Method and device for determining observer gain of flux linkage observer and motor driver

Abstract

The invention relates to an observer gain determination method and device of a flux linkage observer and a motor driver. The method comprises the following steps: acquiring a reference rotating speed of a motor; determining a current observer gain according to the reference rotating speed and a preset gain determination rule; and determining the flux linkage observer of the motor according to the current observer gain. By adopting the method, the observer gain of the motor can be quickly obtained, so that the fluctuation of the motor during steady-state output is greatly reduced.

Description

Technical Field

[0001] The present application relates to the field of computer technology, and in particular to a method and device for determining an observer gain of a flux observer, and a motor driver. Background Art

[0002] The sensorless FOC (field oriented control) control technology of permanent magnet synchronous motors is widely used in cost-sensitive and volume-sensitive home appliances and power tools. Currently, common sensorless FOC control algorithms include back-EMF observation method, flux observation method and other observers as well as high-frequency injection method. Among them, the flux observation method is not restricted by the rotation speed. At low speed, medium speed and high speed, the flux of the permanent magnet synchronous motor is basically the same, and the low-speed performance is better, so it is widely used. The observer gain of the flux observer has a certain influence on the control effect of the motor. Therefore, after completing the construction of the flux observer, it is necessary to select a suitable observer gain. The traditional method calculates the stator voltage and stator current to obtain a suitable observer gain. However, this method is complex to calculate, resulting in a lag in the observer gain adjustment during the operation of the motor. Summary of the invention

[0003] Based on this, it is necessary to provide an observer gain determination method, device and motor driver for the above technical problems, which can quickly obtain the observer gain of the motor so that the fluctuation of the motor in steady-state output is greatly reduced.

[0004] A method for determining an observer gain of a flux linkage observer, the method comprising:

[0005] Get the reference speed of the motor;

[0006] Determining a current observer gain according to the reference speed and a preset gain determination rule;

[0007] A flux observer of the motor is determined according to the current observer gain.

[0008] An observer gain determination device for a flux observer, the device comprising:

[0009] An acquisition module is used to obtain the reference speed of the motor;

[0010] A current observer gain determination module, used to determine the current observer gain according to the reference speed and a preset gain determination rule;

[0011] The flux observer determination module is used to determine the flux observer of the motor according to the current observer gain.

[0012] A field programmable gate array is provided, on which a computer program is stored. The field programmable gate array is used to implement the steps of an embodiment of a method for determining an observer gain of each flux observer.

[0013] A motor driver comprises a memory, a processor and a three-phase inverter, wherein the memory stores a computer program, and the processor implements the steps of an embodiment of a method for determining observer gains of each flux observer when executing the computer program, and the three-phase inverter is used to drive a motor.

[0014] A computer device includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of an embodiment of a method for determining an observer gain of each flux observer when executing the computer program.

[0015] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of an embodiment of a method for determining observer gains of each flux observer.

[0016] The observer gain determination method, device and motor driver of the above-mentioned flux observer have been tested many times and found that there is a certain rule between the reference speed and the observer gain. Therefore, the reference speed of the motor is obtained, and the current observer gain is determined according to the reference speed and the preset gain determination rule. The flux observer of the motor is determined according to the current observer gain, that is, the current observer gain of the motor can be quickly calculated, so that the fluctuation of the motor in steady-state output is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 An application environment diagram of a method for determining an observer gain of a flux observer in one embodiment;

[0018] Figure 2 1 is a flow chart of a method for determining an observer gain of a flux observer in one embodiment;

[0019] Figure 3 is a functional relationship diagram between an observer gain and a reference speed in one embodiment;

[0020] Figure 4 It is a schematic diagram of the actual speed of the towing motor when the reference speed is 300 rpm and the observer gain γ=2000 in one embodiment;

[0021] Figure 5 It is a schematic diagram of the actual speed of the towing motor when the reference speed is 500 rpm and the observer gain γ=2000 in one embodiment;

[0022] Figure 6 It is a schematic diagram of the actual speed of the towing motor when the reference speed is 600 rpm and the observer gain γ=2200 in one embodiment;

[0023] Figure 7It is a schematic diagram of the actual speed of the towing motor when the reference speed is 1000 rpm and the observer gain γ is 2800 in one embodiment;

[0024] Figure 8 It is a schematic diagram of the actual speed of the towing motor when the reference speed is 1500rpm and the observer gain γ=3500 in one embodiment;

[0025] Fig. 9 It is a schematic diagram of the actual speed of the towing motor when the reference speed is 2000rpm and the observer gain γ=4400 in one embodiment;

[0026] Fig.10 It is a schematic diagram of the actual speed of the towing motor when the reference speed is 2500rpm and the observer gain γ=5100 in one embodiment;

[0027] Fig.11 It is a schematic diagram of the actual speed of the towing motor when the reference speed is 3000rpm and the observer gain γ=6000 in one embodiment;

[0028] Fig.12 is a structural block diagram of an observer gain determination device of a flux observer in one embodiment;

[0029] Fig.13 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0030] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly. The connection can be a direct connection or an indirect connection.

[0033] In addition, in this application, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0034] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0035] The observer gain determination method of the flux observer provided in this application can be applied to Figure 1 application environment. Figure 1 The diagram is an application environment diagram of an observer gain determination method of a flux observer in an embodiment. It includes a motor driver 100 and a motor 200, and the motor driver 110 includes a processor 110. The processor 110 can specifically be an FPGA (Field Programmable Gate Array), a CPU (Central Processing Unit), an MCU (Microcontroller Unit), etc. The motor can specifically be, but is not limited to, a permanent-magnet synchronous motor (PMSM). The processor can be used to execute the observer gain determination method of the flux observer in each embodiment of the present application.

