Sampling filtering method, insulation detection method and vehicle

Abstract

The invention discloses a sampling filtering method, an insulation detection method and a vehicle, and the method comprises the steps: S1, carrying out the initialization, and assigning the sampling target data as a preset value; s2, voltage data are collected a times in a preset time period; s3, screening the voltage data based on the acquisition sequence and the voltage values; s4, judging whether the quantity of the screened voltage data meets the requirement or not; if not, clearing the stored voltage data and returning to the step S2; if yes, calculating a first average value based on the screened voltage data, calculating a first difference value between the first average value and the sampling target data, and updating the assignment of the sampling target data by taking the first average value as the assignment; and S5, determining whether to output the sampling target data or not based on the continuous occurrence frequency of the condition that the first difference value is smaller than the first threshold value. According to the sampling and filtering method, the reliability and the stability of the acquired voltage data can be ensured; according to the insulation detection method, the insulation resistance value can be timely and accurately obtained.

Description

Technical Field

[0001] The invention relates to a battery system, and in particular to a sampling filtering method, an insulation detection method and a vehicle. Background Art

[0002] Problems with the insulation system of the power battery can lead to dangerous situations such as leakage and fire, endangering the lives of drivers and passengers. Therefore, it is very important to detect the insulation condition of the battery in real time, and the battery management controller (BMS) plays an important role in this. The calculation model of the existing national standard method for insulation detection is relatively ideal, requiring that each collected voltage U must reach a stable state in order to accurately calculate the insulation resistance at this time. In practical applications, with the rapid development of new energy vehicles, more and more controllers are carried on vehicles, and the equivalent Y capacitor is getting larger and larger. As the equivalent Y capacitor is getting larger and larger, the charging and discharging time is greatly extended, and the BMS may be disturbed by the external environment. At this time, the calculated voltage fluctuates greatly, and the BMS cannot calculate the insulation resistance, causing the vehicle to be in a state of unknown insulation resistance for a long time.

[0003] CN114355048A discloses an insulation detection method and system for electric vehicles, which predicts the equivalent insulation resistance of the positive and negative electrodes of the power battery to the chassis ground and the capacitance of the equivalent Y capacitor based on the bridge circuit connected between the positive and negative electrodes of the power battery and the chassis ground, including: obtaining the sampled voltage values ​​on the first resistor and the second resistor respectively when the first switch is open or closed and the second switch is open or closed; the sampled voltage values ​​include the first, second, third and fourth voltage values; according to the first, second, third and fourth voltage values ​​and the trained first genetic optimization BP neural network, the first, second, third and fourth predicted stable values ​​of the positive and negative electrode sampled voltages are obtained; according to the first, second, third and fourth predicted stable values ​​of the positive and negative electrode sampled voltages, the resistance values ​​of the positive and negative electrode equivalent insulation resistances are determined. According to the resistance values ​​of the positive and negative electrode equivalent insulation resistances, the capacitance values ​​of the positive and negative electrode equivalent Y capacitors are determined. Among them, the signal acquisition module of the insulation detection method is provided with a filtering circuit to reduce noise and electromagnetic interference in the circuit and improve sampling accuracy. Undoubtedly, the technical solution disclosed in the above patent document is a beneficial attempt in the relevant technical field, but the conventional filtering circuit cannot guarantee the timeliness and reliability of voltage sampling. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a sampling filtering method that can ensure the reliability and stability of the collected voltage data; the object of the present invention is also to provide an insulation detection method that can promptly and accurately obtain the insulation resistance value; the object of the present invention is also to provide a vehicle that applies the above-mentioned sampling filtering method or insulation detection method.

[0005] A sampling filtering method in the present invention comprises:

[0006] S1, initialization, the sampling target data is assigned to the preset value;

[0007] S2, collecting voltage data, collecting voltage data a times in total within a preset time period; where a>3;

[0008] S3, screening the voltage data based on the acquisition order and the voltage value;

[0009] S4, judging whether the quantity of the voltage data after screening meets the requirement; if not, clearing the saved voltage data and returning to step S2; if meeting the requirement, calculating a first average value based on part or all of the voltage data that has passed the screening, calculating a first difference between the first average value and the sampled target data, and updating the value of the sampled target data with the first average value as the value;

[0010] S5. Determine the number of consecutive occurrences of the situation where the first difference is less than the first threshold, and then determine whether the number of consecutive occurrences is not less than the second threshold. If the number of consecutive occurrences is less than the second threshold, return to step S2; if the number of consecutive occurrences is not less than the second threshold, output the sampling target data.

[0011] Further, the sampling filtering method specifically includes:

[0012] S1, initialization, the sampling target data is assigned to the preset value;

[0013] S2, collecting voltage data at point M and point N, and continuously collecting voltage data a times at a preset sampling period within a preset time period; where a>3;

[0014] S3, preliminarily screening the voltage data based on the acquisition order, and saving the voltage data that pass the preliminarily screening as array members in the first array; rescreening the array members of the first array based on the voltage value, and saving the array members that pass the rescreening in the second array;

[0015] S4, judging whether the number of array members of the second array meets the requirement; if not, clearing the data of the first array and the second array and returning to step S2; if yes, calculating the first average value of some or all array members of the second array, subtracting the first average value from the sampling target data to obtain a first difference, deleting the assignment of the sampling target data, assigning the first average value to the sampling target data, clearing the data of the first array and the second array, and then proceeding to the next step;

[0016] S5. Determine whether the first difference is less than a first threshold value. If the first difference is not less than the first threshold value, the counter is cleared and returns to step S2. If the first difference is less than the first threshold value, the counter is incremented by 1, and then determine whether the counter is not less than a second threshold value. If the counter is less than the second threshold value, the counter returns to step S2. If the counter is not less than the second threshold value, the sampling target data is output.

