Long wire driving motor resistance identification method, device and equipment based on double observers

Abstract

The application relates to the technical field of permanent magnet synchronous motor resistance calculation, and discloses a long-line driving motor resistance identification method based on double observers, which comprises the following steps: establishing two observer modules, establishing a full-order current observer state equation for a motor; collecting actual currents and actual voltages at intervals, calculating a current estimation value based on the actual currents and the state equation, and dynamically updating the estimation values of stator resistance and permanent magnet flux linkage of the two observers based on the current estimation value through an adaptive law; performing differential method processing on output voltage equations of the two observers to eliminate the permanent magnet flux linkage term; and solving the real value of the stator resistance based on the actual voltage difference and the set current difference of the two observer modules. The application further discloses a device and a computer equipment for realizing the method. The scheme can accurately track the rotor position under various working conditions, ensures smooth operation of the motor, and reduces the failure rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of permanent magnet synchronous motor resistance calculation, and particularly relates to a long-line driven motor resistance identification method, device and equipment based on double observers. BACKGROUND

[0002] With the deepening of oilfield development, more and more marginal wells or low-yield wells use permanent magnet electric submersible plunger pump / screw pump for intermittent and small displacement operation. However, such working conditions often require long cables to connect the ground control device with the downhole motor, and work at very low speed. The main problems faced are as follows: (1) the influence of long cable impedance on control accuracy. Oil and gas wells are often far away from the central site, and the cable line length used can be thousands of meters or even longer. The traditional standard model is difficult to accurately estimate the impedance change, resulting in unstable motor control; (2) motor temperature affects the magnetic field strength. The magnetic pole material of the permanent magnet motor will produce magnetic flux decay or increase with temperature change, and the rotor position tracking failure or overcurrent is prone to occur; (3) the limitation of the existing low-frequency open-loop control method. The traditional method mostly uses low-frequency open-loop voltage or current control, which cannot accurately track the rotor position in real time.

[0003] In permanent magnet motor control, motor parameters have a crucial influence on the stability and accuracy of the mathematical model of the system. In the standard control system, before the system starts running, the motor resistance, inductance and magnetic field parameters are identified through the self-learning process of the motor and initialized as constants to the motor voltage equation and flux equation, and the observer is modeled and run based on this. In most motor application scenarios, the range of motor parameter changes is not large, and the motor system can run. However, in the oil and gas exploitation field, because of the different cable lengths and motor processes, the motor system itself has a large resistance value, and the range of resistance changes during system operation is also large, so the resistance observer scheme of the general motor driver cannot meet the needs of the field.

[0004] Therefore, there is a need in the prior art to improve the long-line driven motor resistance identification method. SUMMARY

[0005] Therefore, the purpose of the embodiments of the present application is to provide a long-line driven motor resistance identification method and device based on double observers, which self-learns and adaptively observes the impedance characteristics of the long cable and the permanent magnet magnetic field strength of the motor, establishes a new mathematical control model to calculate the motor resistance, and thus accurately tracks the rotor position under various working conditions, ensures the smooth operation of the motor and reduces the failure rate.

[0006] Based on the above purpose, one aspect of the embodiments of the present application provides a long-line driven motor resistance identification method based on double observers, comprising the following steps:

[0007] S1 establishes two observer modules working synchronously at different direct-axis currents, and builds full-order current observer state equations for the motor;

[0008] S2 collects actual currents and actual voltages at intervals, calculates current estimation values based on the actual currents and the state equations, and dynamically updates the estimation values of the stator resistance and the permanent magnet flux linkage of the two observers based on the current estimation values through an adaptive law;

[0009] S3 performs difference method processing on the output voltage equations of the two observers to eliminate the permanent magnet flux linkage term;

[0010] S4 calculates the real value of the stator resistance based on the actual voltage difference and the set current difference of the two observer modules.

[0011] In some embodiments, the method further comprises:

[0012] feeding back the real value of the resistance into the full-order current observer state equations for parameter updating and returning to S2 until a preset condition is reached.

[0013] In some embodiments, in S1, establishing two observer modules working synchronously at different direct-axis currents comprises:

[0014] establishing two observer modules working synchronously at different direct-axis currents, the first observer module working at , and the second observer module working at , wherein, is the rated current of the motor.

