Insulation detection method, insulation detection device, insulation detection system and vehicle

Abstract

The present application discloses an insulation detection method, an insulation detection device, an insulation detection system, a vehicle and a computer-readable storage medium, and belongs to the field of insulation detection technology. The present application provides an insulation detection method, which is applied to an insulation bridge arm circuit, and the method includes: obtaining voltage data sets in multiple stages of the insulation bridge arm circuit in a single-sided detection cycle; determining the confidence level corresponding to each voltage data set; determining a target voltage data set that meets the confidence condition based on the confidence level and the voltage data set; and calculating the insulation resistance value based on the target voltage data set. According to the insulation detection method of the present application, the single-sided detection cycle is divided into multiple stages, and the confidence level of the voltage data set in each stage is calculated respectively. The target voltage data set that meets the confidence condition is used to calculate the insulation resistance, and unreliable data is removed, which can improve the insulation detection accuracy under various working conditions.

Description

Technical Field

[0001] The present application belongs to the technical field of insulation detection, and in particular, relates to an insulation detection method, an insulation detection device, an insulation detection system, a vehicle, and a computer-readable storage medium. Background Art

[0002] The power battery packs used in electric vehicles are generally hundreds of volts high, much higher than the human safety voltage of 60V. If the insulation performance of the high-voltage system deteriorates, it may endanger the safety of passengers. Therefore, it is very necessary to perform insulation testing on the high-voltage system of electric vehicles and update the insulation resistance value.

[0003] In the prior art, a fixed insulation calculation cycle is usually used to calculate the insulation resistance. If there is external interference during the insulation sampling process, or when the Y capacitor has not reached a stable charging and discharging state, the insulation resistance calculation will lead to problems such as poor accuracy. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes an insulation detection method, an insulation detection device, an insulation detection system, a vehicle and a computer-readable storage medium, which divides a single-side detection cycle into multiple stages, and calculates the confidence of a voltage data set in each stage respectively, uses a target voltage data set that meets the confidence condition to calculate insulation resistance, removes unreliable data, and can improve the insulation detection accuracy under various working conditions.

[0005] In a first aspect, the present application provides an insulation detection method, which is applied to an insulation bridge arm circuit, and the method comprises:

[0006] Acquire voltage data sets of the insulated bridge arm circuit in multiple stages within a single-side detection cycle;

[0007] Determine the confidence level corresponding to each voltage data set;

[0008] Determine a target voltage data set that meets a confidence condition according to the confidence level and the voltage data set;

[0009] Perform insulation resistance calculation based on target voltage data set.

[0010] According to the insulation detection method of the present application, the single-side detection cycle is divided into multiple stages, and the confidence of the voltage data set in each stage is calculated respectively. The target voltage data set that meets the confidence condition is used to calculate the insulation resistance, and unreliable data is removed, which can improve the insulation detection accuracy under various working conditions.

[0011] According to an embodiment of the present application, determining the confidence level corresponding to each voltage data set includes:

[0012] Determine target voltage data that meets reliability conditions in each voltage data set;

[0013] The ratio of the data volume of each target voltage data to the data volume of the corresponding voltage data set is used as the confidence level corresponding to the voltage data set.

[0014] According to an embodiment of the present application, the unilateral detection cycle includes a continuous voltage change phase and a voltage stabilization phase, and each voltage data set includes a first voltage data set corresponding to the voltage change phase and a second voltage data set corresponding to the voltage stabilization phase;

[0015] The target voltage data includes voltage data of n consecutive sampling cycles, and the voltage data of each sampling cycle includes a bridge arm voltage and a total insulation voltage of the insulating bridge arm circuit.

[0016] According to an embodiment of the present application, when the target voltage data corresponding to the first voltage data set meets the following conditions, it is determined that the reliability condition is met:

[0017] During the n consecutive sampling periods, the variation trend of the n consecutive bridge arm voltages is the same as the overall variation trend of the bridge arm voltage in the corresponding single-side detection period;

[0018] During n consecutive sampling periods, the change rate of the two bridge arm voltages obtained in every two adjacent sampling periods decreases monotonically; and,

[0019] During n consecutive sampling periods, the change value of the total insulation voltage is smaller than the first threshold.

[0020] According to an embodiment of the present application, when the target voltage data corresponding to the second voltage data set meets the following conditions, it is determined that the reliability condition is met:

[0021] During the n consecutive sampling periods, the variation trend of the n consecutive bridge arm voltages is the same as the overall variation trend of the bridge arm voltage in the corresponding single-side detection period;

[0022] During n consecutive sampling periods, the change rate of the two bridge arm voltages obtained in every two adjacent sampling periods decreases monotonically, and the change rate is less than the second threshold; and,

[0023] During n consecutive sampling periods, the change value of the total insulation voltage is smaller than the third threshold.

[0024] According to one embodiment of the present application, determining a target voltage data set that satisfies a confidence condition according to a confidence level and a voltage data set includes:

[0025] The voltage data set with a confidence level greater than the reference value is used as a reference voltage data set satisfying the confidence condition;

[0026] The target voltage data corresponding to each reference voltage data set is used as the target voltage data set.

[0027] According to one embodiment of the present application, performing insulation resistance calculation according to a target voltage data set includes:

[0028] Determine a target bridge arm voltage of the insulated bridge arm circuit when the voltage is stable according to the target voltage data set;

[0029] The insulation resistance is calculated according to the target bridge arm voltage.

