Method and device for evaluating high-voltage ripples of electric vehicle

Abstract

The invention provides a high-voltage ripple assessment method and device for an electric vehicle. The method comprises the steps of obtaining to-be-assessed high-voltage system data of the electric vehicle; establishing a high-voltage system equivalent circuit model according to the high-voltage system data of the electric vehicle; calculating resonance characteristics of the equivalent circuit model of the high-voltage system; judging whether a high-voltage ripple risk exists or not according to the high-voltage system equivalent circuit model; if yes, determining a ripple forbidden zone of high-voltage ripples according to the high-voltage system equivalent circuit model; and determining a high-voltage ripple risk solution according to the resonance characteristics and the ripple forbidden zone. According to the method and the device, ripple risk assessment of the high-voltage system can be carried out in the early stage of automobile design and development, an impedance matching optimization scheme is provided in time, the efficiency is high, the flexibility is good, and the development period is shortened.

Description

Technical Field

[0001] The present application relates to the field of automobile simulation technology, and in particular to a method and device for evaluating high-voltage ripple of an electric vehicle. Background Art

[0002] With the rapid development and popularization of new energy electric vehicle technology, the problem of abnormal high-voltage ripple faced in actual operation has become increasingly prominent, becoming one of the key factors restricting the performance stability and safety of electric vehicles. The high-voltage ripple of electric vehicles is usually highly correlated with the impedance matching of the high-voltage system. When the impedance matching design of the high-voltage system is not well considered, the circuit resonance of the high-voltage system causes the high-voltage ripple to double, affecting the stable operation of the high-voltage system. In the prior art, a large number of test case verifications are usually carried out at the prototype stage to fully cover the vehicle usage conditions that may be brought about by drivers and passengers, which brings a considerable time cycle cost and makes it difficult to guarantee the project development node. It can be seen that the existing methods require a lot of time and resources to design and implement test cases. In addition, due to the complexity and diversity of electric vehicle systems, this process is often lengthy and difficult to advance efficiently, which seriously restricts the flexibility of the project development cycle. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a high-voltage ripple assessment method and device for electric vehicles, which can perform ripple risk assessment of the high-voltage system in the early stage of automobile design and development, and promptly propose impedance matching optimization solutions with high efficiency and good flexibility, thus reducing the development cycle.

[0004] The first aspect of the present application provides a high-voltage ripple evaluation method for an electric vehicle, comprising:

[0005] Obtain data on the high voltage system of the electric vehicle to be evaluated;

[0006] Establishing a high-voltage system equivalent circuit model according to the electric vehicle high-voltage system data;

[0007] Calculating the resonant characteristics of the high voltage system equivalent circuit model;

[0008] Determining whether there is a high voltage ripple risk based on the high voltage system equivalent circuit model;

[0009] If yes, determining the ripple forbidden zone of the high voltage ripple according to the high voltage system equivalent circuit model;

[0010] A high voltage ripple risk solution is determined based on the resonance characteristics and the ripple forbidden zone.

[0011] In the above implementation process, the method can conduct ripple risk assessment of high-voltage systems in the early stages of automotive design and development, and promptly propose impedance matching optimization solutions with high efficiency and good flexibility, thus reducing the development cycle.

[0012] Further, the high-voltage system equivalent circuit model includes an equivalent high-voltage circuit model of high-voltage components and connecting cables;

[0013] The resonance characteristics include voltage resonance characteristics, current resonance characteristics and impedance resonance characteristics.

[0014] Furthermore, judging whether there is a high voltage ripple risk according to the high voltage system equivalent circuit model includes:

[0015] Determining a high voltage ripple interference source in the high voltage system equivalent circuit model;

[0016] Collecting interference source ripple of the high-voltage ripple interference source through a sensor in the high-voltage system equivalent circuit model;

[0017] Determine whether the interference source ripple is greater than a preset protection threshold;

[0018] If yes, it is determined that there is a high-voltage ripple risk in the high-voltage system equivalent circuit model, and the ripple forbidden zone of the high-voltage ripple is determined according to the high-voltage system equivalent circuit model.