[0015] In some embodiments, in S1, building full-order current observer state equations for the motor comprises:

[0016] In the synchronous rotating dq coordinates of the motor, the voltage equation is:

[0017]

[0018] Taking and as state variables, the state equation is:

[0019]

[0020] wherein, is the direct-axis current; is the quadrature-axis current; is the stator current, ; A and B are both state matrices, A=- + J, B= ; = ; J= ; d is a disturbance term, = ; is direct-axis voltage; is quadrature-axis voltage; is stator resistance; is stator voltage, ; is inductance; is permanent magnet flux linkage; is rotor speed;

[0021] The state equation of the full-order current observer is constructed using the state equation:

[0022]

[0023] wherein, is an estimated state matrix; is an estimated disturbance term; K is an adjustable gain coefficient; is an estimated stator current; is an estimated rotor speed.

[0024] In some embodiments, in S2, the estimated values of the stator resistance and the permanent magnet flux linkage of the two observers are dynamically updated based on the current estimated values by an adaptive law, comprising:

[0025] The adaptive law updates the estimated values of the stator resistance and the permanent magnet flux linkage based on a proportional-integral form The estimated values of the estimated values of the stator resistance and the permanent magnet flux linkage are calculated by the following formula:

[0026]

[0027] wherein, and are adjustable gain coefficients, is rotor speed, p is a differential operator, is direct-axis current; is quadrature-axis current; is an estimated direct-axis current; is an estimated quadrature-axis current.

[0028] In some embodiments, in S3, the output voltage equations of the two observers are processed by a difference method to eliminate the permanent magnet flux linkage term, comprising:

[0029] The output voltage equations of the two observers are:

[0030] *( )+ ;

[0031] ​Subtracting the voltages of the two observers gives:

[0032]

[0033] wherein, is the stator resistance; is the direct-axis current; is the quadrature-axis current; is the back EMF, and are the back EMFs of the two observers, the back EMF difference is approximately equal to 0, is the direct-axis current difference of the two observers, and are the voltages of the two observers.

[0034] In some embodiments, in S4, calculating the real value of the stator resistance based on the actual voltage difference of the two observer modules and the set current difference includes:

[0035] calculating the real value of the stator resistance based on the following formula

[0036]

[0037] wherein, is the stator resistance; is the measured voltage value, is the direct-axis current difference of the two observers.

[0038] In some embodiments, in S2, the interval time for interval acquisition of the actual current and the actual voltage is 10-15 ms.

[0039] Another aspect of the embodiment of the present application also provides a long-line driven motor resistance identification device based on double observers, comprising:

[0040] a double observer construction module configured to establish two observer modules that work synchronously under different direct-axis currents, and to construct a full-order current observer state equation for the motor;

[0041] a first calculation module configured to interval acquire actual current and actual voltage, to calculate a current estimation value based on the actual current and the state equation, and to dynamically update the estimation values of the stator resistance and the permanent magnet flux linkage of the two observers based on the current estimation value through an adaptive law;

[0042] a second calculation module configured to perform difference method processing on the output voltage equations of the two observers to eliminate the permanent magnet flux linkage term; ​​​

[0043] The third calculation module calculates the real value of the stator resistance based on the actual voltage difference and the set current difference of the two observer modules.

[0044] In still another aspect, the present application also provides a computer device, comprising: at least one processor; and a memory storing computer instructions executable on the processor, which, when executed by the processor, implement the steps of the above method.

[0045] The present application has at least the following beneficial technical effects:

[0046] (1) More accurate rotor position tracking: By continuously dynamically correcting the cable impedance and the permanent magnet magnetic field strength, the control model mismatch caused by long line characteristics and temperature drift is avoided, and the rotor position detection accuracy under low speed working condition is improved.

[0047] (2) Reduce failure rate and prolong equipment life: Reduce motor stall and overheating caused by load fluctuation or open-loop loss of control, prolong the service life of permanent magnet motor and matching pump machine.

[0048] (3) Energy saving: In the case of small displacement and intermittent work, accurate closed-loop control is used instead of low-frequency open-loop mode, reducing unnecessary energy loss and avoiding frequent shutdown.

[0049] (4) Suitable for various oil well working conditions: Whether the downhole temperature is high or the environment is complex, or the cable is extremely long, the method of the present application can adjust the model in real time according to the field data, and has high adaptability and universality. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other embodiments can be obtained without creative labor on the basis of these drawings.

