Power system matching method and device for pure electric commercial vehicle

Abstract

The invention provides a power system matching method and device for a pure electric commercial vehicle, and the method comprises the steps: obtaining target working condition data of the pure electric commercial vehicle, and determining a first working condition point proportion, a second working condition point proportion and system power consumption according to the obtained target working condition data for a preset parameter matching set of each motor-transmission system; the first working condition point proportion represents the number proportion of working condition points deviating from the first system external characteristic curve, and the second working condition point proportion represents the number proportion of working condition points with working condition point efficiency values larger than a preset efficiency threshold value; according to the first working condition point proportion, the second working condition point proportion and the system power consumption, scores corresponding to the parameter matching sets of all the motor-transmission systems are determined, and the parameter matching set, corresponding to the maximum score, of the motor-transmission system is determined as the optimal parameter matching set of the motor-transmission system. According to the method, the power consumption of the whole vehicle can be calculated by directly adopting the working condition data of the whole vehicle, so that the optimal power system parameter matching combination is obtained.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a power system matching method and device for a pure electric commercial vehicle. Background Art

[0002] Pure electric commercial vehicles are widely used due to their high power performance, high driving comfort, low noise pollution, etc. In the application process of pure electric commercial vehicles, they mainly transport fixed loads on fixed routes.

[0003] The existing technology uses forward simulation to match power system parameters under standard working conditions, such as CHTC-TT working conditions, C-WTVC working conditions, etc., which has the advantages of being simple and easy to obtain and having a certain degree of universality. However, for pure electric commercial vehicles, they are mainly used in working conditions with fixed routes and fixed loads. The characteristics of such working conditions are quite different, and standard working conditions cannot meet the needs. The power consumption results calculated in this way will deviate from the actual power consumption of pure electric commercial vehicles, affect the matching accuracy of the power system, and it is difficult to meet actual needs. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a power system matching method and device for a pure electric commercial vehicle, which can directly use the vehicle operating condition data to calculate the power consumption of the whole vehicle with a small calculation error, so that the calculation result is closer to the actual power consumption of the vehicle, thereby obtaining the optimal power system parameter matching combination.

[0005] In a first aspect, the present application provides a power system matching method for a pure electric commercial vehicle, the method comprising:

[0006] Acquiring target operating condition data of the pure electric commercial vehicle;

[0007] For each preset parameter matching set of the motor-transmission system, the first operating point proportion, the second operating point proportion and the system power consumption are determined according to the acquired target operating condition data; the first operating point proportion represents the proportion of the number of operating points that deviate from the first system external characteristic curve, and the second operating point proportion represents the proportion of the number of operating points whose operating point efficiency values ​​are greater than a preset efficiency threshold;

[0008] According to the proportion of the first operating point, the proportion of the second operating point and the system power consumption, the scores corresponding to the parameter matching sets of each motor-transmission system are determined, and the parameter matching set of the motor-transmission system corresponding to the maximum score is determined as the optimal parameter matching set of the motor-transmission system.

[0009] In a possible implementation manner, obtaining target operating condition data of the pure electric commercial vehicle includes:

[0010] Collecting actual operating data of the pure electric commercial vehicle, wherein the actual operating data includes motor speed and motor torque;

[0011] A second system external characteristic curve is constructed according to the motor speed and the motor torque, and abnormal operating condition data is obtained according to the second system external characteristic curve; the abnormal operating condition data represents operating condition data that deviates from the second system external characteristic curve;

[0012] The abnormal operating condition data is deleted from the actual operating condition data to obtain the target operating condition data of the pure electric commercial vehicle.

[0013] In a possible implementation manner, the stability of the target operating condition data is less than a preset value;

[0014] The stability is calculated by the following formula:

[0015]

[0016] Among them, K represents stability, represents the i-th characteristic parameter value in the j-th actual working condition data, It represents the i-th characteristic parameter value in the j-1-th actual operating condition data, and the characteristic parameter value includes the average vehicle speed and the maximum vehicle speed.

[0017] In a possible implementation manner, for each preset parameter matching set of the motor-transmission system, determining the first operating point proportion, the second operating point proportion and the system power consumption according to the acquired target operating condition data includes:

[0018] For each preset motor-transmission system parameter matching set, according to the selected motor-transmission system transmission ratio, the target operating condition data is converted into operating condition conversion data, so as to convert the motor speed in the target operating condition data into the motor conversion speed and the motor torque in the target operating condition data into the motor conversion torque;

[0019] Determine a first system external characteristic curve according to the operating condition conversion data, and obtain a conversion operating condition point deviating from the first system external characteristic curve according to the first system external characteristic curve; the first system external characteristic curve represents a change relationship between the motor conversion torque and the motor conversion speed;

[0020] Determining the proportion of the first operating point according to the number of converted operating points that deviate from the first system external characteristic curve and the number of all converted operating points in the operating condition conversion data; wherein the proportion of the first operating point is less than a preset proportion threshold;

[0021] Obtaining an operating point efficiency value corresponding to a converted operating point that does not deviate from the first system external characteristic curve;

[0022] Counting the number of converted operating points whose efficiency values ​​of the operating points are greater than a preset efficiency threshold, and determining the proportion of the second operating point according to the number of converted operating points whose efficiency values ​​of the operating points are greater than the preset efficiency threshold and the number of converted operating points that do not deviate from the first system external characteristic curve;

[0023] The power consumption of the system is determined according to the efficiency value at the operating point.

