Current compensation method, electronic equipment and vehicle

Abstract

The invention provides a current compensation method, electronic equipment and a vehicle, and the method comprises the steps: determining the characteristic resistance value of a motor from characteristic value parameters recorded in a preset offline characteristic table based on the working condition parameters of the motor, and enabling the characteristic value parameters to be loss parameters representing the motor; determining a first current value corresponding to the working condition parameter based on a mapping relation between preset working condition data and a current value, and determining a first voltage value based on the first current value; determining a power loss value based on the characteristic resistance value, the first current value and the first voltage value; determining a current compensation value based on the power loss value; and compensating the first current value based on the current compensation value to obtain a target current value. According to the method, the control efficiency and the control precision of the motor can be improved.

Description

Technical Field

[0001] This application relates to the field of vehicles, and more particularly to a current compensation method, electronic equipment, and vehicle. Background Technology

[0002] In the automotive field, effective control of permanent magnet synchronous motors (PMSMs) is crucial for achieving vehicle dynamics and safety. During control, temperature variations can lead to steady-state torque deviations. While thermal network coupling models or torque observers are commonly used for compensation, these techniques are computationally complex and prone to overloading the controller, resulting in limited practicality. Furthermore, the compensation algorithms typically use output torque as the compensation value, requiring a secondary transformation through table lookups. This makes it difficult to decouple the temperature, current, and magnetic flux linkages, further exacerbating the system's steady-state error. Summary of the Invention

[0003] This application discloses a current compensation method, electronic device, and vehicle, which solves the technical problem that related current compensation methods cannot be compatible with control efficiency and control accuracy.

[0004] This application provides a current compensation method, the method comprising: determining a characteristic resistance value of the motor from characteristic value parameters recorded in a preset offline characteristic table based on the motor's operating condition parameters, wherein the characteristic value parameters are loss parameters characterizing the motor; determining a first current value corresponding to the operating condition parameters based on a preset mapping relationship between operating condition data and current values, and determining a first voltage value based on the first current value; determining a power loss value based on the characteristic resistance value, the first current value, and the first voltage value; determining a current compensation value based on the power loss value; and compensating the first current value based on the current compensation value to obtain a target current value.

[0005] In some embodiments of this application, the step of determining the characteristic resistance value of the motor from characteristic value parameters recorded in a preset offline characteristic table based on the motor's operating condition parameters, wherein the characteristic value parameters are loss parameters characterizing the motor, includes: obtaining the motor temperature, calibration temperature, and speed of the motor from the operating condition parameters; when the speed is less than a preset value, determining a first DC copper resistance in the characteristic resistance value based on the motor temperature, the calibration temperature, and the DC copper resistance coefficient corresponding to the motor temperature; and querying a first AC copper resistance in the characteristic resistance value from the offline characteristic table based on the first current value, the speed, and the motor temperature.

[0006] In some embodiments of this application, determining the power loss value based on the characteristic resistance value, the first current value, and the first voltage value includes: determining a second current value based on the direct-axis current component and the quadrature-axis current component in the first current value; determining a first total copper resistance based on the first DC copper resistance and the first AC copper resistance; determining a first copper loss value based on the first total copper resistance and the second current value; and using the first copper loss value as the power loss value.

[0007] In some embodiments of this application, the step of determining the characteristic resistance value of the motor from characteristic value parameters recorded in a preset offline characteristic table based on the motor's operating condition parameters, wherein the characteristic value parameters are loss parameters characterizing the motor, includes: obtaining the motor temperature, calibration temperature, and speed of the motor from the operating condition parameters; when the speed is greater than or equal to a preset value, determining a second DC copper resistance in the characteristic resistance value based on the motor temperature, the calibration temperature, and the DC copper resistance coefficient corresponding to the motor temperature; querying the second AC copper resistance in the characteristic resistance value from the offline characteristic table based on the first current value, the speed, and the motor temperature; and querying the equivalent iron resistance in the characteristic resistance value from the offline characteristic table based on the first current value, the speed, and the motor temperature.

[0008] In some embodiments of this application, determining the power loss value based on the characteristic resistance value, the first current value, and the first voltage value includes: determining a second current value based on the direct-axis current component and the quadrature-axis current component in the first current value; determining a second total copper resistance based on the second DC copper resistance and the second AC copper resistance; determining a second copper loss value based on the second total copper resistance and the second current value; determining an iron loss value based on the second total copper resistance, the first current value, the first voltage value, and the equivalent iron resistance; and determining the power loss value based on the second copper loss value and the iron loss value.

[0009] In some embodiments of this application, determining the current compensation value based on the power loss value includes: determining a second current value based on the direct-axis current component and the quadrature-axis current component in the first current value; determining a second voltage value based on the direct-axis voltage component and the quadrature-axis voltage component in the first voltage value; and determining the current compensation value based on the power loss value, the second current value, the second voltage value, and the first current value.

[0010] In some embodiments of this application, the method further includes constructing the offline feature table, comprising: recording AC power and mechanical power at the same current and different preset motor temperatures when the preset motor speed is less than a preset value, to obtain a first recorded value; and recording AC power and mechanical power at the same preset motor temperature and different preset motor currents, to obtain a second recorded value; determining a first loss value based on the first recorded value, wherein the first loss value represents DC copper loss; determining a second loss value based on the second recorded value, wherein the second loss value represents AC copper loss; determining a first resistance value and a second resistance value based on the first loss value and the second loss value, wherein the first resistance value represents DC copper resistance and the second resistance value represents AC copper resistance; and fitting the first resistance value and the second resistance value under different historical operating conditions to construct the offline feature table.

