Voltage-based motor torque limiting method, system and device and storage medium

Abstract

The invention discloses a voltage-based motor torque limiting method, system and device and a storage medium. The method comprises the steps that the current motor voltage, the current motor rotating speed and the current motor torque of a vehicle are acquired; determining a motor efficiency correction coefficient according to the current motor voltage, determining motor rated efficiency according to the current motor rotating speed and the current motor torque, and determining motor correction efficiency according to the motor efficiency correction coefficient and the motor rated efficiency; obtaining preset motor efficiency upper and lower limits, and determining target motor efficiency according to the motor efficiency upper and lower limits and the motor correction efficiency; determining available power of the motor, determining available torque of the motor according to the available power of the motor and the current rotating speed of the motor, determining limited torque of the motor according to the available torque of the motor and the target motor efficiency, and limiting torque of the motor of the vehicle according to the limited torque of the motor. Real-time and dynamic torque limitation can be carried out on the motor under different voltages, the performance of the battery is improved, the service life of the battery is prolonged, and the method can be applied to the technical field of vehicle control.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a voltage-based motor torque limiting method, system, device and storage medium. Background Art

[0002] The allowable discharge power and discharge current of electric vehicles are small when the battery power and temperature are low. Under rapid acceleration conditions, the actual power and current of the battery may exceed the allowable values, thereby affecting the performance and life of the battery. Therefore, it is necessary to limit the actual power and current used.

[0003] Existing power limiting methods typically use the battery's current allowable discharge power minus the power used by each appliance. The remaining power is used as the motor power limit, assuming that as long as the motor output power does not exceed this value, the vehicle's total power consumption will not exceed the battery's allowable value. When limiting motor power, the torque limit is derived based on the conversion relationship between motor power, speed, and torque, ultimately limiting motor power through torque limiting.

[0004] However, the motor has different efficiencies when operating at different voltages, speeds, and torques. Usually, when the voltage is low, the efficiency of the motor will deteriorate. For example, when the voltage drops from 350V to 320V, the motor efficiency will drop from 95% to 90%. Similarly, if the motor output power is limited to 100kW, the power used by the motor will increase from 105kW to 111kW, which can easily cause the total power used by the vehicle to exceed the battery's allowable value, thereby affecting the performance and service life of the power battery. Summary of the Invention

[0005] The purpose of the present invention is to solve one of the technical problems existing in the prior art to at least a certain extent.

[0006] To this end, one purpose of an embodiment of the present invention is to provide a voltage-based motor torque limitation method, which can perform real-time and dynamic torque limitation on the motor at different voltages, so that the total power used by the entire vehicle is within the allowable range of the battery, avoiding the actual power and actual current of the battery from exceeding the allowable values, thereby improving the performance and service life of the power battery.

[0007] Another object of an embodiment of the present invention is to provide a voltage-based motor torque limiting system.

[0008] In order to achieve the above technical objectives, the technical solutions adopted by the embodiments of the present invention include:

[0009] In a first aspect, an embodiment of the present invention provides a method for limiting motor torque based on voltage, comprising the following steps:

[0010] Get the vehicle's current motor voltage, current motor speed, and current motor torque;

[0011] determining a motor efficiency correction coefficient according to the current motor voltage, determining a motor rated efficiency according to the current motor speed and the current motor torque, and determining a motor corrected efficiency according to the motor efficiency correction coefficient and the motor rated efficiency;

[0012] Obtaining preset upper and lower limits of motor efficiency, and determining a target motor efficiency based on the upper and lower limits of motor efficiency and the motor correction efficiency;

[0013] Determine the available power of the motor, determine the available torque of the motor based on the available power of the motor and the current motor speed, determine the motor limit torque based on the available torque of the motor and the target motor efficiency, and then limit the torque of the motor of the vehicle based on the motor limit torque.

