Adaptive flux-weakening control method and device under speed sensorless condition

Abstract

This application provides an adaptive field weakening control method and apparatus under sensorless conditions. The method includes: planning reference values ​​for excitation current and torque current of an induction motor in a high-speed field weakening region; modifying the voltage flux linkage model in the MRAS speed observer and compensating the rotor time constant in the current flux linkage model to improve the accuracy of speed observation; performing adaptive complex vector current decoupling on the reference values ​​for excitation current, torque current, actual excitation current, and actual torque current to obtain reference values ​​for excitation voltage and torque voltage of the induction motor; performing flux linkage tracking on the reference values ​​for excitation voltage and torque voltage to obtain corresponding pulse width modulation (PWM) waves; and using the PWM waves to drive an inverter to achieve adaptive field weakening control of the motor. This application enables adaptive field weakening control of the induction motor even when it is operating at high speed.

Description

Technical Field

[0001] This application relates to the field of mechanical control, specifically an adaptive field weakening control method and device under sensorless conditions. Background Technology

[0002] High-speed control of induction motors is widely used in new energy vehicles, high-speed train traction, and CNC machine tools. Vector control technology, due to its excellent dynamic and static performance, is widely used in the speed control of induction motors. In harsh environments such as mining motors and tunnel boring machines (TBMs), the installation and maintenance of speed sensors are difficult, so sensorless vector control is generally used to control the motor. When TBMs encounter light-load conditions such as soft soil layers, the cutterhead drive motor often needs to operate above its rated speed to improve efficiency. When the motor frequency exceeds the fundamental frequency, the back electromotive force generated by the motor increases, but the supply voltage of the motor generally cannot be increased, which hinders further increases in motor speed. It is necessary to reduce the motor's magnetic field to keep the motor operating above its rated speed; this method is called field weakening control.

[0003] Traditional field weakening control methods are " "Field weakening control" is a method that makes the rotor magnetic field inversely proportional to the rotational speed to achieve field weakening control. This method is simple to implement and widely used in applications with low control requirements. However, it causes premature voltage saturation, significantly impacting the torque output of the induction motor. Its dynamic response is slow, and the control effect is highly sensitive to the selection of the initial excitation current. It typically cannot achieve maximum torque output. Under load, without studying the maximum torque control mechanism of the induction motor under field weakening acceleration, relying solely on "field weakening control" will be insufficient. The "weakening field control" method cannot meet the requirements of high-performance, high-speed drive. Summary of the Invention

[0004] To address the problems in the prior art, this application provides an adaptive field weakening control method and apparatus under sensorless conditions, which can realize adaptive high-speed field weakening control of the induction motor when the induction motor is running at high speed.

[0005] To solve the above-mentioned technical problems, this application provides the following technical solution:

[0006] In a first aspect, this application provides an adaptive field weakening control method under sensorless conditions, comprising:

[0007] Based on the operating state of the induction motor in the high-speed field-weakening region, the reference values ​​of excitation current and torque current are planned; the motor voltage flux linkage model in the MRAS speed observer is modified, and the rotor time constant in the current flux linkage model is compensated to improve the accuracy of speed observation; adaptive complex vector current decoupling is performed on the reference values ​​of excitation current, torque current, actual excitation current, and actual torque current of the induction motor to obtain the reference values ​​of excitation voltage and torque voltage of the induction motor.

[0008] The excitation voltage reference value and torque voltage reference value are subjected to flux tracking to obtain the corresponding pulse width modulation wave;

[0009] The inverter is driven by the pulse width modulation wave to achieve high-speed field weakening control.

[0010] Furthermore, before performing adaptive complex vector current decoupling on the excitation current reference value, torque current reference value, actual excitation current value, and actual torque current value of the induction motor to obtain the excitation voltage reference value and torque voltage reference value of the induction motor, the process further includes:

[0011] The real-time rotor speed of the induction motor is determined based on the stator current sampling value and the stator voltage sampling value of the induction motor.

[0012] The excitation current reference value and the torque current reference value are determined based on the rotor angular frequency reference value, the real-time rotor speed, and the current reference value of the output voltage of the induction motor.

[0013] Further, the real-time rotor speed includes: synchronous angular frequency and rotor angular frequency; the step of determining the real-time rotor speed of the induction motor based on the stator current sampling value and stator voltage sampling value of the induction motor includes:

[0014] The stator current sample values ​​are subjected to Clarke coordinate transformation to obtain the corresponding stator current α-axis component and stator current β-axis component;

[0015] The stator voltage sample values ​​are subjected to Clarke coordinate transformation to obtain the corresponding stator voltage α-axis component and stator voltage β-axis component;

[0016] The estimated values ​​of the rotor flux linkage α-axis component and the estimated values ​​of the rotor flux linkage β-axis component are determined based on the stator current α-axis component, stator current β-axis component, stator voltage α-axis component and stator voltage β-axis component.

[0017] The rotor angular frequency is determined based on the reference values ​​of the rotor flux linkage α-axis component, the reference values ​​of the rotor flux linkage β-axis component, the estimated values ​​of the rotor flux linkage α-axis component, and the estimated values ​​of the rotor flux linkage β-axis component.

[0018] The rotor time constant compensation value is determined based on the reference values ​​of the rotor flux linkage α-axis component, the reference values ​​of the rotor flux linkage β-axis component, the estimated values ​​of the rotor flux linkage α-axis component and the estimated values ​​of the rotor flux linkage β-axis component, the stator current α-axis component, and the stator current β-axis component.

[0019] The synchronization angular frequency is determined based on the slip angular frequency containing the rotor time constant compensation value.

[0020] Further, determining the excitation current reference value and the torque current reference value based on the rotor angular frequency reference value, the real-time rotor speed, and the current reference value of the output voltage of the induction motor includes:

[0021] The excitation current reference value is determined based on the preset maximum stator voltage, the initial synchronous angular frequency of the constant voltage zone when the induction motor enters the constant voltage working zone, the synchronous angular frequency, the excitation voltage reference value, and the torque voltage reference value.

[0022] The first torque current q-axis limit value is determined based on the preset maximum stator current and the torque current d-axis reference value.

[0023] The second torque current q-axis limit value is determined based on the maximum stator voltage and the excitation voltage reference value.

[0024] The final limiting value is determined based on the first torque current q-axis limiting value and the second torque current q-axis limiting value;

[0025] The torque current reference value is determined based on the rotor angular frequency reference value, the synchronous angular frequency, and the final limiting value.

[0026] Furthermore, adaptive complex vector current decoupling is performed on the excitation current reference value, torque current reference value, actual excitation current value, and actual torque current value of the induction motor to obtain the excitation voltage reference value and torque voltage reference value of the induction motor, including:

[0027] The stator current sample value is subjected to Park transformation to obtain the actual value of the excitation current and the actual value of the torque current.

[0028] When the synchronization angular frequency is less than or equal to the initial synchronization angular frequency of the constant voltage zone, the excitation voltage reference value and the torque voltage reference value are determined based on the excitation current reference value, the torque current reference value, the actual excitation current value, the actual torque current value, and the initial synchronization angular frequency of the constant voltage zone.

[0029] When the synchronization angular frequency is greater than the initial synchronization angular frequency of the constant voltage zone, the excitation voltage reference value and the torque voltage reference value are determined based on the excitation current reference value, the torque current reference value, the actual excitation current value, the actual torque current value, the synchronization angular frequency, and the initial synchronization angular frequency of the constant voltage zone.

[0030] Further, flux linkage tracking is performed on the excitation voltage reference value and torque voltage reference value to obtain the corresponding pulse width modulation wave, including:

[0031] The excitation voltage reference value and torque voltage reference value are subjected to a two-phase rotating to stationary orthogonal transformation to obtain the corresponding α-axis output voltage reference value and β-axis output voltage reference value;

[0032] The output voltage reference values ​​of the α-axis and β-axis are subjected to space vector pulse width modulation to obtain the pulse width modulated wave.

[0033] Furthermore, the adaptive field weakening control includes: a stator voltage control signal; the use of the pulse width modulation wave to drive the inverter to achieve field weakening control of the induction motor includes:

[0034] The pulse width modulation wave is used to drive the fully controlled switching transistor in the inverter, thereby controlling the voltage-source inverter and outputting the stator voltage control signal.

[0035] Secondly, this application provides an adaptive field weakening control device under sensorless conditions, including...

[0036] The voltage reference value determination unit is used to perform adaptive complex vector current decoupling on the excitation current reference value, torque current reference value, actual excitation current value and actual torque current value of the induction motor to obtain the excitation voltage reference value and torque voltage reference value of the induction motor.

[0037] The modulation wave generation unit is used to perform flux tracking on the excitation voltage reference value and torque voltage reference value to obtain the corresponding pulse width modulation wave.

[0038] A field weakening control unit is used to drive the inverter using the pulse width modulation wave to achieve field weakening control.

[0039] Furthermore, the adaptive field weakening control device under sensorless conditions further includes:

[0040] The rotor real-time speed determination unit is used to determine the rotor real-time speed of the induction motor based on the stator current sampling value and the stator voltage sampling value of the induction motor.

[0041] The current reference value determination unit is used to determine the excitation current reference value and the torque current reference value based on the rotor angular frequency reference value, the real-time rotor speed, and the current reference value of the output voltage of the induction motor.

[0042] Furthermore, the real-time rotor speed includes: synchronous angular frequency and rotor angular frequency; the real-time rotor speed determination unit includes:

[0043] The current component determination module is used to perform Clarke coordinate transformation on the stator current sample value to obtain the corresponding stator current α-axis component and stator current β-axis component.