[0017] Further, the step S3 is specifically as follows:

[0018] S301, saving the last b voltage data of a voltage data into a first array, wherein the voltage data of point M and the voltage data of point N collected each time are taken as one array member, b<a;

[0019] S302, calculating a second average value of the first array;

[0020] S303: Calculate a second difference between each array member in the first array and the second average value, and save the array members whose second difference is less than a third threshold into the second array.

[0021] Furthermore, the first average value in step S4 is calculated by summing the last c array members of the second array and calculating the average value, which is the first average value, wherein c<b.

[0022] An insulation detection method in the present invention comprises:

[0023] Apply the above sampling and filtering method to the insulation resistance detection circuit to update the sampling target data;

[0024] An insulation resistance value is calculated based on the sampled target data.

[0025] Furthermore, the insulation resistance detection circuit includes a power supply, a first equivalent Y capacitor C POS , the second equivalent Y capacitor C NEG , the first equivalent insulation resistance R POS , the second equivalent insulation resistance R NEG , the first resistor R A , the second resistor R B , the third resistor R C , the fourth resistor R D , the fifth resistor R E , the sixth resistor R F , a first switch K1 and a second switch K2;

[0026] The first equivalent Y capacitor C POS The first end of the first equivalent insulation resistance R POS The first end of the first resistor R AThe first end and the third resistor R C The first end of each of the first resistor R A The second end of the third resistor R C The second end of the fourth resistor R D A first end is connected;

[0027] The second equivalent Y capacitor C NEG The second end of the second equivalent insulation resistance R NEG The second end of the second resistor R B The second end of the sixth resistor R C The second ends of the second resistor R B The first end of the sixth resistor R is connected to the second end of the second switch K2; F The first end of the fifth resistor R E The second end of the connection;

[0028] The first equivalent Y capacitor C POS The second end of the second equivalent Y capacitor C NEG The first ends of the two terminals meet and are connected to the ground terminal;

[0029] The first equivalent insulation resistance R POS The second end and the second equivalent insulation resistance R NEG The first ends of the two terminals meet and are connected to the ground terminal;

[0030] The second end of the first switch K1 intersects with the first end of the second switch K2 and is connected to the ground end;

[0031] The fourth resistor R D The second end of the fifth resistor R E The first ends of the two terminals meet and are connected to the ground terminal;

[0032] The point M is located at the third resistor R C The second end of the fourth resistor R D between the first ends of

[0033] The point N is located at the sixth resistor R F The first end of the fifth resistor R E between the second ends.

[0034] Further, the insulation detection method specifically includes:

[0035] P1, initialization, sampling target data U1, U2, U3, U4, U5 and U6 are assigned to preset values;

[0036] P2, disconnect the first switch K1 and disconnect the second switch K2, and update the assignment of the sampled target data U1 and U2;

[0037] P3, close the first switch K1 and open the second switch K2, and update the assignment of the sampled target data U3 and U4;

[0038] P4, opening the first switch K1 and closing the second switch K2, updating the assignment of the sampled target data U5 and U6;

[0039] P5. Determine whether the values ​​of the updated sampling target data U1, U2, U3, U4, U5 and U6 meet the requirements. If not, return directly to step P2. If yes, output the sampling target data U1, U2, U3, U4, U5 and U6, calculate and upload the insulation resistance values ​​RNEG and RPOS, and then return to step P2.

[0040] Further, the insulation detection method specifically includes:

[0041] P1, initialization, sampling target data U1, U2, U3, U4, U5 and U6 are assigned to preset values;

[0042] P2, update the assignment of sampling target data U1 and U2; specifically includes the following steps:

[0043] P201, disconnect the first switch K1 and disconnect the second switch K2;

[0044] P202, collecting voltage data at point M and point N, and continuously collecting voltage data a times at a preset sampling period within a preset time period; where a>3;

[0045] P203, save the last b voltage data of a voltage data to the first array, wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member, b<a;

[0046] P204, calculating a second average value of the first array;

[0047] P205, calculating a second difference between each array member in the first array and the second average value, and saving the array members whose second difference is less than a third threshold into the second array;

[0048] P206, determine whether the number of array members of the second array meets the requirements; if not, clear the data of the first array and the second array and return to step P201; if yes, sum the last c voltage data in the b voltage array of the second array and calculate a first average value, subtract the first average value from the sampling target data to obtain a first difference, delete the assignment of the sampling target data, assign the first average value to the sampling target data, wherein the first average value of point M is assigned to U1, and the first average value of point N is assigned to U2, and clear the data of the first array and the second array, and then proceed to the next step;

[0049] P207, determine whether the first difference is less than a first threshold value, if not, reset the counter and return to step P201, if less, proceed to step P3;

[0050] P3, update the assignment of sampling target data U3 and U4; specifically includes the following steps:

[0051] P301, close the first switch K1 and open the second switch K2;

[0052] P302, collecting voltage data at point M and point N, and continuously collecting voltage data a times at a preset sampling period within a preset time period; where a>3;

[0053] P303, save the last b voltage data of a voltage data to the first array, wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member, b<a;

[0054] P304, calculating a second average value of the first array;

[0055] P305, calculating a second difference between each array member in the first array and the second average value, and saving the array members whose second difference is less than a third threshold into the second array;

[0056] P306, determine whether the number of array members of the second array meets the requirements; if not, clear the data of the first array and the second array and return to step P301; if yes, sum the last c voltage data in the b voltage array of the second array and calculate a first average value, subtract the first average value from the sampling target data to obtain a first difference, delete the assignment of the sampling target data, assign the first average value to the sampling target data, wherein the first average value of point M is assigned to U3, and the first average value of point N is assigned to U4, and clear the data of the first array and the second array, and then proceed to the next step;

[0057] P307, determine whether the first difference is less than a first threshold value, if not, reset the counter and return to step P301, if less, proceed to step P4;