[0051] Figure 1 The schematic diagram of the embodiment of the long-line driven motor resistance identification method based on double observers provided by the present application;

[0052] Figure 2 The schematic diagram of the embodiment of the long-line driven motor resistance identification device based on double observers provided by the present application;

[0053] Figure 3 The schematic diagram of the embodiment of the computer device provided by the present application. DETAILED DESCRIPTION

[0054] In order to make the objects, technical solutions and advantages of the present application clearer, the following further describes the embodiments of the present application in detail with reference to the accompanying drawings and in conjunction with specific embodiments.

[0055] It should be noted that all the expressions of "first" and "second" in the embodiments of the present application are used to distinguish two same-named different entities or different parameters, and the "first" and "second" are only for the convenience of description and should not be understood as a limitation of the embodiments of the present application. The subsequent embodiments will not be described one by one.

[0056] Based on the above purpose, in a first aspect, an embodiment of a long-line driving motor resistance identification method based on double observers is provided. Figure 1 The embodiment of the long-line driving motor resistance identification method based on double observers provided by the present application is shown in the schematic diagram. As shown in Figure 1 The long-line driving motor resistance identification method based on double observers of the embodiments of the present application includes the following steps:

[0057] S1, two observer modules working synchronously under different direct-axis currents are established, and a full-order current observer state equation is established for the motor;

[0058] S2, actual currents and actual voltages are collected at intervals, current estimation values are calculated based on the actual currents and the state equation, and the estimation values of the stator resistance and the permanent magnet flux linkage of the two observers are dynamically updated based on the current estimation values through an adaptive law;

[0059] S3, the output voltage equation of the two observers is processed by difference method to eliminate the permanent magnet flux linkage term;

[0060] S4, the actual voltage difference and the set current difference based on the two observer modules are used to calculate the real value of the stator resistance.

[0061] In the embodiment, the method further includes:

[0062] The real value of the resistance is fed back to the full-order current observer state equation for parameter updating and returns to S2 until a preset condition is reached, such as a preset number of cycles is reached.

[0063] Specifically, in S1, establishing two observer modules working synchronously under different direct-axis currents includes:

[0064] Two observer modules working synchronously under different direct-axis currents are established, the first observer module works at , and the second observer module works at , wherein, is the rated current of the motor.

[0065] Specifically, the system establishes two observer modules during the operation of the motor, one module works at magnetic field = 20%, and the other observer module works at magnetic field = 35%, and the magnetic field current is operated every time interval (10 ms) "magnetic field current change" operation, in this embodiment, theoretically, the two observer modules are synchronous, because the speed, voltage error should be consistent in a short time.

[0066] The observer model is established as follows:

[0067] The adaptive observer can not only be used to estimate the rotor speed and identify the motor parameters, but also be used to estimate the rotor position of the PMSM and identify other parameters to reduce the influence of parameter changes and improve the stability of the system.

[0068] The state equation of the full-order current observer is established for the motor as follows:

[0069] In the synchronous rotating dq coordinate of the motor, the voltage equation is:

[0070]

[0071] Take and as state variables, and the state equation is:

[0072]

[0073] wherein, is the direct-axis current; is the quadrature-axis current; is the stator current, ; A and B are both state matrices, A=- + J, B= ; = ; J= ; d is a disturbance term, = ; is the direct-axis voltage; is the quadrature-axis voltage; is the stator resistance; is the stator voltage, ; is the inductance; is the permanent magnet flux linkage; is the rotor speed;

[0074] The state equation of the full-order current observer is constructed by using the state equation as follows:

[0075]

[0076] where, is the estimated state matrix; is the estimated disturbance term; K is the adjustable gain coefficient; is the estimated stator current; is the estimated rotor speed.

[0077] Only if the parameters in the observer are accurate, the correct estimation result can be given. The estimated state matrix and the estimated disturbance term contain the stator resistance , inductance and , among which the stator resistance has a greater impact on the accuracy of the speed estimation at low speed, is affected by temperature, while is also affected by temperature, and both have a certain correlation, while the estimation of the electromagnetic torque is crucial, so and should be identified at the same time.

[0078] Further, an observer for estimating the rotor speed can be used, which can be obtained from the above formula:

[0079] = -W

[0080] In the formula:

[0081]

[0082] W=-△A -△d

[0083] △A=A- = I

[0084] △d=d- =

[0085] Here, and are the direct-axis component and the quadrature-axis component of e respectively; △ = ; △ =

[0086] Similarly, the following integral inequality can be obtained, that is

[0087] ​

[0088] decomposes into

[0089]

[0090]

[0091] wherein, , and are limited positive numbers, is the transpose of e-matrix.