[0030] According to one embodiment of the present application, the target bridge arm voltage includes a first bridge arm voltage, a second bridge arm voltage, or a third bridge arm voltage, and determining the target bridge arm voltage when the insulated bridge arm circuit is in a stable state according to the target voltage data set includes:

[0031] When the target voltage data set includes target voltage data corresponding to the first voltage data set, predicting the target voltage data set according to the prediction algorithm to obtain a first bridge arm voltage when the insulated bridge arm circuit is in a voltage stable state;

[0032] When the target voltage data set includes target voltage data corresponding to the second voltage data set, an average value of the target voltage data is used as the second bridge arm voltage; or,

[0033] When the target voltage data set includes target voltage data corresponding to the first voltage data set and target voltage data corresponding to the second voltage data set, a weighted average of the first bridge arm voltage and the second bridge arm voltage is used as the third bridge arm voltage.

[0034] According to one embodiment of the present application, the detection cycle of the insulating bridge arm circuit includes an alternating first unilateral detection cycle and a second unilateral detection cycle, and the overall change trend of the bridge arm voltage of the insulating bridge arm circuit in the first unilateral detection cycle and the second unilateral detection cycle is opposite;

[0035] Insulation resistance calculation based on target voltage data set, including:

[0036] The insulation resistance value is calculated according to the target voltage data sets corresponding to the adjacent first unilateral detection cycle and the second unilateral detection cycle respectively.

[0037] In a second aspect, the present application provides a vehicle, including a power battery, an insulating bridge arm circuit and a controller, wherein the insulating bridge arm circuit is electrically connected to the power battery and the controller, respectively, and the controller is configured to execute the aforementioned insulation detection method.

[0038] According to the vehicle of the present application, when performing insulation detection, the controller divides the single-sided detection cycle into multiple stages, and calculates the confidence of the voltage data set in each stage respectively, uses the target voltage data set that meets the confidence condition to calculate the insulation resistance, removes unreliable data, and can improve the insulation detection accuracy under various working conditions.

[0039] In a third aspect, the present application provides an insulation detection device, the insulation detection device comprising:

[0040] An acquisition module, used for acquiring voltage data sets of the insulated bridge arm circuit in multiple stages within a single-side detection cycle;

[0041] A determination module, used to determine the confidence level corresponding to each voltage data set;

[0042] The control module is used to determine a target voltage data set that meets the confidence condition according to the confidence level and the voltage data set, and to calculate the insulation resistance according to the target voltage data set.

[0043] According to the insulation detection device of the present application, when performing insulation detection, the single-side detection cycle is divided into multiple stages, and the confidence of the voltage data set in each stage is calculated respectively. The target voltage data set that meets the confidence condition is used to calculate the insulation resistance, and unreliable data is removed, which can improve the insulation detection accuracy under various working conditions.

[0044] In a fourth aspect, the present application provides an insulation detection system, which includes one or more processors and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the aforementioned insulation detection method is implemented.

[0045] According to the insulation detection system of the present application, when performing insulation detection, the single-side detection cycle is divided into multiple stages, and the confidence of the voltage data set in each stage is calculated respectively. The target voltage data set that meets the confidence condition is used to calculate the insulation resistance and remove unreliable data, which can improve the insulation detection accuracy under various working conditions.

[0046] In a fifth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and when the program is executed by a processor, the aforementioned insulation detection method is implemented.

[0047] According to the computer-readable storage medium of the present application, when performing insulation detection, the single-sided detection cycle is divided into multiple stages, and the confidence of the voltage data set in each stage is calculated respectively. The target voltage data set that meets the confidence condition is used to calculate the insulation resistance, and unreliable data is removed, which can improve the insulation detection accuracy under various working conditions.

[0048] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0050] Figure 1 is a circuit diagram of an insulating bridge arm circuit provided in an embodiment of the present application;

[0051] Figure 2 This is one of the flow charts of the insulation detection method provided in the embodiment of the present application;

[0052] Figure 3 This is the second flow chart of the insulation detection method provided in the embodiment of the present application;

[0053] Figure 4 is a schematic diagram of the voltage variation trend of the insulating bridge arm provided in an embodiment of the present application;

[0054] Figure 5 This is the third flow chart of the insulation detection method provided in the embodiment of the present application;

[0055] Figure 6 This is the fourth flow chart of the insulation detection method provided in the embodiment of the present application;

[0056] Figure 7 It is a module schematic diagram of the insulation detection device provided in an embodiment of the present application;

[0057] Figure 8 It is a module schematic diagram of the insulation detection system provided in an embodiment of the present application.

[0058] Reference numerals:

[0059] Insulation detection device 10, acquisition module 11, determination module 12, control module 13, insulation detection system 20, processor 21, memory 22, power battery Vbat, ground node PE, first to fourth resistors R1~R4, first to second switches S1~S2. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0061] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0062] The voltage of the power battery pack commonly used in electric vehicles is as high as hundreds of volts, far exceeding the safe voltage threshold that the human body can withstand. This feature makes the safety of the high-voltage system particularly critical. If the insulation protection capability of the system is weakened, it is very likely to pose a safety hazard to passengers. Therefore, regular and strict insulation testing of the high-voltage system of electric vehicles and timely updating of the accurate value of insulation resistance have become an indispensable part of ensuring driving safety.

[0063] In related technologies, the calculation of insulation resistance often relies on a preset, fixed detection cycle. When the detection process is interfered by external environmental factors, or the Y capacitor has not yet reached a stable state during its charging and discharging process, directly calculating the insulation resistance will often lead to inaccurate results, affecting the accurate assessment of the system's insulation performance, and may ignore potential safety risks.

[0064] The present application proposes an insulation detection method, an insulation detection circuit, an insulation detection device 10, an insulation detection system 20, a vehicle and a computer-readable storage medium, which divides a single-side detection cycle into multiple stages, and calculates the confidence of a voltage data set in each stage respectively, uses a target voltage data set that meets the confidence condition to calculate insulation resistance, removes unreliable data, and can improve the insulation detection accuracy under various working conditions.