[0058] P4, updating the assignment of sampling target data U5 and U6; specifically including the following steps:

[0059] P401, opening the first switch K1 and closing the second switch K2;

[0060] P402, collecting voltage data at point M and point N, and continuously collecting voltage data a times at a preset sampling period within a preset time period; where a>3;

[0061] P403, save the last b voltage data of a voltage data to the first array, wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member, b<a;

[0062] P404, calculating a second average value of the first array;

[0063] P405, calculating a second difference between each array member in the first array and the second average value, and saving the array members whose second difference is less than a third threshold into the second array;

[0064] P406, determine whether the number of array members of the second array meets the requirements; if not, clear the data of the first array and the second array and return to step P401; if it meets, sum the last c voltage data in the b voltage array of the second array and calculate the first average value, subtract the first average value from the sampling target data to obtain a first difference, delete the assignment of the sampling target data, assign the first average value to the sampling target data, wherein the first average value of point M is assigned to U1, and the first average value of point N is assigned to U2, and clear the data of the first array and the second array, and then proceed to the next step

[0065] P406, determine whether the first difference is less than a first threshold value, if not, reset the counter and return to step P401, if less, proceed to step P5;

[0066] P5, determine whether the counter is not less than the second threshold value, if it is less than, directly return to step P2, if it is not less than, output the sampled target data U1, U2, U3, U4, U5 and U6, calculate and upload the insulation resistance value R NEG and R POS Then return to step P2.

[0067] Further, the insulation resistance R in step P5 NEG and RPOS The calculation method is:

[0068]

[0069] The values ​​of U1, U2, U3, U4, U5 and U6 in the formula are respectively the values ​​of the sampled target data U1, U2, U3, U4, U5 and U6 output in step P5, and R in the formula A , R B , R C , R D , R E and R F The values ​​of the first resistor R A , the second resistor R B , the third resistor R C , the fourth resistor R D , the fifth resistor R E , the sixth resistor R F The resistance values ​​correspond one to one.

[0070] A vehicle in the present invention applies the above sampling and filtering method or the above insulation detection method.

[0071] The beneficial effects of the present invention are:

[0072] (1) The sampling and filtering method of the present invention saves the relatively stable voltage data at the end of the acquisition sequence and then performs a screening based on the voltage value, thereby eliminating the voltage data with obviously too large or too small voltage values ​​and retaining the voltage data with voltage values ​​within a predetermined range, thereby eliminating abnormal fluctuation data, making it easier to judge whether the acquisition of this cycle is reliable based on the proportion or number of voltage data that meet the requirements.

[0073] (2) The sampling and filtering method of the present invention can obtain circuit fluctuations by comparing the first average value obtained in this cycle with the sampling target data assigned in the previous cycle, and output the sampling target data for calculating the required data after the assignment of the sampling target data is updated multiple times and the changes in the assignments of the multiple consecutive updates are relatively small.

[0074] (3) The insulation detection method of the present invention can timely and accurately obtain the insulation resistance value R NEG and R POS .

[0075] (4) The insulation detection method of the present invention continuously changes the circuit switch state and collects data in a cycle, continuously updates the assignment of the sampling target data U1, U2, U3, U4, U5 and U6, and based on the comparison between the current cycle and the previous cycle, it can determine whether the voltage and insulation resistance of the circuit have changed significantly compared with the previous cycle. If the change is large, re-sampling is required. At the same time, after the change occurs and becomes stable, the sampling target data U1, U2, U3, U4, U5 and U6 are updated again, and the insulation resistance is calculated and uploaded.

[0076] (5) In the insulation detection method of the present invention, if the first average value obtained in this cycle is compared with the sampled target data assigned in the previous cycle, and the first difference between the two meets the requirements, it can be considered that the circuit fluctuation between this cycle and the previous cycle is not large, and the insulation resistance value changes little. The counter can be incremented by 1 until the counter is not less than 3, and the sampled target data is output, and the insulation resistance value is calculated by the sampled target data, and the insulation resistance value is uploaded, and the voltage data is collected in the cycle. If the circuit fluctuation is not large and the insulation resistance value changes little in the subsequent cycles, the counter continues to be incremented by 1, and the sampled target data can be directly output at this time. If the first difference between the two does not meet the requirements, it can be considered that the circuit fluctuation between this cycle and the previous cycle is large, and the insulation resistance value changes greatly. The counter is cleared to enter the next cycle, and the number of consecutive occurrences of the first difference value being less than the first threshold value is recalculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0078] Figure 1 This is a schematic diagram of a process of Embodiment 1 of the present invention;

[0079] Figure 2 This is a schematic diagram of the process of Embodiment 2 of the present invention;

[0080] Figure 3 It is a schematic diagram of the structure of the insulation resistance detection circuit of the present invention;

[0081] Figure 4 This is a schematic diagram of a flow chart of a fourth embodiment of the present invention;

[0082] Figure 5 This is a schematic diagram of the process of Embodiment 5 of the present invention. DETAILED DESCRIPTION

[0083] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0084] Embodiment 1:

[0085] like Figure 1As shown, a sampling filtering method in this embodiment includes:

[0086] S1. Initialization: The sampled target data is assigned a preset value. The preset value may be 0 or other constants, and the selection of the preset value is not limited.

[0087] S2. Collect voltage data. Collect voltage data a times in a preset time period; wherein a>3; for example, a may be 50, 60, 70 or other integers greater than 3.

[0088] S3. Screen the voltage data based on the acquisition sequence and voltage value; after the state of the switch changes, the voltage in the circuit fluctuates and tends to be stable after a certain period of time, so the voltage data collected later is relatively stable. After saving this part of the voltage data collected later, screen it again by voltage value, remove the voltage data with obviously too large or too small voltage value, and retain the voltage data with voltage value within the predetermined range, so as to eliminate abnormal fluctuation data, and facilitate the subsequent judgment of whether the acquisition of this cycle is reliable based on the proportion or number of voltage data that meet the requirements.

