Inverter power overload adjustment method and device, and vehicle

Abstract

The application relates to the technical field of vehicle inverters, and discloses an inverter power overload adjustment method and device and a vehicle, wherein the method comprises the following steps: determining a power overload threshold corresponding to a current working condition; acquiring a driving parameter of the vehicle under the current working condition, and determining input power of the inverter under the condition that the driving parameter meets a preset condition; if the input power is continuously greater than the power overload threshold within a first preset time, generating a target torque instruction according to a first difference value between the input power and the power overload threshold, so that the inverter adjusts output power in response to the target torque instruction. The application can enable the inverter to judge the overload condition by itself and adaptively adjust the output power of the motor, so that the vehicle battery is prevented from overcurrent or overdischarge, and the battery service life is improved.

Description

Technical Field

[0001] This application relates to the field of automotive inverter technology, and in particular to an inverter power overload adjustment method, device and vehicle. Background Technology

[0002] In the electric vehicle's motor drive system, the inverter acts as the control hub between the battery and the motor, converting the battery's direct current (DC) into alternating current (AC) to drive the motor and output torque. During actual vehicle operation, the inverter is prone to overload, leading to excessively high actual output power to the motor. This ultimately results in over-discharge of the battery, significantly impacting its safety and lifespan.

[0003] Related technologies typically rely on the vehicle control unit (VCU) to identify the over-discharge state of the battery management system (BMS) and then adjust the inverter's output power to the motor. However, this method is easily limited by communication conditions and it is difficult to quickly adjust the power in response to overload conditions. Summary of the Invention

[0004] This application provides an inverter power overload adjustment method, device, and vehicle, which solves the technical problem that it is difficult to quickly adjust the power of the inverter in response to overload conditions. It enables the inverter to automatically judge the overload condition and adaptively adjust the output power to the motor, thereby ensuring that the vehicle battery will not experience overcurrent or over-discharge, which is beneficial to improving battery life.

[0005] To achieve the above objectives, the main technical solutions adopted in this application include:

[0006] In a first aspect, embodiments of this application provide a method for adjusting inverter power overload, the method comprising:

[0007] Determine the power overload threshold corresponding to the current operating condition;

[0008] The vehicle's driving parameters under the current operating conditions are obtained, and the input power of the inverter is determined when the driving parameters meet preset conditions.

[0009] If the input power is continuously greater than the power overload threshold for a first preset time, a target torque command is generated based on the first difference between the input power and the power overload threshold, so that the inverter adjusts the output power in response to the target torque command.

[0010] The inverter power overload adjustment method proposed in this application determines an appropriate power overload threshold based on the current operating conditions. This better adapts to actual operating conditions and triggers a power overload protection mechanism when the input power continuously exceeds the power overload threshold, improving robustness and enabling timely and accurate identification of inverter overload conditions. Furthermore, by utilizing the first difference between the input power and the power overload threshold, the inverter can autonomously detect overload conditions and adaptively adjust accordingly in a timely and effective manner. Compared with related technologies, it does not rely on VCU and BMS to obtain relevant information, thus overcoming the limitations of vehicle communication speed and avoiding the risk of communication interference. This significantly improves the response speed to power overload conditions, allowing the inverter to quickly reduce the output power to the motor, effectively preventing battery overcurrent or over-discharge, and improving battery stability and reliability.

[0011] Optionally, in some embodiments of this application, determining the power overload threshold corresponding to the current operating condition includes:

[0012] Obtain the maximum allowable discharge power of the vehicle's battery under the current operating conditions;

[0013] If the maximum allowable discharge power is greater than the preset power threshold, the power overload threshold is determined by the product of the maximum allowable discharge power and the preset overload coefficient.

[0014] If the maximum allowable discharge power is less than or equal to the preset power threshold, the power overload threshold is determined based on the sum of the maximum allowable discharge power and the preset overload value.

[0015] Based on the maximum allowable discharge power of the VCU relative to a preset power threshold, the embodiments of this application can flexibly and accurately determine the power overload threshold, enabling more accurate identification of inverter overload conditions under different operating conditions. This ensures timely activation of the power overload protection mechanism to adaptively adjust the inverter's output power, effectively improving the accuracy of inverter power overload detection.

[0016] Optionally, in some embodiments of this application, the driving parameters include the vehicle's current motor torque and current motor speed;

[0017] Determining the input power of the inverter when the driving parameters meet preset conditions includes:

[0018] When the current motor torque is greater than a preset torque threshold and the current motor speed is greater than a preset speed threshold, the bus voltage and bus current of the inverter are obtained;

[0019] The input power is determined based on the product of the bus voltage and the bus current.

[0020] This application embodiment uses the current motor torque and current motor speed as the judgment criteria. When the current motor torque is greater than a preset torque threshold and the current motor speed is greater than a preset speed threshold, it is considered to be in a normal driving state. The inverter input power is calculated in the normal driving state to avoid invalid or inaccurate power calculations under abnormal vehicle driving conditions, thereby improving the accuracy of input power.