[0092] In S2, dynamically updating the estimated values of stator resistance and permanent magnet flux linkage of the two observers based on the current estimated values by an adaptive law comprises:

[0093] the adaptive law updates the estimated values of stator resistance and permanent magnet flux linkage based on a proportional-integral form:

[0094] defining an adaptive law as follows,

[0095] = d +

[0096]

[0097] wherein, the observer functions for flux and resistance, ; ; J= ;

[0098] By inverse solving, the adaptive laws of and are respectively

[0099]

[0100] wherein, and are adjustable gain coefficients, is the rotor speed, p is a differential operator, is the direct-axis current; is the quadrature-axis current; is the direct-axis current estimate; is the quadrature-axis current estimate.

[0101] This method is a standard theoretical implementation, and it can achieve normal tracking of resistance on commonly used motors, but in the oil system, the system cable is very long, and the voltage drop is very large, so the error of this method is very large. We improve it by adding a resistance observer with magnetic field current.

[0102] Further, in S3, the output voltage equations of the two observers are processed by difference method to eliminate the permanent magnet flux linkage term, including:

[0103] The output voltage equations of the two observers are:

[0104]

[0105] Subtracting the voltages of the two observers, we get:

[0106]

[0107] wherein, is the stator resistance; is the direct axis current; is the quadrature axis current; is the back EMF, specifically, and are the back EMFs of the two observers, the difference of the back EMFs is approximately equal to 0, is the difference of the direct axis currents of the two observers, and are the voltages of the two observers.

[0108] Further, in S4, the real value of the stator resistance is calculated based on the actual voltage difference and the set current difference of the two observer modules, including:

[0109] The real value of the stator resistance is calculated based on the following formula

[0110]

[0111] wherein, is the measured voltage value, is the difference of the direct axis currents of the two observers, which is the initial set value here.

[0112] The following will be described in detail in conjunction with an exemplary embodiment, and it is emphasized that this embodiment is only for illustration and not for limitation of the present application.

[0113] 1. Hardware composition ​​​​​​​

[0114] (1) Controller: including DSP or MCU and FPGA, etc., responsible for sampling, algorithm operation and output control.

[0115] (2) Inverter: output controllable voltage and frequency to motor.

[0116] (3) Long cable: connecting ground control device and downhole permanent magnet motor.

[0117] (4) Permanent magnet motor: driving plunger pump or screw pump, used for oil well exploitation.

[0118] 2. Software flow example

[0119] (1) Start and initialize: after power on, load the nominal parameters of motor, pump and cable; establish the preliminary mathematical model (including the nominal values of line impedance and permanent magnet magnetic field strength).

[0120] (2) Double observer dynamic tracking resistance change starts to work;

[0121] (3) Model update and closed loop control: write the latest resistance and magnetic field strength value into the control parameters; recalculate the dq axis current reference value and PI (or other way) controller gain; ensure that the rotor position tracking error of the motor in the low speed working condition is kept within the acceptable range, and enough torque output can be maintained when the load fluctuates.

[0122] (4) Fault protection: if the motor has abnormal temperature rise or cannot maintain normal rotation, the controller starts emergency stop or alarm mechanism; record relevant data for operation and maintenance personnel to analyze, to prevent further damage to the equipment.

[0123] The steps and beneficial effects of the present application include:

[0124] 1. Motor cable impedance double observer dynamic identification

[0125] The standard resistance dynamic identification method is observer dynamic identification, but the accuracy of this scheme is difficult to be higher than 10%, and our double observer difference method can achieve an identification accuracy of about 3% for resistance.

[0126] 2. Permanent magnet motor magnetic field strength (temperature characteristic) self-learning

[0127] (1) By tracking the torque, current and other key parameters at different temperatures, combined with the correction of flux linkage model, the motor magnetic field strength is dynamically corrected.

[0128] (2) Since temperature change usually has a large time constant, the control software can use a small amount of test data to automatically fit or interpolate the magnetic field parameters within a long sampling period (such as tens of minutes to several hours).

[0129] 3. New mathematical control model and rotor position tracking

[0130] (1) After each completion of cable impedance and permanent magnet field strength update, the controller introduces the parameters into the vector control (FOC) or other adaptive control algorithm, recalculates the rotor flux linkage and current loop gain.

[0131] (2) Through accurate dq-axis current decoupling and control, real-time tracking of the rotor position is realized, stable operation can be maintained even at extremely low speed, and loss of step or stop rotation is avoided.

