Other faults, however, do not damage resistors, capacitors and other components, so power-on is allowed. This allows for adaptive adjustments for faults that do not affect safety.

[0081] In another embodiment of this application, the above-mentioned device further includes a sending unit, which is used to send corresponding fault information to the load when a pre-charging failure is determined. By promptly sending fault information when a fault occurs, maintenance personnel can quickly determine the type of fault and take different actions for different faults, ensuring normal operation without compromising safety. Furthermore, after a fault occurs, a fault report is made, which effectively locates the fault point and facilitates fault repair.

[0082] According to another aspect of this application, a precharge fault detection system is provided, including a precharge circuit and a controller, wherein in the precharge circuit, a DC power supply, a first main relay, a capacitor, and a second main relay are sequentially connected to form a closed loop, and the first main relay is connected in parallel with a precharge resistor and a precharge relay connected in series; the controller is communicatively connected to the precharge circuit and is used to execute any of the above-mentioned precharge fault detection methods.

[0083] The aforementioned precharge fault detection system includes a precharge circuit and a controller. The controller is communicatively connected to the precharge circuit and is used to execute any of the aforementioned precharge fault detection methods. This method obtains the first voltage across the capacitor within a predetermined time period after precharging in the precharge circuit, and determines whether the precharging is successful by judging whether each first voltage is within a first predetermined range. If it is not within the first predetermined range, the type of precharge fault is determined based on whether multiple voltages within the precharge time meet predetermined conditions, thereby determining the cause of the fault and facilitating fault repair. This solves the problem in the prior art where the inability to accurately determine precharge faults leads to repair difficulties.

[0084] The aforementioned precharge fault detection device includes a processor and a memory. The aforementioned acquisition unit, first determination unit, second determination unit, and third determination unit are all stored in the memory as program units, and the processor executes the aforementioned program units stored in the memory to realize the corresponding functions.

[0085] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and adjusting kernel parameters can address the difficulty in accurately diagnosing precharge faults, which hinders repairs in existing technologies.

[0086] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0087] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the precharge fault detection method.

[0088] This invention provides a processor for running a program, wherein the program executes the precharge fault detection method.

[0089] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps:

[0090] Step S101: During a predetermined time period after the pre-charging circuit is pre-charged, the voltage across the capacitor is obtained to obtain first voltages at multiple times, and it is determined whether each of the first voltages is within a first predetermined range.

[0091] Step S102: If each of the aforementioned first voltages is within the aforementioned first predetermined range, pre-charging is confirmed to be successful;

[0092] Step S103: If each of the first voltages is not within the first predetermined range, it is determined that a pre-charging failure has occurred, and the voltages across the capacitors at multiple moments during the pre-charging process are obtained to obtain multiple second voltages.

[0093] Step S104: Determine the pre-charge fault type based on whether at least a plurality of the aforementioned second voltages meet predetermined conditions. The aforementioned pre-charge fault types include short circuit faults, open circuit faults, resistor-capacitor faults, and other faults.

[0094] The devices mentioned in this article can be servers, PCs, tablets, mobile phones, etc.

[0095] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps:

[0096] Step S101: During a predetermined time period after the pre-charging circuit is pre-charged, the voltage across the capacitor is obtained to obtain first voltages at multiple times, and it is determined whether each of the first voltages is within a first predetermined range.

[0097] Step S102: If each of the aforementioned first voltages is within the aforementioned first predetermined range, pre-charging is confirmed to be successful;

[0098] Step S103: If each of the first voltages is not within the first predetermined range, it is determined that a pre-charging failure has occurred, and the voltages across the capacitors at multiple moments during the pre-charging process are obtained to obtain multiple second voltages.

[0099] Step S104: Determine the pre-charge fault type based on whether at least a plurality of the aforementioned second voltages meet predetermined conditions. The aforementioned pre-charge fault types include short circuit faults, open circuit faults, resistor-capacitor faults, and other faults.