[0024] In a possible implementation manner, the first system external characteristic curve is calculated by the following formula:

[0025]

[0026] Among them, T m is the peak torque of the motor, n m P is the peak value of the motor speed. m is the motor converted power peak value in the working condition converted data, n is the motor converted speed, and T is the motor converted torque.

[0027] In a possible implementation manner, obtaining the operating point efficiency value corresponding to the converted operating point that does not deviate from the first system external characteristic curve includes:

[0028] Obtaining an efficiency MAP diagram corresponding to the motor-transmission system; the efficiency MAP diagram represents the distribution of the motor converted efficiency under different motor converted speeds and motor converted torques;

[0029] The operating point efficiency value corresponding to the converted operating point that does not deviate from the first system external characteristic curve is obtained from the efficiency MAP diagram through an interpolation method.

[0030] In a possible implementation manner, the system power consumption is calculated by the following formula:

[0031]

[0032] Among them, W c Indicates system power consumption, μ c represents the controller efficiency, μ e Indicates motor efficiency, μ m represents the transmission system efficiency, T j represents the motor torque converted by the transmission ratio of the jth motor-transmission system, n j It represents the motor converted speed obtained by converting the transmission ratio of the j-th motor-transmission system.

[0033] In a possible implementation manner, determining scores corresponding to parameter matching sets of each motor-transmission system according to the proportion of the first operating point, the proportion of the second operating point, and the system power consumption, and determining the parameter matching set of the motor-transmission system corresponding to the maximum score as the optimal parameter matching set of the motor-transmission system includes:

[0034] Normalizing the first operating point proportion, the second operating point proportion, and the system power consumption to obtain a normalized result of the first operating point proportion, a normalized result of the second operating point proportion, and a normalized result of the system power consumption;

[0035] Setting weight coefficients for the normalized result of the first operating point proportion, the normalized result of the second operating point proportion, and the normalized result of the system power consumption, respectively, and calculating the scores corresponding to the parameter matching sets of each motor-transmission system;

[0036] The parameter matching set of the motor-transmission system corresponding to the maximum score is selected from the scores corresponding to the parameter matching sets of each motor-transmission system as the optimal parameter matching set of the motor-transmission system.

[0037] In a possible implementation manner, the first operating point proportion or the system power consumption is normalized by the following formula:

[0038]

[0039] P i1min =min(P i1 )

[0040] in, is the normalized result of the first operating point ratio or the normalized result of the system power consumption, P i1 is the proportion of the first operating point or the system power consumption, P i1min is the minimum value of the first operating point proportion or the minimum value of the system power consumption;

[0041] And / or, the proportion of the second operating point is normalized by the following formula:

[0042]

[0043] P i2max =max(P i2 )

[0044] in, is the normalized result of the proportion of the second operating point, P i2 is the proportion of the second operating point, P i2max It is the maximum value of the proportion of the second operating point.

[0045] In a second aspect, the present application provides a power system matching device for a pure electric commercial vehicle, the device comprising:

[0046] A data acquisition module, used to acquire target operating condition data of the pure electric commercial vehicle;

[0047] A data processing module, for determining, for each preset parameter matching set of the motor-transmission system, a first operating point ratio, a second operating point ratio and system power consumption according to the acquired target operating condition data; the first operating point ratio represents the number of operating points that deviate from the first system external characteristic curve, and the second operating point ratio represents the number of operating points whose operating point efficiency values ​​are greater than a preset efficiency threshold;

[0048] A data determination module is used to determine the scores corresponding to the parameter matching sets of each motor-transmission system according to the proportion of the first operating point, the proportion of the second operating point and the system power consumption, and determine the parameter matching set of the motor-transmission system corresponding to the maximum score as the optimal parameter matching set of the motor-transmission system.

[0049] In a third aspect, the present application also provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is actually in operation, the processor communicates with the memory via the bus, and when the machine-readable instructions are executed by the processor, the steps of the above method are performed.

[0050] In a fourth aspect, the present application also provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the steps of the above method.

[0051] The present application provides a power system matching method for a pure electric commercial vehicle, the method comprising: first obtaining the target operating condition data of the pure electric commercial vehicle; then for each preset parameter matching set of the motor-transmission system, determining the first operating point ratio, the second operating point ratio and the system power consumption according to the obtained target operating condition data, the first operating point ratio represents the number of operating points that deviate from the first system external characteristic curve, and the second operating point ratio represents the number of operating points whose operating point efficiency value is greater than the preset efficiency threshold; finally, according to the first operating point ratio, the second operating point ratio and the system power consumption, determining the score corresponding to the parameter matching set of each motor-transmission system, and determining the parameter matching set of the motor-transmission system corresponding to the maximum score as the optimal parameter matching set of the motor-transmission system. Compared with the solution of matching the power system parameters by forward simulation of standard operating conditions in the prior art, the embodiment of the present application directly uses the whole vehicle operating condition data to calculate the whole vehicle power consumption, which is smaller than the actual situation, and thus the calculation error is small, so that the calculation result is closer to the actual power consumption of the vehicle, thereby obtaining the optimal power system parameter matching combination.