[0044] The voltage component determination module is used to perform Clarke coordinate transformation on the stator voltage sampled values ​​to obtain the corresponding stator voltage α-axis component and stator voltage β-axis component;

[0045] The flux linkage estimation module is used to determine the estimated values ​​of the rotor flux linkage α-axis component and the rotor flux linkage β-axis component based on the stator current α-axis component, stator current β-axis component, stator voltage α-axis component and stator voltage β-axis component.

[0046] The rotor time constant compensation value confirmation module determines the rotor time constant compensation value based on the reference values ​​of the rotor flux linkage α-axis component, the rotor flux linkage β-axis component, the estimated values ​​of the rotor flux linkage α-axis component and the estimated values ​​of the rotor flux linkage β-axis component, the stator current α-axis component, and the stator current β-axis component.

[0047] The rotor angular frequency determination module is used to determine the rotor angular frequency based on the reference values ​​of the rotor flux linkage α-axis component, the reference values ​​of the rotor flux linkage β-axis component, the estimated values ​​of the rotor flux linkage α-axis component, and the estimated values ​​of the rotor flux linkage β-axis component.

[0048] The synchronization angular frequency determination module is used to determine the synchronization angular frequency based on the slip angular frequency containing the rotor time constant compensation value.

[0049] Furthermore, the current reference value determination unit includes:

[0050] The excitation current reference value determination module is used to determine the excitation current reference value based on the preset maximum stator voltage, the synchronous angular frequency when the induction motor enters the constant voltage working area, the synchronous angular frequency, the excitation voltage reference value, and the torque voltage reference value.

[0051] The first limit value determination module is used to determine the first torque current q-axis limit value based on the preset maximum stator current and the torque current d-axis reference value.

[0052] The second limit value determination module is used to determine the second torque current q-axis limit value based on the maximum stator voltage and the excitation voltage reference value.

[0053] The final limit value determination module is used to determine the final limit value based on the first torque current q-axis limit value and the second torque current q-axis limit value;

[0054] The torque current reference value determination module is used to determine the torque current reference value based on the rotor angular frequency reference value, the synchronous angular frequency, and the final limiting value.

[0055] Furthermore, the voltage reference value determination unit includes:

[0056] The actual current value determination module is used to perform Park transformation on the stator current sample value to obtain the actual value of the excitation current and the actual value of the torque current.

[0057] The first voltage reference value determination module is used to determine the excitation voltage reference value and the torque voltage reference value based on the excitation current reference value, the torque current reference value, the actual value of the excitation current, the actual value of the torque current and the synchronization angular frequency when the synchronization angular frequency is less than or equal to the initial synchronization angular frequency of the constant voltage region.

[0058] The second voltage reference value determination module is used to determine the excitation voltage reference value and the torque voltage reference value based on the excitation current reference value, the torque current reference value, the actual excitation current value, the actual torque current value, the synchronization angular frequency, and the synchronization angular frequency when the synchronization angular frequency is greater than the initial synchronization angular frequency of the constant voltage zone.

[0059] Further, the modulation wave generation unit includes:

[0060] The orthogonal voltage reference value determination module is used to perform a two-phase rotation to a stationary orthogonal transformation on the excitation voltage reference value and the torque voltage reference value to obtain the corresponding α-axis output voltage reference value and β-axis output voltage reference value;

[0061] The modulation wave generation module is used to perform space vector pulse width modulation on the output voltage reference values ​​of the α-axis and the β-axis to obtain the pulse width modulated wave.

[0062] Furthermore, the adaptive field weakening control includes: a stator voltage control signal; the field weakening control unit includes:

[0063] The fully controlled switching transistor in the inverter is driven by the pulse width modulation wave to output the stator voltage control signal.

[0064] Thirdly, this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the adaptive field weakening control method.

[0065] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the adaptive field weakening control method.

[0066] Fifthly, this application provides a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of the adaptive field weakening control method.

[0067] To address the problems in the prior art, the adaptive field weakening control method and device for induction motors without speed sensors provided in this application can observe the rotor speed of the induction motor under complex working conditions using an improved speed observer. By combining the complex vector model of the induction motor and the vector control principle of the induction motor, an adaptive complex vector current controller and a field weakening controller are designed, thereby realizing voltage closed-loop adaptive field weakening control of the induction motor under the condition of no speed sensor. Attached Figure Description

[0068] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0069] Figure 1 This is a schematic diagram of the architecture of the adaptive field weakening control system in the embodiments of this application;

[0070] Figure 2 This is a schematic diagram of the induction motor flux linkage voltage model in an embodiment of this application;

[0071] Figure 3 This is a schematic diagram of the induction motor flux linkage current model in an embodiment of this application;

[0072] Figure 4 This is a block diagram of a standard feedback system for velocity estimation in an embodiment of this application;

[0073] Figure 5 This is a schematic diagram of the adaptive speed estimator in the embodiments of this application;

[0074] Figure 6 This is a schematic diagram of the adaptive field weakening controller in the embodiments of this application;

[0075] Figure 7 This is a diagram showing the optimal voltage and current vector variation trajectory when the maximum torque output is achieved in the embodiments of this application.

[0076] Figure 8 This is a schematic diagram of the adaptive complex vector current decoupling controller in an embodiment of this application;

[0077] Figure 9 This is a schematic diagram of the complex vector current decoupling controller in an embodiment of this application;

[0078] Figure 10 This is one of the flowcharts for the adaptive field weakening control method in the embodiments of this application;

[0079] Figure 11 This is the second flowchart of the adaptive field weakening control method in the embodiments of this application;

[0080] Figure 12 This is a flowchart illustrating the determination of the rotor's real-time speed in an embodiment of this application;

[0081] Figure 13 This is a flowchart illustrating the determination of the excitation current reference value and the torque current reference value in the embodiments of this application;

[0082] Figure 14 This is a flowchart illustrating the determination of the excitation voltage reference value and the torque voltage reference value in the embodiments of this application;

[0083] Figure 15 This is a flowchart illustrating the process of obtaining the corresponding pulse width modulation wave in the embodiments of this application;

[0084] Figure 16 This is one of the structural diagrams of the induction motor voltage closed-loop adaptive field weakening control device in the embodiments of this application;

[0085] Figure 17 This is the second structural diagram of the induction motor voltage closed-loop adaptive field weakening control device in the embodiments of this application;

[0086] Figure 18 This is a structural diagram of the rotor real-time speed determination unit in an embodiment of this application;

[0087] Figure 19 This is a structural diagram of the current reference value determination unit in an embodiment of this application;

[0088] Figure 20 This is a structural diagram of the voltage reference value determination unit in an embodiment of this application;

[0089] Figure 21 This is a structural diagram of the modulation wave generation unit in an embodiment of this application;

[0090] Figure 22 This is a schematic diagram of the structure of the electronic device in the embodiments of this application. Detailed Implementation

[0091] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0092] In one embodiment, in order to achieve adaptive field weakening control of the induction motor when it is running at high speed, see [reference needed]. Figure 10 This application provides an adaptive field weakening control method, comprising:

[0093] S101: Reference value I for the excitation current of the induction motor sd * Torque current reference value I sq * Actual value of excitation current I sd and actual value of torque current I sq Adaptive complex vector current decoupling is performed to obtain the excitation voltage reference value u of the induction motor. sd * and torque voltage reference value u sq *;

[0094] S102: Regarding the excitation voltage reference value u sd * and torque voltage reference value u sq *Perform flux tracking to obtain the corresponding pulse width modulation wave;

[0095] S103: The inverter is driven by the pulse width modulation wave to obtain an adaptive field weakening control signal.

[0096] Understandably, high-speed control technology for induction motors (hereinafter referred to as motors) is widely used in new energy vehicles, high-speed train traction, and CNC machine tools. Among these, vector control technology, due to its excellent dynamic and static performance, is widely used in motor speed control. In harsh environments such as those used in mining motors and tunnel boring machines, the installation and maintenance of speed sensors are difficult; therefore, sensorless vector control is generally used to control the motor. When the motor's operating frequency exceeds its fundamental frequency, the back electromotive force generated by the motor increases, but the motor's supply voltage cannot be increased, thus hindering further increases in motor speed. Therefore, it is necessary to reduce the motor's magnetic field to keep the motor operating above its rated speed; this method is called field weakening control.

[0097] Traditional field weakening control methods are " "Field weakening control" is a method that makes the rotor magnetic field inversely proportional to the rotational speed to achieve field weakening control. This method is simple to implement and widely used in applications with low control requirements. However, it causes premature voltage saturation, significantly impacting the torque output of the induction motor and resulting in slow dynamic response. The control effect is also highly sensitive to the selection of the initial excitation current, typically failing to maximize torque output. Under load, without improving the maximum torque control method for the induction motor in field weakening acceleration mode, relying solely on "field weakening control" will not be sufficient. The "field weakening control" method cannot meet the high-performance, high-speed drive requirements of motors. Furthermore, at high speeds, rotor temperature rises or magnetic circuit saturation can cause significant changes in the rotor electromagnetic time constant, leading to substantial deviations in the flux linkage current model output of the Model Reference Adaptive System (MRAS) speed estimation algorithm. Additionally, the flux linkage voltage model contains a pure integral element. When the input signal contains a DC component, the output exhibits DC bias, causing integral saturation and drift, resulting in inaccurate estimates of rotor flux linkage and orientation angle. Since flux linkage orientation is a critical issue in sensorless vector control, rotor time constant compensation is necessary to reduce current model errors in the MRAS speed estimation algorithm. Simultaneously, the reference voltage model should be improved to eliminate DC bias and integral saturation drift caused by the pure integral element, thereby improving the observation accuracy of flux linkage angular velocity and magnetic field orientation angle. Finally, the maximum torque output mechanism of the induction motor should be investigated, and a current and voltage vector control scheme that maximizes the output torque of the induction motor should be designed to achieve high-speed field weakening vector control of the induction motor without a speed sensor.