[0019] Furthermore, determining the ripple forbidden zone of the high-voltage ripple according to the high-voltage system equivalent circuit model includes:

[0020] Determining the interference source frequency characteristics and the circuit current-frequency response characteristics according to the high voltage system equivalent circuit model;

[0021] The ripple forbidden zone is determined according to the interference source frequency characteristics and the current-frequency response characteristics of the circuit; wherein the ripple forbidden zone includes at least a ripple forbidden zone frequency interval and a ripple forbidden zone current amplitude interval, and the ripple forbidden zone frequency interval includes at least the interference source frequency.

[0022] Further, the method of determining a high-voltage ripple risk solution according to the resonance characteristics and the ripple forbidden zone includes:

[0023] Determining the impedance relationship and the resonance relationship of the high voltage system equivalent circuit model according to the resonance characteristics;

[0024] Determining a functional relationship among ripple current, ripple voltage and impedance according to the impedance relationship and the resonance relationship;

[0025] A high-voltage ripple risk solution is determined based on the ripple forbidden zone, the functional relationship and the preset protection threshold; wherein the high-voltage ripple risk solution is one or more of changing the frequency of the high-voltage ripple interference source, adjusting the loop impedance in the high-voltage system equivalent circuit model, and reducing the interference amplitude of the high-voltage ripple interference source.

[0026] A second aspect of the present application provides a high-voltage ripple evaluation device for an electric vehicle, the high-voltage ripple evaluation device for an electric vehicle comprising:

[0027] An acquisition unit, used for acquiring high voltage system data of an electric vehicle to be evaluated;

[0028] An establishing unit, used for establishing a high-voltage system equivalent circuit model according to the electric vehicle high-voltage system data;

[0029] A calculation unit, used for calculating the resonance characteristics of the high voltage system equivalent circuit model;

[0030] A judging unit, configured to judge whether there is a high voltage ripple risk according to the high voltage system equivalent circuit model;

[0031] A first determining unit is used to determine a ripple forbidden zone of the high-voltage ripple according to the high-voltage system equivalent circuit model when it is determined that there is a high-voltage ripple risk;

[0032] A second determining unit is configured to determine a high-voltage ripple risk solution according to the resonance characteristic and the ripple forbidden zone.

[0033] Further, the high-voltage system equivalent circuit model includes an equivalent high-voltage circuit model of high-voltage components and connecting cables;

[0034] The resonance characteristics include voltage resonance characteristics, current resonance characteristics and impedance resonance characteristics.

[0035] Furthermore, the judging unit comprises:

[0036] A first determining subunit, used to determine a high voltage ripple interference source in the high voltage system equivalent circuit model;

[0037] A collection subunit, used for collecting interference source ripple of the high-voltage ripple interference source through a sensor in the high-voltage system equivalent circuit model;

[0038] A judging subunit, used to judge whether the interference source ripple is greater than a preset protection threshold;

[0039] The second determination subunit is used to determine that there is a high-voltage ripple risk in the high-voltage system equivalent circuit model when it is determined that the interference source ripple is greater than the preset protection threshold, and trigger the first determination unit to determine the ripple forbidden zone of the high-voltage ripple according to the high-voltage system equivalent circuit model.

[0040] Furthermore, the first determination unit is specifically used to determine the interference source frequency characteristics and the current-frequency response characteristics of the circuit according to the high-voltage system equivalent circuit model; and determine the ripple forbidden zone according to the interference source frequency characteristics and the current-frequency response characteristics of the circuit; wherein the ripple forbidden zone includes at least a ripple forbidden zone frequency interval and a ripple forbidden zone current amplitude interval, and the ripple forbidden zone frequency interval includes at least the interference source frequency.

[0041] Furthermore, the second determination unit is specifically configured to determine the impedance relationship and the resonance relationship of the high voltage system equivalent circuit model according to the resonance characteristic;

[0042] The second determining unit is further configured to determine a functional relationship among the ripple current, the ripple voltage and the impedance according to the impedance relationship and the resonance relationship;

[0043] The second determination unit is specifically used to determine a high-voltage ripple risk solution based on the ripple forbidden zone, the functional relationship and a preset protection threshold; wherein the high-voltage ripple risk solution is one or more of changing the frequency of the high-voltage ripple interference source, adjusting the loop impedance in the high-voltage system equivalent circuit model, and reducing the interference amplitude of the high-voltage ripple interference source.

