Motor flux linkage processing method and device, computer equipment, storage medium and computer program product

Abstract

The invention relates to a motor flux linkage processing method and device, computer equipment, a storage medium and a computer program product. The method comprises the steps of obtaining a current carrier wave ratio of a motor according to current rotating speed information of the motor and switching frequency information of a motor controller; if it is detected that the current carrier wave ratio meets a preset carrier wave ratio condition, obtaining a target resistance voltage loss value of the motor according to a control period and a current value of the motor and a correction coefficient for a pulse voltage signal of the motor; the preset carrier ratio condition is determined according to the rotating speed fluctuation range of the motor; if it is detected that the current carrier wave ratio does not meet the preset carrier wave ratio condition, obtaining a target resistance voltage loss value of the motor according to the control period and the current values of two adjacent time points of the motor; and obtaining the stator flux linkage of the motor according to the target resistance voltage loss value and the voltage value of the motor. By adopting the method, the observation accuracy of the stator flux linkage of the motor can be improved.

Description

Technical Field

[0001] This application relates to the field of motor control technology, and in particular to a method, apparatus, computer equipment, storage medium and computer program product for processing motor flux linkage. Background Technology

[0002] Motor flux linkage, as one of the most important physical quantities in a motor, directly reflects the motor's operating status. Therefore, motor flux linkage is often used to achieve motor control functions, such as torque monitoring, rotor temperature estimation, permanent magnet health assessment, and positionless motor control.

[0003] Traditional techniques include methods for observing motor flux linkage using pure voltage integration and methods using current models. However, these methods only consider the observation principle and observer design, neglecting the operational compensation issues faced by high-speed motors in actual operation, resulting in low accuracy in flux linkage observation. Therefore, improving the accuracy of motor flux linkage observation has become one of the important research directions in current motor control technology. Summary of the Invention

[0004] Therefore, it is necessary to provide a motor flux processing method, apparatus, computer equipment, computer-readable storage medium, and computer program product that can improve the accuracy of motor flux observation in response to the above-mentioned technical problems.

[0005] Firstly, this application provides a method for processing magnetic flux linkage in an electric motor. The method includes:

[0006] The current carrier ratio of the motor is obtained based on the current speed information of the motor and the switching frequency information of the motor controller;

[0007] If the current carrier ratio is detected to meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the motor's control cycle and current value, as well as the correction coefficient for the motor's pulse voltage signal; the preset carrier ratio condition is determined based on the motor's speed fluctuation range.

[0008] If it is detected that the current carrier ratio does not meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the control cycle and the current values ​​of two adjacent time points of the motor.

[0009] The stator flux linkage of the motor is obtained based on the target resistor voltage loss value and the motor voltage value.

[0010] In one embodiment, the target resistance voltage drop value of the motor is obtained based on the control cycle and current value of the motor, and a correction coefficient for the pulse voltage signal of the motor, including:

[0011] The first resistance voltage loss value of the motor is obtained based on the stator resistance of the motor and the current value of the motor in the two-phase stationary coordinate system.

[0012] According to the control cycle, the first resistor voltage loss value is discretized to obtain the second resistor voltage loss value of the motor;

[0013] Based on the correction coefficient for the pulse voltage signal of the motor, the second resistor voltage loss value is corrected to obtain the target resistor voltage loss value of the motor at the first speed.

[0014] In one embodiment, before correcting the second resistor voltage loss value based on a correction coefficient for the pulse voltage signal of the motor to obtain the target resistor voltage loss value of the motor at the first speed, the method further includes:

[0015] When the motor outputs a pulse voltage signal through space vector pulse width modulation, based on the switching ripple of the space vector pulse width modulation, the first correction coefficient of the fundamental wave of the motor in the positive half-cycle and the second correction coefficient of the fundamental wave in the negative half-cycle are obtained.

[0016] The first correction factor and the second correction factor are set as correction factors for the pulse voltage signal of the motor.

[0017] In one embodiment, the target resistance voltage drop value of the motor is obtained based on the control cycle and the current values ​​of the motor at two adjacent time points, including:

[0018] The average current value is obtained by averaging the current values ​​of the motor at two adjacent time points in the two-phase stationary coordinate system.

[0019] The target resistance voltage drop value of the motor at the second speed is obtained based on the average current, the stator resistance, and the control cycle.

[0020] Wherein, the first rotational speed is greater than the second rotational speed.

[0021] In one embodiment, after obtaining the current carrier ratio of the motor based on the current speed information of the motor and the switching frequency information of the motor controller, the method further includes:

[0022] Based on the switching frequency information, the number of pole pairs of the motor, and the speed fluctuation range, the carrier ratio threshold of the motor is obtained;

[0023] If the current carrier ratio is less than the carrier ratio threshold, then it is confirmed that the current carrier ratio meets the preset carrier ratio condition;

[0024] If the current carrier ratio is greater than or equal to the carrier ratio threshold, then it is confirmed that the current carrier ratio does not meet the preset carrier ratio condition.

[0025] In one embodiment, the current rotational speed information is an estimated value or an actual value;

[0026] Based on the current speed information of the motor and the switching frequency information of the motor controller, the current carrier ratio of the motor is obtained, including:

[0027] The current carrier ratio of the motor is obtained based on the switching frequency information, the current rotational speed information, and the number of pole pairs.