[0098] To address the problems existing in the prior art, this application provides an adaptive field weakening control method, specifically involving a voltage closed-loop adaptive field weakening control strategy based on rotor magnetic field orientation.

[0099] Based on complex vector theory, this application establishes a complex vector current decoupling regulation model for an induction motor and designs a complex vector current decoupling regulator and a field weakening controller in conjunction with the field weakening control principle. A current compensation loop is used to compensate the current loop, improving the dq-axis current coupling problem. Adaptive rules are designed to adjust the control parameters of the complex vector current decoupling regulator and the field weakening controller in real time, improving the problem of large fluctuations in stator current and voltage, leading to large fluctuations in electromagnetic torque, when the induction motor is running at high speed. Considering that the accuracy of the speed sensor can be greatly affected under certain operating conditions, such as high temperature and high humidity, and that speed sensors are costly and relatively difficult to install and maintain, this application uses an improved speed estimation method to observe the speed, ensuring that the speed observer still has high output accuracy when the induction motor is running at high speed. Ultimately, adaptive field weakening control of the induction motor is achieved without a speed sensor.

[0100] Specifically, Figure 1 This is a schematic diagram of a voltage closed-loop adaptive field weakening control strategy based on rotor field orientation in one embodiment of this application, including:

[0101] The system includes an adaptive field weakening controller, a speed controller, an adaptive field weakening controller, an adaptive complex vector current decoupling regulator, a voltage space vector PWM, an inverter, an asynchronous motor, and an improved rotor speed observer, which also involves coordinate transformation processes such as Park and Clarke.

[0102] By limiting the output of field weakening controller one, the given value of the excitation current is obtained. Field weakening controller two limits the speed controller, obtaining the given value of the torque current. The given and actual values ​​of the excitation current and torque current are then input into the adaptive complex vector current decoupling controller for decoupling control, and the output voltage given value u is then generated. sd * u sq * The voltage setpoint is obtained by coordinate transformation to obtain u. sα * u sβ * The voltage setpoint after coordinate transformation is then input into the voltage space vector PWM to obtain the PWM wave. This PWM wave is then input to the inverter to drive the motor. Since sensorless rotor field-oriented control is used, the accuracy of the field-oriented angle significantly affects the control precision. Therefore, by… Figure 1 The improved rotor speed sensor obtains the rotor speed. Since the rotor speed is known, the slip angular velocity can be calculated using the formula:

[0103]

[0104] Therefore, the magnetic field orientation angle is:

[0105]

[0106] in,

[0107] ω s It is the slip angular velocity;

[0108] ω r This refers to the rotor angular velocity;

[0109] ω e The rotor flux linkage angular velocity;

[0110] θ is the magnetic field orientation angle;

[0111] τ0 is the initial rotor electromagnetic time constant;

[0112] The identified rotor electromagnetic time constant compensation value;

[0113] ψ r For rotor flux linkage;

[0114] i sq The torque component of the actual stator current;

[0115] n p This represents the number of pole pairs of the motor.

[0116] L m For mutual induction.

[0117] The above methods enable high-speed field weakening control of induction motors without speed sensors.

[0118] As can be seen from the above description, the adaptive field weakening control method provided in this application can observe the rotor speed of the induction motor under complex working conditions using an improved speed observer. By combining the complex vector model of the induction motor and the vector control principle of the induction motor, an adaptive complex vector current controller and a field weakening controller are designed, thereby realizing voltage closed-loop adaptive field weakening control of the induction motor under the condition of no speed sensor.

[0119] In one embodiment, see Figure 11 The reference value I for the excitation current of the induction motor sd * Torque current reference value I sq * Actual value of excitation current I sd and actual value of torque current I sq Adaptive complex vector current decoupling is performed to obtain the excitation voltage reference value u of the induction motor. sd * and torque voltage reference value u sq *Previously, it also included:

[0120] S201: Determine the real-time rotor speed of the induction motor based on the stator current sampling value and the stator voltage sampling value of the induction motor;

[0121] It is understood that, in one embodiment, see [reference] Figure 6 and Figure 12 The real-time rotor speed includes: synchronous angular frequency ω e and rotor angular frequency ω r The specific implementation of step S201 includes:

[0122] S301: Perform Clarke coordinate transformation on the stator current sampled value to obtain the corresponding stator current α-axis component and stator current β-axis component;

[0123] S302: Perform Clarke coordinate transformation on the stator voltage sampled values ​​to obtain the corresponding stator voltage α-axis component and stator voltage β-axis component;

[0124] S303: Determine the estimated value of the rotor flux linkage α-axis component, the estimated value of the rotor flux linkage β-axis component, the reference value of the rotor flux linkage α-axis component, and the reference value of the rotor flux linkage β-axis component based on the stator current α-axis component, stator current β-axis component, stator voltage α-axis component, and stator voltage β-axis component.

[0125] S304: Determine the rotor angular frequency ω based on the reference values ​​of the rotor flux linkage α-axis component, the rotor flux linkage β-axis component, the estimated value of the rotor flux linkage α-axis component, and the estimated value of the rotor flux linkage β-axis component. r ;

[0126] S305: Determine the rotor time constant compensation value τ based on the reference values ​​of the rotor flux linkage α-axis component, the rotor flux linkage β-axis component, the estimated values ​​of the rotor flux linkage α-axis component and the rotor flux linkage β-axis component, the stator current α-axis component, and the stator current β-axis component.

[0127] S306: Based on the slip angular frequency ω containing rotor time constant compensation value s Determine the synchronization angular frequency ω e .

[0128] Specifically, Figure 2 This is a schematic diagram of the structure of a model reference adaptive speed estimator in one embodiment of this application.

[0129] exist Figure 2In this embodiment, the model reference adaptive system method is used. Its principle is as follows: two models with equal output are needed. One model without unknown parameters is used to construct the reference model, and the other model with unknown parameters is used to construct the adjustable model. By adjusting the unknown parameters in the adjustable model, the output of the adjustable model can approximate the output of the reference model, thus effectively identifying the unknown parameters. In this embodiment, the rotational speed is set as the unknown parameter, and the current model of the induction motor rotor flux contains rotational speed information, so the current model is made adjustable. The voltage model of the induction motor rotor flux does not contain rotational speed information, so it serves as the reference model. The voltage model of the induction motor rotor flux is as follows:

[0130]

[0131] The flux linkage observation module for the voltage model can be obtained from formula (3), see [link to formula]. Figure 2 .

[0132] Depend on Figure 2 It is known that the flux linkage calculation formula of the voltage model contains a pure integration stage. If the input signal is purely DC biased, the error signal will continuously increase after passing through the pure integration stage, resulting in integration saturation. This will eventually lead to saturation deviation of the reference signal output by the reference model. If the adjustable model is made to approximate the reference signal containing the error, the speed signal identified in the adjustable model will also be inaccurate. The voltage model should be improved by replacing the pure integrator with a low-pass filter. This can improve the effect of DC bias. In order to compensate for the effect of the low-pass filter on the output phase and amplitude, the output of the low-pass filter needs to be compensated. Finally, the flux linkage voltage model is determined as shown in formula (4):

[0133]

[0134] The current model of the rotor flux linkage of the induction motor is shown in formulas (5A) and (5B), which are equivalent:

[0135]

[0136]

[0137] Formula (5A) is more suitable for real-time calculation by a microcomputer than Formula (5B), and it is easier to converge. The actual current collected is in the ABC three-phase stationary coordinate system, which requires coordinate transformation (such as Clarke coordinate transformation). Therefore, the overall current model flux linkage observation module, such as Figure 3 As shown.

[0138] By observing the current model of the induction motor flux linkage, it can be found that the current model includes the rotor electromagnetic time constant τ. The rotor time constant changes with the temperature and the degree of magnetic circuit saturation, and the range of change is large. It is necessary to compensate and correct the rotor time constant, so the rotor time constant also needs to be identified.

[0139] First, a standard model reference adaptive system structure can be obtained through the reference model and the adjustable model, and the state generalized error is defined.

[0140]

[0141] in

[0142] According to formula (6), the standard feedback system block diagram for velocity estimation can be obtained, such as... Figure 4 As shown,

[0143]

[0144] I is the identity matrix;

[0145] The adaptive rate of the parameters can be obtained using the Popov integral inequality, so the Popov integral inequality can be written as follows:

[0146]

[0147] The above equation holds true for any t1 greater than 0, and γ0 2 It is a finite positive number independent of t1;

[0148] Based on the structure of MRAS, it can be represented as follows:

[0149]

[0150] Therefore, formula (8) can be rewritten as:

[0151]

[0152]

[0153]

[0154] The above equation holds true for any t1 greater than 0, and γ1 2 γ2 2 It is a finite positive number independent of t1; by performing an adaptive rate derivation of the Popov integral inequality (11) for rotational speed, formula (11) is split into the following form:

[0155]

[0156]

[0157] The above equation holds true for any t1 greater than 0, and γ 11 2 γ 12 2 All are finite positive numbers independent of t1;

[0158] To satisfy inequality (13), we can use the conventional inequality (15):

[0159]

[0160] Therefore

[0161]

[0162]

[0163] At this point, formula (13) holds true. Taking the derivative of formula (13) gives us:

[0164]

[0165] To satisfy formula (14), the integrand of the inequality must be positive, so F2(v,t) can be chosen as:

[0166]

[0167] From formulas (18) and (19), the estimated equation for the rotational speed can be obtained as follows:

[0168]

[0169] Similarly, the estimation equation for the rotor electromagnetic time constant can be obtained:

[0170]

[0171] Bundle Substituting into formulas (20) and (21), the estimation formulas for the rotor electromagnetic time constant and rotor speed derived from Popov's hyperstability law are:

[0172]

[0173]

[0174] Rotor speed is estimated using improved current and voltage models, with the model structure referencing an adaptive speed estimator as shown below. Figure 5 As shown.