[0014] Furthermore, in one embodiment of the present invention, the step of determining the motor efficiency correction coefficient according to the current motor voltage specifically includes:

[0015] Get the preset motor rated voltage, low voltage threshold, and high voltage threshold;

[0016] When the current motor voltage is less than or equal to the low voltage threshold, the motor efficiency correction coefficient is calculated according to a preset first correction formula;

[0017] When the current motor voltage is greater than the low voltage threshold and less than the motor rated voltage, the motor efficiency correction coefficient is calculated according to a preset second correction formula;

[0018] When the current motor voltage is equal to the motor rated voltage, determining the motor efficiency correction coefficient to be 1;

[0019] When the current motor voltage is greater than the motor rated voltage and less than the high voltage threshold, the motor efficiency correction coefficient is calculated according to a preset third correction formula;

[0020] When the current motor voltage is greater than or equal to the high voltage threshold, the motor efficiency correction coefficient is calculated according to a preset fourth correction formula.

[0021] Furthermore, in one embodiment of the present invention, the first correction formula is:

[0022]

[0023] The second correction formula is:

[0024]

[0025] The third correction formula is:

[0026]

[0027] The fourth correction formula is:

[0028]

[0029] Among them, k represents the motor efficiency correction coefficient, U L Indicates the low voltage threshold, U H Indicates the high voltage threshold, U N Indicates the rated voltage of the motor, and U indicates the current motor voltage.

[0030] Furthermore, in one embodiment of the present invention, determining the motor rated efficiency according to the current motor speed and the current motor torque, and determining the motor corrected efficiency according to the motor efficiency correction coefficient and the motor rated efficiency, specifically includes:

[0031] Querying a pre-built motor efficiency matching library according to the current motor speed and the current motor torque to obtain the motor rated efficiency;

[0032] The product of the motor efficiency correction coefficient and the motor rated efficiency is used as the motor corrected efficiency.

[0033] Furthermore, in one embodiment of the present invention, determining the target motor efficiency according to the upper and lower limits of the motor efficiency and the motor corrected efficiency specifically includes:

[0034] Determine the motor efficiency lower limit value and the motor efficiency upper limit value according to the motor efficiency upper and lower limits;

[0035] When the motor corrected efficiency is less than or equal to the motor efficiency lower limit, determining the motor efficiency lower limit to be the target motor efficiency;

[0036] When the motor corrected efficiency is greater than the motor efficiency lower limit value and less than the motor efficiency upper limit value, determining the motor corrected efficiency as the target motor efficiency;

[0037] When the motor corrected efficiency is greater than or equal to the motor efficiency upper limit value, the motor efficiency upper limit value is determined to be the target motor efficiency.

[0038] Furthermore, the determining of the available power of the motor specifically includes:

[0039] Obtaining the current battery allowable power, total power of electrical appliances, and a preset redundancy value of the vehicle;

[0040] The current battery allowed power is subtracted from the total power of the electrical appliances and the redundancy value to obtain the available power of the motor.

[0041] Furthermore, in one embodiment of the present invention, determining the motor available torque according to the motor available power and the current motor speed, and determining the motor limited torque according to the motor available torque and the target motor efficiency specifically include:

[0042] The motor available torque is calculated based on the motor available power, the current motor speed, and a preset motor power-speed-torque conversion formula;

[0043] The motor limit torque is determined according to a product of the motor available torque and the target motor efficiency.

[0044] In a second aspect, an embodiment of the present invention provides a voltage-based motor torque limiting system, comprising:

[0045] An information acquisition module is used to obtain the current motor voltage, current motor speed, and current motor torque of the vehicle;

[0046] a motor correction efficiency determination module, configured to determine a motor efficiency correction coefficient according to the current motor voltage, determine a motor rated efficiency according to the current motor speed and the current motor torque, and determine a motor correction efficiency according to the motor efficiency correction coefficient and the motor rated efficiency;

[0047] a target motor efficiency determination module, configured to obtain preset upper and lower limits of motor efficiency, and determine a target motor efficiency based on the upper and lower limits of motor efficiency and the motor correction efficiency;

[0048] The torque limiting module is used to determine the available power of the motor, determine the available torque of the motor according to the available power of the motor and the current motor speed, determine the motor limit torque according to the available torque of the motor and the target motor efficiency, and then limit the torque of the motor of the vehicle according to the motor limit torque.