[0028] Secondly, this application also provides an electric motor flux linkage processing device. The device includes:

[0029] The carrier ratio determination module is used to obtain the current carrier ratio of the motor based on the current speed information of the motor and the switching frequency information of the motor controller;

[0030] The first loss determination module is used to determine the target resistance voltage loss value of the motor based on the control cycle and current value of the motor, and the correction coefficient for the pulse voltage signal of the motor, if the current carrier ratio is detected to meet the preset carrier ratio condition; the preset carrier ratio condition is determined based on the speed fluctuation range of the motor.

[0031] The second loss determination module is used to determine the target resistance voltage loss value of the motor based on the control cycle and the current values ​​of two adjacent time points of the motor if the current carrier ratio is detected to not meet the preset carrier ratio condition.

[0032] The stator flux linkage determination module is used to obtain the stator flux linkage of the motor based on the target resistor voltage loss value and the motor voltage value.

[0033] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0034] The current carrier ratio of the motor is obtained based on the current speed information of the motor and the switching frequency information of the motor controller;

[0035] If the current carrier ratio is detected to meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the motor's control cycle and current value, as well as the correction coefficient for the motor's pulse voltage signal; the preset carrier ratio condition is determined based on the motor's speed fluctuation range.

[0036] If it is detected that the current carrier ratio does not meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the control cycle and the current values ​​of two adjacent time points of the motor.

[0037] The stator flux linkage of the motor is obtained based on the target resistor voltage loss value and the motor voltage value.

[0038] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, performs the following steps:

[0039] The current carrier ratio of the motor is obtained based on the current speed information of the motor and the switching frequency information of the motor controller;

[0040] If the current carrier ratio is detected to meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the motor's control cycle and current value, as well as the correction coefficient for the motor's pulse voltage signal; the preset carrier ratio condition is determined based on the motor's speed fluctuation range.

[0041] If it is detected that the current carrier ratio does not meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the control cycle and the current values ​​of two adjacent time points of the motor.

[0042] The stator flux linkage of the motor is obtained based on the target resistor voltage loss value and the motor voltage value.

[0043] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, performs the following steps:

[0044] The current carrier ratio of the motor is obtained based on the current speed information of the motor and the switching frequency information of the motor controller;

[0045] If the current carrier ratio is detected to meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the motor's control cycle and current value, as well as the correction coefficient for the motor's pulse voltage signal; the preset carrier ratio condition is determined based on the motor's speed fluctuation range.

[0046] If it is detected that the current carrier ratio does not meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the control cycle and the current values ​​of two adjacent time points of the motor.

[0047] The stator flux linkage of the motor is obtained based on the target resistor voltage loss value and the motor voltage value.

[0048] The aforementioned motor flux linkage processing method, apparatus, computer equipment, storage medium, and computer program product obtain the current carrier ratio of the motor based on the current speed information of the motor and the switching frequency information of the motor controller. If the current carrier ratio is detected to meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the motor control cycle, current value, and correction coefficient for the motor pulse voltage signal. The preset carrier ratio condition is determined based on the speed fluctuation range of the motor. If the current carrier ratio is detected to not meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the control cycle and the current values ​​of two adjacent time points of the motor. The stator flux linkage of the motor is obtained based on the target resistance voltage loss value and the voltage value of the motor. This method determines the current carrier ratio based on the motor's current speed information and the motor controller's switching frequency information. Then, it combines this with a preset carrier ratio condition determined by the motor speed fluctuation range. This allows for precise calculation of the target resistance voltage loss value under different conditions. Specifically, when the preset carrier ratio condition is met, the target resistance voltage loss value is calculated by combining the control cycle, current value, and correction coefficient of the pulse voltage signal. When the preset carrier ratio condition is not met, the target resistance voltage loss value is calculated by combining the control cycle and current values ​​at adjacent time points. Finally, the stator flux linkage is calculated based on the target resistance voltage loss value, improving the accuracy of stator flux linkage observation. Furthermore, determining the preset carrier ratio condition based on the speed fluctuation range allows the motor to adapt to the corresponding compensation method under different speed fluctuation conditions, further improving the accuracy of stator flux linkage observation. This method comprehensively enhances the control of various motors based on stator flux linkage. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a flowchart illustrating a motor flux linkage processing method in one embodiment;

[0051] Figure 2This is a flowchart illustrating the steps of obtaining the target resistance voltage loss value of the motor based on the motor's control cycle and current value, as well as a correction coefficient for the motor's pulse voltage signal, in one embodiment.

[0052] Figure 3 This is a flowchart illustrating the steps of obtaining the target resistance voltage loss value of the motor based on the control cycle and the current values ​​of two adjacent time points of the motor in one embodiment.

[0053] Figure 4 This is a flowchart illustrating the motor flux linkage processing method in another embodiment;

[0054] Figure 5 This is a comparative diagram of the target resistor voltage drop values ​​in one embodiment;

[0055] Figure 6 This is a partially enlarged schematic diagram of the comparison of target resistor voltage drop values ​​in one embodiment;

[0056] Figure 7 This is a structural block diagram of a motor flux linkage processing device in one embodiment;

[0057] Figure 8 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0059] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0060] In one embodiment, such as Figure 1As shown, a method for processing motor flux linkage is provided. This embodiment illustrates the application of this method to a motor control unit (MCU) installed in an electric vehicle. It is understood that this method can also be applied to servers, and to systems including in-vehicle terminals and servers, and implemented through the interaction between the in-vehicle terminal and the server. The motor controller is a core component of the power system of a new energy vehicle; it controls the motor's operating state. For example, the motor controller can convert the DC power from the power battery into high-voltage AC power to drive the motor to output mechanical energy, and precisely control the motor's speed, torque, and direction of rotation by receiving commands from the vehicle controller. The in-vehicle terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, and IoT devices mounted on the vehicle. The server can be an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services. In this embodiment, the method includes the following steps:

[0061] Step S101: Obtain the current carrier ratio of the motor based on the current speed information of the motor and the switching frequency information of the motor controller.