[0065] Reference Figure 1In order to better illustrate the insulation detection method of the present application, an insulating bridge arm circuit is introduced here. The insulating bridge arm circuit includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first switch S1 and a second switch S2. The first end of the first resistor R1 is electrically connected to the positive electrode of the power battery Vbat, the second end of the first resistor R1 is electrically connected to the first end of the second resistor R2, the second end of the second resistor R2 is electrically connected to the first end of the third resistor R3, the second end of the third resistor R3 is electrically connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is electrically connected to the negative electrode of the power battery Vbat. The first switch S1 is electrically connected between the second end of the first resistor R1 and the negative electrode of the power battery Vbat, and the second switch S2 is electrically connected between the second end of the second resistor R2 and the ground node PE.

[0066] In some embodiments, the insulating bridge arm circuit is electrically connected to the main control unit, and the main control unit can sample the voltage at the connection node of the third resistor R3 and the fourth resistor R4, that is, the insulating bridge arm voltage can be obtained. When performing insulation detection, the main control unit controls the second switch S2 to be turned on, and controls the first switch S1 to switch between the on and off working modes according to a certain duty cycle.

[0067] Reference Figure 2 An embodiment of the present application proposes an insulation detection method, which is applied to the aforementioned insulating bridge arm circuit, but is not limited to being applied only to the aforementioned insulating bridge arm circuit. The insulation detection method includes: step 10, step 20, step 30 and step 40.

[0068] Step 10, obtaining voltage data sets of the insulated bridge arm circuit in multiple stages within a single-side detection cycle;

[0069] Step 20: determining the confidence level corresponding to each voltage data set;

[0070] Step 30: determining a target voltage data set that meets the confidence condition according to the confidence level and the voltage data set;

[0071] Step 40: Calculate insulation resistance according to the target voltage data set.

[0072] An embodiment of the present application provides an insulation detection method. The executor of the insulation detection method may be the aforementioned main control unit or a functional module or functional entity in the main control unit that can implement the insulation detection method. The insulation detection method provided by the embodiment of the present application is described below using the main control unit as an example of the executor.

[0073] In the above embodiment, the on-phase of the first switch S1 corresponds to the first unilateral detection cycle, and the off-phase of the first switch S1 corresponds to the second unilateral detection cycle. A unilateral detection cycle includes multiple phases, and the number of phases in a unilateral detection cycle and the method for determining each phase can be determined according to the actual application scenario, which is not limited here.

[0074] As an example, one unilateral cycle is 10 seconds, and one unilateral cycle includes four stages, each stage is 2.5 seconds.

[0075] In other embodiments, the duration of each stage is different, and one unilateral cycle is 10 seconds. One unilateral cycle includes three stages, wherein the first stage is 2 seconds, the second stage is 3 seconds, and the third stage is 5 seconds.

[0076] The voltage data set can be obtained by sampling the bridge arm voltage and the total insulation voltage of the insulating bridge arm circuit in the unilateral detection period at a certain sampling period. Taking the insulation detection of the power battery Vbat as an example, the total insulation voltage refers to the output voltage of the power battery Vbat. The duration of the sampling period is less than the duration of each stage in the unilateral detection period. The various stages in the unilateral detection period can be determined according to the actual application scenario and are not limited here.

[0077] It is understandable that the duration of the sampling period and the duration of the unilateral detection period can also be selected according to the actual application scenario, and is not limited here. It only needs to ensure that the duration of the sampling period is less than the duration of each stage in the unilateral detection period. For example, the unilateral detection period can be 500ms~10s, and the sampling period can be 10ms~1s.

[0078] As an example, the unilateral detection cycle is 6s, the first stage is 4s, the second stage is 2s, and the detection cycle is 20ms. The total number of insulated bridge arm voltages that can be obtained in the first stage is 4000ms / 20ms=200, and the total number of insulated bridge arm voltages that can be obtained in the second stage is 2000ms / 20ms=100. Similarly, the total number of insulation voltages that can be obtained in the first stage is also 200, and the total number of insulation voltages that can be obtained in the second stage is also 100. The number of data in the first voltage data set is 200.

[0079] The confidence level corresponding to each voltage data set can be expressed as a percentage or a decimal. The confidence level corresponding to each voltage data set is used to quantify the credibility or reliability of the voltage data in the voltage data set. The confidence level corresponding to each voltage data set can be determined by extracting part of the data in each voltage data set and the total number of voltages in each voltage data set. The specific determination method can be selected according to the actual application scenario.

[0080] The target voltage data set usually refers to a data set in the voltage data set whose confidence level is higher than a threshold. By determining the target voltage data set that meets the confidence condition, low-quality data caused by external interference or circuit instability can be effectively excluded, providing high-quality data for subsequent insulation resistance calculations.

[0081] As an example, the confidence threshold is 75%, and a unilateral cycle includes four stages. The confidence of the voltage data set corresponding to the first stage is 70%, the confidence of the voltage data set corresponding to the second stage is 85%, the confidence of the voltage data set corresponding to the third stage is 90%, and the confidence of the voltage data set corresponding to the fourth stage is 95%. The main control unit can use all data in the voltage data sets corresponding to the second stage, the third stage and the fourth stage that meet the confidence conditions as the target voltage data sets.

[0082] In other embodiments, the confidence threshold is 70%, and a unilateral cycle includes four stages. The confidence of the voltage data set corresponding to the first stage is 75%, and the confidence of the voltage data sets corresponding to the second stage, the third stage, and the fourth stage are all 90%. Although the confidence of the voltage data sets in the four stages meets the requirements, the confidence of the voltage data sets corresponding to the second stage, the third stage, and the fourth stage is much greater than the confidence of the voltage data set corresponding to the first stage. The main control unit can choose to use all data in the voltage data sets corresponding to the second stage, the third stage, and the fourth stage as the target voltage data sets, and exclude voltage data sets with relatively small confidence levels, which can further improve the accuracy of the insulation resistance calculation.