[0011] In some embodiments of this application, the method further includes constructing the offline feature table, including: recording the AC power and mechanical power under the same current, different preset motor temperatures, and preset motor speeds when the preset motor speed is greater than or equal to a preset value, to obtain a third recorded value; recording the AC power and mechanical power under the same current and different preset motor temperatures to obtain a fourth recorded value; and recording the AC power and mechanical power under the same preset motor temperature and different preset motor currents to obtain a fifth recorded value; determining a third loss value based on the third recorded value, the third loss value representing copper and iron losses; determining a third resistance value based on the fourth and fifth recorded values, the third resistance value representing the total copper resistance; determining a fourth resistance value representing the equivalent iron resistance based on the third loss value, the third resistance value, the first current value, and the first voltage value; fitting the third resistance value under different historical operating conditions to construct a first sub-table; fitting the fourth resistance value under different historical operating conditions to construct a second sub-table; and obtaining the offline feature table based on the first sub-table and the second sub-table.

[0012] This application also provides an electronic device, which includes a processor and a memory, wherein the processor is used to implement the current compensation method when executing a computer program stored in the memory.

[0013] This application also provides a vehicle that includes electronic devices.

[0014] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the current compensation method described above.

[0015] In the current compensation method provided in this application, based on the motor's operating parameters, the characteristic resistance value of the motor is determined from the characteristic value parameters recorded in a preset offline characteristic table. By identifying the relationship between the operating parameters and characteristic group values ​​calibrated in the offline characteristic table, the characteristic resistance value representing motor losses can be determined. Based on the preset mapping relationship between operating data and current values, a first current value corresponding to the operating parameters is determined, and a first voltage value is determined based on the first current value, reflecting the optimal current value (i.e., the first current value) corresponding to the current losses of the motor. Thus, the first voltage value is obtained based on the optimal current value. With the characteristic resistance value, the first current value, and the first voltage value determined, the power loss value of the motor is calculated, and the current compensation value is determined based on the power loss value. By compensating the first current value with the current compensation value, the target current value is obtained. This method can directly compensate for the current components of the direct-axis current and the quadrature-axis current, thereby decoupling the loss components in the current command of traditional technology and improving the accuracy and efficiency of motor torque control. Attached Figure Description

[0016] Figure 1 This is a flowchart of the current compensation method provided in the embodiments of this application.

[0017] Figure 2 This is a flowchart illustrating the determination of the characteristic resistance value provided in the embodiments of this application.

[0018] Figure 3 This is a flowchart illustrating the determination of the characteristic resistance value provided in another embodiment of this application.

[0019] Figure 4 This is a flowchart illustrating the construction process of the offline feature table provided in this application embodiment.

[0020] Figure 5 This is a flowchart illustrating the construction process of an offline feature table provided in another embodiment of this application.

[0021] Figure 6 This is a schematic diagram illustrating the determination of a target current value for a motor under high-speed operation, as provided in an embodiment of this application.

[0022] Figure 7 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0023] To facilitate understanding, some illustrations of concepts related to the embodiments of the present application are given for reference.

[0024] It should be noted that in this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and drawings of this application are used to distinguish similar objects, not to describe a specific order or sequence.

[0025] In the automotive field, effective control of permanent magnet synchronous motors (PMSMs) is crucial for achieving vehicle dynamics and safety. During control, temperature variations can lead to steady-state torque deviations. Current technologies primarily employ Maximum Torque per Ampere (MTPA) and Maximum Torque per Voltage (MTPV) strategies. These strategies use a given torque to look up direct-axis and quadrature-axis current commands, followed by field-oriented control (FOC) calculations to obtain the direct-axis and quadrature-axis voltage values. Finally, a three-phase pulse width modulation (PWM) waveform is output using a modulation algorithm. Clearly, these techniques do not consider the impact of temperature variations during system operation.

[0026] Temperature changes affect parameters such as those of the Insulated Gate Bipolar Transistor (IGBT) and the motor, causing the system's output torque and speed to gradually deviate from their expected values. In the automotive field, this deviation can lead to reduced driving force, vehicle slippage, and false fault detections. Therefore, related technologies typically employ thermal network coupling models or torque observers for compensation. However, these techniques involve calculations of high-order and nonlinear functions, which limit the algorithm's execution cycle in the controller and can easily result in excessive controller load, leading to poor practicality. Furthermore, the compensation algorithms usually output torque as the compensation value, requiring a second transformation through table lookups. This makes it difficult to decouple the temperature, current, and magnetic flux linkages, further exacerbating the system's steady-state error.

[0027] Therefore, in order to solve the technical problem that related current compensation methods cannot be compatible with control efficiency and control accuracy, this application provides a current compensation method, electronic device and vehicle. The current compensation value is determined by calculating the power loss value, and then the current compensation value is used to compensate the first current value obtained based on the operating condition parameters. It can directly compensate the current of the direct axis current component and the quadrature axis current component, thereby decoupling the loss component in the current command of the traditional technology and improving the accuracy and efficiency of motor torque control.

[0028] Figure 1 This is a flowchart of a current compensation method provided in an embodiment of this application, applied to electronic devices in vehicles (e.g., Figure 7 In the electronic device 70). Depending on different needs, the order of the steps in this flowchart can be changed, and some steps can be omitted.