[0089] S4. Determine whether the quantity of the filtered voltage data meets the requirements; if not, clear the saved voltage data and return to step S2; if yes, calculate a first average value based on part or all of the filtered voltage data, calculate a first difference between the first average value and the sampled target data, and update the assignment of the sampled target data with the first average value as the assignment.

[0090] S5, determining the number of consecutive occurrences of the situation where the first difference is less than the first threshold, and then determining whether the number of consecutive occurrences is not less than the second threshold, if the number of consecutive occurrences is less than the second threshold, returning to step S2, if the number of consecutive occurrences is not less than the second threshold, outputting the sampled target data. The first threshold may be 0.1V or other values, and the second threshold may be 3 or other values.

[0091] If the voltage data screened twice in step S3 can be regarded as relatively qualified samples, if the number of voltage data screened twice in step S3 is too small, it means that the reliability and stability of the voltage data collected in S2 do not meet the standards, then the collected voltage data is discarded and re-collected.

[0092] If the number of voltage data screened twice in step S3 meets the expected requirements, it means that the voltage data collected in S2 is relatively reliable and stable, and the first average value can be calculated based on part or all of the screened voltage data, and then the first average value is compared with the assigned sampling target data (if it is the first cycle, the sampling target data is assigned to the preset value in step S1, and if it is the second cycle and subsequent cycles, the sampling target data is assigned in step S4 in the previous cycle of this cycle, and the assignment is updated with the newly obtained first average value in each cycle). After comparison, if the first difference between the two is not less than the first threshold, it means that a large change has occurred in the circuit and re-sampling is required. Therefore, at this time, the first average value obtained in this cycle is only used to update the assignment of the sampling target data. After the sampling target data is assigned to the first average value obtained in this cycle, it can be used for comparison in the next cycle, but the sampling target data is not output.

[0093] If the first average value obtained in this cycle is compared with the sampled target data assigned in the previous cycle, and the first difference between the two meets the requirements, it can be considered that the circuit fluctuation between this cycle and the previous cycle is not large. After the number of consecutive occurrences of the first difference being less than the first threshold is not less than the second threshold (that is, by updating the assignment of the sampled target data multiple times, after the changes in the assignments of multiple consecutive updates are relatively small), the sampled target data is output for calculating the required data (such as insulation resistance).

[0094] The preferred solution is: if the number of consecutive occurrences is not less than the second threshold, the sampled target data is output and the process returns to step S2. This preferred solution allows: regardless of whether the sampled target data is output, the process enters the next cycle after the current cycle ends. If the result that the first difference is less than the first threshold is still obtained in the next cycle, the sampled target data can be directly output without having to repeat the cycle multiple times. New sampled target data can be output in time to update the data required for calculation (such as insulation resistance).

[0095] Embodiment 2:

[0096] a can be 50, 60, 70 or other integers greater than 3, b can be an integer smaller than a by 5, 10 or 15, etc., the preset collection period can be 10ms, 15ms or other suitable values. For the sake of convenience, this embodiment takes a=60, the preset collection period is 10ms, and b=a-10=50 as an example.

[0097] like Figure 2 As shown, this embodiment further refines the sampling filtering method in the first embodiment, including:

[0098] S1. Initialization: The sampled target data is assigned a preset value. The preset value may be 0 or other constants, and the selection of the preset value is not limited.

[0099] S2. Collect the voltage data of point M and point N. Within the preset time period, collect the voltage data 60 times continuously with the preset sampling period of 10ms. That is, collect the voltage data once every 10ms, and collect the voltage data of point M and point N 60 times in this cycle.

[0100] S3. Based on the acquisition order, the voltage data is preliminarily screened, and the voltage data that passes the preliminary screening is saved as an array member in the first array U

[50] ; based on the voltage value, the array members of the first array U

[50] are rescreened, and the array members that pass the rescreening are saved in the second array U'[i]. After the state of the switch changes, the voltage in the circuit fluctuates and tends to be stable after a certain period of time. Therefore, the voltage data at the end of the acquisition order is relatively stable. After the voltage data at the end of the acquisition order is saved, it is screened again by the voltage value. The voltage data with obviously too large or too small voltage values ​​are eliminated, and the voltage data with voltage values ​​within the predetermined range are retained.

[0101] Among them, the step S3 is specifically as follows: S301, save the last 50 voltage data of 60 voltage data to the first array U

[50] , wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member; this means that the voltage data collected for the first 10 times are discarded, and only the voltage data collected for the last 50 times are retained.

[0102] S302, calculate the second average value of the first array U

[50] .

[0103] S303, calculating the second difference between each array member in the first array U

[50] and the second average value, and saving the array members whose second difference is less than a third threshold to the second array U'[i]; the third threshold may be 5mV or other values.

[0104] S4, judging whether the number of array members of the second array U'[i] meets the requirements, that is, judging whether i is greater than d, where d is an integer less than b, such as 40; if not, clearing the data of the first array U

[50] and the second array U'[i] and returning to step S2; if compliant, calculating the first average value of some or all array members of the second array U'[i], subtracting the first average value from the sampling target data to obtain first difference values ​​ΔU1 and ΔU2, deleting the assignment of the sampling target data, assigning the first average value to the sampling target data, clearing the data of the first array U

[50] and the second array U'[i], and then proceeding to the next step;

[0105] The calculation method of the first average value is preferably: summing up and calculating the average value of the last c array members of the second array U'[i], and the average value is the first average value, wherein c<b. c is an integer less than i, for example, c=5 means summing up and calculating the average value of the last 5 array members of the second array U'[i], and the average value is the first average value. Selecting some array members of the second array U'[i] instead of all can reduce the amount of calculation.