[0083] After determining the target voltage data set, the main control unit can obtain a reliable insulating bridge arm voltage through the target voltage data set, and calculate the insulation resistance based on the insulating bridge arm voltage. The method for calculating the insulation resistance with a known insulating bridge arm voltage is relatively mature in the relevant technology and will not be repeated here.

[0084] According to the insulation detection method of the present application, the single-side detection cycle is divided into multiple stages, and the confidence of the voltage data set in each stage is calculated respectively. The target voltage data set that meets the confidence condition is used to calculate the insulation resistance, and unreliable data is removed, which can improve the insulation detection accuracy under various working conditions.

[0085] Reference Figure 3 In some embodiments, determining the confidence level corresponding to each voltage data set includes: step 21 and step 22.

[0086] Step 21, determining target voltage data that meets reliability conditions among the voltage data sets;

[0087] Step 22: taking the ratio of the data volume of each target voltage data to the data volume of the corresponding voltage data set as the confidence level corresponding to the voltage data set.

[0088] The target voltage data refers to the data in the voltage data set that meets the reliability condition. The reliability condition can be determined according to the actual application scenario. For example, if the n consecutive insulation bridge arm voltages obtained in n consecutive sampling periods in the first stage all meet the monotonically decreasing condition, and the change difference of the n insulation total voltages is less than or equal to the confidence threshold, it can be considered that the n insulation bridge arm voltages and the n insulation total voltages meet the reliability condition, and the n insulation bridge arm voltages and the insulation total voltage are the target voltage data.

[0089] The ratio of the data volume of the target voltage data to the data volume of the voltage data set in the first stage is the confidence level corresponding to the voltage data set in the first stage.

[0090] As an example, the total number of insulated bridge arm voltages that can be obtained in the first stage is 200, and the total number of insulation voltages that can be obtained in the first stage is also 200. In the first stage, the number of insulated bridge arm voltages and the total insulation voltage that meet the reliability condition are obtained for 160 consecutive sampling cycles, that is, the number of insulated bridge arm voltages and the total insulation voltage that meet the reliability condition are both 160, that is, the confidence level corresponding to the voltage data set in the first stage is 160+160 / 200+200=80%.

[0091] By calculating the confidence level corresponding to the voltage data set using the target voltage data that meets the reliability condition, it can be ensured that the data used to calculate the insulation resistance value is obtained in a reliable environment, thereby improving the accuracy of the insulation resistance value calculation.

[0092] Reference Figure 4 , Figure 4 The figure shows the voltage variation trend of the insulation bridge arm during the insulation resistance detection calculation process. In some embodiments, the unilateral detection cycle includes a continuous voltage change phase and a voltage stabilization phase, and each voltage data set includes a first voltage data set corresponding to the voltage change phase and a second voltage data set corresponding to the voltage stabilization phase; the target voltage data includes voltage data of n consecutive sampling cycles, and the voltage data of each sampling cycle includes the bridge arm voltage and the total insulation voltage of the insulation bridge arm circuit.

[0093] The bridge arm voltages and the total insulation voltage of all the insulated bridge arm circuits detected with a certain sampling period during the voltage change phase constitute a first voltage data set, and the bridge arm voltages and the total insulation voltage of all the insulated bridge arm circuits detected with a certain sampling period during the voltage stabilization phase constitute a second voltage data set.

[0094] The target voltage data includes the voltage data of n consecutive sampling cycles, that is, when the bridge arm voltage and the total insulation voltage of the insulated bridge arm circuit sampled for n consecutive sampling cycles in the voltage change stage meet the reliability conditions, the voltage data sampled for the n consecutive sampling cycles are determined as the target voltage data in the voltage change stage, and the confidence level corresponding to the voltage data in the voltage change stage is determined based on the target voltage data in the voltage change stage, and the same applies to the voltage stabilization stage.

[0095] The confidence levels of the corresponding first and second voltage data sets are determined using the voltage data sampled during the voltage change phase and the voltage stabilization phase, respectively. The insulation resistance is calculated based on the voltage data sets corresponding to the phases that meet the confidence level conditions. This can eliminate low-quality data caused by external interference or circuit instability at each phase, thereby ensuring the accuracy of insulation detection.

[0096] In some embodiments, the reliability condition is determined to be met when the target voltage data corresponding to the first voltage data set meets the following conditions: during n consecutive sampling cycles, the change trend of n consecutive bridge arm voltages is the same as the overall change trend of the bridge arm voltage in the corresponding unilateral detection cycle; during n consecutive sampling cycles, the change rate of the two bridge arm voltages obtained in every two adjacent sampling cycles is monotonically decreasing; and during n consecutive sampling cycles, the change value of the total insulation voltage is less than the first threshold.

[0097] The change value of the total insulation voltage refers to the difference between the maximum and minimum values ​​of the total insulation voltage in the corresponding stage. The smaller the change value of the total insulation voltage is, the smaller the fluctuation of the total insulation voltage is.

[0098] During n consecutive sampling periods, the change trend of n consecutive bridge arm voltages is the same as the overall change trend of the bridge arm voltages in the corresponding unilateral detection period, indicating that no large interference voltage appears in the n consecutive bridge arm voltages; during n consecutive sampling periods, the change rate of the two bridge arm voltages obtained in every two adjacent sampling periods is monotonically decreasing, indicating that the voltage gradually tends to be stable during the change process; during n consecutive sampling periods, the change value of the total insulation voltage is less than the first threshold value, indicating that the fluctuation of the total insulation voltage is small. If the voltage data collected during n consecutive sampling periods simultaneously meets the above three conditions, it means that the voltage change trend within the n sampling periods is consistent with the theoretical trend and the circuit is relatively stable, so it can be determined that the voltage data within the n sampling periods meets the reliability conditions.