[0021] Optionally, in some embodiments of this application, generating the target torque command based on the first difference between the input power and the power overload threshold includes:

[0022] Determine the calibrated torque reduction value and the dynamically adjusted torque reduction value corresponding to the first difference, respectively;

[0023] The initial torque reduction value is determined based on the calibrated torque reduction value and the dynamically adjusted torque reduction value;

[0024] Obtain the calibration slope corresponding to the first difference, and determine the target torque reduction value based on the calibration slope and the initial torque reduction value, so as to generate the target torque command based on the target torque reduction value.

[0025] This application embodiment determines a calibrated torque reduction value and a dynamically adjusted torque reduction value, and then utilizes the synergistic effect of the calibrated torque reduction value and the dynamically adjusted torque reduction value. The calibrated torque reduction value can react quickly when the power is overloaded, while the dynamically adjusted torque reduction value can serve as a compensation value for torque fine-tuning and can achieve stable power regulation control under long-term overload scenarios. In addition, this application embodiment also uses a calibration slope to limit the change in torque reduction value, avoiding excessively large target torque reduction values ​​that could cause sudden torque changes. This ensures both effective reduction of output power and smooth changes in vehicle power, so that the driver does not feel a loss of power after triggering torque reduction, thus improving driving comfort.

[0026] Optionally, in some embodiments of this application, the calibration torque reduction value is determined in the following manner:

[0027] The vehicle was tested under rapid acceleration conditions to determine the mapping relationship between the calibrated torque reduction value and the calibrated power difference based on the test results.

[0028] Based on the mapping relationship and the matching between the first difference and the calibration power difference, the calibration torque reduction value corresponding to the first difference is determined.

[0029] This application embodiment utilizes the characteristic that inverters are more prone to power overload under rapid vehicle acceleration conditions. By using the test results of vehicles under rapid acceleration conditions, the mapping relationship between the calibrated torque reduction value and the calibrated power difference is obtained, thereby quickly determining the calibrated torque reduction value that meets the actual power overload adjustment requirements.

[0030] Optionally, in some embodiments of this application, the dynamically adjusted torque reduction value is determined in the following manner:

[0031] The first difference is input into a preset PI controller to determine the dynamic torque reduction value based on the output of the PI controller.

[0032] This application embodiment utilizes the proportional and integral adjustment functions of a PI controller to dynamically output a dynamically adjusted torque reduction value that matches the first difference, thereby improving the accuracy of the initial torque reduction value through the synergistic effect of the dynamically adjusted torque reduction value and the calibrated torque reduction value.

[0033] Optionally, in some embodiments of this application, generating the target torque command based on the target torque reduction value includes:

[0034] Obtain the current motor torque of the vehicle, and determine a second difference between the current motor torque and the target torque reduction value;

[0035] If the current motor torque is greater than or equal to zero, and the second difference is less than zero, then a target torque command is generated to make the current motor torque zero; otherwise, a target torque command is generated to reduce the current motor torque to the second difference.

[0036] When the current motor torque is less than zero, a target torque command is generated to keep the current motor torque unchanged.

[0037] This application embodiment generates an accurate target torque command based on the current motor torque (positive or negative) and the difference between it and the target torque reduction value. On the one hand, when the current motor torque is greater than or equal to zero and the second difference is less than zero, it avoids abnormal power caused by excessive torque reduction to a negative value. On the other hand, when the current motor torque is less than zero, it can effectively avoid excessive interference from overload protection under undesirable power overload protection conditions. This effectively realizes torque adjustment and output power adjustment when the inverter power is overloaded, and also ensures the rationality of vehicle power output.

[0038] Optionally, in some embodiments of this application, during the process of the inverter adjusting the input power in response to the target torque command, the method further includes:

[0039] If the input power is adjusted to be less than the power overload threshold and this continues for a second preset time, the adjustment of the input power is stopped.

[0040] The embodiments of this application exit the power overload protection mechanism when the input power is continuously less than the power overload threshold, thereby avoiding frequent start-up and shutdown of the power overload protection mechanism due to short-term power fluctuations and improving robustness.

[0041] Secondly, embodiments of this application provide an inverter power overload adjustment device, the device comprising:

[0042] The threshold determination module is used to determine the power overload threshold corresponding to the current operating condition;

[0043] The power acquisition module is used to acquire the vehicle's driving parameters under the current operating conditions, and determine the input power of the inverter when the driving parameters meet preset conditions.

[0044] The power adjustment module is used to generate a target torque command based on a first difference between the input power and the power overload threshold if the input power is continuously greater than the power overload threshold for a first preset time, so that the inverter adjusts the output power in response to the target torque command.