[0044] A third aspect of the present application provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the high-voltage ripple evaluation method for an electric vehicle described in any one of the first aspects of the present application.

[0045] A fourth aspect of the present application provides a computer-readable storage medium storing computer program instructions, wherein when the computer program instructions are read and executed by a processor, the high-voltage ripple evaluation method for an electric vehicle described in any one of the first aspects of the present application is executed.

[0046] The beneficial effects of the present application are as follows: the method is applied in the field of high-voltage ripple design of new energy electric vehicles, and can be combined with computer EDA simulation analysis tools to advance the prototype vehicle test verification for high-voltage ripple that needs to be carried out in the middle and late stages of project development to the early and middle stages of project development for computer simulation analysis, thereby facilitating early discovery of the high-voltage ripple risk caused by poor high-voltage impedance matching, and early analysis of countermeasures to solve the high-voltage ripple problem, thereby better grasping the development nodes of new models, reducing the cost of trial and error, and achieving cost reduction and efficiency improvement in model development. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application 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.

[0048] Figure 1 A schematic diagram of a flow chart of a high-voltage ripple evaluation method for an electric vehicle provided in an embodiment of the present application;

[0049] Figure 2 A schematic diagram of an example flow chart of a high-voltage ripple evaluation method for an electric vehicle provided in an embodiment of the present application;

[0050] Figure 3 A schematic flow chart of another high-voltage ripple evaluation method for an electric vehicle provided in an embodiment of the present application;

[0051] Figure 4 A basic schematic diagram of an equivalent series resonant circuit provided in an embodiment of the present application;

[0052] Figure 5 An example diagram of an impedance-frequency response characteristic of a series resonant circuit provided in an embodiment of the present application;

[0053] Figure 6 An example diagram of a current-frequency response characteristic of an interference source provided in an embodiment of the present application;

[0054] Figure 7 An example diagram of the combination of the current-frequency response characteristics and the ripple risk of an interference source provided in an embodiment of the present application;

[0055] Figure 8 An example diagram of a current-frequency response characteristic curve corresponding to a solution provided in an embodiment of the present application;

[0056] Fig. 9 A schematic diagram of the structure of a high-voltage ripple evaluation device for an electric vehicle provided in an embodiment of the present application;

[0057] Fig.10 A schematic structural diagram of another high-voltage ripple evaluation device for an electric vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0059] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0060] Example 1

[0061] Please see Figure 1 , Figure 1 A schematic flow chart of a high-voltage ripple evaluation method for an electric vehicle provided in this embodiment. The high-voltage ripple evaluation method for an electric vehicle includes:

[0062] S101. Obtaining high-voltage system data of an electric vehicle to be evaluated.

[0063] S102. Establishing a high-voltage system equivalent circuit model based on the electric vehicle high-voltage system data.

[0064] In this embodiment, the high-voltage system equivalent circuit model includes equivalent high-voltage circuit models of high-voltage components and connecting cables.

[0065] S103. Calculate the resonant characteristics of the high voltage system equivalent circuit model.

[0066] In this embodiment, the resonance characteristics include voltage resonance characteristics, current resonance characteristics and impedance resonance characteristics.

[0067] S104. Determine whether there is a high voltage ripple risk based on the high voltage system equivalent circuit model. If yes, execute step S105; if no, end this process.

[0068] S105. Determine a ripple forbidden zone of the high voltage ripple according to an equivalent circuit model of the high voltage system.

[0069] S106. Determine a high-voltage ripple risk solution based on the resonance characteristics and the ripple forbidden zone.

[0070] Please see Figure 2 , Figure 2 An example flow chart of a high voltage ripple evaluation method for an electric vehicle is shown.

[0071] In this embodiment, the execution subject of the method may be a computing device such as a computer or a server, and no limitation is made in this embodiment.