[0106] S5, judging whether the first difference ΔU1 and ΔU2 are less than the first threshold value, if the first difference ΔU1 and ΔU2 are not less than the first threshold value, the counter is cleared and the process returns to step S2; if the first difference is less than the first threshold value, the counter is incremented by 1, and then judging whether the counter is not less than the second threshold value, if the counter is less than the second threshold value, the process returns to step S2, and if the counter is not less than the second threshold value, the sampled target data is output. The first threshold value may be 0.1V or other values, and the second threshold value may be 3 or other values.

[0107] The function of the counter is to record the number of consecutive occurrences of the situation where the first difference is less than the first threshold, so as to facilitate subsequent judgment on whether the number of consecutive occurrences of the situation where the first difference is less than the first threshold is not less than the second threshold.

[0108] The preferred solution is: if the counter is not less than the second threshold, the sampled target data is output and the process returns to step S2. The preferred solution is such that: regardless of whether the sampled target data is output, the process enters the next cycle after the current cycle ends. If the result that the first difference is still less than the first threshold is obtained in the next cycle, the sampled target data can be directly output without having to repeat the cycle multiple times. New sampled target data can be output in time to update the data required for calculation (such as insulation resistance).

[0109] Embodiment three:

[0110] like Figure 3 As shown, an insulation detection method in this embodiment includes:

[0111] Applying the sampling and filtering method of the first or second embodiment to the insulation resistance detection circuit to update the sampling target data;

[0112] An insulation resistance value is calculated based on the sampled target data.

[0113] The insulation resistance detection circuit includes a power supply, a first equivalent Y capacitor C POS , the second equivalent Y capacitor C NEG , the first equivalent insulation resistance R POS , the second equivalent insulation resistance R NEG, the first resistor R A , the second resistor R B , the third resistor R C , the fourth resistor R D , the fifth resistor R E , the sixth resistor R F , a first switch K1 and a second switch K2;

[0114] The first equivalent Y capacitor C POS The first end of the first equivalent insulation resistance R POS The first end of the first resistor R A The first end and the third resistor R C The first end of each of the first resistor R A The second end of the third resistor R C The second end of the fourth resistor R D A first end is connected;

[0115] The second equivalent Y capacitor C NEG The second end of the second equivalent insulation resistance R NEG The second end of the second resistor R B The second end of the sixth resistor R C The second ends of the second resistor R B The first end of the sixth resistor R is connected to the second end of the second switch K2; F The first end of the fifth resistor R E The second end of the connection;

[0116] The first equivalent Y capacitor C POS The second end of the second equivalent Y capacitor C NEG The first ends of the two terminals meet and are connected to the ground terminal;

[0117] The first equivalent insulation resistance R POS The second end and the second equivalent insulation resistance R NEG The first ends of the two terminals meet and are connected to the ground terminal;

[0118] The second end of the first switch K1 intersects with the first end of the second switch K2 and is connected to the ground end;

[0119] The fourth resistor R D The second end of the fifth resistor R E The first ends of the two terminals meet and are connected to the ground terminal;

[0120] The point M is located at the third resistor R C The second end of the fourth resistor RD between the first ends of

[0121] The point N is located at the sixth resistor R F The first end of the fifth resistor R E between the second ends.

[0122] The insulation detection method of this embodiment can reduce the impact of voltage fluctuations on insulation resistance calculation by ensuring that voltage sampling is timely and reliable, and quickly respond to insulation detection needs while ensuring reliable insulation resistance calculation.

[0123] Embodiment 4:

[0124] like Figure 4 As shown, an insulation detection method in this embodiment includes:

[0125] P1, initialization, the sampling target data U1, U2, U3, U4, U5 and U6 are all assigned to preset values, which can be 0;

[0126] P2, disconnect the first switch K1 and disconnect the second switch K2, and update the assignment of the sampled target data U1 and U2;

[0127] P3, close the first switch K1 and open the second switch K2, and update the assignment of the sampled target data U3 and U4;

[0128] P4, opening the first switch K1 and closing the second switch K2, updating the assignment of the sampled target data U5 and U6;

[0129] P5. Determine whether the values ​​of the updated sampling target data U1, U2, U3, U4, U5 and U6 meet the requirements. If not, return directly to step P2. If yes, output the sampling target data U1, U2, U3, U4, U5 and U6, calculate and upload the insulation resistance values ​​RNEG and RPOS, and then return to step P2.

[0130] The insulation resistance R in step P5 NEG and R POS The calculation method is:

[0131]

[0132] The values ​​of U1, U2, U3, U4, U5 and U6 in the formula are respectively the values ​​of the sampled target data U1, U2, U3, U4, U5 and U6 output in step P5, and R in the formula A , R B , R C , R D , R Eand R F The values ​​of the first resistor R A , the second resistor R B , the third resistor R C , the fourth resistor R D , the fifth resistor R E , the sixth resistor R F The resistance values ​​correspond one to one.

[0133] Through the above method and calculation method, the insulation resistance R can be obtained timely and accurately. NEG and R POS .

[0134] Embodiment five:

[0135] a can be 50, 60, 70 or other integers greater than 3, b can be an integer smaller than a by 5, 10 or 15, etc., the preset collection period can be 10ms, 15ms or other suitable values. For the sake of convenience, this embodiment takes a=60, the preset collection period is 10ms, and b=a-10=50 as an example.

[0136] like Figure 5 As shown, this embodiment further refines an insulation detection method in Embodiment 4, including:

[0137] P1, initialization, sampling target data U1, U2, U3, U4, U5 and U6 are assigned to preset values;

[0138] P2, update the assignment of sampling target data U1 and U2; specifically includes the following steps:

[0139] P201, disconnect the first switch K1 and disconnect the second switch K2;

[0140] P202, collect voltage data at point M and point N, and collect voltage data 60 times continuously at a preset sampling period of 10ms within a preset time period. That is, collect voltage data once every 10ms, and collect voltage data at point M and point N 60 times in total in this cycle.