[0099] It should be noted that the specific value of the first threshold value can be selected according to the actual application scenario and is not limited here. For example, the first threshold value can be 15V, 22V or 30V.

[0100] Continue to refer to Figure 4, the following takes the interval corresponding to t1~t2, t3~t4 as the first unilateral detection period, t2~t3, t4~t5 as the second unilateral detection period as the corresponding interval, t1~t1', t2~t2', t3~t3' and t4~t4' as the voltage change stage, and t1'~t2, t2'~t3, t3'~t4, t4'~t5 as the voltage stabilization stage as an example for explanation.

[0101] As an example, in the interval t1~t2, the overall change trend of the bridge arm voltage is a downward trend. Therefore, if in the interval t1~t1', if during n consecutive sampling cycles, the changes in n consecutive bridge arm voltages are monotonically decreasing, during n consecutive sampling cycles, the change rate of the two bridge arm voltages obtained in each two adjacent sampling cycles is monotonically decreasing, and during n consecutive sampling cycles, the change value of the total insulation voltage is less than the first threshold value, it can be determined that the voltage data collected during n consecutive sampling cycles meets the reliability condition, that is, the voltage data collected during the n sampling cycles is the target data of the voltage change stage in the first unilateral detection cycle.

[0102] As an example, in the interval t2~t3, the overall change trend of the bridge arm voltage is an upward trend. Therefore, if in the interval t2~t2', if during n consecutive sampling cycles, the changes in n consecutive bridge arm voltages are monotonically increasing, during n consecutive sampling cycles, the change rate of the two bridge arm voltages obtained in each two adjacent sampling cycles is monotonically decreasing, and during n consecutive sampling cycles, the change value of the total insulation voltage is less than the first threshold value, it can be determined that the voltage data collected during n consecutive sampling cycles meets the reliability condition, that is, the voltage data collected during the n sampling cycles is the target data of the voltage change stage in the second unilateral detection cycle.

[0103] In some embodiments, the reliability condition is determined to be met when the target voltage data corresponding to the second voltage data set meets the following conditions: during n consecutive sampling cycles, the change trend of n consecutive bridge arm voltages is the same as the overall change trend of the bridge arm voltage in the corresponding unilateral detection cycle; during n consecutive sampling cycles, the change rate of the two bridge arm voltages obtained in every two adjacent sampling cycles is monotonically decreasing, and the change rate is less than the second threshold; and, during n consecutive sampling cycles, the change value of the total insulation voltage is less than the third threshold.

[0104] The second voltage data set corresponds to the voltage stabilization stage, in which the rate of change of two adjacent voltages is small. During the n consecutive sampling periods, the rate of change of the two bridge arm voltages obtained in each two adjacent sampling periods is monotonically decreasing, and the rate of change is less than the second threshold, indicating that the voltage gradually stabilizes during the change process, and the rate of change is small, which meets the characteristics of the voltage stabilization stage. The second threshold is usually less than the first threshold, and the specific value of the second threshold can be selected according to the actual application scenario, which is not limited here. For example, the second threshold can be 10V, 20V or 30V, etc.

[0105] The change value of the total insulation voltage is less than the third threshold, indicating that the fluctuation of the total insulation voltage is smaller. The third threshold can be the same as the first threshold, or different from the first threshold. The specific value of the third threshold can be selected according to the actual application scenario and is not limited here. For example, the first threshold is 15V, the third threshold is 15V, the first threshold is 20V, the third threshold is 25V, etc.

[0106] As an example, in the interval t1~t2, the overall change trend of the bridge arm voltage is a downward trend. Therefore, if in the interval t1'~t2, if during n consecutive sampling cycles, the changes of n consecutive bridge arm voltages are monotonically decreasing, during n consecutive sampling cycles, the change rate of the two bridge arm voltages obtained in each two adjacent sampling cycles is monotonically decreasing, and the change rate is less than the second threshold value, and during n consecutive sampling cycles, the change value of the total insulation voltage is less than the first threshold value, it can be determined that the voltage data collected during n consecutive sampling cycles meets the reliability condition, that is, the voltage data collected during the n sampling cycles is the target data of the voltage stabilization stage in the first unilateral detection cycle.

[0107] As an example, in the interval t2~t3, the overall change trend of the bridge arm voltage is an upward trend. Therefore, if in the interval t2'~t3, if during n consecutive sampling cycles, the changes of n consecutive bridge arm voltages are monotonically increasing, during n consecutive sampling cycles, the change rate of the two bridge arm voltages obtained in each two adjacent sampling cycles is monotonically decreasing, and the change rate is less than the second threshold, and during n consecutive sampling cycles, the change value of the total insulation voltage is less than the first threshold, it can be determined that the voltage data collected during n consecutive sampling cycles meets the reliability condition, that is, the voltage data collected during the n sampling cycles is the target data in the voltage stabilization stage within the second unilateral detection cycle.

[0108] Reference Figure 5 In some embodiments, determining a target voltage data set that meets a confidence condition based on the confidence level and the voltage data set includes: step 31 and step 32.

[0109] Step 31, taking the voltage data set with a confidence level greater than the reference value as a reference voltage data set satisfying the confidence condition;

[0110] Step 32: Use the target voltage data corresponding to each reference voltage data set as the target voltage data set.

[0111] The higher the confidence, the higher the credibility of the voltage data in the voltage data set. The voltage data set with a confidence greater than the reference value refers to a data set with a confidence greater than the reference value in the first voltage data set or the second voltage data set.