[0100] In one specific embodiment of this application, the logical process of the pre-charge fault detection method is as follows: Figure 8 As shown,

[0101] Within a predetermined time period after the pre-charging circuit has performed pre-charging, the voltage across the capacitor is acquired to obtain the first voltage at multiple moments.

[0102] Determine whether each first voltage is within a first predetermined range;

[0103] If each first voltage is within a predetermined range, the pre-charging is successful; otherwise, the difference between the second voltages at any two adjacent moments is calculated according to the order of pre-charging time to obtain the first dataset.

[0104] Calculate the difference between any two adjacent values ​​in the first dataset to obtain multiple first differences;

[0105] Determine whether the first difference is within the second predetermined range;

[0106] If the first difference is within the second predetermined range, it is determined whether each second voltage is less than the first predetermined voltage value at the corresponding time. If each second voltage is less than the first predetermined voltage value at the corresponding time, a short circuit fault occurs in the pre-charging circuit, and power-on is not allowed. If each second voltage is greater than the first predetermined voltage value at the corresponding time, an open circuit fault occurs in the pre-charging circuit, and power-on is not allowed.

[0107] If the first difference is not within the second predetermined range, determine whether each first difference is not within the third predetermined range at the corresponding time. If each first difference is not within the third predetermined range at the corresponding time, then a resistor-capacitor fault occurs in the pre-charging circuit, and power-on is not allowed. If each first difference is within the third predetermined range at the corresponding time, then another fault occurs in the pre-charging circuit, and power-on is allowed.

[0108] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0109] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units described above can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0110] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0111] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0112] If the aforementioned integrated units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0113] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0114] 1) The pre-charge fault detection method of this application includes: acquiring the voltage across the capacitor during a predetermined time period after pre-charging in the pre-charging circuit, obtaining multiple first voltages at various times, and determining whether each of the first voltages is within a first predetermined range; determining that pre-charging is successful if each of the first voltages is within the first predetermined range; determining that pre-charging has failed if each of the first voltages is outside the first predetermined range, and acquiring the voltage across the capacitor at various times during the pre-charging process, obtaining multiple second voltages; and determining the type of pre-charging fault based on whether the multiple second voltages meet predetermined conditions, wherein the pre-charging fault types include short-circuit faults, open-circuit faults, resistor-capacitor faults, and other faults. This method determines whether pre-charging is successful by acquiring the first voltage across the capacitor during a predetermined time period after pre-charging in the pre-charging circuit and determining whether each first voltage is within a first predetermined range. If it is outside the first predetermined range, the type of pre-charging fault is determined based on whether the multiple voltages within the pre-charging time meet predetermined conditions, thereby determining the cause of the fault, facilitating fault repair, and solving the problem in the prior art where accurate determination of pre-charging faults leads to repair difficulties.

[0115] 2) The pre-charge fault detection device of this application acquires the voltage across the capacitor during a predetermined time period after pre-charging in the pre-charging circuit by the acquisition unit, obtains first voltages at multiple moments, and determines whether each of the first voltages is within a first predetermined range; if the first determination unit determines that pre-charging is successful when each of the first voltages is within the first predetermined range, the second determination unit determines that a pre-charging fault has occurred when each of the first voltages is not within the first predetermined range, and acquires the voltage across the capacitor at multiple moments during the pre-charging process to obtain multiple second voltages; the third determination unit determines the type of pre-charging fault based at least on whether the multiple second voltages meet predetermined conditions, and the type of pre-charging fault includes short circuit fault, open circuit fault, resistor-capacitor fault, and other faults. This device determines whether precharging is successful by acquiring the first voltage across the capacitor during a predetermined time period after precharging in the aforementioned precharging circuit, and judging whether each first voltage is within a first predetermined range. If it is not within the first predetermined range, the device determines the type of precharging fault based on whether multiple voltages within the precharging time meet predetermined conditions, thereby determining the cause of the fault and facilitating fault repair. This solves the problem in the prior art where it is impossible to accurately determine precharging faults, leading to repair difficulties.