[0049] In a third aspect, an embodiment of the present invention provides a voltage-based motor torque limiting device, comprising:

[0050] at least one processor;

[0051] at least one memory for storing at least one program;

[0052] When the at least one program is executed by the at least one processor, the at least one processor is enabled to implement the above-mentioned voltage-based motor torque limiting method.

[0053] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium storing a program executable by a processor, wherein the program executable by the processor is used to execute the above-mentioned voltage-based motor torque limitation method when executed by the processor.

[0054] The advantages and benefits of the present invention will be described in part in the following description and will become apparent from the following description or learned through practice of the present invention:

[0055] The embodiment of the present invention obtains the current motor voltage, current motor speed, and current motor torque of the vehicle, determines a motor efficiency correction coefficient based on the current motor voltage, determines the motor rated efficiency based on the current motor speed and current motor torque, and determines the motor corrected efficiency based on the motor efficiency correction coefficient and the motor rated efficiency, obtains preset motor efficiency upper and lower limits, determines a target motor efficiency based on the motor efficiency upper and lower limits and the motor corrected efficiency, determines the motor available power, determines the motor available torque based on the motor available power and the current motor speed, determines the motor limit torque based on the motor available torque and the target motor efficiency, and then limits the torque of the vehicle's motor based on the motor limit torque. When limiting the motor torque, the embodiment of the present invention determines the motor efficiency correction coefficient based on the current motor voltage to correct the motor rated efficiency, determines the target motor efficiency based on the motor efficiency upper and lower limits, multiplies the motor available torque calculated based on the motor available power by the target motor efficiency to obtain the motor limit torque, and can perform real-time and dynamic torque limiting on the motor at different voltages, so that the total power used by the entire vehicle is within the battery's allowable range, prevents the actual power and actual current of the battery from exceeding the allowable values, and thus improves the performance and service life of the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following introduction is made to the drawings required for use in the embodiments of the present invention. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative work.

[0057] Figure 1 A flowchart of a method for limiting motor torque based on voltage according to an embodiment of the present invention;

[0058] Figure 2 A structural block diagram of a voltage-based motor torque limiting system provided by an embodiment of the present invention;

[0059] Figure 3 This is a structural block diagram of a voltage-based motor torque limiting device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0060] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. The step numbers in the following embodiments are provided for ease of explanation only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0061] In the description of the present invention, "a plurality" means two or more. The terms "first" and "second" are used solely to distinguish technical features and are not to be construed as indicating or implying relative importance, or as implicitly indicating the number of the indicated technical features, or as implicitly indicating the order of the indicated technical features. Furthermore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art.

[0062] Reference Figure 1 The embodiment of the present invention provides a method for limiting motor torque based on voltage, which specifically includes the following steps:

[0063] S101, obtaining the current motor voltage, current motor speed, and current motor torque of the vehicle;

[0064] S102, determining a motor efficiency correction coefficient according to the current motor voltage, determining a motor rated efficiency according to the current motor speed and the current motor torque, and determining a motor corrected efficiency according to the motor efficiency correction coefficient and the motor rated efficiency;

[0065] S103, obtaining preset upper and lower limits of motor efficiency, and determining a target motor efficiency based on the upper and lower limits of motor efficiency and the motor correction efficiency;

[0066] S104 , determining the available power of the motor, determining the available torque of the motor according to the available power of the motor and the current motor speed, determining the motor limit torque according to the available torque of the motor and the target motor efficiency, and then limiting the torque of the motor of the vehicle according to the motor limit torque.

[0067] When limiting the motor torque, the embodiment of the present invention determines the motor efficiency correction coefficient according to the current motor voltage to correct the motor rated efficiency, determines the target motor efficiency in combination with the upper and lower limits of the motor efficiency, and multiplies the motor available torque calculated according to the motor available power by the target motor efficiency to obtain the motor limited torque. The motor can be subjected to real-time and dynamic torque limitation at different voltages, so that the total power used by the entire vehicle is within the allowable range of the battery, and the actual power and actual current of the battery are prevented from exceeding the allowable values, thereby improving the performance and service life of the power battery.