[0062] The current speed information refers to the number of revolutions per minute of the motor rotor under the current operating conditions.

[0063] Among them, the switching frequency information refers to the on and off frequency of the power switching devices in the motor controller.

[0064] The current carrier ratio is used to reflect the ratio of the switching frequency to the current rotational speed under the current operating conditions.

[0065] For example, during the operation of an electric vehicle, the motor controller monitors the current speed information of the motor and the switching frequency information of the motor controller in real time, so as to calculate the carrier ratio of the motor controller under the current operating condition, i.e., the current carrier ratio, using the current speed information and the switching frequency information.

[0066] Furthermore, the motor controller determines the carrier ratio threshold based on the motor's speed fluctuation range, and sets carrier ratio conditions based on the carrier ratio threshold. For example, the preset carrier ratio condition can be set to the current carrier ratio being less than the carrier ratio threshold. Then, the motor controller compares the current carrier ratio with the carrier ratio threshold to determine whether the current carrier ratio meets the preset carrier ratio condition.

[0067] Step S102: If the current carrier ratio is detected to meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained according to the motor control cycle and current value, as well as the correction coefficient for the motor pulse voltage signal; the preset carrier ratio condition is determined according to the motor speed fluctuation range.

[0068] Among them, the pulse voltage signal is the signal characteristic output by the motor (such as a motor inverter using space vector pulse width modulation technology).

[0069] Among them, the preset carrier ratio condition refers to the judgment condition set for the comparison relationship between the current carrier ratio and the carrier ratio threshold.

[0070] For example, if the motor detects that the current carrier ratio is less than the carrier ratio threshold and confirms that the current carrier ratio meets the preset carrier ratio condition, the motor controller can input the motor's control cycle and current value, as well as the correction coefficient for the motor's pulse voltage signal, into the compensation formula corresponding to the first speed to calculate the target resistance voltage loss value of the motor at the first speed.

[0071] Step S103: If the current carrier ratio is detected to be not satisfied with the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the control cycle and the current values ​​of two adjacent time points of the motor.

[0072] For example, if the current carrier ratio is greater than or equal to the carrier ratio threshold, it is confirmed that the current carrier ratio does not meet the preset carrier ratio condition. Then, the motor controller can input the control cycle and the current values ​​of two adjacent time points of the motor into the compensation formula corresponding to the second speed to calculate the target resistance voltage loss value of the motor at the second speed.

[0073] Step S104: Obtain the stator flux linkage of the motor based on the target resistor voltage loss value and the motor voltage value.

[0074] Among them, stator flux linkage is a physical quantity in electrical machinery that describes the total effect of the magnetic field generated by the stator windings of an electric motor.

[0075] For example, after calculating the target resistance voltage loss value using the compensation formula corresponding to the first speed (e.g., high speed) or the compensation formula corresponding to the second speed (e.g., medium and low speed), the motor controller inputs the target resistance voltage loss value and the motor voltage value in the two-phase stationary coordinate system into the voltage and flux linkage integral model, and outputs the stator flux linkage of the motor in the two-phase stationary coordinate system, thereby realizing the accurate observation of the stator flux linkage of the motor.

[0076] In practical applications, the voltage and flux linkage integral model can be represented in the following form:

[0077]

[0078] In the formula, This represents the stator flux linkage in a two-phase stationary coordinate system. U represents the voltage value in a two-phase stationary coordinate system. Rt represents the target resistor voltage drop value; t represents time.

[0079] In the aforementioned motor flux linkage processing method, the current carrier ratio is determined based on the motor's current speed information and the motor controller's switching frequency information. Then, a preset carrier ratio condition is determined based on the motor speed fluctuation range. This allows for accurate calculation of the target resistance voltage loss value under different conditions. Specifically, when the preset carrier ratio condition is met, the target resistance voltage loss value is calculated by combining the control cycle, current value, and correction coefficient of the pulse voltage signal. When the preset carrier ratio condition is not met, the target resistance voltage loss value is calculated by combining the control cycle and current values ​​at adjacent time points. Finally, the stator flux linkage is calculated based on the target resistance voltage loss value, improving the accuracy of stator flux linkage observation. Furthermore, determining the preset carrier ratio condition based on the speed fluctuation range allows the motor to adapt to the corresponding compensation method under different speed fluctuation conditions, further improving the accuracy of stator flux linkage observation. This comprehensively enhances the control of various motors based on stator flux linkage.

[0080] In one embodiment, such as Figure 2 As shown, step S102 above, based on the motor's control cycle and current value, and the correction coefficient for the motor's pulse voltage signal, obtains the target resistance voltage loss value of the motor, specifically including the following:

[0081] Step S201: Based on the stator resistance of the motor and the current value of the motor in the two-phase stationary coordinate system, obtain the first resistance voltage loss value of the motor.

[0082] Specifically, the motor controller calculates the first resistance voltage loss value of the motor in the continuous domain based on the stator resistance of the motor and the current value in the two-phase stationary coordinate system.