[0141] P203, save the last 50 voltage data out of 60 voltage data to the first array U

[50] , wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member; this means that the voltage data collected in the first 10 times are discarded, and only the voltage data collected in the last 50 times are retained.

[0142] P204. Calculate the second average value of the first array U

[50] .

[0143] P205. Calculate the second difference between each array member in the first array U

[50] and the second average value, and save the array members whose second difference is less than a third threshold into the second array U'[i]; the third threshold may be 5mV or other values.

[0144] P206, determine whether the number of array members of the second array U'[i] meets the requirements, that is, determine whether i is greater than d, where d is an integer less than b, such as 40; if not, clear the data of the first array U

[50] and the second array U'[i] and return to step P201; if yes, sum the last c voltage data in the b voltage array of the second array and calculate the first average value, subtract the first average value from the sampling target data to obtain the first difference, delete the assignment of the sampling target data, assign the first average value to the sampling target data, wherein the first average value of point M is assigned to U1, and the first average value of point N is assigned to U2, and clear the data of the first array U

[50] and the second array U'[i], and then proceed to the next step; wherein c<b. c is an integer less than i, for example, c=5 means summing and calculating the average value from the last 5 array members of the second array U'[i], and the average value is the first average value. Selecting some array members of the second array U'[i] instead of all can reduce the amount of calculation.

[0145] P207, determine whether the first difference is less than a first threshold value, if not, clear the counter and return to step P201, if less, proceed to step P3; the first threshold value may be 0.1V or other values.

[0146] P3, update the assignment of sampling target data U3 and U4; specifically includes the following steps:

[0147] P301, close the first switch K1 and open the second switch K2;

[0148] P302, collect voltage data at point M and point N, and collect voltage data 60 times continuously at a preset sampling period of 10ms within a preset time period. That is, collect voltage data once every 10ms, and collect voltage data at point M and point N 60 times in total in this cycle.

[0149] P303, save the last 50 voltage data out of 60 voltage data to the first array U

[50] , wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member; this means that the voltage data collected in the first 10 times are discarded, and only the voltage data collected in the last 50 times are retained.

[0150] P304. Calculate the second average value of the first array U

[50] .

[0151] P305. Calculate the second difference between each array member in the first array U

[50] and the second average value, and save the array members whose second difference is less than a third threshold into the second array U'[i]; the third threshold may be 5mV or other values.

[0152] P306, determine whether the number of array members of the second array U'[i] meets the requirements, that is, determine whether i is greater than d, where d is an integer less than b, such as 40; if not, clear the data of the first array U

[50] and the second array U'[i] and return to step P301; if compliant, sum the last c voltage data in the b voltage array of the second array and calculate the first average value, subtract the first average value from the sampling target data to obtain a first difference, delete the assignment of the sampling target data, assign the first average value to the sampling target data, wherein the first average value of point M is assigned to U3, and the first average value of point N is assigned to U4, and clear the data of the first array U

[50] and the second array U'[i], and then proceed to the next step.

[0153] P307, determine whether the first difference is less than the first threshold value, if not, clear the counter and return to step P301, if less, proceed to step P4.

[0154] P4, updating the assignment of sampling target data U5 and U6; specifically including the following steps:

[0155] P401, opening the first switch K1 and closing the second switch K2;

[0156] P402, collect voltage data at point M and point N, and collect voltage data 60 times continuously at a preset sampling period of 10ms within a preset time period. That is, collect voltage data once every 10ms, and collect voltage data at point M and point N 60 times in total in this cycle.

[0157] P403, save the last 50 voltage data out of 60 voltage data into the first array U

[50] , wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member; this means that the voltage data collected in the first 10 times are discarded, and only the voltage data collected in the last 50 times are retained.

[0158] P404. Calculate the second average value of the first array U

[50] .

[0159] P405. Calculate the second difference between each array member in the first array U

[50] and the second average value, and save the array members whose second difference is less than a third threshold into the second array U'[i]. The third threshold may be 5mV or other values.

[0160] P406, determine whether the number of array members of the second array U'[i] meets the requirements, that is, determine whether i is greater than d, where d is an integer less than b, such as 40; if not, clear the data of the first array U

[50] and the second array U'[i] and return to step P401; if compliant, sum the last c voltage data in the b voltage array of the second array and calculate the first average value, subtract the first average value from the sampling target data to obtain a first difference, delete the assignment of the sampling target data, assign the first average value to the sampling target data, wherein the first average value of point M is assigned to U5, and the first average value of point N is assigned to U6, and clear the data of the first array U

[50] and the second array U'[i], and then proceed to the next step.

[0161] P406, determine whether the first difference is less than the first threshold value, if not, clear the counter and return to step P401, if less, proceed to step P5.

[0162] P5, determine whether the counter is not less than the second threshold value, if it is less than, directly return to step P2, if it is not less than, output the sampled target data U1, U2, U3, U4, U5 and U6, calculate and upload the insulation resistance value R NEG and R POS Then return to step P2. The second threshold value can be 3 or other values.

[0163] The insulation resistance R in step P5 NEG and R POS The calculation method is:

[0164]

[0165] The values ​​of U1, U2, U3, U4, U5 and U6 in the formula are respectively the values ​​of the sampled target data U1, U2, U3, U4, U5 and U6 output in step P5, and R in the formula A , R B , R C , R D , R E and R F The values ​​of the first resistor R A , the second resistor R B , the third resistor R C , the fourth resistor R D , the fifth resistor R E , the sixth resistor R F The resistance values ​​correspond one to one.