[0068] It should be noted that the embodiment of the present invention only shows a torque limiting process for one cycle. After the motor is torque limited, the current motor torque will change, and the current motor voltage will also change as the battery power is consumed. Therefore, the process of correcting the motor efficiency and calculating the motor limiting torque can be cyclically executed at preset time intervals, thereby realizing real-time and dynamic torque limiting.

[0069] As an optional implementation, the step of determining the motor efficiency correction coefficient according to the current motor voltage specifically includes:

[0070] S1021. Obtaining a preset motor rated voltage, a low voltage threshold, and a high voltage threshold;

[0071] S1022: When the current motor voltage is less than or equal to the low voltage threshold, calculate the motor efficiency correction coefficient according to a preset first correction formula;

[0072] S1023: When the current motor voltage is greater than the low voltage threshold and less than the motor rated voltage, calculate the motor efficiency correction coefficient according to a preset second correction formula;

[0073] S1024, when the current motor voltage is equal to the motor rated voltage, determining the motor efficiency correction coefficient to be 1;

[0074] S1025: When the current motor voltage is greater than the motor rated voltage and less than the high voltage threshold, calculate the motor efficiency correction coefficient according to a preset third correction formula;

[0075] S1026: When the current motor voltage is greater than or equal to the high voltage threshold, a motor efficiency correction coefficient is calculated according to a preset fourth correction formula.

[0076] As an optional implementation, the first correction formula is:

[0077]

[0078] The second revised formula is:

[0079]

[0080] The third revised formula is:

[0081]

[0082] The fourth revised formula is:

[0083]

[0084] Among them, k represents the motor efficiency correction coefficient, U L Indicates the low voltage threshold, U H Indicates the high voltage threshold, U N Indicates the rated voltage of the motor, and U indicates the current motor voltage.

[0085] Specifically, according to the motor rated voltage U N , low voltage threshold U L , high voltage threshold U H The current motor voltage U is divided into the following intervals to calculate the efficiency correction factor k:

[0086] 1) When U≤U L When the efficiency correction factor

[0087] 2) When U L <U<U N When the efficiency correction factor

[0088] 3) When U=U N When, the efficiency correction coefficient k=1;

[0089] 4) When U N <U<U H When the efficiency correction factor

[0090] 5) When U≥U H When the efficiency correction factor

[0091] It should be noted that different types of motors have different rated motor voltages U N , low voltage threshold U L And the high voltage threshold U H , the specific needs are determined according to the design specifications provided by the motor manufacturer.

[0092] As a further optional implementation, the motor rated efficiency is determined according to the current motor speed and the current motor torque, and the motor corrected efficiency is determined according to the motor efficiency correction coefficient and the motor rated efficiency, which specifically includes:

[0093] S1027, querying a pre-built motor efficiency matching library based on the current motor speed and the current motor torque to obtain the motor rated efficiency;

[0094] S1028. The product of the motor efficiency correction coefficient and the motor rated efficiency is used as the motor correction efficiency.

[0095] Specifically, the rated efficiency of the motor at different motor speeds and different motor torques is pre-calibrated through experiments to obtain a motor efficiency matching library, as shown in Table 1 below.

[0096] Table 1

[0097]

[0098] Get the current motor speed n based on the motor efficiency matching library query x and the current motor torque T y Corresponding motor rated efficiency η xy Then, according to the motor rated efficiency η xy The product of the motor efficiency correction coefficient k determines the motor correction efficiency, that is, the motor correction efficiency η1 = η xy *k.