[0052] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 A flow chart of a power system matching method for a pure electric commercial vehicle provided in an embodiment of the present application;

[0055] Figure 2 A flow chart of another power system matching method for a pure electric commercial vehicle provided in an embodiment of the present application;

[0056] Figure 3 A schematic diagram of the structure of a power system matching device for a pure electric commercial vehicle provided in an embodiment of the present application;

[0057] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0059] First, the application scenarios applicable to this application are introduced. In the application process of pure electric commercial vehicles, fixed routes are mainly used to transport fixed loads of goods, and the characteristic differences are quite significant. The prior art uses standard working condition forward simulation to match the power system parameters, but when applied to fixed routes and fixed load conditions, the power consumption results calculated in this way will deviate from the actual power consumption of pure electric commercial vehicles, affecting the matching accuracy of the power system, and it is difficult to meet actual needs.

[0060] Based on this, the present application embodiment provides a power system matching method for a pure electric commercial vehicle, please refer to Figure 1 , Figure 1 This is a flow chart of a power system matching method for a pure electric commercial vehicle provided in an embodiment of the present application. Figure 1 As shown in, the method provided in the embodiment of the present application includes:

[0061] S101, obtaining target operating condition data of a pure electric commercial vehicle;

[0062] S102, for each preset parameter matching set of the motor-transmission system, determine the first operating point ratio, the second operating point ratio and the system power consumption according to the acquired target operating condition data; the first operating point ratio represents the number of operating points that deviate from the first system external characteristic curve, and the second operating point ratio represents the number of operating points whose operating point efficiency values ​​are greater than a preset efficiency threshold;

[0063] S103, determining scores corresponding to parameter matching sets of each motor-transmission system according to the proportion of the first operating point, the proportion of the second operating point and the system power consumption, and determining the parameter matching set of the motor-transmission system corresponding to the maximum score as the optimal parameter matching set of the motor-transmission system.

[0064] In step S101 to step S103, the embodiment of the present application can directly use the vehicle operating condition data to calculate the vehicle power consumption, which is smaller than the actual situation and thus has a smaller calculation error, making the calculation result closer to the actual power consumption of the vehicle, thereby obtaining the optimal combination of power system parameters.

[0065] In step S101, target operating condition data of a pure electric commercial vehicle is obtained.

[0066] Here, pure electric commercial vehicles refer to vehicles that use electricity as a driving energy source and are mainly used for commercial operations, including all trucks, special-purpose vehicles, engineering vehicles, etc., which have the characteristics of fixed loads and fixed routes.

[0067] Among them, the target operating condition data represents the operating data obtained during the actual operation of the pure electric commercial vehicle. The target operating condition data can be data obtained after data screening, or a large amount of data directly collected from the vehicle interface.

[0068] Specifically, a CANDTU recorder device can be used to directly collect vehicle operation data from the vehicle interface. It should be noted that the data acquisition device is not limited to the CANDTU recorder device, and any device that can collect vehicle data can be used in the embodiments of the present application. The collected vehicle operation data may include: motor speed, motor torque, vehicle speed, gear information, battery state of charge (State of Charge, SOC), battery output voltage, battery output current, MCU input voltage, MCU input current, etc. In the embodiments of the present application, the target operating condition data includes at least motor speed, motor torque and vehicle speed.

[0069] The embodiment of the present application performs calculations based on the actual operating data of the collected pure electric commercial vehicle, and the calculation results will be closer to the actual energy consumption of the vehicle, which is conducive to improving the accuracy of the subsequent selection of the optimal parameter combination set.

[0070] In a possible implementation, step S101 specifically includes:

[0071] Step 1011: Collect actual operating data of the pure electric commercial vehicle, where the actual operating data includes motor speed and motor torque;

[0072] Step 1012: construct a second system external characteristic curve according to the motor speed and the motor torque, and obtain abnormal operating condition data according to the second system external characteristic curve; the abnormal operating condition data represents operating condition data that deviates from the second system external characteristic curve;

[0073] In this step, the actual operating condition data can be simulated to simulate the second system external characteristic curve. Specifically, the second system external characteristic curve represents the change relationship between the motor speed and the motor torque. Then, the operating condition data that deviates from the second system external characteristic curve is determined as abnormal operating condition data.

[0074] Step 1013: Delete the abnormal operating condition data from the actual operating condition data to obtain the target operating condition data of the pure electric commercial vehicle.

[0075] In the above steps 1011 to 1013, in order to reduce the possible erroneous data in the data collection process of the recorder device, the accuracy of the data in the subsequent calculation is guaranteed.

[0076] Before subsequent calculations, it is necessary to remove abnormal operating data, such as abnormal motor speed, abnormal motor torque, etc. Optionally, for abnormal operating data, linear interpolation of the two previous and next operating points can be used to replace it. The calculation method is as follows:

[0077]

[0078] Among them, T e *Indicates the abnormal operating point of the motor torque, n e *Indicates the abnormal operating point of the motor speed, T e+1 , T e-1 Respectively represent the motor torque before and after the abnormal operating point, n e+1 、n e-1 They respectively represent the motor speed at the moment before and after the abnormal operating point.

[0079] The embodiments of the present application can remove erroneous data that may exist in the data collection process through the above steps, ensure data quality, and improve data accuracy in subsequent calculations.

[0080] In an optional embodiment, the stability of the target operating condition data is less than a preset value.