[0132] The specific embodiments of the present application will be further described below according to specific embodiments.

[0133] It should be particularly pointed out that each step in each embodiment of the above-mentioned long-line driven motor resistance identification method based on double observers can be crossed, replaced, added, deleted, and therefore, these reasonable permutations and combinations of the long-line driven motor resistance identification method based on double observers should also belong to the protection scope of the present application, and the protection scope of the present application should not be limited to the embodiments.

[0134] Based on the above purpose, a second aspect of the embodiment of the present application proposes a long-line driven motor resistance identification device based on double observers. Figure 2 The embodiment of the long-line driven motor resistance identification device based on double observers provided by the present application is shown. As shown in the figure, Figure 2 The long-line driven motor resistance identification device based on double observers of the embodiment of the present application includes the following modules:

[0135] The double observer construction module 011 is configured to establish two observer modules working synchronously under different direct-axis currents, and to construct full-order current observer state equations for the electric machine;

[0136] The first calculation module 012 is configured to collect actual currents and actual voltages at intervals, calculate current estimation values based on the actual currents and the state equations, and dynamically update the estimation values of the stator resistance and the permanent magnet flux linkage of the two observers based on the current estimation values through an adaptive law;

[0137] The second calculation module 013 is configured to perform difference method processing on the output voltage equations of the two observers to eliminate the permanent magnet flux linkage term;

[0138] The third calculation module 014 calculates the real value of the stator resistance based on the actual voltage difference and the set current difference of the two observer modules.

[0139] Based on the above purpose, a third aspect of the embodiment of the present application proposes a computer device. Figure 3Fig. 1 shows a schematic diagram of an embodiment of the computer device provided by the present application. As shown in Fig. 1, the computer device of the embodiment of the present application comprises the following devices: at least one processor 021; and a memory 022, the memory 022 storing computer instructions 023 executable on the processor, the instructions being executed by the processor to implement the steps of the above method. Figure 3

[0140] Finally, it needs to be explained that those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing relevant hardware, and the program of the long-line driving motor resistance identification method based on double observers can be stored in a computer readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiment of each method. Among them, the storage medium of the program can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc. The above-mentioned computer program embodiment can achieve the same or similar effect as any of the above-mentioned method embodiments.

[0141] In addition, the method disclosed by the embodiment of the present application can also be implemented as a computer program executed by a processor, which can be stored in a computer readable storage medium. When the computer program is executed by the processor, the above-mentioned functions defined in the method disclosed by the embodiment of the present application are executed.

[0142] In addition, the above-mentioned method steps and system units can also be implemented by using a controller and a computer readable storage medium for storing a computer program for enabling the controller to implement the above-mentioned steps or unit functions.

[0143] Those skilled in the art will also appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Skilled persons can implement the functions described in various ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the embodiments disclosed herein.

[0144] ​In one or more exemplary designs, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or other wire-based, fiber-based, or wireless technologies, then the coaxial cable, fiber optic cable, twisted pair, DSL, or other wire-based, fiber-based, or wireless technologies are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0145] The foregoing is a summary of the example embodiments disclosed herein, but it should be noted that various changes and modifications can be made without departing from the scope of the example embodiments disclosed by the claims. The functions, steps and / or actions of the method claims described herein need not be performed in any particular order. Furthermore, although the elements of the example embodiments disclosed herein can be described or claimed in individual forms, other embodiments can include a combination of some or all of them.

[0146] It should be understood that, as used herein, "a" or "an" can mean one or more things unless context clearly indicates otherwise. It should also be understood that "and / or" as used herein means any and all possible combinations of one or more of the associated listed items.

[0147] The above example embodiment numbers of the example embodiments disclosed herein are merely for description, and do not represent the advantages or disadvantages of the example embodiments.

[0148] Those skilled in the art can understand that all or part of the steps of the above-mentioned embodiments can be completed by hardware, or by program instructing relevant hardware to complete, and the program can be stored in a computer readable storage medium. The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0149] Those skilled in the art shall understand that the above discussion of any embodiment is only exemplary, and is not intended to imply that the scope (including claims) of the embodiments of the present application is limited to these examples; the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes of different aspects of the embodiments of the present application as above. In order to be brief, they are not provided in details. Therefore, any omission, modification, equivalent replacement, improvement, etc. made in the spirit and principle of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Claims

1. A method for identifying the resistance of a long-line drive motor based on dual observers, characterized in that, Includes the following steps: S1 establishes two observer modules that operate synchronously under different direct-axis currents, and constructs the full-order current observer state equation for the motor. S2 intervals collect actual current and actual voltage, calculate current estimates based on the actual current and the state equation, and dynamically update the stator resistance and permanent magnet flux estimates of the two observers based on the current estimates using an adaptive law; S3 performs a finite difference method on the output voltage equations of the two observers to eliminate permanent magnet flux terms; S4 calculates the true value of the stator resistance based on the actual voltage difference and the set current difference between the two observer modules.