[0083] The voltage drop across the first resistor is defined as the error-free voltage drop across the resistor in the continuous domain. The formula for calculating the voltage drop across the first resistor is shown below:

[0084]

[0085] In the formula, U RH (t) represents the voltage value of the first resistor in the continuous domain; i αβ Represents the current value in a two-phase stationary coordinate system; R s Represents the stator resistance; j represents the imaginary unit; ω e Indicates electric angular velocity; k represents the point in time, t represents time. .

[0086] Step S202: Discretize the first resistor voltage loss value according to the control cycle to obtain the second resistor voltage loss value of the motor.

[0087] The control cycle refers to the time interval between the motor controller executing a complete control algorithm once.

[0088] Specifically, when the current carrier ratio is less than the carrier ratio threshold, it indicates that the motor is at its first speed (e.g., high speed). At this time, the current value changes rapidly within the control cycle. Therefore, the motor controller also needs to consider the discretization compensation of the first resistor voltage loss value within the control cycle. Thus, the first resistor voltage loss value is converted into a discretized form, and the motor controller obtains the second resistor voltage loss value. The formula for calculating the second resistor voltage loss value is as follows:

[0089]

[0090] In the formula, T represents the voltage drop across the second resistor in discretized form. s Indicates the control cycle.

[0091] Step S203: Based on the correction coefficient for the pulse voltage signal of the motor, the second resistor voltage loss value is corrected to obtain the target resistor voltage loss value of the motor at the first speed.

[0092] The first speed can be a high speed.

[0093] It should be noted that the second resistor voltage drop value is obtained by converting the error-free first resistor voltage drop value in the continuous domain. Therefore, the second resistor voltage drop value is a discrete, error-free resistor voltage drop value. In other words, the second resistor voltage drop value still does not take into account the shaping effect of the pulse voltage signal (generated by switching action) output by the Space Vector Pulse Width Modulation (SVPWM) of the motor on the current. When the pulse voltage signal acts on the motor windings, it shapes a specific current waveform. For example, ideally, SVPWM can make the motor current approximate a sine wave (reducing harmonics, improving motor efficiency and torque smoothness), which is the "shaping effect on the current".

[0094] Since SVPWM generates switching ripple (i.e., high-frequency fluctuations in the voltage / current waveform) during the output pulse voltage signal process, considering the impact of switching ripple on the voltage loss value of the second resistor, a correction coefficient for the motor's pulse voltage signal can be introduced to correct the voltage loss value of the second resistor, thereby obtaining the target voltage loss value of the motor at the first speed. For example, the formula for calculating the target voltage loss value (i.e., the compensation formula corresponding to the second speed) is as follows:

[0095]

[0096] In the formula, U RH (k) represents the target resistance voltage loss value calculated under the condition that the current carrier ratio meets the preset carrier ratio (i.e., using the compensation formula under high speed); s PWM This represents the correction factor. When s PWM When =1, it means that the effect of the switching ripple on the voltage drop of the second resistor is ignored.

[0097] The correction coefficient can also be calibrated according to the actual application scenario.

[0098] In this embodiment, the first resistance voltage loss value without error in the continuous domain is obtained by using the stator resistance of the motor and the current value in the two-phase stationary coordinate system. Then, it is discretized in combination with the control cycle to obtain the discretized second resistance voltage loss value without error. The second resistance voltage loss value is then corrected by the correction coefficient for the pulse voltage signal to obtain the target resistance voltage loss value of the motor at the first speed. This discretization process adapts to the timing characteristics of the motor controller, considers the influence of the switching ripple generated by the pulse voltage signal on the resistance voltage loss value, and further reduces the deviation and discretization error caused by the pulse voltage signal by the correction coefficient. This significantly improves the accuracy of the target resistance voltage loss value, lays a solid foundation for the accurate acquisition of key parameters such as the stator flux linkage of the motor, effectively optimizes the accuracy and stability of motor control, and ensures that the motor operates efficiently and smoothly at the first speed.

[0099] In one embodiment, before correcting the second resistor voltage loss value based on the correction coefficient for the motor's pulse voltage signal in step S203 to obtain the target resistor voltage loss value of the motor at the first speed, the method further includes: when the motor outputs a pulse voltage signal through space vector pulse width modulation, obtaining a first correction coefficient for the fundamental wave of the motor in the positive half-cycle and a second correction coefficient for the fundamental wave in the negative half-cycle based on the switching ripple of the space vector pulse width modulation; and setting the first correction coefficient and the second correction coefficient as the correction coefficient for the motor's pulse voltage signal.

[0100] The fundamental wave refers to the sinusoidal wave component in a complex periodic oscillation that has the longest period of that oscillation, and the frequency corresponding to this period is called the fundamental wave frequency.

[0101] For example, when the motor outputs a pulse voltage signal via space vector pulse width modulation, the power switching devices in the motor controller can only operate in two states, "on" and "off," and cannot output an ideal continuous sinusoidal voltage. Therefore, a series of discrete pulse voltage signals are output by rapidly switching the switching states. Switching ripple is a high-frequency fluctuation generated during the switching of the pulse voltage signal. For instance, when the switching device rapidly switches on and off, the voltage jumps instantaneously from a high potential to a low potential. This rapid voltage change is superimposed on the waveform by high-frequency oscillations through parasitic parameters such as the inductance and capacitance of the motor windings (e.g., the "back electromotive force" of the winding inductance, the charging and discharging of stray capacitance in the lines), forming switching ripple. Switching ripple causes two symmetrical coefficients for the motor's fundamental frequency in both the positive and negative half-cycles. The motor controller then obtains a first correction coefficient for the motor's fundamental frequency in the positive half-cycle and a second correction coefficient for the motor's fundamental frequency in the negative half-cycle, and sets both the first and second correction coefficients as correction coefficients for the motor's pulse voltage signal.