[0112] As an example, the amount of data in the first voltage data set in the first unilateral detection cycle is 300, of which 280 voltage data collected during 140 consecutive sampling cycles meet the reliability requirements, and 280 / 300=93%, satisfying the confidence condition, then, the first voltage data set is the reference voltage data set, and the 280 voltage data are the target voltage data set.

[0113] The specific value of the reference value of the confidence level can be selected according to the actual application scenario and is not limited here. For example, the reference value can be 80% or 90%.

[0114] Reference Figure 6 In some embodiments, performing insulation resistance calculation according to the target voltage data set includes: step 41 and step 42.

[0115] Step 41, determining a target bridge arm voltage when the insulated bridge arm circuit is in a voltage stable state according to the target voltage data set;

[0116] Step 42: Calculate the insulation resistance according to the target bridge arm voltage.

[0117] The target voltage data set is the data value obtained by sampling for multiple consecutive sampling cycles. The target bridge arm voltage when the insulated bridge arm circuit is in a voltage stable state is determined based on the target voltage data set. The target bridge arm voltage can characterize the bridge arm voltage in the voltage stable state during the entire insulation detection cycle, thereby ensuring the accuracy of the detection result.

[0118] There are relatively detailed methods for calculating the insulation resistance value according to the target bridge arm voltage of the insulated bridge arm circuit when the voltage is stable in the related art, which will not be described in detail here.

[0119] In some embodiments, the target bridge arm voltage includes a first bridge arm voltage, a second bridge arm voltage or a third bridge arm voltage, and the target bridge arm voltage of the insulated bridge arm circuit in a stable state is determined according to the target voltage data set, including: when the target voltage data set includes target voltage data corresponding to the first voltage data set, predicting the target voltage data set according to a prediction algorithm to obtain the first bridge arm voltage of the insulated bridge arm circuit in a voltage stable state; when the target voltage data set includes target voltage data corresponding to the second voltage data set, taking the average value of the target voltage data as the second bridge arm voltage; or, when the target voltage data set includes target voltage data corresponding to the first voltage data set and target voltage data corresponding to the second voltage data set, taking the weighted average value of the first bridge arm voltage and the second bridge arm voltage as the third bridge arm voltage.

[0120] The target voltage data set includes target voltage data corresponding to the first voltage data set, indicating that within the corresponding unilateral detection cycle, the target voltage data set in the voltage change stage meets the confidence condition, and a certain algorithm is used to predict the trend of the bridge arm voltage sampling value changing over time based on the target voltage data to determine the first bridge arm voltage value when the insulated bridge arm circuit is in a voltage stable state.

[0121] When the target voltage data set includes target voltage data corresponding to the first voltage data set, predicting the voltage of the insulating bridge arm circuit in a voltage stable state as the first bridge arm voltage can improve the reliability of the bridge arm voltage used to calculate the insulation resistance, thereby improving the calculation accuracy of the insulation resistance value.

[0122] It should be noted that the algorithm used to determine the first bridge arm voltage value when the insulated bridge arm circuit is in a voltage stable state can be selected according to the actual application scenario and is not limited here. For example, the predicted bridge arm voltage value at time t=infinity can be used as the first bridge arm voltage value by curve fitting.

[0123] The target voltage data set includes target voltage data corresponding to the second voltage data set, indicating that within the corresponding unilateral detection cycle, the target voltage data set in the voltage stabilization stage meets the confidence condition. Taking the average value of the target voltage data as the second bridge arm voltage can ensure that the second bridge arm voltage used to calculate the insulation resistance is the voltage obtained when the circuit is stable. The use of the average value of the second bridge arm voltage to determine the voltage eliminates the influence of small disturbances in the circuit on the voltage, thereby improving the calculation accuracy of the insulation resistance.

[0124] The target voltage data set includes the target voltage data corresponding to the first voltage data set and the target voltage data set corresponding to the second voltage data set, indicating that in the corresponding unilateral detection cycle, the target voltage data sets in the voltage change stage and the voltage stabilization stage all meet the confidence conditions. The weighted average of the first bridge arm voltage and the second bridge arm voltage is used as the third bridge arm voltage, and the product of the first bridge arm voltage and the target voltage data corresponding to the first voltage data set and the confidence plus the product of the second bridge arm voltage and the target voltage data corresponding to the second voltage data set and the confidence can be used as the third bridge arm voltage, that is, the value with high confidence accounts for a larger proportion, thereby improving the calculation accuracy of the insulation resistance value.

[0125] As an example, the first bridge arm voltage is V1, the second bridge arm voltage is V2, the confidence of the target voltage data set corresponding to the first voltage data set is P1, and the confidence of the target voltage data set corresponding to the second voltage data set is P2, then the third bridge arm voltage V3=V1*P1+V2*P2.

[0126] In some embodiments, the detection cycle of the insulating bridge arm circuit includes alternating first unilateral detection cycles and second unilateral detection cycles, and the overall change trends of the bridge arm voltages of the insulating bridge arm circuit in the first unilateral detection cycles and the second unilateral detection cycles are opposite; the insulation resistance value is calculated according to the target voltage data set, including: the insulation resistance value is calculated according to the target voltage data sets corresponding to the adjacent first unilateral detection cycles and the second unilateral detection cycles.

[0127] Continue to refer to Figure 4 , where t1~t3 can be a detection cycle of the insulated bridge arm circuit, where t1~t2 is the first unilateral detection cycle, and t2~t3 is the second unilateral detection cycle. t2~t4 can also be a detection cycle of the insulated bridge arm circuit, where t2~t3 is the second unilateral detection cycle, and t3~t4 is the first unilateral detection cycle.