2. The method for identifying the resistance of a long-line drive motor based on dual observers according to claim 1, characterized in that, Also includes: The actual resistance value is fed back to the state equation of the full-order current observer for parameter update and then returned to S2 until the preset condition is met.

3. The method for identifying the resistance of a long-line drive motor based on dual observers according to claim 2, characterized in that, In S1, two observer modules that operate synchronously under different direct-axis currents are established, including: Two observer modules are established to operate synchronously under different direct-axis currents. The first observer module is in The second observer module operates during this time. Working hours, among which, This is the rated current of the motor.

4. The method for identifying the resistance of a long-line drive motor based on dual observers according to claim 2, characterized in that, In S1, the state equations for constructing a full-order current observer for the motor include: In the dq coordinate system of the synchronously rotating motor, the voltage equation is: Will and As state variables, the state equation is: in, It is the direct-axis current; It is the quadrature-axis current; For stator current, A and B are both state matrices, A = - + J, B = ; = J= ; d is the disturbance term, = ; It is the direct-axis voltage; It is the quadrature axis voltage; Stator resistance; Stator voltage, ; It is an inductor; It is a permanent magnet flux linkage; This refers to the rotor speed; The state equations for constructing a full-order current observer using state equations are as follows: in, To predict the state matrix; K represents the predicted disturbance term; K is the adjustable gain coefficient. To estimate the stator current; The estimated rotor speed is given.

5. The method for identifying the resistance of a long-line drive motor based on dual observers according to claim 2, characterized in that, In S2, the dynamic updating of the stator resistance and permanent magnet flux estimates of the two observers based on the current estimates using an adaptive law includes: The adaptive law updates the stator resistance based on a proportional-integral form. Estimated value and permanent magnet chain The formula for calculating the estimated value is: in, and All are adjustable gain coefficients. Let p be the rotor speed, and p be the differential operator. It is the direct-axis current; It is the quadrature-axis current; Estimated value for direct-axis current; This is the estimated value for the quadrature axis current.

6. The method for identifying the resistance of a long-line drive motor based on dual observers according to claim 2, characterized in that, In S3, the output voltage equations of the two observers are processed using the finite difference method to eliminate permanent magnet flux terms, including: The output voltage equations for the two observers are as follows: *( )+ ； Subtracting the voltages of the two observers yields: * +（ ）= in, Stator resistance; It is the direct-axis current; It is the quadrature-axis current; For back potential, and These are the back potentials of the two observers. The back potential difference is approximately zero. The difference between the direct-axis currents of the two observers. and These represent the voltages of the two observers.

7. The method for identifying the resistance of a long-line drive motor based on dual observers according to claim 2, characterized in that, In S4, the calculation of the true value of the stator resistance based on the actual voltage difference and the set current difference between the two observer modules includes: The true value of the stator resistance is calculated based on the following formula. in, Stator resistance; and This is the measured voltage value. The difference in direct-axis current between the two observers is denoted as .

8. The method for identifying the resistance of a long-line drive motor based on dual observers according to claim 2, characterized in that, In S2, the interval between sampling the actual current and actual voltage is 10~15ms.

9. A resistance identification device for a long-line drive motor based on dual observers, characterized in that, include: A dual observer construction module is configured to establish two observer modules that operate synchronously under different direct-axis currents, and to construct the full-order current observer state equations for the motor. The first calculation module is configured to periodically collect actual current and actual voltage, calculate current estimates based on the actual current and the state equation, and dynamically update the estimated values ​​of stator resistance and permanent magnet flux of the two observers based on the current estimates using an adaptive law. The second calculation module is configured to perform finite difference processing on the output voltage equations of the two observers to eliminate permanent magnet flux terms. The third calculation module calculates the true value of the stator resistance based on the actual voltage difference and the set current difference between the two observer modules.

10. A computer device, characterized in that, include: At least one processor; as well as A memory storing computer instructions executable on the processor, which, when executed by the processor, implement the steps of the method according to any one of claims 1-8.

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