[0029] Step S101: Based on the motor's operating parameters, determine the characteristic resistance value of the motor from the characteristic value parameters recorded in the preset offline characteristic table.

[0030] In some embodiments of this application, the characteristic parameters are loss parameters characterizing the motor, including but not limited to DC copper resistance, AC copper resistance, and equivalent iron loss resistance. Specifically, DC copper resistance characterizes the resistance value of the winding measured under DC (or low-frequency) conditions, reflecting the inherent resistance, length, and cross-sectional area of ​​copper. AC copper resistance characterizes the additional copper loss value under AC conditions. Equivalent iron loss resistance characterizes the core loss value. Operating condition parameters can be relevant parameters during vehicle operation, including motor operating parameters such as motor temperature, motor rated temperature, and motor speed.

[0031] In some embodiments of this application, the offline feature table can be pre-constructed based on historical operating condition parameters. The feature value parameters are calibrated using these historical operating condition parameters to characterize the correlation between the feature value parameters and the operating condition parameters. The construction of the offline feature table can be described as follows: Figure 4 and Figure 5 Description of the illustrated embodiment.

[0032] In some embodiments of this application, real-time operating parameters are acquired during motor operation. The characteristic resistance value of the motor is then retrieved from an offline characteristic table based on these parameters. In one example, if the motor speed is less than a preset value, the first DC copper resistance and the first AC copper resistance in the characteristic resistance value can be determined based on the motor temperature, the calibration temperature, and the DC copper resistance coefficient corresponding to that temperature. If the motor speed is greater than or equal to the preset value, the second DC copper resistance, the second AC copper resistance, and the equivalent iron resistance can be determined based on the motor temperature, the calibration temperature, and the DC copper resistance coefficient. These are merely examples, and this application does not limit the scope of the application. A detailed description of determining the characteristic resistance value can be found below. Figure 2 and Figure 3 The illustrated embodiment.

[0033] Step S102: Based on the preset mapping relationship between operating condition data and current value, determine the first current value corresponding to the operating condition parameter, and determine the first voltage value based on the first current value.

[0034] In some embodiments of this application, the preset operating condition data includes historical operating condition parameters, such as motor temperature, motor calibration temperature, and motor speed. The mapping relationship between the preset operating condition data and current values ​​can be recorded using a mapping table, which can be an MTPA / MTPV table representing the mapping from torque / speed to optimal current. The motor speed is obtained from the operating condition parameters, and the desired motor output torque is calculated based on the operating condition parameters. In one example, the current driving state (e.g., vehicle speed, gradient) and vehicle characteristics (e.g., resistance, transmission ratio) are obtained from the operating condition parameters, and the vehicle control system determines the overall driver intention (accelerator / brake pedal) based on the operating condition parameters. The desired motor output torque is calculated based on the current driving state, vehicle characteristics, and driver intention.

[0035] Based on the torque and speed, the optimal current corresponding to the torque / speed is looked up from the MTPA / MTPV table, and this optimal current is recorded as the first current value. After determining the first current value, the first voltage value is calculated based on it. In one example, the first voltage value is calculated based on the first current value, stator resistance, direct-axis / quadrature-axis inductance, permanent magnet flux linkage, and electric angular velocity. Here, stator resistance represents the stator winding resistance to conduction; direct-axis / quadrature-axis inductance represents the permeability of the direct-axis / quadrature-axis magnetic circuit; permanent magnet flux linkage represents the permanent magnet magnetic field strength; and electric angular velocity represents the rate of rotation of the rotor magnetic field at electrical angles.

[0036] Step S103: Determine the power loss value based on the characteristic resistance value, the first current value, and the first voltage value.

[0037] In some embodiments of this application, if the characteristic resistance value is determined to include the first DC copper resistance and the first AC copper resistance, indicating that all losses of the motor come from copper losses, the power loss value can be calculated based on the first DC copper resistance, the first AC copper resistance, the first current value, and the first voltage value.

[0038] In one embodiment, the second current value is determined based on the direct-axis current component and the quadrature-axis current component of the first current value, as expressed by the following formula: , in, This indicates the second current value. This represents the direct-axis current component in the first current value. This represents the quadrature-axis current component in the first current value.

[0039] Calculate the first total copper resistance based on the first DC copper resistance and the first AC copper resistance. Calculate the first copper loss value based on the first total copper resistance and the second current value, and use this first copper loss value as the power loss value. This can be expressed by the following formula: , , in, This indicates the first DC copper resistor. This indicates the first AC copper resistor. This indicates the first total copper resistance. This represents the first copper loss value. This represents the power loss value.

[0040] In some embodiments of this application, if the characteristic resistance value is determined to include the second DC copper resistance, the second AC copper resistance, and the equivalent iron resistance, indicating that all losses of the motor come from copper losses and iron losses, then the power loss value can be calculated based on the second DC copper resistance, the second AC copper resistance, the equivalent iron resistance, the first current value, and the first voltage value.

[0041] In one embodiment, a second current value is determined based on the direct-axis and quadrature-axis current components of the first current value. A second total copper resistance is calculated based on the second DC copper resistance and the second AC copper resistance. A second copper loss value is determined based on the second total copper resistance and the second current value. This can be expressed by the following formula: , , in, This indicates the second DC copper resistor. This indicates the second AC copper resistor. This indicates the second total copper resistance. This indicates the second copper loss value.