[0045] The inverter power overload adjustment device proposed in this application determines a suitable power overload threshold based on the current operating conditions. This better adapts to actual operating conditions and triggers a power overload protection mechanism when the input power continuously exceeds the power overload threshold, improving robustness and enabling timely and accurate identification of inverter overload conditions. Furthermore, by utilizing the first difference between the input power and the power overload threshold, the inverter can autonomously detect overload conditions and adaptively adjust accordingly in a timely and effective manner. Compared with related technologies, it does not rely on VCU and BMS to obtain relevant information, thus overcoming the limitations of vehicle communication speed and avoiding the risk of communication interference. This significantly improves the response speed to power overload conditions, allowing the inverter to quickly reduce output power to effectively prevent battery overcurrent or over-discharge, thereby improving battery stability and reliability.

[0046] Thirdly, embodiments of this application provide a vehicle, including:

[0047] Inverter;

[0048] And an inverter power overload adjustment device as described in the above embodiments, the power overload adjustment device being used to adjust the output power of the inverter.

[0049] Fourthly, embodiments of this application provide a computer device, including:

[0050] The system includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes these computer instructions to perform the inverter power overload adjustment method described in the above embodiments. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0052] Figure 1 This is one of the flowcharts illustrating the inverter power overload adjustment method proposed in this application.

[0053] Figure 2 This is a second schematic flowchart of the inverter power overload adjustment method proposed in the embodiments of this application;

[0054] Figure 3 This is the third flowchart illustrating the inverter power overload adjustment method proposed in this application.

[0055] Figure 4 This is the fourth flowchart illustrating the inverter power overload adjustment method proposed in this application.

[0056] Figure 5 This is the fifth flowchart illustrating the inverter power overload adjustment method proposed in this application.

[0057] Figure 6 This is a structural block diagram of the inverter power overload adjustment device proposed in the embodiments of this application. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] The terms "first," "second," etc., used in this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0060] In the electric vehicle's motor drive system, the vehicle inverter acts as the control hub between the battery and the motor. Upon receiving a torque request from the VCU, the inverter converts the battery's DC power into AC power, thereby driving the motor to rotate and output torque. The inverter's ability to respond to the VCU's torque commands and output power according to the target value corresponding to the torque command is crucial to ensuring the normal operation of the entire vehicle's electric drive system.

[0061] During actual vehicle operation, the inverter may experience overload after responding to torque commands issued by the VCU due to factors such as position sensor installation problems, current sensor accuracy issues, and component performance variations. This means that the inverter's actual output power to the motor is too high, which in turn leads to excessive output power from the battery to the inverter, ultimately causing the battery to be over-discharged. This greatly affects the battery's safety status and lifespan, and consequently, the overall vehicle safety and reliability.

[0062] Related technologies typically rely on the VCU to identify the over-discharge state of the BMS, and then the VCU sends a command to the inverter to reduce the output power, thereby adjusting the inverter's output power. This approach involves multiple functional components, such as the BMS providing power overload information, the VCU for judging power overload and controlling the logic, and the inverter for final execution. Communication between these three mainly depends on the vehicle's CAN communication network. However, the transmission speed of the vehicle's CAN communication network is limited and subject to interference. Therefore, the adjustment of the inverter's output power is easily limited by communication conditions and it is difficult to quickly adjust the power in response to overload conditions.

[0063] To address the aforementioned technical problems, this specification provides an embodiment of an inverter power overload adjustment method. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0064] This embodiment provides a method for adjusting inverter power overload. Figure 1 This is a flowchart of an inverter power overload adjustment method according to an embodiment of this application, such as... Figure 1 As shown, the process includes the following steps:

[0065] Step S1: Determine the power overload threshold corresponding to the current operating condition.

[0066] Specifically, after an electric vehicle starts, the inverter outputs a wide range of power to the motor under different operating conditions during actual vehicle operation, and the corresponding power overload varies depending on the power level. Therefore, this application embodiment determines the corresponding power overload threshold for different operating conditions to adapt to the overload protection requirements at each power level.

[0067] Step S3: Obtain the vehicle's driving parameters under the current operating conditions, and determine the inverter's input power if the driving parameters meet preset conditions.

[0068] Specifically, this embodiment uses driving parameters to determine the current driving status of the vehicle. If the driving parameters meet preset conditions, it indicates that the vehicle is in a normal driving state, and the function of calculating the input power is activated at this time. If the driving parameters do not meet the preset conditions, it indicates that the vehicle is in an abnormal driving state, and the calculation of the inverter's input power may be inaccurate at this time. Therefore, this embodiment only calculates the inverter's input power when the vehicle is in a normal driving state.

[0069] Step S5: If the input power continues to be greater than the power overload threshold within a first preset time, a target torque command is generated based on the first difference between the input power and the power overload threshold, so that the inverter adjusts the input power in response to the target torque command.