[0102] In practical applications, the first correction factor can be expressed as: The second correction factor can be expressed as: Where Δs represents the correction factor of the correction coefficient for the pulse voltage signal after considering the switching ripple.

[0103] In this embodiment, when the motor outputs a pulse voltage signal using space vector pulse width modulation, the first correction coefficient of the positive half-cycle and the second correction coefficient of the negative half-cycle of the fundamental wave are obtained based on its switching ripple, and these two are set as correction coefficients for the pulse voltage signal. This achieves accurate capture of the symmetrical influence characteristics of the switching ripple in the positive and negative half-cycles of the fundamental wave, making the correction coefficients highly compatible with the actual waveform characteristics of the pulse voltage signal. It fully considers the shaping effect of the pulse voltage signal on the current under space vector pulse width modulation, and effectively compensates for the deviation caused by the switching ripple through accurate half-cycle correction, thereby improving the accuracy of the subsequent calculation of the target resistance voltage loss value.

[0104] In one embodiment, such as Figure 3 As shown, step S103 above, based on the control cycle and the current values ​​of two adjacent time points of the motor, obtains the target resistance voltage drop value of the motor, specifically including the following:

[0105] Step S301: Obtain the average current value based on the average current value between two adjacent time points of the motor in the two-phase stationary coordinate system.

[0106] For example, when the current carrier ratio is greater than or equal to the carrier ratio threshold, it means that the motor is at the second speed (e.g., medium-low speed). At this time, the current value changes relatively slowly within the control cycle. Therefore, the motor controller can approximate the actual current value within the control cycle as the average value between the current values ​​at two adjacent time points, and the motor controller obtains the average current value.

[0107] In practical applications, the average current can be expressed by the following formula:

[0108]

[0109] In the formula, k represents the time point.

[0110] Since the current value at time k+1 cannot be obtained at time k, the estimated current value at time k+1 can be used instead of the actual current value.

[0111] Step S302: Based on the average current, stator resistance, and control cycle, obtain the target resistance voltage loss value of the motor at the second speed.

[0112] The first speed is greater than the second speed. The second speed can be a medium or low speed.

[0113] For example, the motor controller uses the average current, stator resistance, and control cycle to calculate the target resistance voltage drop value of the motor at the second speed. The calculation formula for the target resistance voltage drop value (i.e., the compensation formula corresponding to the first speed) is as follows:

[0114]

[0115] In the formula, U RL This indicates the target resistance voltage loss value calculated when the current carrier ratio does not meet the preset carrier ratio condition (i.e., the compensation formula under medium and low speed is used).

[0116] In this embodiment, by taking the average value of the current values ​​of the motor at two adjacent time points in the two-phase stationary coordinate system, and combining the stator resistance and control cycle to calculate the target resistance voltage loss value at the second speed, the influence of instantaneous fluctuations in the current values ​​at adjacent times can be fully utilized, making the current parameters more consistent with the actual operating conditions of the motor. This makes the calculated target resistance voltage loss value more suitable for the motor operating characteristics at the second speed, providing reliable data support for subsequent stator flux calculation.

[0117] In one embodiment, after obtaining the current carrier ratio of the motor based on the current speed information of the motor and the switching frequency information of the motor controller in step S101, the method further includes: obtaining the carrier ratio threshold of the motor based on the switching frequency information, the number of pole pairs of the motor and the speed fluctuation range; if the current carrier ratio is less than the carrier ratio threshold, it is confirmed that the current carrier ratio meets the preset carrier ratio condition; if the current carrier ratio is greater than or equal to the carrier ratio threshold, it is confirmed that the current carrier ratio does not meet the preset carrier ratio condition.

[0118] It should be noted that, considering the potential inclusion of sampling noise, speed fluctuations caused by torque pulsation, and speed fluctuations due to sudden load changes in the current speed information under actual operating conditions, and considering the possibility of using the motor's stator flux linkage for sensorless control, the electrical angular velocity of the motor corresponding to the current speed information may be zero-crossing. This could lead to an anomaly where the compensation amount used to calculate the target resistance voltage loss value is infinite. Therefore, to address this potential anomaly in the compensation amount, a method for calculating the carrier ratio threshold based on the speed fluctuation range is proposed.

[0119] The speed fluctuation range can be obtained by evaluating the actual operating conditions.

[0120] For example, the motor controller can calculate the carrier ratio threshold of the motor based on the ratio between the switching frequency information and the speed fluctuation range and the number of pole pairs of the motor. The formula for calculating the carrier ratio threshold is as follows:

[0121]

[0122] In the formula, R limit Indicates the carrier ratio threshold; f sw Represents switching frequency information; |Δn| represents current rotational speed information, with the unit of current rotational speed being revolutions per minute; N p It represents the extreme logarithm.