[0042] The iron loss value is calculated based on the second total copper resistance, the first current value, the first voltage value, and the equivalent iron resistance.

[0043] , , in, This represents the iron loss value. It represents the equivalent iron resistance. , These represent the direct-axis voltage component and the quadrature-axis voltage component in the first voltage value, respectively. This indicates the second total copper resistance.

[0044] The power loss value is calculated based on the second copper loss value and the iron loss value. The formula is as follows: .

[0045] Step S104: Determine the current compensation value based on the power loss value.

[0046] In some embodiments of this application, the first current value includes a direct-axis current component and a quadrature-axis current component, and the second current value is calculated based on the direct-axis current component and the quadrature-axis current component. The first voltage value includes a direct-axis voltage component and a quadrature-axis voltage component. The second voltage value is calculated based on the direct-axis voltage component and the quadrature-axis voltage component. The formula is as follows: , in, This indicates the second voltage value. This represents the direct-axis voltage component in the first voltage value. This represents the quadrature-axis voltage component in the first voltage value.

[0047] Based on the power loss value, the direct-axis current component, the quadrature-axis current component, and the first current value, calculate the compensation values ​​for the direct-axis current component and the quadrature-axis current component in the current compensation value. This can be expressed by the following formula: , , in, This represents the compensation value for the direct-axis current component. This represents the compensation value for the quadrature axis current component.

[0048] Step S105: Compensate the first current value based on the current compensation value to obtain the target current value.

[0049] In some embodiments of this application, the direct-axis current component in the first current value is compensated based on the compensation value of the direct-axis current component in the current compensation value to obtain the target direct-axis current component in the target current value. The quadrature-axis current component in the first current value is compensated based on the compensation value of the quadrature-axis current component in the current compensation value to obtain the target quadrature-axis current component in the target current value.

[0050] After directly superimposing the calculated current compensation value onto the first current value obtained from a preset table (such as the MTPA / MTPV table), the FOC operation is then performed to obtain the direct-axis voltage value and the quadrature-axis voltage value, and then the PWM wave is output through the modulation algorithm.

[0051] Through the above embodiments, based on the motor's operating parameters and offline characteristic table, the characteristic resistance value of the motor is determined. By analyzing the relationship between the operating parameters and characteristic group values ​​calibrated in the offline characteristic table, the characteristic resistance value representing motor losses can be determined. The first current value and the first voltage value are determined according to the operating parameters and mapping table, reflecting the optimal current value (i.e., the first current value) corresponding to the current motor losses. The first voltage value is then obtained based on the optimal current value. Given the characteristic resistance value, the first current value, and the first voltage value, the motor's power loss value is calculated, and the current compensation value is determined based on the power loss value. The first current value is compensated using the current compensation value to obtain the target current value. This allows for direct compensation of the direct-axis current component and the quadrature-axis current component, thereby decoupling the loss component in the current command of traditional technology and improving the accuracy and efficiency of motor torque control.

[0052] Figure 2 This is a flowchart illustrating the determination of the characteristic resistance value provided in an embodiment of this application. When the motor speed is less than a preset value, the determination is made by... Figure 2 The steps shown determine the characteristic resistance value.

[0053] Step S201: Obtain the motor temperature, calibration temperature and speed of the motor from the operating parameters.

[0054] In some embodiments of this application, motor temperature refers to the temperature at which the motor is currently rotating. Calibration temperature refers to the initial temperature of the motor windings or the ambient reference temperature. Rotational speed refers to the current rotational speed of the vehicle's motor.

[0055] Step S202: When the rotational speed is less than the preset value, the first DC copper resistance in the characteristic resistance value is determined based on the motor temperature, the calibration temperature and the DC copper resistance coefficient corresponding to the motor temperature.

[0056] In some embodiments of this application, if the motor speed is less than a preset value, it indicates that all motor losses originate from copper losses. The loss value is used to distinguish between low and high speeds and can be preset according to the actual application scenario; this application does not impose any restrictions on this. The corresponding DC copper resistance coefficient is retrieved based on the motor temperature. The first DC copper resistance is calculated based on the motor temperature, the calibration temperature, and the DC copper resistance coefficient. This is expressed by the following formula: , in, This indicates the motor temperature. Indicates the calibration temperature. This represents the DC copper resistance coefficient.

[0057] Step S203: Based on the first current value, speed and motor temperature, query the first AC copper resistance in the characteristic resistance value from the offline characteristic table.

[0058] In some embodiments of this application, the offline feature table includes an AC copper resistance table. The first AC copper resistance is retrieved from the AC copper resistance table based on the first current value, rotational speed, and motor temperature.

[0059] Through the above embodiments, when the motor speed is less than the preset value, all motor losses originate from the copper resistance. Therefore, the determined characteristic resistance values ​​include the first DC copper resistance and the first AC copper resistance. These embodiments reduce computational complexity. Furthermore, by considering changes in motor temperature, the effects of motor temperature can be avoided. This improves the control efficiency and accuracy of the motor to a certain extent.

[0060] Figure 3 This is a flowchart illustrating the determination of the characteristic resistance value according to another embodiment of this application. When the motor speed is greater than or equal to a preset value, the determination is performed as follows: Figure 3 The steps shown determine the characteristic resistance value.

[0061] Step S301: Obtain the motor temperature, calibration temperature and speed of the motor from the operating parameters.