[0070] Specifically, when the inverter detects that the input power is greater than the power overload threshold, it triggers the power overload counting function and counts the cases where the input power is greater than the power overload threshold based on a certain counting period T. When the accumulated count exceeds the first accumulated threshold k1, the inverter is determined to be overloaded and the power overload protection mechanism is triggered. It can be seen that the aforementioned first preset time is the product of the counting period T and the first accumulated threshold k1.

[0071] In the power overload protection mechanism, the first difference between the input power and the power overload threshold represents the extent to which the inverter needs to reduce its output power. This determines the corresponding target torque command, which represents the motor torque that the inverter needs to generate to drive the motor. The motor torque is positively correlated with the inverter's output power. Therefore, in response to this target torque command, the inverter adjusts its output power to the motor to decrease, thus achieving overload protection on its own.

[0072] The inverter power overload adjustment method provided in this embodiment determines an appropriate power overload threshold based on the current operating conditions. This better adapts to actual operating conditions and triggers a power overload protection mechanism when the input power continuously exceeds the power overload threshold, improving robustness and enabling timely and accurate identification of inverter overload conditions. Furthermore, by utilizing the first difference between the input power and the power overload threshold, the inverter can autonomously detect overload conditions and adaptively adjust accordingly in a timely and effective manner. Compared with related technologies, it does not rely on VCU and BMS to obtain relevant information, thus overcoming the limitations of vehicle communication speed and avoiding the risk of communication interference. This significantly improves the response speed to power overload conditions, allowing the inverter to quickly reduce output power to effectively prevent battery overcurrent or over-discharge, thereby improving battery stability and reliability.

[0073] Figure 2 A flowchart illustrating step S1 in an embodiment of this application is shown, as follows: Figure 2 As shown, step S1 may include the following steps:

[0074] Step S11: Obtain the maximum allowable discharge power of the vehicle's battery under the current operating conditions.

[0075] Specifically, the inverter acquires the maximum operating discharge power sent by the VCU in real time. The maximum operating discharge power is calculated by the VCU based on the current state parameters of the battery and the current operating conditions, and it represents the maximum power limit that the battery can safely output under the current operating conditions.

[0076] Step S12: Determine whether the maximum allowable discharge power is greater than the preset power threshold. If yes, proceed to step S13; otherwise, proceed to step S14.

[0077] Step S13: When the maximum allowable discharge power is greater than the preset power threshold, determine the power overload threshold based on the product of the maximum allowable discharge power and the preset overload coefficient.

[0078] Specifically, when the maximum allowable discharge power is greater than the preset power threshold, the maximum allowable discharge power is proportionally amplified or proportionally reduced using a preset overload coefficient, thereby obtaining a suitable power overload threshold.

[0079] Step S14: When the maximum allowable discharge power is less than or equal to the preset power threshold, determine the power overload threshold based on the sum of the maximum allowable discharge power and the preset overload value.

[0080] Specifically, when the maximum allowable discharge power is less than the preset power threshold, because the maximum allowable discharge power is relatively small, directly using the preset overload coefficient to proportionally adjust the small maximum allowable discharge power would result in an overly sensitive adjustment of the power overload threshold, making the adjustment of the power overload threshold insufficient. Therefore, when the maximum allowable discharge power is less than the preset power threshold, the adjustment dimension is increased by adding the preset overload value to the maximum allowable discharge power to determine a suitable power overload threshold.

[0081] and Figure 1 Compared to the embodiments shown, the embodiments of this application can flexibly and accurately determine the power overload threshold based on the magnitude of the maximum allowable discharge power of the VCU relative to the preset power threshold. This allows for more accurate identification of the inverter's overload condition under different operating conditions, thereby ensuring the timely activation of the power overload protection mechanism to adaptively adjust the inverter's output power and effectively improving the accuracy of inverter power overload detection.

[0082] In some embodiments of this application, the aforementioned driving parameters include the vehicle's current motor torque and current motor speed. Current motor torque refers to the torque generated by the motor actually driving the load during current operation, and current motor speed refers to the number of rotations of the rotor per unit time during current operation. Both together reflect the vehicle's driving state.

[0083] Figure 3 The following is a flowchart illustrating steps S3 and S5 in an embodiment of this application. Figure 3 As shown, step S3 may include the following steps:

[0084] Step S31: Determine whether the current motor torque is greater than the preset torque threshold and whether the current motor speed is greater than the preset speed threshold. If yes, proceed to step S32; otherwise, proceed to step S57.

[0085] Step S32: When the current motor torque is greater than a preset torque threshold and the current motor speed is greater than a preset speed threshold, obtain the inverter bus voltage U. DC and bus current I DC .

[0086] Specifically, if the current motor torque is greater than the preset torque threshold and the current motor speed is greater than the preset speed threshold, it indicates that the vehicle is currently in normal driving condition, and at this time the inverter's input power calculation function is triggered.