[0166] By continuously looping steps P2-P4, the assignment of sampling target data U1, U2, U3, U4, U5 and U6 is continuously updated. At the same time, based on the comparison between this cycle and the previous cycle, it can be determined whether the voltage and insulation resistance of the circuit have changed significantly compared with the previous cycle. If the change is large, re-sampling is required. At the same time, after the change occurs and becomes stable, the sampling target data U1, U2, U3, U4, U5 and U6 are updated again, and the insulation resistance is calculated and uploaded.

[0167] In the automotive battery system, the insulation resistance needs to be uploaded at a high frequency at intervals of a certain period of time. Therefore, if the first average value obtained in this cycle is compared with the sampled target data assigned in the previous cycle, and the first difference between the two meets the requirements, it can be considered that the circuit fluctuation between this cycle and the previous cycle is not large, and the insulation resistance value changes little. The counter can be incremented by 1 until the counter is not less than 3, and the sampled target data is output, and the insulation resistance value is calculated by the sampled target data, and the insulation resistance value is uploaded, and the voltage data is collected in the cycle. In the subsequent cycles, if the circuit fluctuation is not large and the insulation resistance value changes little, the counter continues to be incremented by 1, and the sampled target data can be directly output at this time. If the first difference between the two does not meet the requirements, it can be considered that the circuit fluctuation between this cycle and the previous cycle is large, and the insulation resistance value changes greatly. The counter is cleared to enter the next cycle, and the number of consecutive occurrences of the first difference value being less than the first threshold value is recalculated.

[0168] Embodiment six:

[0169] A vehicle in this embodiment applies the sampling filtering method in the first or second embodiment.

[0170] Embodiment seven:

[0171] A vehicle in this embodiment applies the insulation detection method in embodiment three, four, five or six.

[0172] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A sampling filtering method, characterized in that: The sampling filtering method comprises: S1, initialization, the sampling target data is assigned to the preset value; S2, collecting voltage data, collecting voltage data a times in total within a preset time period; where a>3; S3, screening the voltage data based on the acquisition order and the voltage value; S4, judging whether the quantity of the voltage data after screening meets the requirement; if not, clearing the saved voltage data and returning to step S2; if meeting the requirement, calculating a first average value based on part or all of the voltage data that has passed the screening, calculating a first difference between the first average value and the sampled target data, and updating the value of the sampled target data with the first average value as the value; S5. Determine the number of consecutive occurrences of the situation where the first difference is less than the first threshold, and then determine whether the number of consecutive occurrences is not less than the second threshold. If the number of consecutive occurrences is less than the second threshold, return to step S2; if the number of consecutive occurrences is not less than the second threshold, output the sampling target data.

2. The sampling filtering method according to claim 1, characterized in that: The sampling and filtering method specifically comprises: S1, initialization, the sampling target data is assigned to the preset value; S2, collecting voltage data at point M and point N, and continuously collecting voltage data a times at a preset sampling period within a preset time period; where a>3; S3, preliminarily screening the voltage data based on the acquisition order, and saving the voltage data that pass the preliminarily screening as array members in the first array; rescreening the array members of the first array based on the voltage value, and saving the array members that pass the rescreening in the second array; S4, judging whether the number of array members of the second array meets the requirement; if not, clearing the data of the first array and the second array and returning to step S2; if yes, calculating the first average value of some or all array members of the second array, subtracting the first average value from the sampling target data to obtain a first difference, deleting the assignment of the sampling target data, assigning the first average value to the sampling target data, clearing the data of the first array and the second array, and then proceeding to the next step; S5. Determine whether the first difference is less than a first threshold value. If the first difference is not less than the first threshold value, the counter is cleared and returns to step S2. If the first difference is less than the first threshold value, the counter is incremented by 1, and then determine whether the counter is not less than a second threshold value. If the counter is less than the second threshold value, the counter returns to step S2. If the counter is not less than the second threshold value, the sampling target data is output.

3. The sampling filtering method according to claim 2, characterized in that: The step S3 is specifically as follows: S301, saving the last b voltage data of a voltage data into a first array, wherein the voltage data of point M and the voltage data of point N collected each time are taken as one array member, b<a; S302, calculating a second average value of the first array; S303: Calculate a second difference between each array member in the first array and the second average value, and save the array members whose second difference is less than a third threshold into the second array.

4. The sampling filtering method according to claim 2, characterized in that: The first average value in step S4 is calculated by summing the last c array members of the second array and calculating the average value, which is the first average value, wherein c<b.

5. An insulation detection method, characterized in that: include: Applying the sampling and filtering method as described in any one of claims 2 to 4 to an insulation resistance detection circuit to update sampling target data; An insulation resistance value is calculated based on the sampled target data.

6. The insulation detection method according to claim 5, characterized in that: The insulation resistance detection circuit includes a power supply, a first equivalent Y capacitor C POS , the second equivalent Y capacitor C NEG , the first equivalent insulation resistance R POS , the second equivalent insulation resistance R NEG , the first resistor R A , the second resistor R B , the third resistor R C , the fourth resistor R D , the fifth resistor R E , the sixth resistor R F , a first switch K1 and a second switch K2; The first equivalent Y capacitor C POS The first end of the first equivalent insulation resistance R POS The first end of the first resistor R A The first end and the third resistor R C The first end of each of the first resistor R A The second end of the third resistor R C The second end of the fourth resistor R D A first end is connected; The second equivalent Y capacitor C NEG The second end of the second equivalent insulation resistance R NEG The second end of the second resistor R B The second end of the sixth resistor R C The second ends of the second resistor R B The first end of the sixth resistor R is connected to the second end of the second switch K2; F The first end of the fifth resistor R E The second end of the connection; The first equivalent Y capacitor C POS The second end of the second equivalent Y capacitor C NEG The first ends of the two terminals meet and are connected to the ground terminal; The first equivalent insulation resistance R POS The second end and the second equivalent insulation resistance R NEG The first ends of the two terminals meet and are connected to the ground terminal; The second end of the first switch K1 intersects with the first end of the second switch K2 and is connected to the ground end; The fourth resistor R D The second end of the fifth resistor R E The first ends of the two terminals meet and are connected to the ground terminal; The point M is located at the third resistor R C The second end of the fourth resistor R D between the first ends of The point N is located at the sixth resistor R F The first end of the fifth resistor R E between the second ends.