[0062] In some embodiments of this application, motor temperature refers to the temperature at which the motor is currently rotating. Calibration temperature refers to the initial temperature of the motor windings or the ambient reference temperature. Rotational speed refers to the current rotational speed of the vehicle's motor.

[0063] Step S302: When the rotational speed is greater than or equal to a preset value, determine the second DC copper resistance in the characteristic resistance value based on the motor temperature, the calibration temperature and the DC copper resistance coefficient corresponding to the motor temperature.

[0064] In some embodiments of this application, if the rotational speed is greater than or equal to a preset value, it indicates that the total losses of the motor include copper losses and iron losses. The corresponding DC copper resistance coefficient is looked up based on the motor temperature. The second DC copper resistance is calculated based on the motor temperature, the calibration temperature, and the DC copper resistance coefficient. This is expressed by the following formula: , in, This indicates the motor temperature. Indicates the calibration temperature. This represents the DC copper resistance coefficient.

[0065] Step S303: Based on the first current value, speed and motor temperature, query the second AC copper resistance from the characteristic resistance value in the offline characteristic table.

[0066] In some embodiments of this application, the second AC copper resistance is determined from an AC copper resistance table based on the first current value, rotational speed, and motor temperature.

[0067] Step S304: Based on the first current value, rotational speed, and motor temperature, query the equivalent iron resistance in the characteristic resistance value from the offline characteristic table.

[0068] In some embodiments of this application, the offline feature table includes an equivalent resistance table. Since the motor's loss values ​​also include iron losses, the equivalent iron resistance in the feature resistance values ​​can be retrieved from the equivalent resistance table based on the first current value, speed, and motor temperature.

[0069] Through the above embodiments, when the motor speed is greater than or equal to a preset value, all motor losses originate from copper resistance and iron resistance. Therefore, the determined characteristic resistance values ​​include the first DC copper resistance, the first AC copper resistance, and the equivalent iron resistance. These embodiments reduce computational complexity. Furthermore, by considering changes in motor temperature, the effects of motor temperature can be avoided. This improves the control efficiency and accuracy of the motor to a certain extent.

[0070] Figure 4 This is a flowchart illustrating the construction of the offline feature table provided in this application embodiment. When the motor speed is less than a preset value, the offline feature table includes an AC copper resistance table and a DC copper resistance coefficient table. Through, as shown... Figure 4 The steps shown construct an offline feature table.

[0071] Step S401: When the preset motor speed is less than the preset value, record the AC power and mechanical power at the same current and different preset motor temperatures to obtain the first recorded value.

[0072] In some embodiments of this application, when the preset motor speed is less than a preset value, it indicates that the motor is running at low speed, and at this time, all losses of the motor include copper losses. The AC power and mechanical power are recorded under the same current and different preset motor temperatures to obtain a first recorded value.

[0073] In one example, the current of the preset motor at time i, the first AC power and the first mechanical power at the preset motor temperature at time i are recorded. The current of the preset motor at time i+1, the second AC power and the second mechanical power at the preset motor temperature at time i+1 are also recorded. Since the current is kept constant, the current at time i and the current at time i+1 are the same.

[0074] Step S402: Record the AC power and mechanical power at the same temperature and different preset motor currents to obtain the second recorded value.

[0075] In some embodiments of this application, the AC power and mechanical power at the same temperature and different preset motor currents are recorded to obtain a second recorded value.

[0076] In one example, the preset motor current at time i, the third AC power and the third mechanical power under the preset motor current at time i are recorded. The preset motor current at time i+1, the fourth AC power and the fourth mechanical power under the preset motor current at time i+1 are also recorded.

[0077] Step S403: Determine the first loss value based on the first recorded value.

[0078] In some embodiments of this application, the first loss value characterizes the DC copper loss. The first loss value is calculated based on the recorded AC power and mechanical power. Continuing with the example of step S401 above, the difference between the first AC power and the first mechanical power is taken as the first loss value corresponding to time i, that is, the DC copper loss corresponding to time i. The difference between the second AC power and the second mechanical power is taken as the first loss value corresponding to time i+1, that is, the DC copper loss corresponding to time i+1.

[0079] Step S404: Determine the second loss value based on the second recorded value.

[0080] In some embodiments of this application, the second loss value characterizes the AC copper loss. The second loss value is calculated based on the recorded AC power and mechanical power. Continuing with the example of step S402 above, the difference between the third AC power and the third mechanical power is used as the second loss value corresponding to time i, that is, the AC copper loss corresponding to time i. The difference between the fourth AC power and the fourth mechanical power is used as the second loss value corresponding to time i+1, that is, the AC copper loss corresponding to time i+1.

[0081] Step S405: Determine the first resistance value and the second resistance value based on the first loss value and the second loss value.

[0082] In some embodiments of this application, the first resistance value represents the DC copper resistance, and the second resistance value represents the AC copper resistance. In one example, it is assumed that the first loss value includes the DC copper loss corresponding to time i and the DC copper loss corresponding to time i+1. The second loss value includes the AC copper loss corresponding to time i and the AC copper loss corresponding to time i+1. Using the power calculation formula ( The calculation of the first and second resistance values ​​includes: calculating the DC copper resistance at time i based on the DC copper loss at time i and the preset motor current at time i; calculating the DC copper resistance at time i+1 based on the DC copper loss at time i+1 and the preset motor current at time i+1; calculating the AC copper resistance at time i based on the AC copper loss at time i and the preset motor current at time i; and calculating the AC copper resistance at time i+1 based on the AC copper loss at time i+1 and the preset motor current at time i+1.