[0128] That is, if within the detection cycle of the first insulating bridge arm circuit, the voltages in the voltage change stage and the voltage stability stage within the first unilateral detection cycle do not meet the confidence conditions, there is at least one stage of voltage within the second unilateral detection cycle that meets the confidence conditions, and within the detection cycle of the second insulating bridge arm circuit, there is at least one stage of voltage within the first unilateral detection cycle that meets the confidence conditions, then the insulation resistance is calculated based on the target voltage data sets corresponding to the second unilateral detection cycle within the detection cycle of the first insulating bridge arm circuit and the first unilateral detection cycle within the detection cycle of the second insulating bridge arm circuit, thereby realizing the calculation of the insulation resistance within the detection cycle of an insulating bridge arm circuit, effectively eliminating low-quality data caused by external interference or circuit instability, and improving the accuracy of the insulation resistance calculation.

[0129] An embodiment of the present application proposes a vehicle, including a power battery Vbat, an insulating bridge arm circuit and a controller, wherein the insulating bridge arm circuit is electrically connected to the power battery Vbat and the controller, respectively, and the controller is configured to execute the aforementioned insulation detection method.

[0130] The power battery Vbat is electrically connected to the insulating bridge arm circuit, and the controller is mainly used to calculate the insulation resistance value in the insulating bridge arm circuit.

[0131] It should be pointed out that the explanation of the insulation detection method in the aforementioned embodiment is also applicable to the vehicle of the embodiment of the present application and will not be elaborated here.

[0132] According to the vehicle of the present application, when performing insulation detection, the controller divides the single-sided detection cycle into multiple stages, and calculates the confidence of the voltage data set in each stage respectively, uses the target voltage data set that meets the confidence condition to calculate the insulation resistance, removes unreliable data, and can improve the insulation detection accuracy under various working conditions.

[0133] Reference Figure 7 An embodiment of the present application provides an insulation detection device 10, which includes: an acquisition module 11, a determination module 12 and a control module 13. The acquisition module 11 is used to acquire voltage data sets of the insulation bridge arm circuit in multiple stages within a single-side detection cycle; the determination module 12 is used to determine the confidence level corresponding to each voltage data set; the control module 13 is used to determine a target voltage data set that meets the confidence condition according to the confidence level and the voltage data set, and calculate the insulation resistance value according to the target voltage data set.

[0134] The acquisition module 11 samples the bridge arm voltage and the total insulation voltage of the insulation bridge arm circuit in the unilateral detection period at a certain sampling period, so as to obtain a voltage data set.

[0135] The determination module 12 determines the target voltage data that meets the reliability condition in each voltage data set, and uses the ratio of the data volume of each target voltage data set to the data volume of the corresponding voltage data set as the confidence level corresponding to the voltage data set.

[0136] The control module 13 uses the voltage data set with a confidence level greater than the reference value as a reference voltage data set that meets the confidence condition, and uses the target voltage data corresponding to each reference voltage data set as a target voltage data set, determines the target bridge arm voltage when the insulated bridge arm circuit is in a voltage stable state according to the target voltage data set, and calculates the insulation resistance according to the target bridge arm voltage.

[0137] It should be pointed out that the explanation of the insulation detection method in the aforementioned embodiment is also applicable to the vehicle of the embodiment of the present application and will not be elaborated here.

[0138] According to the insulation detection device 10 of the present application, when performing insulation detection, the single-side detection cycle is divided into multiple stages, and the confidence of the voltage data set in each stage is calculated respectively. The target voltage data set that meets the confidence condition is used to calculate the insulation resistance, and unreliable data is removed, which can improve the insulation detection accuracy under various working conditions.

[0139] Reference Figure 8 An embodiment of the present application provides an insulation detection system 20, which includes one or more processors 21 and a memory 22. The memory 22 stores a computer program. When the computer program is executed by the processor 21, the aforementioned insulation detection method is implemented.

[0140] For example, when the computer program is executed by the processor 21, the following insulation detection method is implemented:

[0141] Step 10, obtaining voltage data sets of the insulated bridge arm circuit in multiple stages within a single-side detection cycle;

[0142] Step 20: determining the confidence level corresponding to each voltage data set;

[0143] Step 30: determining a target voltage data set that meets the confidence condition according to the confidence level and the voltage data set;

[0144] Step 40: Calculate insulation resistance according to the target voltage data set.

[0145] For another example, when the computer program is executed by the processor 21, the following insulation detection method is implemented:

[0146] Step 21, determining target voltage data that meets reliability conditions among the voltage data sets;

[0147] Step 22: taking the ratio of the data volume of each target voltage data to the data volume of the corresponding voltage data set as the confidence level corresponding to the voltage data set.

[0148] It should be noted that the explanation of the insulation detection method in the aforementioned embodiment is also applicable to the insulation detection system 20 of the embodiment of the present application, and will not be elaborated here.

[0149] According to the insulation detection system 20 of the present application, when performing insulation detection, the single-sided detection cycle is divided into multiple stages, and the confidence of the voltage data set in each stage is calculated respectively. The target voltage data set that meets the confidence condition is used to calculate the insulation resistance and remove unreliable data, which can improve the insulation detection accuracy under various working conditions.

[0150] An embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the aforementioned insulation detection method is implemented.

[0151] For example, when the computer program is executed by the processor, the following insulation detection method is implemented:

[0152] Step 10, obtaining voltage data sets of the insulated bridge arm circuit in multiple stages within a single-side detection cycle;

[0153] Step 20: determining the confidence level corresponding to each voltage data set;

[0154] Step 30: determining a target voltage data set that meets the confidence condition according to the confidence level and the voltage data set;

[0155] Step 40: Calculate insulation resistance according to the target voltage data set.