7. The insulation detection method according to claim 6, characterized in that: The insulation detection method specifically comprises: P1, initialization, sampling target data U1, U2, U3, U4, U5 and U6 are assigned to preset values; P2, disconnect the first switch K1 and disconnect the second switch K2, and update the assignment of the sampled target data U1 and U2; P3, close the first switch K1 and open the second switch K2, and update the assignment of the sampled target data U3 and U4; P4, opening the first switch K1 and closing the second switch K2, updating the assignment of the sampled target data U5 and U6; P5. Determine whether the values ​​of the updated sampling target data U1, U2, U3, U4, U5 and U6 meet the requirements. If not, return directly to step P2. If yes, output the sampling target data U1, U2, U3, U4, U5 and U6, calculate and upload the insulation resistance values ​​RNEG and RPOS, and then return to step P2.

8. The insulation detection method according to claim 6, characterized in that: The insulation detection method specifically comprises: P1, initialization, sampling target data U1, U2, U3, U4, U5 and U6 are assigned to preset values; P2, update the assignment of sampling target data U1 and U2; specifically includes the following steps: P201, disconnect the first switch K1 and disconnect the second switch K2; P202, collecting voltage data at point M and point N, and continuously collecting voltage data a times at a preset sampling period within a preset time period; where a>3; P203, save the last b voltage data of a voltage data to the first array, wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member, b<a; P204, calculating a second average value of the first array; P205, calculating a second difference between each array member in the first array and the second average value, and saving the array members whose second difference is less than a third threshold into the second array; P206, determine whether the number of array members of the second array meets the requirements; if not, clear the data of the first array and the second array and return to step P201; if yes, sum the last c voltage data in the b voltage array of the second array and calculate a first average value, subtract the first average value from the sampling target data to obtain a first difference, delete the assignment of the sampling target data, assign the first average value to the sampling target data, wherein the first average value of point M is assigned to U1, and the first average value of point N is assigned to U2, and clear the data of the first array and the second array, and then proceed to the next step; P207, determine whether the first difference is less than a first threshold value, if not, reset the counter and return to step P201, if less, proceed to step P3; P3, update the assignment of sampling target data U3 and U4; specifically includes the following steps: P301, close the first switch K1 and open the second switch K2; P302, collecting voltage data at point M and point N, and continuously collecting voltage data a times at a preset sampling period within a preset time period; where a>3; P303, save the last b voltage data of a voltage data to the first array, wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member, b<a; P304, calculating a second average value of the first array; P305, calculating a second difference between each array member in the first array and the second average value, and saving the array members whose second difference is less than a third threshold into the second array; P306, determine whether the number of array members of the second array meets the requirements; if not, clear the data of the first array and the second array and return to step P301; if yes, sum the last c voltage data in the b voltage array of the second array and calculate a first average value, subtract the first average value from the sampling target data to obtain a first difference, delete the assignment of the sampling target data, assign the first average value to the sampling target data, wherein the first average value of point M is assigned to U3, and the first average value of point N is assigned to U4, and clear the data of the first array and the second array, and then proceed to the next step; P307, determine whether the first difference is less than a first threshold value, if not, reset the counter and return to step P301, if less, proceed to step P4; P4, updating the assignment of sampling target data U5 and U6; specifically including the following steps: P401, opening the first switch K1 and closing the second switch K2; P402, collecting voltage data at point M and point N, and continuously collecting voltage data a times at a preset sampling period within a preset time period; where a>3; P403, save the last b voltage data of a voltage data to the first array, wherein the voltage data of point M and the voltage data of point N collected each time are used as an array member, b<a; P404, calculating a second average value of the first array; P405, calculating a second difference between each array member in the first array and the second average value, and saving the array members whose second difference is less than a third threshold into the second array; P406, determine whether the number of array members of the second array meets the requirements; if not, clear the data of the first array and the second array and return to step P401; if it meets, sum the last c voltage data in the b voltage array of the second array and calculate the first average value, subtract the first average value from the sampling target data to obtain a first difference, delete the assignment of the sampling target data, assign the first average value to the sampling target data, wherein the first average value of point M is assigned to U1, and the first average value of point N is assigned to U2, and clear the data of the first array and the second array, and then proceed to the next step P406, determine whether the first difference is less than a first threshold value, if not, reset the counter and return to step P401, if less, proceed to step P5; P5, determine whether the counter is not less than the second threshold value, if it is less than, directly return to step P2, if it is not less than, output the sampled target data U1, U2, U3, U4, U5 and U6, calculate and upload the insulation resistance value R NEG and R POS Then return to step P2.

9. The insulation detection method according to claim 7 or 8, characterized in that: The insulation resistance R in step P5 NEG and R POS The calculation method is: The values ​​of U1, U2, U3, U4, U5 and U6 in the formula are respectively the values ​​of the sampled target data U1, U2, U3, U4, U5 and U6 output in step P5, and R in the formula A , R B , R C , R D , R E and R F The values ​​of the first resistor R A , the second resistor R B , the third resistor R C , the fourth resistor R D , the fifth resistor R E , the sixth resistor R F The resistance values ​​correspond one to one.

10. A vehicle, characterized in that: The sampling and filtering method as described in any one of claims 1 to 4 or the insulation detection method as described in any one of claims 5 to 9 is applied.

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