[0072] In this embodiment, the execution subject of the method may also be a smart device such as a smart phone, a tablet computer, etc., which is not limited in this embodiment.

[0073] It can be seen that the implementation of the high-voltage ripple assessment method for electric vehicles described in this embodiment can perform ripple risk assessment of the high-voltage system in the early stage of automobile design and development, and promptly propose impedance matching optimization solutions with high efficiency and good flexibility, thereby reducing the development cycle.

[0074] Example 2

[0075] Please see Figure 3 , Figure 3 A schematic flow chart of a high-voltage ripple evaluation method for an electric vehicle provided in this embodiment. The high-voltage ripple evaluation method for an electric vehicle includes:

[0076] S201. Obtaining high voltage system data of an electric vehicle to be evaluated.

[0077] S202. Establish a high-voltage system equivalent circuit model based on the electric vehicle high-voltage system data.

[0078] In this embodiment, the high-voltage system equivalent circuit model is an equivalent circuit model of the high-voltage system of a new energy electric vehicle. Specifically, since the high-voltage system of a new energy electric vehicle is composed of various high-voltage components, connecting cables, etc., the high-voltage system equivalent circuit model is an equivalent model obtained by converting the high-voltage components, connecting cables, etc. Among them, the high-voltage system of a new energy electric vehicle is composed of high-voltage components, connecting cables, etc., and these high-voltage components and connecting cables can be equivalently replaced by equivalent circuits composed of resistors, capacitors, inductors, etc.

[0079] In this embodiment, the high-voltage system equivalent circuit model is composed of various electronic components in the high-voltage circuit, and the high-voltage system equivalent circuit model is usually obtained by querying the circuit design manual. Specifically, the relevant electronic components in the high-voltage system equivalent circuit model are equivalently converted into a combination of resistance, capacitance, and inductance parameters. Among them, the relevant equivalent parameters can be obtained in the following ways: ① query the technical manual of electronic components; ② test the frequency-impedance characteristic curve or scattering parameter curve of electronic components and convert it into an equivalent circuit model; ③ obtain it through different technical means such as computer three-dimensional electromagnetic simulation.

[0080] S203. Calculate the resonant characteristics of the high voltage system equivalent circuit model.

[0081] In this embodiment, the resonant characteristics of the high voltage system equivalent circuit model are generally divided into voltage resonance characteristics, current resonance characteristics and impedance resonance characteristics, and are usually represented by a two-dimensional graph, where the horizontal axis is generally frequency and the vertical axis is generally voltage, current or impedance amplitude.

[0082] In this embodiment, when there are resistors, capacitors, and inductors in the circuit, the circuit will inevitably have corresponding resonance characteristics.

[0083] S204. Determine the high voltage ripple interference source in the high voltage system equivalent circuit model.

[0084] S205. Collect interference source ripple of the high-voltage ripple interference source through a sensor in the high-voltage system equivalent circuit model.

[0085] For example, the high voltage system of new energy electric vehicles is prone to series resonance composed of resistance, capacitance and inductance. The basic equivalent series resonance circuit diagram can be found in Figure 4 As shown. Assuming the resistance is 10 milliohms, the inductance is 1uH, and the capacitance is 350uF, its impedance-frequency response characteristics (resonance characteristics) are as follows: Figure 5 At this time, assuming that the interference source (i.e., the high-voltage ripple interference source) is a voltage signal with a constant amplitude, its current-frequency response characteristics can be found in Figure 6 shown.

[0086] In this case, the impedance of the series resonant circuit is given by Equation 1:

[0087] Z=R+jωL+1 / jωC (Formula 1)

[0088] When the condition of formula 2 is met, the circuit undergoes series resonance, and the formula is as follows:

[0089] ωL=1 / ωC (Formula 2)

[0090] At this time, the inductive reactance and capacitive reactance of the circuit cancel each other out, presenting a pure resistance characteristic, and the impedance of the circuit is minimal. According to Ohm's law, the relationship between ripple current, ripple voltage and impedance is shown in Formula 3:

[0091] I=U / Z (Formula 3)

[0092] In the above formula, Z is the impedance of the entire circuit, R is the resistance in the circuit, L is the inductance in the circuit, C is the capacitance in the circuit, ω is the angular frequency, U is the ripple voltage, and I is the ripple current.