[0123] Furthermore, after obtaining the current carrier ratio, the motor controller compares the current carrier ratio with a carrier ratio threshold to calculate the target resistance voltage loss value using compensation formulas for different speed conditions. If the current carrier ratio is detected to be less than the carrier ratio threshold, it is confirmed that the current carrier ratio meets the preset carrier ratio condition, and the target resistance voltage loss value can be calculated using the compensation formula for high speed. If the current carrier ratio is greater than or equal to the carrier ratio threshold, it is confirmed that the current carrier ratio does not meet the preset carrier ratio condition, and the target resistance voltage loss value can be calculated using the compensation formula for medium and low speeds. This is used to calculate the target resistance voltage loss value U of the stator flux linkage. R It can be represented in the following form:

[0124]

[0125] In the formula, R represents the current carrier ratio.

[0126] In this embodiment, the carrier ratio threshold of the motor is calculated based on the ratio between the switching frequency information, the speed fluctuation range, and the number of pole pairs of the motor. Then, the relationship between the current carrier ratio and the carrier ratio threshold is used to determine whether the preset carrier ratio condition is met. This achieves accurate quantification of the carrier ratio threshold and ensures that the carrier ratio threshold is adapted to the actual working conditions of motor speed fluctuation. This provides a reliable basis for subsequent selection of the compensation formula corresponding to each speed to calculate the target resistance voltage loss value.

[0127] In one embodiment, the current rotational speed information is an estimated value or an actual value. Step S101 above, obtaining the current carrier ratio of the motor based on the current rotational speed information of the motor and the switching frequency information of the motor controller, includes: obtaining the current carrier ratio of the motor based on the switching frequency information, the current rotational speed information, and the number of pole pairs.

[0128] It should be noted that, considering that the current speed information may include sampling noise, speed fluctuations caused by torque pulsation, and speed fluctuations caused by sudden load changes under actual operating conditions, and considering that the stator flux of the motor can be used for sensorless control in the future, the current speed information may not be the actual speed value but an estimated speed value.

[0129] For example, the motor controller uses the ratio between the switching frequency information, the current speed information, and the number of pole pairs of the motor to calculate the current carrier ratio under the current operating conditions in real time. In practical applications, the formula for calculating the current carrier ratio R is as follows:

[0130]

[0131] In the formula, |n| represents the current rotational speed information.

[0132] In this embodiment, by using the estimated or actual value of the motor's current speed information, combined with the switching frequency information of the motor controller and the number of pole pairs of the motor, the current carrier ratio is calculated in real time, realizing the accurate acquisition of the carrier ratio under the current operating condition, and providing a reliable processing basis for subsequent observation of the target resistance voltage loss value and stator flux linkage of the motor.

[0133] In one embodiment, such as Figure 4 As shown, another method for handling motor flux linkage is provided. Taking the application of this method to a motor controller as an example, the method includes the following steps:

[0134] Step S401: Based on the switching frequency information, current speed information, and number of pole pairs, obtain the current carrier ratio of the motor.

[0135] Step S402: Based on the switching frequency information, the number of pole pairs of the motor, and the speed fluctuation range, the carrier ratio threshold of the motor is obtained.

[0136] Then, based on the comparison between the current carrier ratio and the carrier ratio threshold, the system selects to execute either step S403 or step S404: if the current carrier ratio is less than the carrier ratio threshold, it confirms that the current carrier ratio meets the preset carrier ratio condition and proceeds to step S403. If the current carrier ratio is greater than or equal to the carrier ratio threshold, it confirms that the current carrier ratio does not meet the preset carrier ratio condition and proceeds to step S404.

[0137] Step S403: Obtain the average current value based on the average current value between two adjacent time points of the motor in the two-phase stationary coordinate system; obtain the target resistance voltage loss value of the motor at the second speed based on the average current value, stator resistance, and control cycle.

[0138] Proceed to step S407.

[0139] Step S404: Based on the stator resistance of the motor and the current value of the motor in the two-phase stationary coordinate system, obtain the first resistance voltage loss value of the motor.

[0140] Step S405: Discretize the first resistor voltage loss value according to the control cycle to obtain the second resistor voltage loss value of the motor.

[0141] Step S406: Based on the correction coefficient for the pulse voltage signal of the motor, the second resistor voltage loss value is corrected to obtain the target resistor voltage loss value of the motor at the first speed.

[0142] Proceed to step S407.

[0143] Step S407: Obtain the stator flux linkage of the motor based on the target resistor voltage loss value and the motor voltage value.

[0144] The above-described motor flux linkage processing method achieves the following beneficial effects: By determining the current carrier ratio based on the motor's current speed information and the motor controller's switching frequency information, and then combining this with a preset carrier ratio condition determined by the motor speed fluctuation range, the target resistance voltage loss value can be accurately calculated under different conditions. Specifically, when the preset carrier ratio condition is met, the target resistance voltage loss value is calculated by combining the control cycle, current value, and correction coefficient of the pulse voltage signal; when the preset carrier ratio condition is not met, the target resistance voltage loss value is calculated by combining the control cycle and current value at adjacent time points. Finally, the stator flux linkage is calculated based on the target resistance voltage loss value, improving the accuracy of stator flux linkage observation. Furthermore, determining the preset carrier ratio condition based on the speed fluctuation range allows the motor to adapt to the corresponding speed compensation method under different speed fluctuation conditions, further improving the accuracy of stator flux linkage observation. This comprehensively enhances the control of various motors based on stator flux linkage.