[0083] Step S406: Fit the first and second resistance values ​​under different historical operating conditions to construct an offline feature table.

[0084] In some embodiments of this application, first resistance values ​​under different historical operating conditions are fitted to determine the DC copper resistance coefficients corresponding to different historical operating conditions, which are denoted as a DC copper resistance coefficient table. In subsequent applications, the corresponding DC copper resistance coefficient can be looked up from the DC copper resistance coefficient table based on the motor temperature.

[0085] A second resistance value is fitted under different historical operating conditions to construct an AC copper resistance meter. In subsequent applications, the corresponding AC copper resistance meter can be determined by the motor speed. For example, the above embodiment is constructed under the condition that the motor speed is less than a preset value, then the AC copper resistance meter can be marked as the AC copper resistance meter for low-speed operation. In one example, in subsequent applications, assuming that the AC copper resistance meter for low-speed operation has been determined, the AC copper resistance can be retrieved from the AC copper resistance meter for low-speed operation based on the currently queried current value (such as the first current value) and the motor temperature.

[0086] Through the above embodiments, the characteristic resistance value is calibrated for different operating conditions, thereby decoupling the temperature-affected loss component during normal motor calibration. This improves the accuracy and efficiency of data calibration to a certain extent.

[0087] Figure 5 This is a flowchart illustrating the construction of an offline feature table according to another embodiment of this application. When the motor speed is greater than or equal to a preset value, the offline feature table includes a DC copper resistance coefficient table, an AC copper resistance table, and an equivalent resistance table. Through... Figure 5 The steps shown construct an offline feature table.

[0088] Step S501: When the preset motor speed is greater than or equal to the preset value, record the AC power and mechanical power under the same current, different preset motor temperatures and preset motor speeds to obtain the third recorded value.

[0089] In some embodiments of this application, if the speed of the preset motor is greater than or equal to a preset value, it indicates that the preset motor is operating at high speed, and the total loss value of the preset motor includes copper loss and iron loss. The AC power and mechanical power are recorded under the same current, different preset motor temperatures, and preset motor speeds to obtain a third recorded value. In one example, the fifth AC power and fifth mechanical power at the preset motor temperature and preset motor speed at time i are recorded. The sixth AC power and sixth mechanical power at the preset motor temperature and preset motor speed at time i+1 are recorded. The preset motor temperature and preset motor speed at time i are different from those at time i+1. Therefore, the third recorded value includes the fifth AC power, the fifth mechanical power, the sixth AC power, and the sixth mechanical power.

[0090] In other embodiments of this application, a third recorded value can be obtained by recording the AC power and mechanical power of a preset motor at the same rotational speed but different preset motor temperatures and currents. In one example, the seventh AC power and seventh mechanical power at the preset motor temperature and current at time i are recorded. The eighth AC power and eighth mechanical power at the preset motor temperature and current at time i+1 are recorded. The preset motor temperature and current at time i are different from those at time i+1. Therefore, the third recorded value includes the seventh AC power, the seventh mechanical power, the eighth AC power, and the eighth mechanical power.

[0091] Step S502: Record the AC power and mechanical power under the same current and different preset motor temperatures to obtain the fourth recorded value; and record the AC power and mechanical power under the same preset motor temperature and different preset motor currents to obtain the fifth recorded value.

[0092] In some embodiments of this application, the current is set to a constant current, and the AC power and mechanical power at different preset motor temperatures are recorded when the current remains constant, thereby obtaining a fourth recorded value. The temperature is set to a constant temperature, and the AC power and mechanical power at different preset motor currents are recorded when the temperature remains constant, thereby obtaining a fifth recorded value.

[0093] In one example, the AC power and mechanical power at the preset motor temperature at time i and time i+1 are recorded. The preset motor temperature at time i is different from the preset motor temperature at time i+1.

[0094] Record the AC power and mechanical power at the preset motor current at time i, and record the AC power and mechanical power at the preset motor current at time i+1. The preset motor current at time i is different from the preset motor current at time i+1.

[0095] Step S503: Determine the third loss value based on the third recorded value.

[0096] In some embodiments of this application, the third loss value characterizes the copper and iron loss. The third recorded value can be determined by the AC power and mechanical power under the same current, different preset motor temperatures, and preset motor speeds. Continuing with the above examples, the third recorded value includes the fifth AC power, the fifth mechanical power, the sixth AC power, and the sixth mechanical power.

[0097] The copper and iron losses at time i are determined based on the difference between the fifth AC power and the fifth mechanical power. The copper and iron losses at time i+1 are determined based on the difference between the sixth AC power and the sixth mechanical power.

[0098] In some embodiments of this application, the third recorded value can also be determined by the AC power and mechanical power of the preset motor at the same speed, different preset motor temperatures and currents. Continuing with the above example, the third recorded value includes the seventh AC power, the seventh mechanical power, the eighth AC power and the eighth mechanical power.

[0099] The copper and iron losses at time i are determined based on the difference between the seventh AC power and the seventh mechanical power. The copper and iron losses at time i+1 are determined based on the difference between the eighth AC power and the eighth mechanical power.

[0100] Step S504: Determine the third resistance value based on the fourth and fifth recorded values.