[0175] in,

[0176]

[0177] The estimated value of the rotor angular frequency is ω, which is used as the actual value of the rotor angular frequency. r ;

[0178] K p3 K i3 These are the proportional-integral parameters of the model adaptive speed observer;

[0179] K p4 K i4 These are the proportional-integral parameters of the model's adaptive rotor time constant observer.

[0180] For integral calculation;

[0181] p is a differential operator

[0182] τ is the rotor electromagnetic time constant;

[0183] This is an estimate of the reciprocal of the rotor electromagnetic time constant;

[0184] The initial value of the reciprocal of the rotor electromagnetic time constant is given.

[0185] R r This is the resistance value of the rotor winding;

[0186] i sα This represents the component of the stator current along the α-axis.

[0187] i sβ This represents the component of the stator current on the β-axis.

[0188] u sα This represents the component of the stator voltage along the α-axis.

[0189] u sβ This represents the component of the stator voltage on the β-axis.

[0190] This is an estimate of the component of the flux linkage on the α-axis based on the current model;

[0191] ψ rα This is a reference value for the component of the magnetic flux on the α-axis based on the voltage model.

[0192] This is an estimate of the component of the flux linkage on the β-axis based on the current model;

[0193] ψ rβThis is a reference value for the component of the magnetic flux on the β-axis based on the voltage model;

[0194] For low-pass filter; ω c This is the cutoff frequency of the low-pass filter.

[0195] S202: Based on the rotor angular frequency reference value ω r * The real-time rotor speed and the current reference value of the output voltage of the induction motor determine the excitation current reference value I. sd *and the torque current reference value I sq *

[0196] In one embodiment, step S202 is specifically implemented as follows: See Figure 6 and Figure 13 The reference value ω of the rotor angular frequency r * The real-time rotor speed and the current reference value of the output voltage of the induction motor determine the excitation current reference value I. sd *and the torque current reference value I sq *,include:

[0197] S401: Based on the preset maximum stator voltage U SMAX The initial synchronization angular frequency ω of the induction motor when it enters the constant voltage operating region. g Synchronous angular frequency ω e The excitation voltage reference value u sd *and the torque voltage reference value u sq *Determine the reference value I of the excitation current. sd *;

[0198] S402: Based on the preset maximum stator current I SMAX and the torque current d-axis reference value I sd *Determine the first torque current q-axis limit value I sqlim.max ;

[0199] S403: According to the maximum stator voltage U SMAX and the excitation voltage reference value u sd *Determine the q-axis limit value of the second torque current I sq-u-limit ;

[0200] S404: Based on the first torque current q-axis limiting value I sqlim.max With the second torque current q-axis limiting value (I) sq-u-limit The minimum value in () determines the final amplitude limit;

[0201] S405: According to the rotor angular frequency reference value ω r * The rotor angular frequency ω output by the observerr The final limiting value determines the torque current reference value I. sq *

[0202] Speed ​​controller formula:

[0203]

[0204] i′ sq * The torque current reference value I in S405 needs to be obtained by passing the limiting function in S404. sq *

[0205] Specifically, Figure 6 This is a schematic diagram of the adaptive field weakening controller structure in one embodiment of this application, including adaptive field weakening controller one and adaptive field weakening controller two.

[0206] The design principles of adaptive field weakening controller one and adaptive field weakening controller two follow Figure 7 The diagram shows the optimal current-voltage vector trajectory for the maximum output torque. Figure 7 Based on the stator voltage equation of the induction motor, we get:

[0207]

[0208] When the motor is running in steady state in the high-speed field weakening region, the differential terms of current and flux linkage are zero, and since the stator resistance accounts for a small proportion, it can be ignored. Therefore, formula (25) can be simplified to:

[0209]

[0210] Combining current constraints and voltage constraints:

[0211]

[0212] achievable

[0213]

[0214] (ω e L s i sd ) 2 +(ω e σL s i sq ) 2 ≤U SMAX 2 (29)

[0215] From formulas (28) and (29), it can be seen that as the rotational speed increases, the voltage limiting loop at i sq -i sdThe coordinate system gradually shrinks, while the current limiting loop is in u sq -u sd Gradually increasing in the coordinate system, such as Figure 7 As shown, its left half-plane contains u sq -u sd Coordinate system, right half-plane is i sq -i sd Coordinate system; When the motor transitions from zero speed to above base speed, the excitation input of the adaptive field weakening controller is very large, so it is necessary to limit its output. The upper limit of the excitation current is set to I. sdn * Meanwhile, the torque current in the second field weakening controller is output based on the maximum current limit, and the given torque current is also very large. This allows for rapid excitation establishment and enables the induction motor to obtain a large torque, quickly passing through the constant torque operating region, such as... Figure 7 As shown, when the current and voltage reach point A, it is the transition point between the constant torque operating region and the field weakening constant power operating region of the induction motor. After entering the constant power field weakening region, the operation of the motor is jointly restricted by the maximum current loop and the maximum voltage loop. Its optimal voltage and current vector trajectory is determined by the maximum output torque, as shown in formulas (30) and (31):

[0216]

[0217]

[0218] The above equation is the current-voltage expression for the electromagnetic torque of an induction motor. From the equation, we can obtain that when i sd *i sq u sd *u sq When the maximum value is achieved, the output torque is at its maximum. When the induction motor operates in the constant power region, it is limited by the maximum voltage loop and the maximum current loop. To obtain the maximum torque output, the current and voltage should be maximized within the intersection of the current limiting loop and the voltage limiting loop; that is, the boundary of the intersection of the voltage limiting loop and the current limiting loop is determined. Therefore, from... Figure 7 As shown. In the current coordinate system, because the voltage limiting loop shrinks as the rotational speed increases, the trajectory of the current vector transitions from point A to point B of the current limiting loop. The current vector trajectory AB is the maximum current vector trajectory within the intersection of the current limiting loop and the voltage limiting loop as the rotational speed increases; similarly, in... Figure 7In the voltage coordinate system, because the current limiting loop expands with increasing rotational speed, the voltage vector trajectory transitions from point A to point B of the voltage limiting loop. The voltage vector trajectory AB is the maximum voltage vector trajectory within the intersection of the current limiting loop and the voltage limiting loop. Therefore, in the constant power operating region, the optimal voltage and current vector trajectories are AB. Based on these voltage and current vector trajectories, a field weakening controller is designed as follows:

[0219]

[0220] The above formula represents the maximum voltage loop limit, while the current loop limit is the current limiting part of the field weakening controller 2:

[0221]

[0222] Point B is the transition point between constant power and constant voltage because, taking the current vector trajectory in the current coordinate system as an example, as the rotational speed increases, the current vector should continue to move counterclockwise along the AB trajectory, that is, the torque current continues to increase and the excitation current continues to decrease. As can be seen from formula (34), an excessively large torque current i sq This can lead to excessive slip frequency:

[0223]

[0224] As can be seen from the mechanical characteristic curve of the induction motor, an excessively large slip angular frequency will affect the stable operation of the motor. Therefore, point B is set as the transition point between the constant power operating region and the constant voltage operating region. The given values ​​of torque current or excitation current are limited to prevent the slip angular frequency from being too large and affecting the stable operation of the motor. The limiting mechanism is as follows:

[0225] The maximum angular slip frequency of the induction motor can be obtained from the induction motor model as follows:

[0226]

[0227] Simultaneously, considering the voltage-current relationship along the dq axis:

[0228]

[0229] This yields the following slip angular frequency constraint for the current and voltage vectors:

[0230]

[0231]

[0232] Therefore, the output of the field weakening controller is limited, and the minimum value of its output excitation current is set to σi. sq * .

[0233] As the motor speed increases further, the voltage limiting loop shrinks further and is contained within the current loop. Therefore, only the voltage loop limitation needs to be considered, and this region is called the weak magnetic constant voltage region. When the induction operates in the weak magnetic constant voltage region, it is constrained by the maximum slip angular frequency and the voltage limiting loop. In this region, the voltage vector should satisfy formula (38). Similarly, it can be seen that the current always satisfies formula (37) in steady state. Figure 7 As shown, the voltage vector should be fixed at point B. Therefore, voltage control is set in the field weakening controller 2 to maintain the voltage vector fixed at point B when the motor is running in the field weakening constant voltage zone. Its structure is as follows:

[0234]

[0235] Assuming no overmodulation occurs in SVPWM modulation, u can be considered... sd =u sd * Formula (39) can be interpreted as: u sd It increases with increasing rotational speed, when u sd Exceed At that time, that is: At this point, formula (38) is no longer satisfied, and the voltage vector is not the optimal voltage vector for maximum torque output. Therefore, the torque current is adjusted using formula (39), thereby adjusting u. sd The detailed adjustment process is as follows: At the transition point between the constant power region and the constant voltage region, adjust K of the field weakening controller two. p2 K i2 This makes the output of formula (39) consistent with the output of formula (33). When the motor enters the constant voltage region, as u sd As the output of formula (39) increases, it begins to decrease, leading to a decrease in the given torque current. Furthermore, due to the limitation of the slip frequency, as shown in formula (37), the excitation current decreases proportionally. Combining this with the simplified model of the motor, as shown in formula (26), it can be seen that the proportional decrease in current offsets the voltage increase caused by the increase in speed. Therefore, as... Figure 7 As shown, in the voltage coordinate system, the voltage vector remains at point B, and in the current coordinate system, the trajectory of the current vector is BC. The selection of point C is limited by the minimum current.