[0093] S206, determine whether the interference source ripple is greater than a preset protection threshold, if so, execute step S207; if not, end this process.

[0094] In the above example, the impedance Z is the smallest when the circuit is in series resonance, almost equal to the resistance R. Therefore, the amplitude of the ripple current I is the largest, and the risk of high voltage ripple is most likely to occur at this time. Assuming that the protection threshold of the current sampling sensor in the circuit is set to 50A (that is, the preset protection threshold), if the frequency of the interference source is around 9kHz, then combined with the following Figure 7 From the example diagram showing the combination of current-frequency response characteristics and ripple risk, it can be seen that this circuit will generate high-voltage ripple risk.

[0095] In this embodiment, in order to reduce the risk of high voltage ripple, the method proposes a method for determining the ripple forbidden zone according to the frequency characteristics of the interference source and the current-frequency response characteristics of the circuit. Figure 7 Taking the setting of ripple forbidden zone according to frequency range and current amplitude range as an example, the frequency range of ripple forbidden zone should include the interference source frequency (9kHz in this example). Assuming 7kHz-10kHz, the current amplitude range of ripple forbidden zone is 50A and above. The final graphical effect of ripple forbidden zone is as follows Figure 7 As shown in the rectangular box.

[0096] S207. Determine whether there is a high voltage ripple risk in the high voltage system equivalent circuit model.

[0097] In this embodiment, high-voltage ripple exists in the high-voltage circuit loop of the new energy electric vehicle, generally in the form of voltage ripple or current ripple. Because there is a high-voltage ripple interference source in the high-voltage circuit loop, the high-voltage ripple interference source is generally an AC voltage or AC current signal with a fixed or variable frequency and a fixed or variable amplitude; at the same time, there is also a voltage or current sampling sensor in the high-voltage circuit loop, which can collect the ripple from the high-voltage ripple interference source at the sensor position, which is attenuated or amplified through the circuit path. Therefore, when the ripple collected at the sensor is greater than the voltage or current threshold set by the sensor, it can be considered that the resonant characteristics of the high-voltage circuit cause the risk of high-voltage ripple.

[0098] S208. Determine the frequency characteristics of the interference source and the current-frequency response characteristics of the circuit according to the high voltage system equivalent circuit model.

[0099] S209, determining the ripple forbidden zone according to the frequency characteristics of the interference source and the current-frequency response characteristics of the circuit.

[0100] In this embodiment, the ripple forbidden zone includes at least a ripple forbidden zone frequency interval and a ripple forbidden zone current amplitude interval, and the ripple forbidden zone frequency interval includes at least the interference source frequency.

[0101] S210. Determine the impedance relationship and the resonance relationship of the high voltage system equivalent circuit model according to the resonance characteristics.

[0102] S211. Determine a functional relationship among ripple current, ripple voltage and impedance according to an impedance relationship and a resonance relationship.

[0103] S212. Determine a high-voltage ripple risk solution based on the ripple forbidden area, functional relationship, and preset protection threshold.

[0104] In this embodiment, the high-voltage ripple risk solution is one or more of changing the frequency of the high-voltage ripple interference source, adjusting the loop impedance in the high-voltage system equivalent circuit model, and reducing the interference amplitude of the high-voltage ripple interference source.

[0105] In this embodiment, the confirmed high-voltage ripple risk of the new energy electric vehicle is caused by the high-voltage ripple collected by the sensor exceeding the protection threshold; therefore, the high-voltage ripple risk can be solved by making the high-voltage ripple at the sensor lower than the protection threshold.

[0106] In this embodiment, the high-voltage ripple risk solution may include: ① changing the frequency of the high-voltage ripple interference source in the high-voltage circuit loop; ② reducing the interference amplitude of the interference source; ③ adjusting the high-voltage circuit loop impedance.