[0099] As an optional implementation, the target motor efficiency is determined based on the upper and lower limits of the motor efficiency and the motor correction efficiency, which specifically includes:

[0100] S1031, determining a motor efficiency lower limit value and a motor efficiency upper limit value according to the motor efficiency upper and lower limits;

[0101] S1032: When the motor corrected efficiency is less than or equal to the motor efficiency lower limit, determining the motor efficiency lower limit to be the target motor efficiency;

[0102] S1033: When the motor corrected efficiency is greater than the motor efficiency lower limit and less than the motor efficiency upper limit, determine the motor corrected efficiency as the target motor efficiency;

[0103] S1034: When the motor corrected efficiency is greater than or equal to the motor efficiency upper limit, determine the motor efficiency upper limit as the target motor efficiency.

[0104] Specifically, the motor efficiency lower limit value η is determined according to the upper and lower limits of the motor efficiency L and the upper limit of motor efficiency η H To ensure the accuracy of the corrected motor efficiency, the corrected motor efficiency should be limited to the lower limit of the motor efficiency η L and the upper limit of motor efficiency η H In between, there are:

[0105] 1) When η1≤η L When the upper and lower limits are corrected, the target motor efficiency η2=ηL ;

[0106] 2) When η L <η1<η H When the upper and lower limits are corrected, the target motor efficiency η2 = η1;

[0107] 3) When η1≥η H When the upper and lower limits are corrected, the target motor efficiency η2=η H .

[0108] It should be noted that different types of motors have different lower limits of motor efficiency η L and the upper limit of motor efficiency η H , the specific needs need to be determined based on the motor bench test report provided by the motor manufacturer.

[0109] As an optional implementation, determining the available power of the motor may include:

[0110] S1041. Obtain the current battery allowable power of the vehicle, the total power of electrical appliances, and a preset redundancy value;

[0111] S1042: Subtract the total power of electrical appliances and the redundancy value from the current battery allowed power to obtain the available power of the motor.

[0112] Specifically, the current battery allowable power is determined based on the SOC of the power battery, and the total power used by the current control, safety and entertainment electrical equipment is determined at the same time, and a preset redundancy value is obtained to prevent the power from exceeding the battery's allowable range; the current battery allowable power is subtracted from the total power of the electrical appliances and the redundancy value to obtain the available power of the motor.

[0113] As a further optional implementation, the available motor torque is determined based on the available motor power and the current motor speed, and the motor limit torque is determined based on the available motor torque and the target motor efficiency, which specifically includes:

[0114] S1043, calculating the motor available torque based on the motor available power, the current motor speed, and a preset motor power-speed-torque conversion formula;

[0115] S1044: Determine the motor limit torque according to the product of the motor available torque and the target motor efficiency.

[0116] Specifically, the motor power-speed-torque conversion formula of the current motor is obtained, for example, T=P*9550 / n. According to this formula, the available torque T of the motor (unit: Nm) can be calculated, where P represents the available power of the motor, in kW, and n represents the current motor speed, in rpm; the motor limit torque T' can be determined according to the product of the available motor torque T and the target motor efficiency η2, that is, T'=T*η2.

[0117] It should be noted that different types of motors have different motor power-speed-torque conversion formulas, which are not limited in the embodiments of the present invention.

[0118] The above describes the method steps of an embodiment of the present invention. It can be appreciated that when limiting the motor torque, the embodiment of the present invention determines the motor efficiency correction coefficient based on the current motor voltage to correct the motor rated efficiency, determines the target motor efficiency in combination with the upper and lower limits of the motor efficiency, and multiplies the motor available torque calculated based on the motor available power by the target motor efficiency to obtain the motor limited torque. This allows for real-time and dynamic torque limitation of the motor at different voltages, ensuring that the total power used by the vehicle is within the battery's allowable range, preventing the actual power and actual current of the battery from exceeding the allowable values, thereby improving the performance and service life of the power battery.