[0236] In fact, in the field weakening constant voltage region, the increase in rotational speed and the corresponding decrease in current can easily cause voltage vector fluctuations. If the PI parameters in field weakening controller 1 and field weakening controller 2 are not selected reasonably, it can easily cause greater fluctuations, resulting in poor control effect or even system collapse. Therefore, an adaptive rule is adopted to adjust the closed-loop control of voltage in the field weakening controller, as shown in formulas (40) and (41).

[0237]

[0238]

[0239] in,

[0240] For integral calculation;

[0241] L m Mutual induction;

[0242] u sd * This is the given value for the stator voltage excitation component;

[0243] u sq * This is the given value for the stator voltage torque component;

[0244] K p1 K i1 These are the proportional-integral parameters of the field weakening excitation current controller for the induction motor;

[0245] L r The self-inductance of the rotor winding;

[0246] U SMAX The maximum stator voltage allowed by the entire induction motor control system can be determined based on the voltage withstand capability of the inverter's switching transistors or the parameters of the induction motor.

[0247] ω r This is the actual rotor angular frequency.

[0248] ω g The rotational angular velocity of the dq coordinate system when entering the weak magnetic constant voltage region;

[0249] ω e The actual angular velocity of rotation in the dq coordinate system;

[0250] n p This represents the number of pole pairs of the motor.

[0251] We reduce voltage vector fluctuations by introducing rotor flux linkage angular velocity and adjusting the PI parameters in real time in the constant voltage region, as shown in formulas (40) and (41). The adaptive field weakening controller is set to a segmented form so as not to affect the motor's speed in the constant torque and constant power regions. When the motor enters the constant voltage region, the flux linkage angular velocity also increases with the increase of motor speed, as shown in formula (42).

[0252]

[0253] Therefore, in the constant voltage region, by using an adaptive factor... The PI parameter in the field weakening controller is tuned so that the PI parameter is smaller as the speed increases, which can suppress the fluctuation caused by the increase in speed and the decrease in current, so as to maintain the stable operation of the motor.

[0254] At this point, a comprehensive analysis of the structure and control method of the adaptive field weakening controller under sensorless conditions has been completed.

[0255] As can be seen from the above description, the adaptive field weakening control method provided in this application under the condition of no speed sensor can realize the observation of the rotor speed of the induction motor under complex working conditions by using an improved speed observer. In combination with the complex vector model of the induction motor and the vector control principle of the induction motor, an adaptive complex vector current controller and a field weakening controller are designed, thereby realizing the voltage closed-loop adaptive field weakening control of the induction motor under the condition of no speed sensor.

[0256] In one embodiment, see Figure 14 The reference value I for the excitation current of the induction motor sd * Torque current reference value I sq * Actual value of excitation current I sd and actual value of torque current I sq Adaptive complex vector current decoupling is performed to obtain the excitation voltage reference value u of the induction motor. sd * and torque voltage reference value u sq *,include:

[0257] S501: Perform Park transform on the sampled stator current value to obtain the actual excitation current value I. sd and actual value of torque current I sq ;

[0258] S502: When the synchronization angular frequency ω e Less than or equal to the initial synchronization angular frequency ω in the constant voltage region g At that time, according to the excitation current reference value I sd * Torque current reference value I sq * Actual value of excitation current I sd Actual value of torque current I sq and the synchronous angular frequency ω e Determine the excitation voltage reference value u sd * and torque voltage reference value u sq *;

[0259] S503: When the synchronization angular frequency ω e Greater than the initial synchronization angular frequency ω in the constant voltage region g At that time, according to the excitation current reference value I sd * Torque current reference value I sq* Actual value of excitation current I sd Actual value of torque current I sq Synchronous angular frequency ω e and the initial synchronization angular frequency ω in the constant voltage region g Determine the excitation voltage reference value u sd * and torque voltage reference value u sq *

[0260] Understandable Figure 8 This is a schematic diagram of the structure of an adaptive complex vector current decoupling controller in one embodiment of this application.

[0261] Rewrite the stator voltage equation (25) of the induction motor, and respectively i sq i sd Its differential terms are listed together, as in formula (43), for subsequent decoupling analysis:

[0262]

[0263] Using complex vector theory, the expressions for voltage and current vectors are obtained using the complex plane vector expression method, as shown in formulas (44) and (45):

[0264]

[0265]

[0266] From formulas (44) and (45), it can be seen that the stator voltage vector of the motor consists of the following parts: For stator equivalent voltage drop; This is the dynamic component of the current, used to dynamically adjust the voltage; in steady state, this component is zero. The coupling voltage of the dq axis; The motor's rotating back electromotive force changes slowly during the current control cycle and can be considered as a disturbance.

[0267] In summary, the open-loop control vector model of voltage and current of the induction motor in the complex plane can be obtained as follows:

[0268]

[0269] From formula (46), the complex vector poles can be obtained as:

[0270]

[0271] As can be seen from formula (47), the complex vector pole contains synchronous angular velocity information, and the pole gradually moves away from the real axis as the synchronous angular velocity increases. That is, the stability margin of the current loop decreases as the synchronous angular velocity increases. Excessive synchronous angular velocity will affect the stable operation of the motor. From the perspective of coupling, the complex vector pole causes the dq axis current coupling problem during motor operation. As the synchronous angular velocity increases, the coupling becomes more severe, which will worsen the dynamic performance of the system. Therefore, the complex vector decoupling method is adopted to modify the current controller. The modification idea is to eliminate the zero pole pair cancellation method, thereby eliminating the influence of the complex vector pole moving with the speed on the system control.

[0272] A complex vector current decoupling controller is adopted, and its structure is as follows:

[0273]

[0274] Design the parameters of the complex vector current decoupling controller according to the type I system, let K p =σL s ω cb * , Where ω cb * To achieve the desired bandwidth, the zeros of the controller and the complex vector poles of the motor can be canceled out; the schematic diagram of the complex vector current decoupling controller is shown below. Figure 9 As shown.

[0275] Depend on Figure 9 It can be seen that the complex vector current decoupling controller is equivalent to adding a current compensation term for decoupling control to a traditional PI controller. In the high-speed field weakening constant voltage region, this compensation term accounts for a large proportion. During the acceleration process, as can be seen from the above-mentioned voltage closed-loop field weakening control principle, current fluctuations will occur in the constant voltage region. Although the adaptive field weakening controller modifies the PI parameters through adaptive coefficients to reduce output fluctuations, the decoupling compensation coefficient K in the complex vector decoupling controller... p ω e The coefficient contains information about the synchronous angular velocity, which increases with the increase of the synchronous angular velocity. During the dynamic adjustment process in the high-speed constant voltage zone, when the fluctuating current setpoint enters the complex vector decoupling controller, the fluctuation of the current may be amplified, resulting in torque fluctuation and further affecting the stable operation of the motor. Therefore, it is necessary to adjust the parameters in the complex vector field weakening controller in real time to ensure the stable operation of the motor in the high-speed constant voltage zone. Therefore, adaptive rules are set to modify the complex vector decoupling controller, such as formula (49) and formula (50):

[0276]

[0277]

[0278] in,

[0279] K p5 K i5 K p6 K i6 These are the proportional-integral parameters of the complex vector current regulator;

[0280] u sq * This is the given value of the stator voltage on the q-axis;

[0281] u sd * This is the given value of the stator voltage along the d-axis;

[0282] i sq * This is the given value of the stator current on the q-axis;

[0283] i sd * This is the given value of the stator current along the d-axis;

[0284] i sq Stator current in the q-axis component;

[0285] i sd Stator current component on the d-axis;

[0286] ω g The rotational angular velocity of the dq coordinate system when entering the weak magnetic constant voltage region;

[0287] ω e This represents the actual rotational angular velocity in the dq coordinate system.

[0288] The resulting control structure diagram is as follows Figure 8 Its control principle is that when the motor is working below the constant voltage region, the current fluctuation is very small, and the parameters in the complex vector decoupling controller are not modified to ensure its speed. When the motor enters the constant voltage region, the flux linkage angular velocity also increases with the increase of the motor speed, as shown in equation (44). Therefore, in the constant voltage region, the adaptive factor is used to control the current. The parameters in the complex vector decoupling controller are adjusted in real time to reduce the output fluctuations of the complex vector current regulator and maintain the stable operation of the motor.

[0289] As can be seen from the above description, the sensorless adaptive field weakening control method provided in this application can control the excitation current reference value I of the induction motor. sd * Torque current reference value I sq * Actual value of excitation current I sd and actual value of torque current I sqAdaptive complex vector current decoupling is performed to obtain the excitation voltage reference value u of the induction motor. sd * and torque voltage reference value u sq *

[0290] In one embodiment, see Figure 15 The reference value of the excitation voltage u sd * and torque voltage reference value u sq *Perform flux linkage tracking to obtain the corresponding pulse width modulation wave, including:

[0291] S601: Regarding the excitation voltage reference value u sd * and torque voltage reference value u sq *Perform a rotating two-phase to stationary orthogonal transformation to obtain the corresponding α-axis output voltage reference value and β-axis output voltage reference value;

[0292] S602: Perform space vector pulse width modulation on the output voltage reference values ​​of the α-axis and the β-axis to obtain the pulse width modulated wave.