[0081] Here, stability is used to characterize whether the target operating condition data has sufficient data volume. When the stability is less than a preset value, the target operating condition data has sufficient data volume. Sufficient data volume means that the average value of the target operating condition data no longer changes significantly. For example, the average vehicle speed and maximum vehicle speed no longer change significantly, and the data volume is considered sufficient. When the stability is not less than a preset value, the target operating condition data has insufficient data volume. Insufficient target operating condition data may result in inaccurate final calculation results.

[0082] The value of the preset value may be evaluated by engineers and customers with rich experience, that is, the preset value is obtained by those skilled in the art after a large number of experiments and work experience. For example, the value of the preset value may be 10%.

[0083] Specifically, the stability can be calculated by the following formula:

[0084]

[0085] Among them, K represents stability, represents the i-th characteristic parameter value in the j-th actual working condition data, It represents the i-th characteristic parameter value in the j-1-th actual operating condition data, and the characteristic parameter values ​​include the average vehicle speed and the maximum vehicle speed.

[0086] Furthermore, when the value of the stability K that changes with the increase in the amount of data collected from actual working conditions is less than a preset value, it is considered that the data sufficiency is met.

[0087] The embodiment of the present application can ensure that the collected data is sufficient by measuring the stability, thereby improving the accuracy of the output results and improving the credibility of the final optimal parameter matching set.

[0088] In step S102, for each preset parameter combination set of the motor-transmission system, the proportion of the first operating point, the proportion of the second operating point and the system power consumption are determined according to the acquired target operating data; the proportion of the first operating point represents the proportion of the number of operating points that deviate from the first system external characteristic curve, and the proportion of the second operating point represents the proportion of the number of operating points whose efficiency values ​​are greater than the preset efficiency threshold.

[0089] Here, the parameter matching set of the motor-drive system is a set obtained by combining the motor parameters and the drive system parameters in advance. Since there are multiple motor parameters and drive system parameters, multiple combinations can be obtained by arbitrarily combining the motor parameters and the drive system parameters. Here, for each preset motor-drive system parameter matching set, the following steps must be performed: Figure 2 Steps S1021 to S1026 are shown. Exemplarily, the parameter matching set includes at least: motor torque, motor speed, motor efficiency, transmission system transmission ratio, and transmission system mechanical efficiency.

[0090] In an optional embodiment, Figure 2 As shown, step S102 specifically includes:

[0091] Step S1021: for each preset motor-transmission system parameter matching set, according to the selected motor-transmission system transmission ratio, convert the target operating condition data into the operating condition conversion data, so as to convert the motor speed in the target operating condition data into the motor conversion speed and convert the motor torque in the target operating condition data into the motor conversion torque;

[0092] Here, the output speed and output torque of the commercial vehicle wheel end are kept unchanged, and the collected motor speed and motor torque are converted to the new motor conversion speed and motor conversion torque according to the transmission ratio of the jth group of motor-transmission system. Under the condition that the output speed and output torque of the wheel end are kept unchanged and the mechanical transmission efficiency of the transmission system is assumed to be the same, the conversion can be performed using the following formula:

[0093]

[0094] Among them, T0 is the collected motor torque, T j is the motor torque converted by the transmission ratio of the motor-transmission system of the jth group, n0 is the motor speed collected, n j is the motor speed converted from the collected motor speed by the transmission ratio of the jth motor-transmission system, i0 is the original motor-transmission system ratio, i j is the transmission ratio of the jth motor-transmission system.

[0095] Step S1022, determining a first system external characteristic curve according to the operating condition conversion data, and obtaining a conversion operating condition point that deviates from the first system external characteristic curve according to the first system external characteristic curve; the first system external characteristic curve represents a change relationship between the motor converted torque and the motor converted speed;

[0096] Among them, the first system external characteristic curve can be calculated by the following formula:

[0097]

[0098] Among them, T m is the peak torque of the motor, n m P is the peak value of the motor speed. m is the motor converted power peak value in the working condition converted data, n is the motor converted speed, and T is the motor converted torque.

[0099] Here, the first system external characteristic curve is represented as a piecewise function, and the first system external characteristic curve is fitted by the operating condition conversion data and the above formula, and the operating point where the operating condition conversion data deviates from the first system external characteristic curve is determined as the conversion operating condition point.

[0100] Step S1023, determining the proportion of the first operating point according to the number of converted operating points that deviate from the first system external characteristic curve and the number of all converted operating points in the operating condition conversion data; wherein the proportion of the first operating point is less than a preset proportion threshold.

[0101] Here, the first operating point ratio is represented by the ratio between the number of converted operating points deviating from the first system external characteristic curve and the number of all converted operating points in the operating condition conversion data. Exemplarily, the preset ratio threshold may be selected as 5%.

[0102] Step S1024, obtaining the operating point efficiency value corresponding to the converted operating point that does not deviate from the first system external characteristic curve.

[0103] Here, step S1024 specifically includes:

[0104] Step 10241, obtaining an efficiency MAP diagram corresponding to the motor-transmission system; the efficiency MAP diagram represents the distribution of the motor converted efficiency under different motor converted speeds and motor converted torques;

[0105] Step 10242: Obtain the operating point efficiency value corresponding to the converted operating point that does not deviate from the first system external characteristic curve from the efficiency MAP diagram through an interpolation method.