[0116] 3) The precharge fault detection system of this application includes a precharge circuit and a controller. The controller is communicatively connected to the precharge circuit and is used to execute any of the precharge fault detection methods described above. This method obtains the first voltage across the capacitor within a predetermined time period after precharging in the precharge circuit, and determines whether the precharging is successful by judging whether each first voltage is within a first predetermined range. If it is not within the first predetermined range, the type of precharge fault is determined based on whether multiple voltages within the precharge time meet predetermined conditions, thereby determining the cause of the fault and facilitating fault repair. This solves the problem in the prior art where it is impossible to accurately determine the precharge fault, leading to repair difficulties.

[0117] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for detecting precharge faults, characterized in that, The method is applied to a pre-charging circuit, in which a DC power supply, a first main relay, a capacitor, and a second main relay are sequentially connected to form a closed loop, and the first main relay is connected in parallel with a pre-charging resistor and a pre-charging relay connected in series. The method includes: During a predetermined time period after the pre-charging circuit is pre-charged, the voltage across the capacitor is acquired to obtain first voltages at multiple times, and it is determined whether each first voltage is within a first predetermined range. If each of the first voltages is within the first predetermined range, the pre-charge is determined to be successful; If each of the first voltages is outside the first predetermined range, it is determined that a pre-charging failure has occurred, and the voltages across the capacitors at multiple moments during the pre-charging process are obtained to obtain multiple second voltages; The precharge fault type is determined based on at least a plurality of the second voltages whether predetermined conditions are met. The precharge fault type includes short circuit fault, open circuit fault, resistor-capacitor fault, and other faults. The pre-charge fault type is determined based on at least a plurality of second voltages meeting predetermined conditions, including: calculating the difference between the second voltages at any two adjacent moments according to the order of pre-charge times to obtain a first dataset; calculating the difference between any two adjacent values ​​in the first dataset to obtain a plurality of first differences; and determining the pre-charge fault type based at least on whether the first differences are within a second predetermined range. The pre-charge fault type is determined based on whether the first difference is within a second predetermined range, including: when each of the first differences is within the second predetermined range, the type of the pre-charge fault is determined to be either a short-circuit fault or an open-circuit fault based on the relationship between each of the second voltages and the first predetermined voltage value at the corresponding time and the second predetermined voltage value at the corresponding time, wherein each of the first predetermined voltage values ​​satisfies a first relationship and each of the second predetermined voltage values ​​satisfies a second relationship, wherein the first relationship is the relationship between the pre-charge time and the voltage at a first operating temperature threshold, and the second relationship is the relationship between the pre-charge time and the voltage at a second operating temperature threshold; when each of the first differences is not within the second predetermined range, the type of the pre-charge fault is determined to be either a resistor-capacitor fault or another fault based on whether each of the first differences is within a corresponding third predetermined range, wherein the maximum value of each of the third predetermined ranges satisfies a third relationship, and the minimum value of each of the third predetermined ranges satisfies a fourth relationship, wherein the third relationship is the relationship between the pre-charge time and the voltage change when the pre-charge resistor and the capacitor are at their maximum values, and the fourth relationship is the relationship between the pre-charge time and the voltage change when the pre-charge resistor and the capacitor are at their minimum values.

2. The method according to claim 1, characterized in that, When each of the first differences is within the second predetermined range, based on the relationship between each of the second voltages and the corresponding first predetermined voltage value and the corresponding second predetermined voltage value, the type of the pre-charge fault is determined to be one of the short-circuit fault and the open-circuit fault, including: If each of the second voltages is less than the first predetermined voltage value at the corresponding time, the type of the pre-charge fault is determined to be the short-circuit fault; If each of the second voltages is greater than the second predetermined voltage value at the corresponding time, the type of the precharge fault is determined to be the open circuit fault.