[0293] Coordinate transformation matrix:

[0294]

[0295] Generally, the reference voltage is first transformed from the dq coordinate system to the αβ coordinate system. Then, the sector where the reference voltage vector is located is determined by the αβ axis component of the reference voltage. The voltage space vector in the sector is selected and synthesized into the reference voltage vector according to the volt-second balance equation, thereby solving for the action time of the voltage space vector. The pulse width modulation wave is obtained by combining the output time in a certain output order.

[0296] In one embodiment, the adaptive field weakening control signal under sensorless conditions includes: a stator voltage control signal; the high-speed field weakening control of the induction motor by driving the inverter with the pulse width modulation wave includes: driving the fully controlled switching transistor in the inverter with the pulse width modulation wave to output the stator voltage control signal.

[0297] Generally, the pulse width modulation wave obtained in the previous step is sent to the drive circuit for power amplification to realize the conversion of digital quantity to analog quantity. Then, the amplified pulse width modulation signal is used to act on the fully controlled switching transistor of the inverter. By controlling the conduction and cutoff of the switching transistor, the stator voltage control signal is output.

[0298] The proposed voltage-closed-loop adaptive field weakening control strategy based on rotor magnetic field orientation enables high-speed field weakening vector control of induction motors without speed sensors. It solves the problem of decreased accuracy of conventional speed observers as the magnetic circuit saturates and heats up. Through voltage-closed-loop field weakening control, current and voltage vectors are distributed according to the maximum output torque, ensuring the motor consistently outputs maximum torque above its base speed. Furthermore, the use of an adaptive field weakening controller and a complex vector current decoupling controller improves current fluctuations during high-speed operation. Compared to existing technologies, it offers at least the following advantages:

[0299] The present invention relates to a voltage closed-loop adaptive field weakening control strategy based on rotor field orientation, which includes an improved model reference adaptive speed estimator. This improves the pure integral element in the induction motor flux linkage voltage model and adds compensation, solving the problems of integral saturation and error drift in the flux linkage voltage mode output when the input signal contains DC bias. Simultaneously, it employs a model reference adaptive method to identify the rotor electromagnetic time constant online, improving the problem of inaccurate flux linkage current model output due to large changes in the rotor electromagnetic time constant caused by temperature rise and magnetic circuit saturation. This improves the identification accuracy of rotor speed and addresses the issue of large field orientation angle deviation and poor control performance caused by inaccurate speed observation in sensorless rotor field orientation vector control.

[0300] The key to high-speed field weakening control of induction motors lies in the distribution of voltage and current vectors, traditionally... The field weakening control method has a weak load-carrying capacity when the motor is running at high speed, and the control effect is very sensitive to the initial value of the excitation current. Therefore, this invention analyzes the running trajectory of voltage and current vectors when the induction motor is operating at maximum output torque in the high-speed constant power and high-speed constant voltage operating regions, and designs an adaptive voltage closed-loop field weakening controller. This enables the induction motor to achieve maximum torque output when running above the base speed, improving the high-speed load-carrying capacity of the induction motor. Furthermore, the adaptive voltage closed-loop field weakening controller overcomes the shortcomings of traditional field weakening controllers whose control effect is affected by the initial value of the excitation current, and incorporates adaptive rules to modify the parameters in the field weakening controller in real time to reduce the current fluctuation of the motor in the high-speed constant voltage operating region.

[0301] When an induction motor operates at high speed, traditional current controllers suffer from severe d-q axis current coupling, which worsens with increasing speed, significantly impacting the system's dynamic performance. Therefore, a complex vector current decoupling controller is employed. By establishing a complex vector model of the induction motor, the complex vector poles in the complex plane are obtained. By configuring the parameters of the complex vector current decoupling controller, these poles are eliminated, resolving the current coupling problem. Adaptive rules are incorporated to tune the parameters of the controller, improving the stability of the induction motor in the high-speed, field-weakening, constant-voltage region. Ultimately, this achieves high-speed field-weakening vector control of the induction motor without a speed sensor.

[0302] Based on the same inventive concept, this application also provides an adaptive field weakening control device under sensorless conditions, which can be used to implement the method described in the above embodiments, as shown in the following embodiments. Since the principle of the adaptive field weakening control device under sensorless conditions is similar to that of the adaptive field weakening control method under sensorless conditions, the implementation of the adaptive field weakening control device can refer to the implementation of the software performance benchmark determination method, and repeated details will not be elaborated further. As used below, the terms "unit" or "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0303] In one embodiment, see Figure 16 In order to achieve adaptive field weakening control of the induction motor when it is running at high speed, this application provides an adaptive field weakening control device without a speed sensor, comprising:

[0304] The voltage reference value determination unit 801 is used to determine the excitation current reference value I of the induction motor. sd * Torque current reference value I sq * Actual value of excitation current I sd and actual value of torque current I sq Adaptive complex vector current decoupling is performed to obtain the excitation voltage reference value u of the induction motor. sd * and torque voltage reference value u sq *;

[0305] Modulation wave generation unit 802 is used to generate the excitation voltage reference value u. sd * and torque voltage reference value u sq *Perform flux tracking to obtain the corresponding pulse width modulation wave;

[0306] The field weakening control unit 803 is used to drive the inverter using the pulse width modulation wave to obtain the field weakening control signal for the induction motor.

[0307] In one embodiment, see Figure 17 The adaptive field weakening control device under sensorless conditions further includes:

[0308] The rotor real-time speed determination unit 901 is used to determine the real-time speed of the rotor of the induction motor based on the stator current sampling value and the stator voltage sampling value of the induction motor.

[0309] The current reference value determination unit 902 is used to determine the current reference value based on the rotor angular frequency reference value ω. r * The real-time rotor speed and the current reference value of the output voltage of the induction motor determine the excitation current reference value I. sd *and the torque current reference value I sq *

[0310] In one embodiment, see Figure 18 The real-time rotor speed includes: synchronous angular frequency ω e and rotor angular frequency ω r The rotor real-time speed determination unit 901 includes:

[0311] The current component determination module 1001 is used to perform Clarke coordinate transformation on the stator current sample value to obtain the corresponding stator current α-axis component and stator current β-axis component.

[0312] The voltage component determination module 1002 is used to perform Clarke coordinate transformation on the stator voltage sample value to obtain the corresponding stator voltage α-axis component and stator voltage β-axis component.

[0313] The flux linkage estimation module 1003 is used to determine the estimated values ​​of the rotor flux linkage α-axis component and the rotor flux linkage β-axis component based on the stator current α-axis component, stator current β-axis component, stator voltage α-axis component and stator voltage β-axis component.

[0314] The rotor time constant compensation value confirmation module 1004 determines the rotor time constant compensation value based on the reference value of the rotor flux linkage α-axis component, the reference value of the rotor flux linkage β-axis component, the estimated value of the rotor flux linkage α-axis component and the estimated value of the rotor flux linkage β-axis component, the stator current α-axis component, and the stator current β-axis component.

[0315] The rotor angular frequency determination module 1005 is used to determine the rotor angular frequency based on the reference value of the rotor flux linkage α-axis component, the reference value of the rotor flux linkage β-axis component, the estimated value of the rotor flux linkage α-axis component, and the estimated value of the rotor flux linkage β-axis component.

[0316] The synchronization angular frequency determination module 1006 is used to determine the synchronization angular frequency based on the slip angular frequency containing the rotor time constant compensation value.

[0317] In one embodiment, see Figure 19 The current reference value determination unit 902 includes:

[0318] Excitation current reference value determination module 1101 is used to determine the reference value of the excitation current based on the preset maximum stator voltage U. SMAX The synchronous angular frequency ω of the induction motor when it enters the constant voltage operating range g Synchronous angular frequency ω e The excitation voltage reference value u sd *and the torque voltage reference value u sq *Determine the reference value I of the excitation current. sd *;

[0319] The first limiting value determination module 1102 is used to determine the preset maximum stator current I based on the limiting value I. SMAX and the torque current d-axis reference value I sd *Determine the first torque current q-axis limit value I sqlim.max ;

[0320] The second limiting value determination module 1103 is used to determine the maximum stator voltage U based on the maximum stator voltage U. SMAX and the excitation voltage reference value u sd *Determine the q-axis limit value of the second torque current I sq-u-limit ;

[0321] The final limiting value determination module 1104 is used to determine the limiting value I based on the first torque current q-axis. sqlim.max With the second torque current q-axis limiting value I sq-u-limit Determine the final amplitude limit;

[0322] The torque current reference value determination module 1105 is used to determine the rotor angular frequency reference value ω based on the torque current reference value ω. r * The synchronization angular frequency ω r The final limiting value determines the torque current reference value I. sq *

[0323] In one embodiment, see Figure 20 The voltage reference value determination unit 801 includes:

[0324] The actual current value determination module 1201 is used to perform qd coordinate transformation on the stator current sampling value to obtain the actual excitation current value I. sd and actual value of torque current I sq ;

[0325] The first voltage reference value determination module 1202 is used to determine the synchronization angular frequency ω when the voltage reference value is determined. e Less than or equal to the synchronization angular frequency ω gAt that time, according to the excitation current reference value I sd * Torque current reference value I sq * Actual value of excitation current I sd Actual value of torque current I sq and the synchronous angular frequency ω e Determine the excitation voltage reference value u sd * and torque voltage reference value u sq *;

[0326] The second voltage reference value determination module 1203 is used to determine the voltage reference value when the synchronization angular frequency ω e Greater than the synchronization angular frequency ω g At that time, according to the excitation current reference value I sd * Torque current reference value I sq * Actual value of excitation current I sd Actual value of torque current I sq The synchronization angular frequency ω e and the synchronous angular frequency ω g Determine the excitation voltage reference value u sd * and torque voltage reference value u sq *

[0327] In one embodiment, see Figure 21 The modulation wave generation unit 803 includes:

[0328] The quadrature voltage reference value determination module 1301 is used to determine the excitation voltage reference value u. sd * and torque voltage reference value u sq *Perform a rotating two-phase to stationary orthogonal transformation to obtain the corresponding α-axis output voltage reference value and β-axis output voltage reference value;

[0329] The modulation wave generation module 1302 is used to perform space vector pulse width modulation on the output voltage reference values ​​of the α-axis and the output voltage reference values ​​of the β-axis to obtain the pulse width modulated wave.