[0106] Here, efficiency MAP Figure 1 It is generally measured by bench tests or simulations, and mainly reflects the distribution of motor efficiency at different speeds and torques. Furthermore, based on the efficiency MAP, the operating point efficiency value corresponding to the converted operating point that does not deviate from the first system external characteristic curve can be obtained.

[0107] Specifically, the energy input into the motor-transmission system during vehicle driving passes through the controller, motor, and transmission system to the wheel end, and is converted into kinetic energy for vehicle driving after overcoming driving resistance. In this process, there are losses in the controller, motor loss, and transmission system. Based on the selected efficiency MAP diagram, controller efficiency, and transmission system mechanical efficiency, the operating point efficiency value can be obtained through interpolation method.

[0108] For example, the interpolation method here often uses bilinear interpolation, and the specific formula is as follows:

[0109]

[0110] Among them, n j Indicates the motor converted speed, T j Indicates the motor converted torque, f(n j ,T j ) represents the efficiency value of the working point obtained by interpolation, n j0 , n j1 , T j0 , Tj1 Indicates the closest operating point on the efficiency MAP diagram (n j , T j )’s coordinate values.

[0111] The embodiment of the present application directly extracts the efficiency value through the efficiency MAP diagram, so that the calculation result is more accurate and more feasible.

[0112] Step S1025, counting the number of converted operating points whose operating point efficiency values ​​are greater than the preset efficiency threshold, and determining the proportion of the second operating point according to the number of converted operating points whose operating point efficiency values ​​are greater than the preset efficiency threshold and the number of converted operating points that do not deviate from the first system external characteristic curve.

[0113] In this step, the ratio between the number of converted operating points whose operating point efficiency values ​​are greater than the preset efficiency threshold and the number of converted operating points that do not deviate from the first system external characteristic curve is calculated to obtain the second operating point ratio. For example, the preset efficiency threshold may be 90%.

[0114] Step S1026: Determine the system power consumption according to the operating point efficiency value.

[0115] Specifically, the system power consumption is calculated by the following formula:

[0116]

[0117] Among them, W c Indicates system power consumption, μ c represents the controller efficiency, μ e Indicates motor efficiency, μ m represents the transmission system efficiency, T j represents the motor torque converted by the transmission ratio of the jth motor-transmission system, n j It represents the motor converted speed obtained by converting the transmission ratio of the j-th motor-transmission system.

[0118] Since the system energy consumption is calculated based on the actual operation data collected, the calculation result of the above system power consumption is easy to correct. Optionally, the MCU input voltage and MCU input current in the collected vehicle operation data can be used to calculate the motor-transmission system input work to compare with the system power consumption. The calculation method is as follows:

[0119]

[0120] Among them, U MCU is the MCU input voltage, I MCU Input current for MCU.

[0121] For example, W c With W MCUIf the deviation is controlled within 10%, the system power consumption result can be considered accurate.

[0122] The embodiment of the present application selects three indicators, namely, the proportion of the first operating point, the proportion of the second operating point and the system power consumption, for calculation. Among them, the proportion of the first operating point represents the dynamic performance of the selected motor-transmission system under the operating condition; the proportion of the second operating point represents the economy of the selected motor-transmission system under the operating condition and the ability to maintain efficient operation when the operating point changes within a small range; the system power consumption mainly represents the economy of the selected motor-transmission system under the operating condition.

[0123] In summary, in the above steps S1021 to S1025, the proportion of the first operating point, the proportion of the second operating point and the system power consumption are determined mainly based on the acquired target operating condition data. The calculation method is simple, and the data source is stable and accurate, which makes the subsequent calculation of the optimal parameter combination set more reliable.

[0124] In step S103, the scores corresponding to the parameter matching sets of each motor-transmission system are determined according to the proportion of the first operating point, the proportion of the second operating point and the system power consumption, and the parameter matching set of the motor-transmission system corresponding to the maximum score is determined as the optimal parameter matching set of the motor-transmission system.

[0125] Optionally, step S103 specifically includes:

[0126] Step 1031, normalize the proportion of the first operating point, the proportion of the second operating point, and the system power consumption to obtain a normalized result of the proportion of the first operating point, a normalized result of the proportion of the second operating point, and a normalized result of the system power consumption.

[0127] Specifically, the proportion of the first operating point or the system power consumption is normalized by the following formula:

[0128]

[0129] P i1min =min(P i1 )

[0130] in, is the normalized result of the first operating point ratio or the normalized result of the system power consumption, P i1 is the proportion of the first operating point or the system power consumption, P i1min is the minimum value of the first operating point proportion or the minimum value of the system power consumption;

[0131] The proportion of the second operating point is normalized by the following formula:

[0132]

[0133] P i2max=max(P i2 )

[0134] in, is the normalized result of the proportion of the second operating point, P i2 is the proportion of the second operating point, P i2max It is the maximum value of the proportion of the second operating point.

[0135] The embodiment of the present application selects to extract the maximum value for the extremely large index (the proportion of the second operating point) for normalization processing, and selects to extract the minimum value for the extremely small index (the proportion of the first operating point or the system power consumption) for normalization processing. The processing method is flexible and accurate, and a more accurate processing result can be obtained, which is beneficial to improving the accuracy of obtaining the optimal parameter matching set of the motor-transmission system.