3. The method according to claim 1, characterized in that, If each of the first differences is not within the second predetermined range, the type of the precharge fault is determined to be one of the resistor-capacitor fault and the other faults, based on whether each of the first differences is within the corresponding third predetermined range, including: If none of the first differences are within the third predetermined range at the corresponding time, the type of the pre-charge fault is determined to be the resistor-capacitor fault; If each of the first differences is within the third predetermined range at the corresponding time, the type of the precharge fault is determined to be the other fault.

4. The method according to claim 1, characterized in that, The method further includes: In the event that the precharge fault type is one of the short circuit fault, the open circuit fault, and the resistor-capacitor fault, the precharge relay and the second main relay in the precharge circuit are controlled to disconnect.

5. The method according to claim 4, characterized in that, The method further includes: If a pre-charging failure is detected, the corresponding fault information is sent to the controller.

6. A precharge fault detection device, characterized in that, An application in a pre-charging circuit, wherein a DC power supply, a first main relay, a capacitor, and a second main relay are sequentially connected to form a closed loop, and the first main relay is connected in parallel with a pre-charging resistor and a pre-charging relay connected in series. The device includes: The acquisition unit is used to acquire the voltage across the capacitor within a predetermined time period after the pre-charging circuit is pre-charged, obtain the first voltage at multiple times, and determine whether each first voltage is within a first predetermined range. The first determining unit is configured to determine that the pre-charge is successful if each of the first voltages is within the first predetermined range. The second determining unit is used to determine that a pre-charging failure has occurred when each of the first voltages is not within the first predetermined range, and to obtain the voltages across the capacitor at multiple times during the pre-charging process to obtain multiple second voltages. The third determining unit is used to determine the pre-charge fault type based on at least a plurality of the second voltages meeting predetermined conditions. The pre-charge fault type includes short circuit fault, open circuit fault, resistor-capacitor fault, and other faults. The third determining unit includes a first calculation subunit, a second calculation subunit, and a determining subunit. The first calculation subunit is used to calculate the difference between the second voltage at any two adjacent moments according to the order of the pre-charge time to obtain a first dataset. The second calculation subunit calculates the difference between any two adjacent values ​​in the first dataset to obtain a plurality of first differences. The determining subunit is used to determine the pre-charge fault type at least based on whether the first differences are within a second predetermined range. The determining subunit includes a first determining module and a second determining module. The first determining module is used to determine, when each of the first differences is within a second predetermined range, the type of the pre-charge fault is either a short-circuit fault or an open-circuit fault based on the relationship between each of the second voltages and the corresponding first predetermined voltage value and the corresponding second predetermined voltage value. Each of the first predetermined voltage values ​​satisfies a first relationship, and each of the second predetermined voltage values ​​satisfies a second relationship. The first relationship is the relationship between the pre-charge time and the voltage at a first operating temperature threshold, and the second relationship is the relationship between the pre-charge time and the voltage at a second operating temperature threshold. The second determining module is used to determine, when each of the first differences is not within the second predetermined range, the type of the pre-charge fault is either a resistor-capacitor fault or another fault based on whether each of the first differences is within a corresponding third predetermined range. The maximum value of each of the third predetermined ranges satisfies a third relationship, and the minimum value of each of the third predetermined ranges satisfies a fourth relationship. The third relationship is the relationship between the pre-charge time and the voltage change when the pre-charge resistance and capacitance are at their maximum values, and the fourth relationship is the relationship between the pre-charge time and the voltage change when the pre-charge resistance and capacitance are at their minimum values.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the precharge fault detection method according to any one of claims 1 to 5.

8. A precharge fault detection system, characterized in that, include: The pre-charging circuit consists of a DC power supply, a first main relay, a capacitor, and a second main relay connected in sequence to form a closed loop. The first main relay is connected in parallel with the pre-charging resistor and the pre-charging relay, which are connected in series. The controller, which is communicatively connected to the precharge circuit, is used to execute the precharge fault detection method according to any one of claims 1 to 5.

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