[0330] In one embodiment, the adaptive field weakening control signal includes: a stator voltage control signal; the field weakening control unit 803 is specifically used to drive the fully controlled switching transistor in the inverter using the pulse width modulation wave, and output the stator voltage control signal.

[0331] From a hardware perspective, in order to achieve adaptive field weakening control of the induction motor when it is running at high speed, this application provides an embodiment of an electronic device for implementing all or part of the adaptive field weakening control method under sensorless conditions. The electronic device specifically includes the following components:

[0332] The system comprises a processor, a memory, a communications interface, and a bus; wherein the processor, memory, and communications interface communicate with each other via the bus; the communications interface is used to realize information transmission between the adaptive field weakening control device and core business systems, user terminals, and related databases and other related devices; the logic controller can be a desktop computer, tablet computer, or mobile terminal, etc., and this embodiment is not limited to these. In this embodiment, the logic controller can be implemented with reference to the embodiments of the adaptive field weakening control method and the adaptive field weakening control device in the embodiments, the contents of which are incorporated herein, and repeated details will not be described again.

[0333] It is understood that the user terminal may include smartphones, tablet computers, network set-top boxes, portable computers, desktop computers, personal digital assistants (PDAs), in-vehicle devices, smart wearable devices, etc. Among these, the smart wearable devices may include smart glasses, smartwatches, smart bracelets, etc.

[0334] In practical applications, the adaptive field weakening control device under sensorless conditions can be partially executed on the electronic device side as described above, or all operations can be completed in the client device. The specific choice depends on the processing power of the client device and the limitations of the user's usage scenario. This application does not impose any limitations on this. If all operations are completed in the client device, the client device may further include a processor.

[0335] The aforementioned client device may have a communication module (i.e., a communication unit) that can communicate with a remote server to achieve data transmission. The server may include a server on the task scheduling center side; in other implementation scenarios, it may also include a server on an intermediate platform, such as a server on a third-party server platform that has a communication link with the task scheduling center server. The server may include a single computer device, a server cluster consisting of multiple servers, or a distributed server structure.

[0336] Figure 22 This is a schematic block diagram illustrating the system configuration of the electronic device 9600 according to an embodiment of this application. Figure 22 As shown, the electronic device 9600 may include a central processing unit 9100 and a memory 9140; the memory 9140 is coupled to the central processing unit 9100. It is worth noting that... Figure 22 This is an example; other types of structures can also be used to supplement or replace this structure to achieve telecommunications functions or other functions.

[0337] In one embodiment, the adaptive field weakening control method function under sensorless conditions can be integrated into the central processing unit 9100. The central processing unit 9100 can be configured to perform the following control:

[0338] S101: Reference value I for the excitation current of the induction motor sd * Torque current reference value I sq * Actual value of excitation current I sd and actual value of torque current I sq Adaptive complex vector current decoupling is performed to obtain the excitation voltage reference value u of the induction motor. sd * and torque voltage reference value u sq *;

[0339] S102: Regarding the excitation voltage reference value u sd * and torque voltage reference value u sq *Perform flux tracking to obtain the corresponding pulse width modulation wave;

[0340] S103: The inverter is driven by the pulse width modulation wave to obtain an adaptive field weakening control signal.

[0341] As can be seen from the above description, the adaptive field weakening control method provided in this application under the condition of no speed sensor can realize the observation of the rotor speed of the induction motor under complex working conditions by using an improved speed observer. In combination with the complex vector model of the induction motor and the vector control principle of the induction motor, an adaptive complex vector current controller and a field weakening controller are designed, thereby realizing the voltage closed-loop adaptive field weakening control of the induction motor under the condition of no speed sensor.

[0342] In another embodiment, the adaptive field weakening control device can be configured separately from the central processing unit 9100. For example, the adaptive field weakening control device of the data composite transmission device can be configured as a chip connected to the central processing unit 9100, and the function of the adaptive field weakening control method can be realized through the control of the central processing unit.

[0343] like Figure 22 As shown, the electronic device 9600 may further include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It is worth noting that the electronic device 9600 does not necessarily need to include these components. Figure 22 All components shown; in addition, the electronic device 9600 may also include Figure 22 For components not shown, please refer to existing technologies.

[0344] like Figure 22As shown, the central processing unit 9100, sometimes also referred to as a controller or operating control, may include a microprocessor or other processor device and / or logic device, which receives inputs and controls the operation of various components of the electronic device 9600.

[0345] The memory 9140 may be, for example, one or more of a cache, flash memory, hard drive, removable media, volatile memory, non-volatile memory, or other suitable devices. It may store the aforementioned failure-related information, and also store a program for executing that information. The central processing unit 9100 may execute the program stored in the memory 9140 to perform information storage or processing, etc.

[0346] Input unit 9120 provides input to central processing unit 9100. Input unit 9120 may be, for example, a keypad or touch input device. Power supply 9170 provides power to electronic device 9600. Display 9160 displays images and text. Display may be, for example, an LCD display, but is not limited thereto.

[0347] The memory 9140 can be a solid-state memory, such as a read-only memory (ROM), random access memory (RAM), a SIM card, etc. It can also be a memory that retains information even when power is off, can be selectively erased, and contains more data; examples of this type of memory are sometimes referred to as EPROMs. The memory 9140 can also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 may include an application / function storage unit 9142 for storing application programs and function programs or processes for executing the operation of the electronic device 9600 via the central processing unit 9100.

[0348] The memory 9140 may also include a data storage unit 9143 for storing data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 9144 of the memory 9140 may include various drivers for the electronic device's communication functions and / or for performing other functions of the electronic device (such as messaging applications, address book applications, etc.).

[0349] The communication module 9110 is a transmitter / receiver 9110 that transmits and receives signals via the antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processing unit 9100 to provide input signals and receive output signals, which can be the same as in a conventional mobile communication terminal.

[0350] Based on different communication technologies, multiple communication modules 9110 can be configured in the same electronic device, such as cellular network modules, Bluetooth modules, and / or wireless LAN modules. The communication module (transmitter / receiver) 9110 is also coupled to a speaker 9131 and a microphone 9132 via an audio processor 9130 to provide audio output via the speaker 9131 and receive audio input from the microphone 9132, thereby realizing typical telecommunications functions. The audio processor 9130 may include any suitable buffer, decoder, amplifier, etc. Additionally, the audio processor 9130 is also coupled to a central processing unit 9100, enabling on-device recording via the microphone 9132 and on-device playback of stored sound via the speaker 9131.

[0351] Embodiments of this application also provide a computer-readable storage medium capable of implementing all steps of the adaptive magnetic field weakening control method with a server or client execution subject in the above embodiments. The computer-readable storage medium stores a computer program that, when executed by a processor, implements all steps of the adaptive magnetic field weakening control method with a server or client execution subject in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0352] S101: Reference value I for the excitation current of the induction motor sd * Torque current reference value I sq * Actual value of excitation current I sd and actual value of torque current I sq Adaptive complex vector current decoupling is performed to obtain the excitation voltage reference value u of the induction motor. sd * and torque voltage reference value u sq *;

[0353] S102: Regarding the excitation voltage reference value u sd * and torque voltage reference value u sq *Perform flux tracking to obtain the corresponding pulse width modulation wave;

[0354] S103: The inverter is driven by the pulse width modulation wave to obtain an adaptive field weakening control signal.

[0355] As can be seen from the above description, the adaptive field weakening control method provided in this application can observe the rotor speed of the induction motor under complex working conditions using an improved speed observer. By combining the complex vector model of the induction motor and the vector control principle of the induction motor, an adaptive complex vector current controller and a field weakening controller are designed, thereby realizing voltage closed-loop adaptive field weakening control of the induction motor under the condition of no speed sensor.

[0356] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0357] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (devices), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0358] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0359] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0360] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An adaptive field weakening control method under sensorless conditions, characterized in that, include: Adaptive complex vector current decoupling is performed on the obtained excitation current reference value, torque current reference value, actual excitation current value, and actual torque current value of the induction motor to obtain the excitation voltage reference value and torque voltage reference value of the induction motor. The excitation voltage reference value and torque voltage reference value are subjected to flux tracking to obtain the corresponding pulse width modulation wave; The inverter is driven by the pulse width modulation wave to achieve adaptive field weakening control; The steps for obtaining the reference values ​​of the excitation current and torque current of the induction motor include: The real-time rotor speed of the induction motor is determined based on the stator current sampling value and the stator voltage sampling value of the induction motor. The excitation current reference value and the torque current reference value are determined based on the rotor angular frequency reference value, the real-time rotor speed, and the current reference value of the output voltage of the induction motor. The real-time rotor speed includes: synchronous angular frequency and rotor angular frequency; determining the real-time rotor speed of the induction motor based on the stator current sampling value and stator voltage sampling value of the induction motor includes: The stator current sampling value is then processed. Clarke Coordinate transformation yields the corresponding stator current. α Shaft components and stator current β Axial components; Perform the sampling of the stator voltage values Clarke Coordinate transformation yields the corresponding stator voltage. α Shaft components and stator voltage β Axial components; According to the stator current α Shaft component, stator current β Shaft component, stator voltage α Shaft components and stator voltage β Shaft component determines rotor flux linkage α Shaft component estimates and rotor flux β Shaft component estimates, rotor flux linkage α Shaft component reference values ​​and rotor flux β Axis component reference values; According to rotor magnetic flux α Shaft component reference value, rotor flux β Shaft component reference value, the rotor flux linkage α Shaft component estimates and rotor flux β The rotor angular frequency is determined by the shaft component estimation value; According to rotor magnetic flux α Shaft component reference value, rotor flux β Shaft component reference value, the rotor flux linkage α Shaft component estimates and rotor flux β Shaft component estimates, stator current α Shaft component, stator current β Shaft component, determine rotor time constant compensation value; The synchronization angular frequency is determined based on the slip angular frequency containing the rotor time constant compensation value.