[0119] Reference Figure 2 , an embodiment of the present invention provides a voltage-based motor torque limiting system, comprising:

[0120] An information acquisition module is used to obtain the current motor voltage, current motor speed, and current motor torque of the vehicle;

[0121] a motor correction efficiency determination module, configured to determine a motor efficiency correction coefficient based on a current motor voltage, determine a motor rated efficiency based on a current motor speed and a current motor torque, and determine a motor correction efficiency based on the motor efficiency correction coefficient and the motor rated efficiency;

[0122] A target motor efficiency determination module is used to obtain preset upper and lower limits of motor efficiency and determine the target motor efficiency based on the upper and lower limits of motor efficiency and the motor correction efficiency;

[0123] The torque limit module is used to determine the available power of the motor, determine the available torque of the motor based on the available power of the motor and the current motor speed, determine the motor limit torque based on the available torque of the motor and the target motor efficiency, and then limit the torque of the vehicle's motor based on the motor limit torque.

[0124] The contents of the above method embodiments are all applicable to the present system embodiments. The functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0125] Reference Figure 3 , an embodiment of the present invention provides a voltage-based motor torque limiting device, comprising:

[0126] at least one processor;

[0127] at least one memory for storing at least one program;

[0128] When the at least one program is executed by the at least one processor, the at least one processor implements the voltage-based motor torque limiting method.

[0129] The contents of the above method embodiments are all applicable to the present device embodiments. The functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0130] An embodiment of the present invention further provides a computer-readable storage medium storing a program executable by a processor. When the program is executed by the processor, it is used to execute the above-mentioned voltage-based motor torque limiting method.

[0131] A computer-readable storage medium according to an embodiment of the present invention can execute a voltage-based motor torque limiting method provided by an embodiment of the present invention, can execute any combination of implementation steps of the embodiment of the method, and has the corresponding functions and beneficial effects of the method.

[0132] The embodiment of the present invention also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device performs Figure 1 The method shown.

[0133] In some optional embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the above-mentioned boxes can sometimes be executed in reverse order. In addition, the embodiment presented and described in the flow chart of the present invention is provided in an exemplary manner for the purpose of providing a more comprehensive understanding of the technology. The disclosed method is not limited to the operation and logic flow presented herein. Optional embodiments are contemplated in which the order of the various operations is changed and the sub-operations described as a part of a larger operation are performed independently.

[0134] In addition, although the present invention is described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the above-mentioned functions and / or features can be integrated into a single physical device and / or software module, or one or more functions and / or features can be implemented in separate physical devices or software modules. It is also understood that a detailed discussion of the actual implementation of each module is not necessary for understanding the present invention. More specifically, given the properties, functions, and internal relationships of the various functional modules in the devices disclosed herein, the actual implementation of the module will be understood within the routine skills of an engineer. Therefore, a person skilled in the art can implement the present invention set forth in the claims using ordinary skills without undue experimentation. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present invention, which is determined by the full scope of the appended claims and their equivalents.

[0135] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the above methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0136] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0137] More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable media on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0138] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0139] In the above description of this specification, reference to the terms "one embodiment / example," "another embodiment / example," or "certain embodiments / examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0140] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

[0141] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A method for limiting motor torque based on voltage, characterized in that: The following steps are involved: Get the vehicle's current motor voltage, current motor speed, and current motor torque; determining a motor efficiency correction coefficient according to the current motor voltage, determining a motor rated efficiency according to the current motor speed and the current motor torque, and determining a motor corrected efficiency according to the motor efficiency correction coefficient and the motor rated efficiency; Obtaining preset upper and lower limits of motor efficiency, and determining a target motor efficiency based on the upper and lower limits of motor efficiency and the motor correction efficiency; Determine the available power of the motor, determine the available torque of the motor based on the available power of the motor and the current motor speed, determine the motor limit torque based on the available torque of the motor and the target motor efficiency, and then limit the torque of the motor of the vehicle based on the motor limit torque.