[0101] In some embodiments of this application, the third resistance value characterizes the total copper resistance. The third resistance value is calculated based on the data recorded in step S502. In one example, the DC copper loss at time i is calculated based on the AC power and mechanical power at the preset motor temperature at time i. The AC copper loss at time i is calculated based on the AC power and mechanical power at the preset motor current at time i.

[0102] Calculate the DC copper loss and AC copper loss at time i to obtain the total copper resistance at time i.

[0103] Step S505: Based on the third loss value, the third resistance value, the first current value, and the first voltage value, determine the fourth resistance value that characterizes the equivalent iron resistance.

[0104] In some embodiments of this application, a fourth resistance value characterizing the equivalent ferroresistance is determined based on the third loss value, the third resistance value, the first current value, and the first voltage value, and is expressed by the following formula: , in, This indicates the fourth resistance value. , These represent the direct-axis voltage component and the quadrature-axis voltage component in the first voltage value, respectively. This indicates the third resistance value. , These represent the direct-axis current component and the quadrature-axis current component in the first current value, respectively. This represents the third loss value.

[0105] Step S506: Fit the third resistance value under different historical operating conditions to construct the first sub-table.

[0106] In some embodiments of this application, the third resistance value represents the total copper resistance, and the first sub-table may include a DC copper resistance coefficient and an AC copper resistance table. Specifically, the DC copper resistance coefficient can be obtained by fitting the third resistance value under different historical operating conditions. The AC copper resistance table can also be obtained by fitting the third resistance value under different historical operating conditions.

[0107] Step S507: Fit the fourth resistance value under different historical operating conditions and construct the second sub-table.

[0108] In some embodiments of this application, the fourth resistance value characterizes the equivalent iron resistance. The equivalent iron resistance under different operating conditions is fitted to construct a second sub-table, which is used to characterize the relationship between the equivalent iron resistance and the current, speed and motor temperature.

[0109] Step S508: Based on the first sub-table and the second sub-table, obtain the offline feature table.

[0110] In some embodiments of this application, when the preset motor is running at high speed, the first sub-table and the second sub-table can be used as offline feature tables.

[0111] Through the above embodiments, the characteristic resistance value is calibrated for different operating conditions, thereby decoupling the temperature-affected loss component during normal motor calibration. This improves the accuracy and efficiency of data calibration to a certain extent.

[0112] To better understand the above embodiments (e.g., as Figure 1 (The illustrated embodiment) is described below in conjunction with... Figure 6 Describe the process of determining the target current value when the motor is running at high speed.

[0113] like Figure 6 As shown, the motor temperature (Temp) and speed (Speed) are obtained from the operating parameters, and the first current value is determined from the preset mapping table. The DC copper resistance coefficient is determined from the DC copper resistance coefficient table based on the motor temperature (Temp). Based on motor temperature (Temp) and DC copper resistance coefficient and calibration temperature Calculate DC copper resistance Based on the first current value Motor temperature (Temp) and speed (Speed), find the AC copper resistance from the AC copper resistance table. According to DC copper resistor and AC copper resistor The sum of these values ​​yields the total copper resistance loss. Based on the total copper resistance loss Second current value Calculate the power loss value of copper. .

[0114] Based on the first current value Motor temperature (Temp) and speed (Speed), and the equivalent iron resistance can be found in the equivalent resistance table. Based on the total copper resistance loss First current value and the first voltage value ,calculate .according to and equivalent iron resistance Calculate the power loss value of iron. .

[0115] Based on the power loss value of copper Power loss value of iron Calculate the power loss value of the motor. Based on the motor's power loss value The direct-axis current component in the first current value Second current value Second voltage value Calculate the compensation value of the direct-axis current component. Based on the motor's power loss value The quadrature-axis current component in the first current value Second current value Second voltage value Calculate the compensation value of the quadrature axis current component. From the mapping table (such as...) Figure 6 Look up the direct-axis current component in the first current value in the MTPA / MTPV table shown. quadrature axis current components Using the compensation value of the direct-axis current component For the direct-axis current component in the first current value Compensation is performed using the compensation value of the quadrature-axis current component. Regarding the quadrature axis current component Compensation is performed. The target current value obtained after compensation is input into the FOC calculation to obtain the compensated direct-axis voltage component. and cross-axis voltage components .

[0116] Figure 7This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. The above-described current compensation method is applied to electronic device 70, which may be a motor controller of a vehicle. The motor controller is used to determine a target current value, thereby controlling the operation of the vehicle's motor based on the target current value. Electronic device 70 may include: a memory 701, a processor 702, and a computer program stored in the memory 701 and executable on the processor 702. When the processor 702 executes the program, it implements the current compensation method provided in the above embodiments.

[0117] Furthermore, the electronic device also includes a communication interface 703 for communication between the memory 701 and the processor 702.

[0118] The memory 701 is used to store computer programs that can run on the processor 702.

[0119] The memory 701 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0120] If the memory 701, processor 702, and communication interface 703 are implemented independently, then the communication interface 703, memory 701, and processor 702 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc.

[0121] Optionally, in a specific implementation, if the memory 701, processor 702, and communication interface 703 are integrated on a single chip, then the memory 701, processor 702, and communication interface 703 can communicate with each other through an internal interface.

[0122] The processor 702 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0123] This embodiment also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described current compensation method.

[0124] This embodiment also provides a computer program product, including a computer program that is executed to implement the current compensation method of the above embodiment.

[0125] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware, and the program can be stored in a computer-readable storage medium. When executed, the program includes one or a combination of the steps of the method embodiments.