[0145] To more clearly illustrate the motor flux linkage processing method provided in this disclosure, a specific embodiment is given below for detailed description. This application also provides another motor flux linkage processing method, which can be applied to a motor controller, and specifically includes the following:

[0146] The motor controller uses the ratio between the switching frequency information, the current speed information, and the number of pole pairs of the motor to calculate the current carrier ratio of the motor under the current operating conditions in real time.

[0147]

[0148] Furthermore, based on the ratio between the switching frequency information and the speed fluctuation range and the number of pole pairs of the motor, the carrier ratio threshold of the motor is calculated:

[0149]

[0150] when At that time, the target resistor voltage loss value is calculated using the compensation formula corresponding to the second rotational speed:

[0151]

[0152] when At that time, the target resistor voltage loss value is calculated using the compensation formula corresponding to the first rotational speed:

[0153]

[0154] It should be noted that the formulas mentioned above can be found in the explanations of the relevant formulas, and will not be repeated here.

[0155] As the motor speed increases, the target resistance voltage drop values ​​obtained by different calculation methods are compared. Figure 5 This is a schematic diagram comparing the voltage drop values ​​of the target resistor. Figure 6 for Figure 5 A magnified view of a portion of the image. Figure 5 and Figure 6 In the middle, the cross near the outermost circle represents U. RH The cross closest to the inner circle represents U. RL The circle represents the target resistance voltage drop value calculated without considering any compensation. Figure 5 and Figure 6 It can be seen that at low speeds, the target resistance voltage loss values ​​calculated by the three methods are not significantly different. However, as the speed increases, the target resistance voltage loss values ​​calculated by the three methods show significant differences. Therefore, the compensation formula proposed in this application is very important and beneficial. By compensating for the resistance voltage loss, the stator flux linkage can be calculated more accurately at high speeds. This, in turn, comprehensively improves various motor control algorithms based on stator flux linkage, such as torque estimation, sensorless control, and magnet health monitoring.

[0156] In this embodiment, the following beneficial effects can be achieved: by determining the current carrier ratio based on the current speed information of the motor and the switching frequency information of the motor controller, and then combining this with the preset carrier ratio condition determined by the motor speed fluctuation range, the target resistance voltage loss value can be accurately calculated under different conditions. That is, when the preset carrier ratio condition is met, the target resistance voltage loss value is calculated by combining the control cycle, current value, and correction coefficient of the pulse voltage signal; when the preset carrier ratio condition is not met, the target resistance voltage loss value is calculated by combining the control cycle and the current value at adjacent time points. Finally, the stator flux is calculated based on the target resistance voltage loss value, which improves the observation accuracy of the motor's stator flux. At the same time, determining the preset carrier ratio condition based on the speed fluctuation range allows the motor to adapt to the corresponding speed compensation method under different speed fluctuation conditions, further improving the observation accuracy of the stator flux. This has a comprehensive improvement effect on the control of various motors based on stator flux.

[0157] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0158] Based on the same inventive concept, this application also provides a motor flux linkage processing apparatus for implementing the motor flux linkage processing method described above. The solution provided by this apparatus is similar to the implementation described in the above method; therefore, the specific limitations in one or more embodiments of the motor flux linkage processing apparatus provided below can be found in the limitations of the motor flux linkage processing method described above, and will not be repeated here.

[0159] In one embodiment, such as Figure 7 As shown, a motor flux linkage processing device 700 is provided, including: a carrier ratio determination module 701, a first loss determination module 702, a second loss determination module 703, and a stator flux linkage determination module 704, wherein:

[0160] The carrier ratio determination module 701 is used to obtain the current carrier ratio of the motor based on the current speed information of the motor and the switching frequency information of the motor controller.

[0161] The first loss determination module 702 is used to determine the target resistance voltage loss value of the motor based on the motor's control cycle and current value, as well as the correction coefficient for the motor's pulse voltage signal, if the current carrier ratio is detected to meet the preset carrier ratio condition. The preset carrier ratio condition is determined based on the motor's speed fluctuation range.

[0162] The second loss determination module 703 is used to obtain the target resistance voltage loss value of the motor based on the control cycle and the current values ​​of two adjacent time points of the motor if the current carrier ratio is detected to be not satisfied with the preset carrier ratio condition.

[0163] The stator flux linkage determination module 704 is used to obtain the stator flux linkage of the motor based on the target resistance voltage loss value and the motor voltage value.

[0164] In one embodiment, the first loss determination module 702 is further configured to obtain a first resistance voltage loss value of the motor based on the stator resistance of the motor and the current value of the motor in a two-phase stationary coordinate system; to discretize the first resistance voltage loss value according to the control cycle to obtain a second resistance voltage loss value of the motor; and to correct the second resistance voltage loss value based on the correction coefficient for the pulse voltage signal of the motor to obtain a target resistance voltage loss value of the motor at a first speed.

[0165] In one embodiment, the motor flux linkage processing device 700 further includes a correction coefficient acquisition module, which is used to obtain a first correction coefficient of the fundamental wave of the motor in the positive half-cycle and a second correction coefficient of the fundamental wave in the negative half-cycle based on the switching ripple of the space vector pulse width modulation when the motor outputs a pulse voltage signal through space vector pulse width modulation; and set the first correction coefficient and the second correction coefficient as correction coefficients for the pulse voltage signal of the motor.

[0166] In one embodiment, the second loss determination module 703 is further configured to obtain an average current value based on the average current value between two adjacent time points of the motor in a two-phase stationary coordinate system; and to obtain a target resistance voltage loss value of the motor at a second speed based on the average current value, stator resistance, and control cycle; wherein the first speed is greater than the second speed.