[0087] In order to calculate the input power of the inverter, this embodiment of the application uses a voltage sensor placed on the DC side of the inverter to measure the bus voltage U. DC Bus current I DC The bus current is determined through a preset bus current estimation algorithm. Preferably, the bus current on the DC side of the inverter is estimated using the three-phase current sampling values ​​of the motor. Referring to patent CN120357786A, entitled "Method, Apparatus, Device and Storage Medium for Estimating Bus Current of Synchronous Motor," the three-phase current sampling values ​​of the motor at the current control cycle and the target duration of each phase at the current control cycle are obtained. Based on the current control cycle, the three-phase current sampling values, and the target duration of each phase, the bus current I is calculated. DC The estimated value is obtained by calculating the target duration of each phase in the previous control cycle of the motor.

[0088] Step S33, based on the bus voltage U DC and bus current I DC The product of these factors determines the input power, that is, the input power of the inverter P = U. DC *I DC .

[0089] and Figure 1 Compared to the embodiments shown, the embodiments of this application use the current motor torque and the current motor speed as the judgment criteria. When it is determined that the current motor torque is greater than a preset torque threshold and the current motor speed is greater than a preset speed threshold, it is considered to be in a normal driving state. The input power of the inverter is calculated in the normal driving state, avoiding invalid or inaccurate power calculations under abnormal vehicle driving conditions, thereby improving the accuracy of input power.

[0090] Furthermore, such as Figure 3 As shown, step S5 may include the following steps:

[0091] Step S51: Determine whether the input power is greater than the power overload threshold. If yes, proceed to step S52; otherwise, proceed to step S57.

[0092] Step S52, power overload count accumulation, wherein the input power is counted based on a certain counting period T when it is greater than the power overload threshold.

[0093] Step S53: Determine whether the current power overload count accumulation is greater than the first accumulation threshold k1. If yes, proceed to steps S54 to S56; otherwise, return to step S31 and loop.

[0094] Step S54: Determine the calibration torque reduction value and the dynamic adjustment torque reduction value corresponding to the first difference, respectively.

[0095] Specifically, the calibrated torque reduction value is used to achieve rapid protection against power overload, while the dynamically adjusted torque reduction value can serve as a compensation value to fine-tune the torque.

[0096] Furthermore, in some embodiments of this application, the calibrated torque reduction value is determined by: testing the vehicle under rapid acceleration conditions to determine the mapping relationship between the calibrated torque reduction value and the calibrated power difference based on the test results; and determining the calibrated torque reduction value corresponding to the first difference based on the mapping relationship and the matching situation between the first difference and the calibrated power difference.

[0097] Specifically, rapid acceleration refers to a special operating condition where the vehicle's throttle opening reaches 100%. Because inverters are more prone to power overload under rapid acceleration conditions, this application embodiment tests a real vehicle model under full-throttle rapid acceleration conditions. During the test, the difference between the inverter's output power and the set power overload threshold is monitored. The rated torque reduction value applied to the inverter is continuously increased when the test difference is greater than or equal to zero. The value of the rated torque reduction value that would cause the inverter's output power to decrease to the power overload threshold is calculated in real time, thereby determining the above mapping relationship in the form of a one-dimensional table. In one example of this application embodiment, this mapping relationship is shown in Table 1 below:

[0098] Table 1

[0099] Calibrated torque reduction value 0 0 0 2 5 10 10

[0100] As shown in Table 1, when the rated power difference is negative, the inverter's output power is less than the overload power, and the rated torque reduction value is 0. When the rated power difference is positive, the inverter's output power is greater than or equal to the overload power threshold, and the corresponding rated torque reduction value is positive. The larger the rated power difference, the larger the corresponding rated torque reduction value, so as to quickly reduce the inverter's output power.

[0101] Thus, this embodiment of the application utilizes the characteristic that inverters are more prone to power overload under rapid acceleration conditions. By using the test results of vehicles under rapid acceleration conditions, the mapping relationship between the calibrated torque reduction value and the calibrated power difference is obtained, thereby quickly determining the calibrated torque reduction value that meets the actual power overload adjustment requirements.

[0102] Furthermore, in some embodiments of this application, the dynamic adjustment torque reduction value is determined by inputting a first difference into a preset PI controller to determine the dynamic adjustment torque reduction value based on the output of the PI controller.

[0103] Specifically, the PI controller is a closed-loop control controller composed of proportional and integral elements. It is used to calculate and output an adjustment amount in real time based on the input deviation, thereby achieving rapid convergence and steady-state elimination of the deviation. In this embodiment, the PI controller uses conventional PI control logic, with a positive feedback relationship between its input and output. In this embodiment, a first difference is input to the PI controller, which performs PI control logic calculations based on the input first difference, thereby outputting a dynamically adjusted torque reduction value.

[0104] Thus, this embodiment of the application utilizes the proportional and integral adjustment functions of the PI controller to dynamically output a dynamically adjusted torque reduction value that matches the first difference, thereby improving the accuracy of the initial torque reduction value through the synergistic effect of the dynamically adjusted torque reduction value and the calibrated torque reduction value.