[0136] Step 1032, respectively set weight coefficients for the normalized result of the first operating point proportion, the normalized result of the second operating point proportion, and the normalized result of the system power consumption, and calculate the scores corresponding to the parameter matching sets of each motor-drive system.

[0137] The value of the weight coefficient can be scored and evaluated by experienced engineers and customers. The scoring range is [0,1]. The higher the score given by the experts to a parameter, the more important the parameter indicator is.

[0138] For example, the Multiple Criteria Decision Making (MCDM) method can be used to judge and select the optimal parameter matching set. Specifically, the mathematical expression of the MDCM method is as follows:

[0139]

[0140] Among them, U(x) is the total score, P i is the performance parameter, a i is the weight coefficient, usually 0 i <1, and The performance parameters include the proportion of the first operating point, the proportion of the second operating point and the system power consumption.

[0141] The embodiment of the present application can manually intervene in the selection of the optimal parameter matching set by setting the weight coefficient, and then the optimal parameter matching set can be obtained according to different working conditions and customers, so that the final optimal parameter matching set meets customer needs and has higher flexibility.

[0142] Step 1033: Select the parameter matching set of the motor-drive system corresponding to the maximum score from the scores corresponding to the parameter matching sets of the motor-drive system as the optimal parameter matching set of the motor-drive system.

[0143] ​Here, the parameter matching sets of each motor-transmission system may be sorted in descending order according to the corresponding scores, and the parameter matching set ranked first may be selected to obtain the optimal parameter matching set of the motor-transmission system.

[0144] In summary, the embodiment of the present application directly uses the collected vehicle operation data for calculation to match the power system. Since the collected vehicle operation data is directly used, objective factors such as slope, load, and road conditions are taken into consideration, which is not much different from the actual situation, and the obtained results are easy to compare and calibrate with the actual operation data. Compared with the traditional calculation method using standard working conditions, this method has more advantages in matching the power system of pure electric commercial vehicles with fixed loads and fixed routes.

[0145] See also Figure 3 , Figure 3 This is a schematic diagram of the structure of a power system matching device for a pure electric commercial vehicle provided in an embodiment of the present application. Figure 3 As shown in , the device comprises:

[0146] A data acquisition module 301 is used to acquire target operating condition data of the pure electric commercial vehicle;

[0147] The data processing module 302 is used to determine the first operating point ratio, the second operating point ratio and the system power consumption according to the acquired target operating condition data for each preset parameter matching set of the motor-transmission system; the first operating point ratio represents the ratio of the number of operating points that deviate from the first system external characteristic curve, and the second operating point ratio represents the ratio of the number of operating points whose operating point efficiency value is greater than a preset efficiency threshold;

[0148] The data determination module 303 is used to determine the scores corresponding to the parameter matching sets of each motor-transmission system according to the proportion of the first operating point, the proportion of the second operating point and the system power consumption, and determine the parameter matching set of the motor-transmission system corresponding to the maximum score as the optimal parameter matching set of the motor-transmission system.

[0149] In an optional implementation, the data acquisition module 301 is specifically used for:

[0150] Collecting actual operating data of the pure electric commercial vehicle, wherein the actual operating data includes motor speed and motor torque;

[0151] A second system external characteristic curve is constructed according to the motor speed and the motor torque, and abnormal operating condition data is obtained according to the second system external characteristic curve; the abnormal operating condition data represents operating condition data that deviates from the second system external characteristic curve;

[0152] The abnormal operating condition data is deleted from the actual operating condition data to obtain the target operating condition data of the pure electric commercial vehicle.

[0153] In an optional implementation, the stability of the target operating condition data is less than a preset value;

[0154] The stability is calculated by the following formula:

[0155]

[0156] Among them, K represents stability, represents the i-th characteristic parameter value in the j-th actual working condition data, It represents the i-th characteristic parameter value in the j-1-th actual operating condition data, and the characteristic parameter value includes the average vehicle speed and the maximum vehicle speed.

[0157] In an optional implementation, the data processing module 302 is specifically used for:

[0158] For each preset motor-transmission system parameter matching set, according to the selected motor-transmission system transmission ratio, the target operating condition data is converted into operating condition conversion data, so as to convert the motor speed in the target operating condition data into the motor conversion speed and the motor torque in the target operating condition data into the motor conversion torque;

[0159] Determine a first system external characteristic curve according to the operating condition conversion data, and obtain a conversion operating condition point deviating from the first system external characteristic curve according to the first system external characteristic curve; the first system external characteristic curve represents a change relationship between the motor conversion torque and the motor conversion speed;

[0160] Determining the proportion of the first operating point according to the number of converted operating points that deviate from the first system external characteristic curve and the number of all converted operating points in the operating condition conversion data; wherein the proportion of the first operating point is less than a preset proportion threshold;

[0161] Obtaining an operating point efficiency value corresponding to a converted operating point that does not deviate from the first system external characteristic curve;

[0162] Counting the number of converted operating points whose efficiency values ​​of the operating points are greater than a preset efficiency threshold, and determining the proportion of the second operating point according to the number of converted operating points whose efficiency values ​​of the operating points are greater than the preset efficiency threshold and the number of converted operating points that do not deviate from the first system external characteristic curve;

[0163] The power consumption of the system is determined according to the efficiency value at the operating point.