[0167] In one embodiment, the motor flux linkage processing device 700 further includes a carrier ratio comparison module, which is used to obtain the carrier ratio threshold of the motor based on the switching frequency information, the number of pole pairs of the motor and the speed fluctuation range; if the current carrier ratio is less than the carrier ratio threshold, it is confirmed that the current carrier ratio meets the preset carrier ratio condition; if the current carrier ratio is greater than or equal to the carrier ratio threshold, it is confirmed that the current carrier ratio does not meet the preset carrier ratio condition.

[0168] In one embodiment, the current rotational speed information is an estimated value or an actual value. The carrier ratio determination module 701 is further configured to obtain the current carrier ratio of the motor based on the switching frequency information, the current rotational speed information, and the number of pole pairs.

[0169] Each module in the aforementioned motor flux linkage processing device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0170] In one exemplary embodiment, a computer device is provided, which may be a motor controller, and its internal structure diagram may be as follows: Figure 8As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media. The database stores data such as current rotational speed and switching frequency. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a motor flux linkage processing method.

[0171] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0172] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0173] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0174] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0175] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0176] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0177] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0178] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for processing magnetic flux linkage in an electric motor, characterized in that, The method includes: The current carrier ratio of the motor is obtained based on the current speed information of the motor and the switching frequency information of the motor controller; If the current carrier ratio is detected to meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the motor's control cycle and current value, as well as the correction coefficient for the motor's pulse voltage signal; the preset carrier ratio condition is determined based on the motor's speed fluctuation range. If it is detected that the current carrier ratio does not meet the preset carrier ratio condition, the target resistance voltage loss value of the motor is obtained based on the control cycle and the current values ​​of two adjacent time points of the motor. The stator flux linkage of the motor is obtained based on the target resistor voltage loss value and the motor voltage value.

2. The method according to claim 1, characterized in that, The step of obtaining the target resistance voltage loss value of the motor based on the motor's control cycle and current value, and a correction coefficient for the motor's pulse voltage signal, includes: The first resistance voltage loss value of the motor is obtained based on the stator resistance of the motor and the current value of the motor in the two-phase stationary coordinate system. According to the control cycle, the first resistor voltage loss value is discretized to obtain the second resistor voltage loss value of the motor; Based on the correction coefficient for the pulse voltage signal of the motor, the second resistor voltage loss value is corrected to obtain the target resistor voltage loss value of the motor at the first speed.

3. The method according to claim 2, characterized in that, Before correcting the second resistor voltage loss value based on the correction coefficient for the pulse voltage signal of the motor to obtain the target resistor voltage loss value of the motor at the first speed, the method further includes: When the motor outputs a pulse voltage signal through space vector pulse width modulation, based on the switching ripple of the space vector pulse width modulation, the first correction coefficient of the fundamental wave of the motor in the positive half-cycle and the second correction coefficient of the fundamental wave in the negative half-cycle are obtained. The first correction factor and the second correction factor are set as correction factors for the pulse voltage signal of the motor.

4. The method according to claim 2, characterized in that, The step of obtaining the target resistance voltage drop value of the motor based on the control cycle and the current values ​​of two adjacent time points of the motor includes: The average current value is obtained by averaging the current values ​​of the motor at two adjacent time points in the two-phase stationary coordinate system. The target resistance voltage drop value of the motor at the second speed is obtained based on the average current, the stator resistance, and the control cycle. Wherein, the first rotational speed is greater than the second rotational speed.

5. The method according to any one of claims 1 to 4, characterized in that, After obtaining the current carrier ratio of the motor based on the current speed information of the motor and the switching frequency information of the motor controller, the method further includes: Based on the switching frequency information, the number of pole pairs of the motor, and the speed fluctuation range, the carrier ratio threshold of the motor is obtained; If the current carrier ratio is less than the carrier ratio threshold, then it is confirmed that the current carrier ratio meets the preset carrier ratio condition; If the current carrier ratio is greater than or equal to the carrier ratio threshold, then it is confirmed that the current carrier ratio does not meet the preset carrier ratio condition.

6. The method according to claim 5, characterized in that, The current rotational speed information is either an estimated value or an actual value; Based on the current speed information of the motor and the switching frequency information of the motor controller, the current carrier ratio of the motor is obtained, including: The current carrier ratio of the motor is obtained based on the switching frequency information, the current rotational speed information, and the number of pole pairs.

7. A motor flux linkage processing device, characterized in that, The device includes: The carrier ratio determination module is used to obtain the current carrier ratio of the motor based on the current speed information of the motor and the switching frequency information of the motor controller; The first loss determination module is used to determine the target resistance voltage loss value of the motor based on the control cycle and current value of the motor, and the correction coefficient for the pulse voltage signal of the motor, if the current carrier ratio is detected to meet the preset carrier ratio condition; the preset carrier ratio condition is determined based on the speed fluctuation range of the motor. The second loss determination module is used to determine the target resistance voltage loss value of the motor based on the control cycle and the current values ​​of two adjacent time points of the motor if the current carrier ratio is detected to not meet the preset carrier ratio condition. The stator flux linkage determination module is used to obtain the stator flux linkage of the motor based on the target resistor voltage loss value and the motor voltage value.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, The steps of implementing the method of any one of claims 1 to 6 when the processor executes a computer program.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When a computer program is executed by a processor, it implements the steps of the method of any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method of any one of claims 1 to 6.

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