[0105] Step S55: Determine the initial torque reduction value based on the calibrated torque reduction value and the dynamically adjusted torque reduction value.

[0106] Specifically, the initial torque reduction value is obtained by weighting the calibrated torque reduction value and the dynamically adjusted torque reduction value based on preset weights.

[0107] Step S56: Obtain the calibration slope corresponding to the first difference, and determine the target torque reduction value based on the calibration slope and the initial torque reduction value, so as to generate a target torque command based on the target torque reduction value.

[0108] Specifically, the calibration slope mentioned above is determined by looking up a two-dimensional table based on the current motor torque and current motor speed. This two-dimensional table is obtained through calibration. The horizontal axis of the two-dimensional table represents the current motor torque and current motor speed. Different speeds and torques result in different driving sensations due to varying torque reduction rates. Furthermore, an excessively low torque reduction rate can lead to slow response, affecting the inverter's power overload regulation. Therefore, the overall trend of the two-dimensional table is that the higher the current motor speed, the smaller the calibration slope; that is, the smaller the calibration slope at high speeds and the larger the calibration slope at medium and low speeds. Moreover, at medium and low speeds, the calibration slope is related to the current motor torque; the higher the current motor torque, the larger the calibration slope.

[0109] In some embodiments of this application, the calibration slope is generally controlled in the range of 10 Nm / s to 100 Nm / s. The calibration slope mainly takes into account the adjustment effect of power overload and the driving experience when the vehicle reduces torque.

[0110] Step S57: Reset the power overload counter to zero.

[0111] and Figure 1 Compared to the illustrated embodiments, the embodiments of this application determine a calibrated torque reduction value and a dynamically adjusted torque reduction value, respectively. The calibrated and dynamically adjusted torque reduction values ​​work synergistically. The calibrated torque reduction value allows for a rapid response during power overload, while the dynamically adjusted torque reduction value serves as a compensation value for torque fine-tuning, achieving stable output power control under prolonged overload conditions. Furthermore, the embodiments of this application utilize a calibration slope to limit changes in the torque reduction value, preventing excessively large target torque reduction values ​​that could cause sudden torque changes. This ensures both effective reduction of output power and smooth changes in vehicle power, preventing the driver from experiencing power loss after triggering torque reduction and improving driving comfort.

[0112] Figure 4 A flowchart illustrating step S56 in an embodiment of this application is shown, as follows: Figure 4 As shown, step S56 may include the following steps:

[0113] Step S561: Obtain the current motor torque of the vehicle and determine the second difference between the current motor torque and the target torque reduction value.

[0114] Specifically, the current motor torque can be determined based on the original torque command output by the VCU. The second difference obtained by subtracting the target torque reduction value from the current motor torque represents the theoretical torque value of the current motor after power overload protection.

[0115] Step S562: Determine whether the current motor torque is greater than or equal to zero and whether the second difference is less than zero. If yes, proceed to step S563; otherwise, proceed to step S564.

[0116] Step S563: Generate a target torque command that makes the current motor torque zero.

[0117] Specifically, if the current motor torque is positive, but the theoretical torque value after overload protection is negative, the theoretical torque value after power overload protection will be adjusted to 0 to avoid excessive torque reduction.

[0118] Step S564: Determine if the current motor torque is less than zero. If yes, proceed to step S565; otherwise, proceed to step S566.

[0119] Step S565: Generate a target torque command that keeps the current motor torque constant.

[0120] Specifically, if the current motor torque is negative, it means that the motor is in an energy recovery state. At this time, the battery will not be over-discharged, so the current motor torque will not be adjusted.

[0121] Step S566: Generate the target torque command that reduces the current motor torque to the second difference.

[0122] Specifically, if the current motor torque is positive and the theoretical torque value after overload protection is also positive, it means that the current motor torque can be adjusted normally according to the target torque reduction value.

[0123] In this way, the inverter will autonomously reduce its output power according to the target torque command to drive the motor to output the torque value corresponding to the target torque command, without the VCU needing to adjust its original torque command based on the power overload information provided by the BMS, thus realizing the inverter's autonomous power overload protection.

[0124] It should be noted that in some embodiments of this application, for the cases of steps S553 and S555 above, it is considered that the inverter has failed to fully respond to the torque command of the VCU. In this case, the inverter will send the corresponding flag bit so that the VCU can identify the inverter overload state.

[0125] and Figure 1 Compared to the embodiments shown, the embodiments of this application generate accurate target torque commands based on the current motor torque (positive or negative) and the difference between the current motor torque and the target torque reduction value. On the one hand, when the current motor torque is greater than or equal to zero and the second difference is less than zero, it avoids abnormal power caused by excessive torque reduction to a negative value. On the other hand, when the current motor torque is less than zero, it can effectively avoid excessive interference from overload protection under undesirable power overload protection conditions. This effectively realizes torque adjustment and output power adjustment when the inverter power is overloaded, and also ensures the rationality of vehicle power output.