[0107] For example, to prevent high voltage ripple from falling into Figure 7 Within the ripple forbidden zone shown in , the current within the frequency range of the ripple forbidden zone can be reduced as much as possible. According to the above formula 3, the principle of the solution can be determined as: reduce the voltage U or increase the impedance Z. Based on this principle, a variety of solutions can be generated. Among them, the current-frequency response characteristic curves corresponding to some solutions are as follows Figure 8 As shown, Figure 8 Among them, I(V1) corresponds to the state with ripple risk, and I(V2) to I(V7) correspond to the state without ripple risk by adjusting the single variable U or Z.

[0108] In this embodiment, the execution subject of the method may be a computing device such as a computer or a server, and no limitation is made in this embodiment.

[0109] In this embodiment, the execution subject of the method may also be a smart device such as a smart phone, a tablet computer, etc., which is not limited in this embodiment.

[0110] It can be seen that the implementation of the high-voltage ripple assessment method for electric vehicles described in this embodiment can perform ripple risk assessment of the high-voltage system in the early stage of automobile design and development, and promptly propose impedance matching optimization solutions with high efficiency and good flexibility, thereby reducing the development cycle.

[0111] Example 3

[0112] Please see Fig. 9 , Fig. 9 This is a schematic diagram of the structure of a high-voltage ripple evaluation device for an electric vehicle provided in this embodiment. Fig. 9 As shown, the high voltage ripple evaluation device of the electric vehicle includes:

[0113] An acquisition unit 310 is used to acquire high voltage system data of the electric vehicle to be evaluated;

[0114] An establishing unit 320 is used to establish an equivalent circuit model of a high voltage system according to the high voltage system data of the electric vehicle;

[0115] A calculation unit 330, used to calculate the resonance characteristics of the high voltage system equivalent circuit model;

[0116] A judgment unit 340, configured to judge whether there is a high voltage ripple risk according to a high voltage system equivalent circuit model;

[0117] A first determination unit 350 is used to determine a ripple forbidden zone of the high-voltage ripple according to a high-voltage system equivalent circuit model when it is determined that there is a high-voltage ripple risk;

[0118] The second determination unit 360 is configured to determine a high voltage ripple risk solution according to the resonance characteristics and the ripple forbidden zone.

[0119] In this embodiment, the explanation of the high-voltage ripple evaluation device for an electric vehicle can refer to the description in Embodiment 1 or Embodiment 2, and will not be further elaborated in this embodiment.

[0120] It can be seen that the high-voltage ripple assessment device for electric vehicles described in this embodiment can perform ripple risk assessment of the high-voltage system in the early stage of automobile design and development, and promptly propose impedance matching optimization solutions with high efficiency and good flexibility, thus reducing the development cycle.

[0121] Example 4

[0122] Please see Fig.10 , Fig.10 This is a schematic diagram of the structure of a high-voltage ripple evaluation device for an electric vehicle provided in this embodiment. Fig.10 As shown, the high voltage ripple evaluation device of the electric vehicle includes:

[0123] An acquisition unit 310 is used to acquire high voltage system data of the electric vehicle to be evaluated;

[0124] An establishing unit 320 is used to establish an equivalent circuit model of a high voltage system according to the high voltage system data of the electric vehicle;

[0125] A calculation unit 330, used to calculate the resonance characteristics of the high voltage system equivalent circuit model;

[0126] A judgment unit 340, configured to judge whether there is a high voltage ripple risk according to a high voltage system equivalent circuit model;

[0127] A first determination unit 350 is used to determine a ripple forbidden zone of the high-voltage ripple according to a high-voltage system equivalent circuit model when it is determined that there is a high-voltage ripple risk;

[0128] The second determination unit 360 is configured to determine a high voltage ripple risk solution according to the resonance characteristics and the ripple forbidden zone.

[0129] In this embodiment, the high-voltage system equivalent circuit model includes an equivalent high-voltage circuit model of high-voltage components and connecting cables;

[0130] The resonance characteristics include voltage resonance characteristics, current resonance characteristics and impedance resonance characteristics.