[0164] In an optional implementation manner, the data processing module 302 is further configured to calculate the first system external characteristic curve by using the following formula:

[0165]

[0166] Among them, T m is the peak torque of the motor, n m P is the peak value of the motor speed. m is the motor converted power peak value in the working condition converted data, n is the motor converted speed, and T is the motor converted torque.

[0167] In an optional implementation, the data processing module 302 is further configured to:

[0168] Obtaining an efficiency MAP diagram corresponding to the motor-transmission system; the efficiency MAP diagram represents the distribution of the motor converted efficiency under different motor converted speeds and motor converted torques;

[0169] The operating point efficiency value corresponding to the converted operating point that does not deviate from the first system external characteristic curve is obtained from the efficiency MAP diagram through an interpolation method.

[0170] In an optional implementation, the data processing module 302 is further configured to calculate the system power consumption by the following formula:

[0171]

[0172] Among them, W c Indicates system power consumption, μ c represents the controller efficiency, μ e Indicates motor efficiency, μ m represents the transmission system efficiency, T j represents the motor torque converted by the transmission ratio of the jth motor-transmission system, n j It represents the motor converted speed obtained by converting the transmission ratio of the j-th motor-transmission system.

[0173] In an optional implementation, the data determination module 303 is specifically configured to:

[0174] Normalizing the first operating point proportion, the second operating point proportion, and the system power consumption to obtain a normalized result of the first operating point proportion, a normalized result of the second operating point proportion, and a normalized result of the system power consumption;

[0175] Setting weight coefficients for the normalized result of the first operating point proportion, the normalized result of the second operating point proportion, and the normalized result of the system power consumption, respectively, and calculating the scores corresponding to the parameter matching sets of each motor-transmission system;

[0176] The parameter matching set of the motor-transmission system corresponding to the maximum score is selected from the scores corresponding to the parameter matching sets of each motor-transmission system as the optimal parameter matching set of the motor-transmission system.

[0177] In an optional implementation manner, the data determination module 303 is specifically configured to normalize the first operating point proportion or the system power consumption by using the following formula:

[0178]

[0179] P i1min =min(P i1 )

[0180] in, is the normalized result of the first operating point ratio or the normalized result of the system power consumption, P i1 is the proportion of the first operating point or the system power consumption, P i1min is the minimum value of the first operating point proportion or the minimum value of the system power consumption;

[0181] And / or, the proportion of the second operating point is normalized by the following formula:

[0182]

[0183] P i2max =max(P i2 )

[0184] in, is the normalized result of the proportion of the second operating point, P i2 is the proportion of the second operating point, P i2max It is the maximum value of the proportion of the second operating point.

[0185] The embodiment of the present application provides a method of directly using the collected vehicle operation data for calculation to match the power system. Since the collected vehicle operation data is directly used, objective factors such as slope, load, and road conditions are all taken into consideration, which is not much different from the actual situation, and the obtained results are easy to compare and calibrate with the actual operation data. Compared with the traditional calculation method using standard working conditions, this method has more advantages in matching the power system of pure electric commercial vehicles with fixed loads and fixed routes.

[0186] See also Figure 4 , Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 4 As shown in FIG. 4 , the electronic device 400 includes a processor 401 , a memory 402 and a bus 403 .

[0187] The memory 402 stores machine-readable instructions executable by the processor 401. When the electronic device 400 is running, the processor 401 communicates with the memory 402 via the bus 403. When the machine-readable instructions are executed by the processor 401, the above-mentioned Figure 1-2 The steps of the power system matching method for a pure electric commercial vehicle in the method embodiment shown in the figure, and the specific implementation method thereof can be referred to the method embodiment, which will not be described in detail here.

[0188] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the computer program can execute the above-mentioned Figure 1 as well as Figure 2 The steps of the power system matching method for a pure electric commercial vehicle in the method embodiment shown in the figure, and the specific implementation method thereof can be referred to the method embodiment, which will not be described in detail here.

[0189] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0190] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0191] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0192] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0193] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0194] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A power system matching method for a pure electric commercial vehicle, characterized in that: The method comprises: Acquiring target operating condition data of the pure electric commercial vehicle; For each preset parameter matching set of the motor-transmission system, the first operating point proportion, the second operating point proportion and the system power consumption are determined according to the acquired target operating condition data; the first operating point proportion represents the proportion of the number of operating points that deviate from the first system external characteristic curve, and the second operating point proportion represents the proportion of the number of operating points whose operating point efficiency values ​​are greater than a preset efficiency threshold; According to the proportion of the first operating point, the proportion of the second operating point and the system power consumption, the scores corresponding to the parameter matching sets of each motor-transmission system are determined, and the parameter matching set of the motor-transmission system corresponding to the maximum score is determined as the optimal parameter matching set of the motor-transmission system.

2. The method according to claim 1, characterized in that: The obtaining of the target operating condition data of the pure electric commercial vehicle includes: Collecting actual operating data of the pure electric commercial vehicle, wherein the actual operating data includes motor speed and motor torque; A second system external characteristic curve is constructed according to the motor speed and the motor torque, and abnormal operating condition data is obtained according to the second system external characteristic curve; the abnormal operating condition data represents operating condition data that deviates from the second system external characteristic curve; The abnormal operating condition data is deleted from the actual operating condition data to obtain the target operating condition data of the pure electric commercial vehicle.