2. The method for limiting motor torque based on voltage according to claim 1, characterized in that: The step of determining the motor efficiency correction coefficient according to the current motor voltage specifically includes: Get the preset motor rated voltage, low voltage threshold, and high voltage threshold; When the current motor voltage is less than or equal to the low voltage threshold, the motor efficiency correction coefficient is calculated according to a preset first correction formula; When the current motor voltage is greater than the low voltage threshold and less than the motor rated voltage, the motor efficiency correction coefficient is calculated according to a preset second correction formula; When the current motor voltage is equal to the motor rated voltage, determining the motor efficiency correction coefficient to be 1; When the current motor voltage is greater than the motor rated voltage and less than the high voltage threshold, the motor efficiency correction coefficient is calculated according to a preset third correction formula; When the current motor voltage is greater than or equal to the high voltage threshold, the motor efficiency correction coefficient is calculated according to a preset fourth correction formula.

3. The method for limiting motor torque based on voltage according to claim 2, characterized in that: The first correction formula is: The second correction formula is: The third correction formula is: The fourth correction formula is: Among them, k represents the motor efficiency correction coefficient, U L Indicates the low voltage threshold, U H Indicates the high voltage threshold, U N Indicates the rated voltage of the motor, and U indicates the current motor voltage.

4. The method for limiting motor torque based on voltage according to claim 1, characterized in that: The determining of the motor rated efficiency according to the current motor speed and the current motor torque, and determining the motor corrected efficiency according to the motor efficiency correction coefficient and the motor rated efficiency, specifically includes: Querying a pre-built motor efficiency matching library according to the current motor speed and the current motor torque to obtain the motor rated efficiency; The product of the motor efficiency correction coefficient and the motor rated efficiency is used as the motor corrected efficiency.

5. The method for limiting motor torque based on voltage according to claim 1, characterized in that: The step of determining the target motor efficiency according to the upper and lower limits of the motor efficiency and the motor correction efficiency specifically includes: Determine the motor efficiency lower limit value and the motor efficiency upper limit value according to the motor efficiency upper and lower limits; When the motor corrected efficiency is less than or equal to the motor efficiency lower limit, determining the motor efficiency lower limit to be the target motor efficiency; When the motor corrected efficiency is greater than the motor efficiency lower limit value and less than the motor efficiency upper limit value, determining the motor corrected efficiency as the target motor efficiency; When the motor corrected efficiency is greater than or equal to the motor efficiency upper limit value, the motor efficiency upper limit value is determined to be the target motor efficiency.

6. The method for limiting motor torque based on voltage according to claim 1, characterized in that: The determining of the available power of the motor specifically includes: Obtaining the current battery allowable power, total power of electrical appliances, and a preset redundancy value of the vehicle; The current battery allowed power is subtracted from the total power of the electrical appliances and the redundancy value to obtain the available power of the motor.

7. A voltage-based motor torque limiting method according to any one of claims 1 to 6, characterized in that: The determining of the motor available torque according to the motor available power and the current motor speed, and determining the motor limited torque according to the motor available torque and the target motor efficiency specifically includes: The motor available torque is calculated based on the motor available power, the current motor speed, and a preset motor power-speed-torque conversion formula; The motor limit torque is determined according to a product of the motor available torque and the target motor efficiency.

8. A voltage-based motor torque limiting system, characterized in that: include: An information acquisition module is used to obtain the current motor voltage, current motor speed, and current motor torque of the vehicle; a motor correction efficiency determination module, configured to determine a motor efficiency correction coefficient according to the current motor voltage, determine a motor rated efficiency according to the current motor speed and the current motor torque, and determine a motor correction efficiency according to the motor efficiency correction coefficient and the motor rated efficiency; a target motor efficiency determination module, configured to obtain preset upper and lower limits of motor efficiency, and determine a target motor efficiency based on the upper and lower limits of motor efficiency and the motor correction efficiency; The torque limiting module is used to determine the available power of the motor, determine the available torque of the motor according to the available power of the motor and the current motor speed, determine the motor limit torque according to the available torque of the motor and the target motor efficiency, and then limit the torque of the motor of the vehicle according to the motor limit torque.

9. A voltage-based motor torque limiting device, characterized in that: include: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the voltage-based motor torque limiting method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a program executable by a processor, characterized in that: The processor-executable program is used to execute the voltage-based motor torque limiting method according to any one of claims 1 to 7 when executed by the processor.

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