[0131] As an optional implementation, the judging unit 340 includes:

[0132] A first determining subunit 341 is used to determine a high voltage ripple interference source in a high voltage system equivalent circuit model;

[0133] The collecting subunit 342 is used to collect the interference source ripple of the high voltage ripple interference source through the sensor in the high voltage system equivalent circuit model;

[0134] The judging subunit 343 is used to judge whether the interference source ripple is greater than a preset protection threshold;

[0135] The second determination subunit 344 is used to determine that there is a high-voltage ripple risk in the high-voltage system equivalent circuit model when it is determined that the interference source ripple is greater than a preset protection threshold, and trigger the first determination unit to determine the ripple forbidden zone of the high-voltage ripple according to the high-voltage system equivalent circuit model.

[0136] As an optional implementation, the first determination unit 350 is specifically used to determine the frequency characteristics of the interference source and the current-frequency response characteristics of the circuit based on the equivalent circuit model of the high-voltage system; and determine the ripple forbidden zone based on the frequency characteristics of the interference source and the current-frequency response characteristics of the circuit; wherein the ripple forbidden zone includes at least a ripple forbidden zone frequency interval and a ripple forbidden zone current amplitude interval, and the ripple forbidden zone frequency interval includes at least the interference source frequency.

[0137] As an optional implementation manner, the second determination unit 360 is specifically configured to determine the impedance relationship and the resonance relationship of the high voltage system equivalent circuit model according to the resonance characteristics;

[0138] The second determining unit 360 is further configured to determine a functional relationship among the ripple current, the ripple voltage and the impedance according to the impedance relationship and the resonance relationship;

[0139] The second determination unit 360 is further specifically used to determine a high-voltage ripple risk solution based on the ripple forbidden zone, the functional relationship and the preset protection threshold; wherein the high-voltage ripple risk solution is one or more of changing the frequency of the high-voltage ripple interference source, adjusting the loop impedance in the high-voltage system equivalent circuit model, and reducing the interference amplitude of the high-voltage ripple interference source.

[0140] In this embodiment, the explanation of the high-voltage ripple evaluation device for an electric vehicle can refer to the description in Embodiment 1 or Embodiment 2, and will not be further elaborated in this embodiment.

[0141] It can be seen that the high-voltage ripple assessment device for electric vehicles described in this embodiment can perform ripple risk assessment of the high-voltage system in the early stage of automobile design and development, and promptly propose impedance matching optimization solutions with high efficiency and good flexibility, thus reducing the development cycle.

[0142] An embodiment of the present application provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the high-voltage ripple evaluation method for an electric vehicle in Embodiment 1 or Embodiment 2 of the present application.

[0143] An embodiment of the present application provides a computer-readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, the high-voltage ripple evaluation method for an electric vehicle in Embodiment 1 or Embodiment 2 of the present application is executed.

[0144] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0145] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0146] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable 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 methods 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.

[0147] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0148] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0149] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A method for evaluating high voltage ripple of an electric vehicle, characterized in that: include: Obtain data on the high voltage system of the electric vehicle to be evaluated; Establishing a high-voltage system equivalent circuit model according to the electric vehicle high-voltage system data; Calculating the resonant characteristics of the high voltage system equivalent circuit model; Determining whether there is a high voltage ripple risk based on the high voltage system equivalent circuit model; If yes, determining the ripple forbidden zone of the high voltage ripple according to the high voltage system equivalent circuit model; A high voltage ripple risk solution is determined based on the resonance characteristics and the ripple forbidden zone.

2. The high voltage ripple evaluation method of an electric vehicle according to claim 1, characterized in that: The high-voltage system equivalent circuit model includes an equivalent high-voltage circuit model of high-voltage components and connecting cables; The resonance characteristics include voltage resonance characteristics, current resonance characteristics and impedance resonance characteristics.

3. The high voltage ripple evaluation method of an electric vehicle according to claim 1, characterized in that: The determining whether there is a high voltage ripple risk according to the high voltage system equivalent circuit model includes: Determining a high voltage ripple interference source in the high voltage system equivalent circuit model; Collecting interference source ripple of the high-voltage ripple interference source through a sensor in the high-voltage system equivalent circuit model; Determine whether the interference source ripple is greater than a preset protection threshold; If yes, it is determined that there is a high-voltage ripple risk in the high-voltage system equivalent circuit model, and the ripple forbidden zone of the high-voltage ripple is determined according to the high-voltage system equivalent circuit model.