3. The method according to claim 2, characterized in that The stability of the target operating condition data is less than a preset value; The stability is calculated by the following formula: Where K represents stability, represents the i-th characteristic parameter value in the j-th actual working condition data, It represents the i-th characteristic parameter value in the j-1-th actual operating condition data, and the characteristic parameter value includes the average vehicle speed and the maximum vehicle speed.

4. The method according to claim 1, characterized in that: The method of determining the first operating point ratio, the second operating point ratio and the system power consumption according to the acquired target operating condition data for each preset parameter matching set of the motor-transmission system includes: For each preset motor-transmission system parameter matching set, according to the selected motor-transmission system transmission ratio, the target operating condition data is converted into operating condition conversion data, so as to convert the motor speed in the target operating condition data into the motor conversion speed and the motor torque in the target operating condition data into the motor conversion torque; Determine a first system external characteristic curve according to the operating condition conversion data, and obtain a conversion operating condition point deviating from the first system external characteristic curve according to the first system external characteristic curve; the first system external characteristic curve represents a change relationship between the motor conversion torque and the motor conversion speed; Determining the proportion of the first operating point according to the number of converted operating points that deviate from the first system external characteristic curve and the number of all converted operating points in the operating condition conversion data; wherein the proportion of the first operating point is less than a preset proportion threshold; Obtaining an operating point efficiency value corresponding to a converted operating point that does not deviate from the first system external characteristic curve; Counting the number of converted operating points whose efficiency values ​​of the operating points are greater than a preset efficiency threshold, and determining the proportion of the second operating point according to the number of converted operating points whose efficiency values ​​of the operating points are greater than the preset efficiency threshold and the number of converted operating points that do not deviate from the first system external characteristic curve; The power consumption of the system is determined according to the efficiency value at the operating point.

5. The method according to claim 4, characterized in that The first system external characteristic curve is calculated by the following formula: Among them, T m is the peak torque of the motor, n m P is the peak value of the motor speed. m is the motor converted power peak value in the working condition converted data, n is the motor converted speed, and T is the motor converted torque.

6. The method according to claim 4, characterized in that The obtaining of the operating point efficiency value corresponding to the converted operating point that does not deviate from the first system external characteristic curve includes: Obtaining an efficiency MAP diagram corresponding to the motor-transmission system; the efficiency MAP diagram represents the distribution of the motor converted efficiency under different motor converted speeds and motor converted torques; The operating point efficiency value corresponding to the converted operating point that does not deviate from the first system external characteristic curve is obtained from the efficiency MAP diagram through an interpolation method.

7. The method according to claim 4, characterized in that The system power consumption is calculated by the following formula: Among them, W c Indicates system power consumption, μ c represents the controller efficiency, μ e Indicates motor efficiency, μ m represents the transmission system efficiency, T j represents the motor torque converted by the transmission ratio of the jth motor-transmission system, n j It represents the motor converted speed obtained by converting the transmission ratio of the j-th motor-transmission system.

8. The method according to claim 1, characterized in that The step of determining scores corresponding to parameter matching sets of each motor-transmission system according to the proportion of the first operating point, the proportion of the second operating point, and the system power consumption, and determining the parameter matching set of the motor-transmission system corresponding to the maximum score as the optimal parameter matching set of the motor-transmission system includes: Normalizing the first operating point proportion, the second operating point proportion, and the system power consumption to obtain a normalized result of the first operating point proportion, a normalized result of the second operating point proportion, and a normalized result of the system power consumption; Setting weight coefficients for the normalized result of the first operating point proportion, the normalized result of the second operating point proportion, and the normalized result of the system power consumption, respectively, and calculating scores corresponding to the parameter matching sets of each motor-drive system; The parameter matching set of the motor-transmission system corresponding to the maximum score is selected from the scores corresponding to the parameter matching sets of each motor-transmission system as the optimal parameter matching set of the motor-transmission system.

9. The method according to claim 8, characterized in that The first operating point ratio or the system power consumption is normalized by the following formula: P i1min =min(P i1 ) in, is the normalized result of the first operating point ratio or the normalized result of the system power consumption, P i1 is the proportion of the first operating point or the system power consumption, P i1min is the minimum value of the first operating point proportion or the minimum value of the system power consumption; And / or, the proportion of the second operating point is normalized by the following formula: P i2max =max(P i2 ) in, is the normalized result of the proportion of the second operating point, P i2 is the proportion of the second operating point, P i2max It is the maximum value of the proportion of the second operating point.

10. A power system matching device for a pure electric commercial vehicle, characterized in that: The device comprises: A data acquisition module, used to acquire target operating condition data of the pure electric commercial vehicle; A data processing module, for determining, for each preset parameter matching set of the motor-transmission system, a first operating point ratio, a second operating point ratio and system power consumption according to the acquired target operating condition data; the first operating point ratio represents the number of operating points that deviate from the first system external characteristic curve, and the second operating point ratio represents the number of operating points whose operating point efficiency values ​​are greater than a preset efficiency threshold; A data determination module is used to determine the scores corresponding to the parameter matching sets of each motor-transmission system according to the proportion of the first operating point, the proportion of the second operating point and the system power consumption, and determine the parameter matching set of the motor-transmission system corresponding to the maximum score as the optimal parameter matching set of the motor-transmission system.

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