[0126] In some embodiments of this application, during the process of the inverter adjusting the input power in response to the target torque command, the method further includes:

[0127] Step S7: If the input power is adjusted to be less than the power overload threshold and continues for a second preset time, stop adjusting the input power.

[0128] Specifically, after the power overload protection mechanism is activated, it is determined whether the calculated input power is less than the power overload threshold. If the inverter's input power has decreased to below the power overload threshold, the exit counting function of the overload protection mechanism is triggered.

[0129] Similarly, Figure 5 A flowchart illustrating the counting exit function is shown, as follows: Figure 5 The above step S7 includes:

[0130] Step S71: Determine whether the input power is less than the power overload threshold. If yes, proceed to step S72; otherwise, proceed to step S75.

[0131] Step S72, exit the counting accumulation, wherein the counting is performed based on a certain counting period T for cases where the input power is less than the power overload threshold.

[0132] Step S73: Determine whether the current exit count accumulation is greater than the second accumulation threshold k2. If yes, proceed to step S74; otherwise, return to step S71 and loop.

[0133] Step S74: After latching the target torque reduction value, decrease it to zero, and exit the power overload protection mechanism when the target torque reduction value reaches zero.

[0134] Step S75: Continue to execute the power overload protection mechanism.

[0135] and Figure 1 Compared to the embodiments shown, the embodiments of this application exit the power overload protection mechanism when the input power is continuously less than the power overload threshold, thus avoiding frequent start-up and shutdown of the power overload protection mechanism due to short-term power fluctuations and improving robustness.

[0136] Accordingly, please refer to Figure 6 This application provides an inverter power overload adjustment device, which includes:

[0137] The threshold determination module 100 is used to determine the power overload threshold corresponding to the current operating condition. For details, please refer to step S1.

[0138] The power acquisition module 200 is used to acquire the vehicle's driving parameters under the current operating conditions, and determine the inverter's input power when the driving parameters meet preset conditions. For details, please refer to step S3.

[0139] The power adjustment module 300 is used to generate a target torque command based on the first difference between the input power and the power overload threshold if the input power is continuously greater than the power overload threshold within a first preset time, so that the inverter adjusts the output power in response to the target torque command. For details, please refer to step S5.

[0140] In some embodiments of this application, the threshold determination module 100 is further configured to:

[0141] Obtain the maximum allowable discharge power of the vehicle's battery under the current operating conditions;

[0142] When the maximum allowable discharge power is greater than the preset power threshold, the power overload threshold is determined by the product of the maximum allowable discharge power and the preset overload coefficient.

[0143] When the maximum allowable discharge power is less than or equal to the preset power threshold, the power overload threshold is determined based on the sum of the maximum allowable discharge power and the preset overload value.

[0144] In some embodiments of this application, the power acquisition module 200 is further configured to:

[0145] When the current motor torque is greater than a preset torque threshold and the current motor speed is greater than a preset speed threshold, obtain the inverter's bus voltage and bus current.

[0146] The input power is determined by the product of the bus voltage and the bus current.

[0147] In some embodiments of this application, the power adjustment module 300 is further configured to:

[0148] The torque reduction value determination unit 310 is used to determine the calibration torque reduction value and the dynamic adjustment torque reduction value corresponding to the first difference, and to determine the initial torque reduction value based on the calibration torque reduction value and the dynamic adjustment torque reduction value.

[0149] The instruction generation unit 320 is used to obtain the calibration slope corresponding to the first difference, and determine the target torque reduction value based on the calibration slope and the initial torque reduction value, so as to generate a target torque instruction based on the target torque reduction value.

[0150] Furthermore, the aforementioned torque reduction determination unit 310 is used to determine the calibrated torque reduction value in the following manner:

[0151] The vehicle was tested under rapid acceleration conditions to determine the mapping relationship between the calibrated torque reduction value and the calibrated power difference based on the test results.

[0152] Based on the mapping relationship and the matching between the first difference and the calibrated power difference, the calibrated torque reduction value corresponding to the first difference is determined.

[0153] The aforementioned torque reduction determination unit 310 is also used to determine the dynamic adjustment torque reduction value in the following manner:

[0154] The first difference is input to the preset PI controller to determine the dynamic adjustment of the torque reduction value based on the output of the PI controller.

[0155] Furthermore, the instruction generation unit 320 is also used for:

[0156] Obtain the vehicle's current motor torque and determine the second difference between the current motor torque and the target torque reduction value;

[0157] If the current motor torque is greater than or equal to zero, and the second difference is less than zero, a target torque command is generated to make the current motor torque zero; otherwise, a target torque command is generated to reduce the current motor torque to the second difference.

[0158] When the current motor torque is less than zero, generate a target torque command to keep the current motor torque unchanged.