[0126] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0127] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A current compensation method, characterized in that, The method includes: Based on the operating parameters of the motor, the characteristic resistance value of the motor is determined from the characteristic value parameters recorded in the preset offline characteristic table. The characteristic value parameters are loss parameters characterizing the motor. Based on the preset mapping relationship between operating condition data and current value, the first current value corresponding to the operating condition parameter is determined, and the first voltage value is determined based on the first current value. The power loss value is determined based on the characteristic resistance value, the first current value, and the first voltage value. Based on the power loss value, determine the current compensation value; The first current value is compensated based on the current compensation value to obtain the target current value.

2. The current compensation method according to claim 1, characterized in that, The determination of the characteristic resistance value of the motor based on the motor's operating parameters, from the characteristic value parameters recorded in a preset offline characteristic table, includes: The motor temperature, calibration temperature, and speed of the motor are obtained from the operating parameters. When the rotational speed is less than a preset value, the first DC copper resistance in the characteristic resistance value is determined based on the motor temperature, the calibration temperature, and the DC copper resistance coefficient corresponding to the motor temperature. Based on the first current value, the rotational speed, and the motor temperature, the first AC copper resistance value is retrieved from the offline feature table.

3. The current compensation method according to claim 2, characterized in that, The determination of the power loss value based on the characteristic resistance value, the first current value, and the first voltage value includes: The second current value is determined based on the direct-axis current component and the quadrature-axis current component in the first current value; Based on the first DC copper resistance and the first AC copper resistance, the first total copper resistance is determined; The first copper loss value is determined based on the first total copper resistance and the second current value; The first copper loss value is used as the power loss value.

4. The current compensation method according to claim 1, characterized in that, The determination of the characteristic resistance value of the motor based on the motor's operating parameters, from the characteristic value parameters recorded in a preset offline characteristic table, includes: The motor temperature, calibration temperature, and speed of the motor are obtained from the operating parameters. When the rotational speed is greater than or equal to a preset value, the second DC copper resistance in the characteristic resistance value is determined based on the motor temperature, the calibration temperature, and the DC copper resistance coefficient corresponding to the motor temperature. Based on the first current value, the rotational speed, and the motor temperature, the second AC copper resistance in the characteristic resistance value is retrieved from the offline characteristic table; Based on the first current value, the rotational speed, and the motor temperature, the equivalent ferrite resistance in the characteristic resistance value is queried from the offline characteristic table.

5. The current compensation method according to claim 4, characterized in that, The determination of the power loss value based on the characteristic resistance value, the first current value, and the first voltage value includes: The second current value is determined based on the direct-axis current component and the quadrature-axis current component in the first current value; The second total copper resistance is determined based on the second DC copper resistance and the second AC copper resistance; The second copper loss value is determined based on the second total copper resistance and the second current value; The iron loss value is determined based on the second total copper resistance, the first current value, the first voltage value, and the equivalent iron resistance. The power loss value is determined based on the second copper loss value and the iron loss value.

6. The current compensation method according to claim 1, characterized in that, Determining the current compensation value based on the power loss value includes: The second current value is determined based on the direct-axis current component and the quadrature-axis current component in the first current value; The second voltage value is determined based on the direct-axis voltage component and the quadrature-axis voltage component in the first voltage value; The current compensation value is determined based on the power loss value, the second current value, the second voltage value, and the first current value.

7. The current compensation method according to claim 1, characterized in that, The method further includes constructing the offline feature table, including: When the preset motor speed is less than a preset value, record the AC power and mechanical power at the same current and different preset motor temperatures to obtain the first recorded value; and, Record the AC power and mechanical power under the same preset motor temperature and different preset motor currents to obtain the second recorded value; Based on the first recorded value, a first loss value is determined, which characterizes the DC copper loss; Based on the second recorded value, a second loss value is determined, which characterizes the AC copper loss; Based on the first loss value and the second loss value, a first resistance value and a second resistance value are determined, wherein the first resistance value represents the DC copper resistance and the second resistance value represents the AC copper resistance. The offline feature table is constructed by fitting the first and second resistance values ​​under different historical operating conditions.

8. The current compensation method according to claim 1, characterized in that, The method further includes constructing the offline feature table, including: When the preset motor speed is greater than or equal to a preset value, record the AC power and mechanical power under the same current, different preset motor temperatures, and preset motor speeds to obtain a third recorded value; and, The AC power and mechanical power under the same current and different preset motor temperatures are recorded to obtain the fourth recorded value, and the AC power and mechanical power under the same preset motor temperature and different preset motor currents are recorded to obtain the fifth recorded value. Based on the third recorded value, a third loss value is determined, which characterizes the copper and iron loss; Based on the fourth and fifth recorded values, a third resistance value is determined, which characterizes the total resistance of the copper. Based on the third loss value, the third resistance value, the first current value, and the first voltage value, a fourth resistance value characterizing the equivalent iron resistance is determined; Fit the third resistance value under different historical operating conditions to construct the first sub-table; Fit the fourth resistance value under different historical operating conditions to construct the second sub-table; The offline feature table is obtained based on the first sub-table and the second sub-table.

9. An electronic device, characterized in that, The electronic device includes a processor and a memory, the processor being configured to implement the current compensation method as described in any one of claims 1 to 8 when executing a computer program stored in the memory.

10. A vehicle, characterized in that, The vehicle includes the electronic equipment as described in claim 9.

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