[0156] For another example, when the computer program is executed by the processor, the following insulation detection method is implemented:

[0157] Step 21, determining target voltage data that meets reliability conditions among the voltage data sets;

[0158] Step 22: taking the ratio of the data volume of each target voltage data to the data volume of the corresponding voltage data set as the confidence level corresponding to the voltage data set.

[0159] It should be pointed out that the explanation of the insulation detection method in the aforementioned embodiment is also applicable to the insulation detection system in the embodiment of the present application, and will not be elaborated here.

[0160] According to the computer-readable storage medium of the present application, when performing insulation detection, the single-sided detection cycle is divided into multiple stages, and the confidence of the voltage data set in each stage is calculated respectively. The target voltage data set that meets the confidence condition is used to calculate the insulation resistance, and unreliable data is removed, which can improve the insulation detection accuracy under various working conditions.

[0161] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0162] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0163] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0164] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", 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 application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0165] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. An insulation detection method, characterized in that: Applicable to insulated bridge arm circuits, including: Acquiring voltage data sets of the insulated bridge arm circuit in multiple stages within a single-side detection cycle; Determining the confidence level corresponding to each of the voltage data sets; Determining a target voltage data set that meets a confidence condition according to the confidence level and the voltage data set; Calculating insulation resistance according to the target voltage data set; The detection cycle of the insulating bridge arm circuit includes an alternating first unilateral detection cycle and a second unilateral detection cycle, and the overall change trend of the bridge arm voltage of the insulating bridge arm circuit in the first unilateral detection cycle and the second unilateral detection cycle is opposite; The calculating the insulation resistance according to the target voltage data set includes: Calculating insulation resistance according to the target voltage data sets corresponding to the adjacent first unilateral detection cycle and the second unilateral detection cycle respectively; The determining the confidence level corresponding to each of the voltage data sets includes: Determine target voltage data that meets reliability conditions among the voltage data sets; taking the ratio of the data volume of each target voltage data to the data volume of the corresponding voltage data set as the confidence level corresponding to the voltage data set; The unilateral detection cycle includes a continuous voltage change phase and a voltage stabilization phase, and each of the voltage data sets includes a first voltage data set corresponding to the voltage change phase and a second voltage data set corresponding to the voltage stabilization phase; The target voltage data includes voltage data of n consecutive sampling cycles, and the voltage data of each sampling cycle includes the bridge arm voltage and the total insulation voltage of the insulating bridge arm circuit; When the target voltage data corresponding to the first voltage data set meets the following conditions, it is determined that the reliability condition is met: During the n consecutive sampling periods, the variation trend of the n consecutive bridge arm voltages is the same as the overall variation trend of the bridge arm voltage in the corresponding unilateral detection period; During the n consecutive sampling periods, the change rates of the two bridge arm voltages obtained in every two adjacent sampling periods decrease monotonically; and, During the n consecutive sampling periods, a change in the total insulation voltage is smaller than a first threshold.

2. The insulation detection method according to claim 1, characterized in that: When the target voltage data corresponding to the second voltage data set meets the following conditions, it is determined that the reliability condition is met: During the n consecutive sampling periods, the variation trend of the n consecutive bridge arm voltages is the same as the overall variation trend of the bridge arm voltage in the corresponding unilateral detection period; During the n consecutive sampling periods, the change rate of the two bridge arm voltages obtained in every two adjacent sampling periods decreases monotonically, and the change rate is less than a second threshold; and, During the n consecutive sampling periods, a change in the total insulation voltage is smaller than a third threshold.

3. The insulation detection method according to claim 1, characterized in that: Determining a target voltage data set that meets a confidence condition according to the confidence level and the voltage data set includes: taking the voltage data set whose confidence level is greater than a reference value as a reference voltage data set satisfying a confidence condition; The target voltage data corresponding to each of the reference voltage data sets is used as a target voltage data set.

4. The insulation detection method according to claim 3, characterized in that: The calculating the insulation resistance according to the target voltage data set includes: Determining a target bridge arm voltage of the insulated bridge arm circuit when the voltage is in a stable state according to the target voltage data set; The insulation resistance is calculated according to the target bridge arm voltage.

5. The insulation detection method according to claim 4, characterized in that: The target bridge arm voltage includes a first bridge arm voltage, a second bridge arm voltage or a third bridge arm voltage, and determining the target bridge arm voltage of the insulated bridge arm circuit in a voltage stable state according to the target voltage data set includes: When the target voltage data set includes target voltage data corresponding to the first voltage data set, predicting the target voltage data set according to a prediction algorithm to obtain the first bridge arm voltage when the insulated bridge arm circuit is in a voltage stable state; When the target voltage data set includes target voltage data corresponding to the second voltage data set, taking an average value of the target voltage data as the second bridge arm voltage; or, When the target voltage data set includes target voltage data corresponding to the first voltage data set and target voltage data corresponding to the second voltage data set, a weighted average of the first bridge arm voltage and the second bridge arm voltage is used as the third bridge arm voltage.

6. A vehicle, characterized in that: It comprises a power battery, an insulating bridge arm circuit and a controller, wherein the insulating bridge arm circuit is electrically connected to the power battery and the controller respectively, and the controller is configured to execute the insulation detection method according to any one of claims 1-5.

7. An insulation detection device, characterized in that: The device is used to implement the method according to any one of claims 1 to 5, and the device includes: An acquisition module, used for acquiring voltage data sets of the insulated bridge arm circuit in multiple stages within a single-side detection cycle; A determination module, used to determine the confidence level corresponding to each of the voltage data sets; A control module is used to determine a target voltage data set that meets a confidence condition according to the confidence level and the voltage data set, and to calculate insulation resistance according to the target voltage data set.

8. An insulation detection system, characterized in that: The method comprises one or more processors and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the insulation detection method according to any one of claims 1 to 5 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the insulation detection method according to any one of claims 1 to 5 is implemented.

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