[0159] In some embodiments of this application, the inverter power overload adjustment device further includes an overload protection exit module 400, which is used to stop adjusting the input power when the input power is adjusted to be less than the power overload threshold and continues for a second preset time during the process of the inverter adjusting the input power in response to the target torque command.

[0160] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0161] In this embodiment, the inverter power overload adjustment device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0162] Accordingly, embodiments of this application provide a vehicle, including:

[0163] Inverter;

[0164] And an inverter power overload adjustment device as described in the above embodiments, the power overload adjustment device being used to adjust the output power of the inverter.

[0165] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0166] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

[0167] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0168] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0169] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0170] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0171] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0172] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0173] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0174] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0175] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0176] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for adjusting inverter power overload, characterized in that, The method includes: Determine the power overload threshold corresponding to the current operating condition; The vehicle's driving parameters under the current operating conditions are obtained, and the input power of the inverter is determined when the driving parameters meet preset conditions. If the input power is continuously greater than the power overload threshold for a first preset time, a target torque command is generated based on the first difference between the input power and the power overload threshold, so that the inverter adjusts the output power in response to the target torque command; The step of generating a target torque command based on a first difference between the input power and the power overload threshold includes: Determine the calibrated torque reduction value and the dynamically adjusted torque reduction value corresponding to the first difference, respectively; The initial torque reduction value is determined based on the calibrated torque reduction value and the dynamically adjusted torque reduction value; Obtain the calibration slope corresponding to the first difference, and determine the target torque reduction value based on the calibration slope and the initial torque reduction value, so as to generate the target torque command based on the target torque reduction value.

2. The method according to claim 1, characterized in that, Determining the power overload threshold corresponding to the current operating condition includes: Obtain the maximum allowable discharge power of the vehicle's battery under the current operating conditions; If the maximum allowable discharge power is greater than the preset power threshold, the power overload threshold is determined by the product of the maximum allowable discharge power and the preset overload coefficient. If the maximum allowable discharge power is less than or equal to the preset power threshold, the power overload threshold is determined based on the sum of the maximum allowable discharge power and the preset overload value.

3. The method according to claim 1, characterized in that, The driving parameters include the vehicle's current motor torque and current motor speed; Determining the input power of the inverter when the driving parameters meet preset conditions includes: When the current motor torque is greater than a preset torque threshold and the current motor speed is greater than a preset speed threshold, the bus voltage and bus current of the inverter are obtained; The input power is determined based on the product of the bus voltage and the bus current.

4. The method according to claim 1, characterized in that, The calibrated torque reduction value is determined in the following manner: The vehicle was tested under rapid acceleration conditions to determine the mapping relationship between the calibrated torque reduction value and the calibrated power difference based on the test results. Based on the mapping relationship and the matching between the first difference and the calibration power difference, the calibration torque reduction value corresponding to the first difference is determined.

5. The method according to claim 1, characterized in that, The dynamically adjusted torque reduction value is determined in the following manner: The first difference is input into a preset PI controller to determine the dynamic torque reduction value based on the output of the PI controller.

6. The method according to claim 1, characterized in that, The step of generating the target torque command based on the target torque reduction value includes: Obtain the current motor torque of the vehicle, and determine a second difference between the current motor torque and the target torque reduction value; If the current motor torque is greater than or equal to zero, and the second difference is less than zero, then a target torque command is generated to make the current motor torque zero; otherwise, a target torque command is generated to reduce the current motor torque to the second difference. When the current motor torque is less than zero, a target torque command is generated to keep the current motor torque unchanged.

7. The method according to claim 1, characterized in that, During the process of the inverter adjusting the input power in response to the target torque command, the method further includes: If the input power is adjusted to be less than the power overload threshold and this continues for a second preset time, the adjustment of the input power is stopped.

8. An inverter power overload adjustment device, characterized in that, The device includes: The threshold determination module is used to determine the power overload threshold corresponding to the current operating condition; The power acquisition module is used to acquire the vehicle's driving parameters under the current operating conditions, and determine the input power of the inverter when the driving parameters meet preset conditions. The power adjustment module is used to generate a target torque command based on a first difference between the input power and the power overload threshold if the input power is continuously greater than the power overload threshold for a first preset time, so that the inverter adjusts the output power in response to the target torque command. The power adjustment module is also used for: Determine the calibrated torque reduction value and the dynamic torque reduction value corresponding to the first difference respectively, and determine the initial torque reduction value based on the calibrated torque reduction value and the dynamic torque reduction value; Obtain the calibration slope corresponding to the first difference, and determine the target torque reduction value based on the calibration slope and the initial torque reduction value, so as to generate the target torque command based on the target torque reduction value.

9. A vehicle, characterized in that, include: Inverter; And the inverter power overload adjustment device as described in claim 8, wherein the power overload adjustment device is used to adjust the power of the inverter.

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