4. The high voltage ripple evaluation method of an electric vehicle according to claim 1, characterized in that: The step of determining a ripple forbidden zone of a high-voltage ripple according to the high-voltage system equivalent circuit model comprises: Determining the interference source frequency characteristics and the circuit current-frequency response characteristics according to the high voltage system equivalent circuit model; The ripple forbidden zone is determined according to the interference source frequency characteristics and the current-frequency response characteristics of the circuit; wherein the ripple forbidden zone includes at least a ripple forbidden zone frequency interval and a ripple forbidden zone current amplitude interval, and the ripple forbidden zone frequency interval includes at least the interference source frequency.

5. The high voltage ripple evaluation method of an electric vehicle according to claim 1, characterized in that: The method of determining a high-voltage ripple risk solution according to the resonance characteristics and the ripple forbidden zone comprises: Determining the impedance relationship and the resonance relationship of the high voltage system equivalent circuit model according to the resonance characteristics; Determining a functional relationship among ripple current, ripple voltage and impedance according to the impedance relationship and the resonance relationship; A high-voltage ripple risk solution is determined based on the ripple forbidden zone, the functional relationship and the preset protection threshold; wherein the high-voltage ripple risk solution is one or more of changing the frequency of the high-voltage ripple interference source, adjusting the loop impedance in the high-voltage system equivalent circuit model, and reducing the interference amplitude of the high-voltage ripple interference source.

6. A high voltage ripple evaluation device for an electric vehicle, characterized in that: The high voltage ripple evaluation device of the electric vehicle comprises: An acquisition unit, used for acquiring high voltage system data of an electric vehicle to be evaluated; An establishing unit, used for establishing a high-voltage system equivalent circuit model according to the electric vehicle high-voltage system data; A calculation unit, used for calculating the resonance characteristics of the high voltage system equivalent circuit model; A judging unit, configured to judge whether there is a high voltage ripple risk according to the high voltage system equivalent circuit model; A first determining unit is used to determine a ripple forbidden zone of the high-voltage ripple according to the high-voltage system equivalent circuit model when it is determined that there is a high-voltage ripple risk; A second determining unit is configured to determine a high-voltage ripple risk solution according to the resonance characteristic and the ripple forbidden zone.

7. The high voltage ripple evaluation device for electric vehicles according to claim 6, characterized in that: The judging unit comprises: A first determining subunit, used to determine a high voltage ripple interference source in the high voltage system equivalent circuit model; A collection subunit, used for collecting interference source ripple of the high-voltage ripple interference source through a sensor in the high-voltage system equivalent circuit model; A judging subunit, used to judge whether the interference source ripple is greater than a preset protection threshold; The second determination subunit is used to determine that there is a high-voltage ripple risk in the high-voltage system equivalent circuit model when it is determined that the interference source ripple is greater than the preset protection threshold, and trigger the first determination unit to determine the ripple forbidden zone of the high-voltage ripple according to the high-voltage system equivalent circuit model.

8. The high voltage ripple evaluation device for electric vehicles according to claim 6, characterized in that: The first determination unit is specifically used to determine the interference source frequency characteristics and the current-frequency response characteristics of the circuit according to the high-voltage system equivalent circuit model; and to determine the ripple forbidden zone according to the interference source frequency characteristics and the current-frequency response characteristics of the circuit; wherein the ripple forbidden zone at least includes a ripple forbidden zone frequency interval and a ripple forbidden zone current amplitude interval, and the ripple forbidden zone frequency interval at least includes the interference source frequency.

9. An electronic device, characterized in that: The electronic device comprises a memory and a processor, the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to perform the high-voltage ripple evaluation method for an electric vehicle according to any one of claims 1 to 5.

10. A readable storage medium, characterized in that: The readable storage medium stores computer program instructions, and when the computer program instructions are read and executed by a processor, the high-voltage ripple evaluation method for an electric vehicle according to any one of claims 1 to 5 is executed.

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