2. The adaptive field weakening control method under sensorless conditions according to claim 1, characterized in that, The steps for obtaining the actual values ​​of excitation current and torque current include: The stator current sampling value is then processed. Park The actual values ​​of the excitation current and torque current are obtained by transformation.

3. The adaptive field weakening control method under sensorless conditions according to claim 1, characterized in that, The step of determining the excitation current reference value and the torque current reference value based on the rotor angular frequency reference value, the real-time rotor speed, and the current reference value of the output voltage of the induction motor includes: The excitation current reference value is determined based on the preset maximum stator voltage, the initial synchronization angular frequency of the induction motor when it enters the constant pressure working zone and the constant pressure zone, the synchronization angular frequency, the excitation voltage reference value, and the torque voltage reference value. The first torque current q-axis limit value is determined based on the preset maximum stator current and the torque current d-axis reference value. The second torque current q-axis limit value is determined based on the maximum stator voltage and the excitation voltage reference value. The final limiting value is determined based on the first torque current q-axis limiting value and the second torque current q-axis limiting value; The torque current reference value is determined based on the rotor angular frequency reference value, the rotor angular frequency output by the observer, and the final limiting value.

4. The adaptive field weakening control method under sensorless conditions according to claim 3, characterized in that, The adaptive complex vector current decoupling of the acquired excitation current reference value, torque current reference value, actual excitation current value, and actual torque current value of the induction motor to obtain the excitation voltage reference value and torque voltage reference value of the induction motor includes: The stator current sampling value is then processed. Park The actual values ​​of the excitation current and torque current are obtained by transformation. When the synchronization angular frequency is less than or equal to the initial synchronization angular frequency of the constant voltage zone, the excitation voltage reference value and the torque voltage reference value are determined based on the excitation current reference value, the torque current reference value, the actual excitation current value, the actual torque current value and the synchronization angular frequency. When the synchronization angular frequency is greater than the initial synchronization angular frequency of the constant voltage zone, the excitation voltage reference value and the torque voltage reference value are determined based on the excitation current reference value, the torque current reference value, the actual excitation current value, the actual torque current value, the synchronization angular frequency, and the initial synchronization angular frequency of the constant voltage zone.

5. The adaptive field weakening control method under sensorless conditions according to claim 1, characterized in that, The step of tracking the excitation voltage reference value and the torque voltage reference value to obtain the corresponding pulse width modulation wave includes: Perform a rotating two-phase to stationary orthogonal transformation on the excitation voltage reference value and the torque voltage reference value to obtain the corresponding... α Shaft output voltage reference value and β Shaft output voltage reference value; Regarding the α Shaft output voltage reference value and β The output voltage reference value of the shaft is subjected to space vector pulse width modulation to obtain the pulse width modulated wave.

6. The adaptive field weakening control method under sensorless conditions according to claim 1, characterized in that, The adaptive field weakening control includes: a stator voltage control signal; the use of the pulse width modulation wave to drive the inverter to achieve high-speed field weakening control includes: The fully controlled switching transistor in the inverter is driven by the pulse width modulation wave to output the stator voltage control signal.

7. An adaptive field weakening control device under sensorless conditions, characterized in that, include: The voltage reference value determination unit is used to perform adaptive complex vector current decoupling on the excitation current reference value, torque current reference value, actual excitation current value and actual torque current value of the induction motor to obtain the excitation voltage reference value and torque voltage reference value of the induction motor. The modulation wave generation unit is used to perform flux tracking on the excitation voltage reference value and torque voltage reference value to obtain the corresponding pulse width modulation wave; A field weakening control unit is used to drive the inverter using the pulse width modulation wave to achieve high-speed field weakening control. The rotor real-time speed determination unit is used to determine the real-time speed of the induction motor based on the stator current sampling value and the stator voltage sampling value of the induction motor. The current reference value determination unit is used to determine the excitation current reference value and the torque current reference value based on the rotor angular frequency reference value, the real-time rotor speed, the synchronous angular frequency, and the current reference value of the output voltage of the induction motor. The real-time rotor speed includes: synchronous angular frequency and rotor angular frequency; the real-time rotor speed determination unit includes: The current component determination module is used to perform the sampling of the stator current values. Clarke Coordinate transformation yields the corresponding stator current. α Shaft components and stator current β Axial components; The voltage component determination module is used to perform voltage component determination on the stator voltage sample values. Clarke Coordinate transformation yields the corresponding stator voltage. α Shaft components and stator voltage β Axial components; The flux linkage estimation module is used to determine the value based on the stator current. α Shaft component, stator current β Shaft component, stator voltage α Shaft components and stator voltage β Shaft component determines rotor flux linkage α Shaft component estimates, rotor flux linkage β Shaft component estimates, rotor flux linkage α Shaft component reference values ​​and rotor flux β Axis component reference values; The rotor angular frequency determination module is used to determine the rotor angular frequency based on the rotor flux linkage. α Shaft component reference value, rotor flux β Shaft component reference value, the rotor flux linkage α Shaft component estimates and rotor flux β The rotor angular frequency is determined by the shaft component estimation value; The rotor time constant compensation determination module determines the rotor flux linkage based on the rotor flux linkage. α Shaft component reference value, rotor flux β Shaft component reference value, the rotor flux linkage α Shaft component estimates and rotor flux β Shaft component estimates, stator current α Shaft component, stator current β Shaft component, determine rotor time constant compensation value; The synchronization angular frequency determination module is used to determine the synchronization angular frequency based on the slip angular frequency containing the rotor time constant compensation value.

8. The adaptive field weakening control device under sensorless conditions according to claim 7, characterized in that, Also includes: The actual current value determination unit is used to determine the sampled stator current value. Park The actual values ​​of the excitation current and torque current are obtained by transformation.

9. The adaptive field weakening control device under sensorless conditions according to claim 7, characterized in that, The current reference value determination unit includes: The excitation current reference value determination module is used to determine the excitation current reference value based on the preset maximum stator voltage, the initial synchronous angular frequency of the constant voltage zone when the induction motor enters the constant voltage working zone, the synchronous angular frequency, the excitation voltage reference value, and the torque voltage reference value. The first limit value determination module is used to determine the first torque current q-axis limit value based on the preset maximum stator current and the torque current d-axis reference value. The second limit value determination module is used to determine the second torque current q-axis limit value based on the maximum stator voltage and the excitation voltage reference value. The final limit value determination module is used to determine the final limit value based on the first torque current q-axis limit value and the second torque current q-axis limit value; The torque current reference value determination module is used to determine the torque current reference value based on the rotor angular frequency reference value, the rotor angular frequency output by the speed observer, and the final limiting value.

10. The adaptive field weakening control device under sensorless conditions according to claim 9, characterized in that, The voltage reference value determination unit includes: The actual current value determination module is used to determine the sampled stator current value. Park The actual values ​​of the excitation current and torque current are obtained by transformation. The first voltage reference value determination module is used to determine the excitation current reference value, torque current reference value, and actual excitation current value I when the synchronization angular frequency is less than or equal to the initial synchronization angular frequency of the constant voltage region. sd The actual value of the torque current and the synchronous angular frequency are used to determine the reference value of the excitation voltage and the reference value of the torque voltage; The second voltage reference value determination module is used to determine the excitation voltage reference value and the torque voltage reference value based on the excitation current reference value, the torque current reference value, the actual excitation current value, the actual torque current value, the synchronization angular frequency, and the initial synchronization angular frequency of the constant voltage region when the synchronization angular frequency is greater than the initial synchronization angular frequency of the constant voltage region.

11. The adaptive field weakening control device under sensorless conditions according to claim 7, characterized in that, The modulation wave generation unit includes: The orthogonal voltage reference value determination module is used to perform a rotating two-phase to stationary orthogonal transformation on the excitation voltage reference value and torque voltage reference value to obtain the corresponding... α Shaft output voltage reference value and β Shaft output voltage reference value; The modulation wave generation module is used for the modulation wave generation module. α Shaft output voltage reference value and β The output voltage reference value of the shaft is subjected to space vector pulse width modulation to obtain the pulse width modulated wave.

12. The adaptive field weakening control device under sensorless conditions according to claim 7, characterized in that, The adaptive field weakening control includes: a stator voltage control signal; the field weakening control unit includes: The fully controlled switching transistor in the inverter is driven by the pulse width modulation wave to output the stator voltage control signal.

13. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the adaptive field weakening control method according to any one of claims 1 to 6.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the adaptive field weakening control method according to any one of claims 1 to 6.

15. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the adaptive field weakening control method according to any one of claims 1 to 6.

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