[0036] In one embodiment, for some motors, the same observer gain cannot be used to achieve stable control within the rated speed of the motor. However, after multiple actual test results in the embodiments of the present application, it is found that there is a certain relationship between the reference speed and the observer gain. Therefore, the position acquisition method based on the flux observer in the embodiments of the present application is proposed, which can be applied to permanent-magnet synchronous motor (PMSM), induction motor, brushless DC motor (BLDC), etc., but not limited to them. Figure 2 FIG. 1 is a flow chart of a method for obtaining a position based on a flux observer in an embodiment, and the method is described by taking the method applied to a processor as an example, and includes the following steps:

[0037] Step 202, obtaining a reference speed of the motor.

[0038] Specifically, the reference speed may be a speed input by a user, a speed selected from a motor, etc. The reference speed is a speed that the motor is expected to reach.

[0039] Step 204: determine the current observer gain according to the reference speed and a preset gain determination rule.

[0040] Specifically, the preset gain determination rule includes a functional relationship between the reference speed and the corresponding observer gain. The functional relationship may include a linear relationship. Substituting the reference speed into the preset gain determination rule for calculation, the current observer gain corresponding to the reference speed can be obtained.

[0041] Step 206 : determining the flux observer of the motor according to the current observer gain.

[0042] Specifically, the flux observer can be a nonlinear flux observer. The flux observer expression is:

[0043]

[0044] Where k represents the kth calculation, T s is the sampling period, i α and i β is the current component of the stator current on the α-axis and the current component on the β-axis in the stationary coordinate system of the motor, U α and U β is the voltage component of the stator voltage on the α-axis and the voltage component on the β-axis in the stationary coordinate system of the motor, L s is the stator inductance, ψ f is the permanent magnet flux, and θ is the current position. is the stator flux component on the α axis, is the flux component of the stator flux on the β axis, γ is the current observer gain, and Y is the discretization of the state space expression of the flux.

[0045] It is understandable that the above is one of the expressions of the flux observer, and it can also be expressed by other expressions. For example:

[0046]

[0047] This is not limited here.

[0048] In this embodiment, after multiple experimental tests, it is found that the reference speed and the observer gain conform to a certain rule. Therefore, the reference speed of the motor is obtained, and the current observer gain is determined according to the reference speed and the preset gain determination rule. The flux observer of the motor is determined according to the current observer gain, that is, the current observer gain of the motor can be quickly calculated, so that the fluctuation of the motor in steady-state output is greatly reduced, and the convergence speed of the observation angle is basically not affected.

[0049] In one embodiment, the preset gain determination rule includes a linear functional relationship between the reference speed and the current observer gain.

[0050] Specifically, there is a linear relationship between the reference speed and the current observer gain. Specifically, it can be a piecewise linear function relationship. For example, when the reference speed is less than or equal to the first preset speed, there is a first linear function relationship; when the reference speed is greater than the first preset speed and less than the second preset speed, there is a second linear function relationship; when the reference speed is greater than or equal to the second preset speed, there is a third linear function relationship. Then when the reference speed is less than or equal to the first preset speed, the current observer gain can be determined according to the first linear function relationship. When the reference speed is greater than the first preset speed and less than the second preset speed, the current observer gain can be determined according to the second linear function relationship. When the reference speed is greater than or equal to the second preset speed, the current observer gain can be determined according to the third linear function relationship.

[0051] In this embodiment, the observer gain can be determined accurately and quickly by using the linear functional relationship between the reference rotation speed and the current observer gain.

[0052] In one embodiment, determining the current observer gain according to the reference speed and the preset gain determination rule includes:

[0053] When the reference speed is less than or equal to the preset speed, the preset gain is used as the current observer gain;

[0054] When the reference speed is greater than the preset speed, the current observer gain is determined according to the product of the preset proportional coefficient and the reference speed plus the preset bias coefficient.

[0055] Specifically, Figure 3 The graph is a functional relationship between the observer gain and the reference speed in one embodiment. ref Linear relationship of absolute value:

[0056]

[0057] Among them, n ref is the reference speed, n0 is the preset speed, γ0 is the preset gain value, k is the preset proportional coefficient, b is the preset bias coefficient, nmax is the rated speed.

[0058] The above relationship shows that when the reference speed is less than n0, the observer gain γ can be selected as a fixed value (preset gain) γ0. This is because under low speed conditions, the control of the motor is more obviously affected by nonlinear factors such as the dead zone of the three-phase inverter. At this time, no matter how the observer gain is adjusted, the control effect has almost no change. When the speed is greater than the preset speed, different observer gains have a greater impact on the control effect, so it is necessary to determine the specific observer gain. After multiple actual measurement results, the above linear relationship is obtained.

[0059] In this embodiment, the motor control effect of the same observer gain is almost the same under low speed conditions. Therefore, when the reference speed is less than or equal to the preset speed, the preset gain value is used as the observer gain; when the reference speed is greater than the preset speed, there is a linear relationship between the reference speed and the observer gain. Therefore, the current observer gain in the flux observer is determined based on the product of the preset proportional coefficient and the reference speed plus the preset bias coefficient, which can greatly reduce the steady-state output fluctuation of the motor and has a weak impact on the angle convergence speed.

[0060] In one embodiment, the preset gain is the observer gain corresponding to the minimum fluctuation degree; the preset rotation speed is the maximum rotation speed corresponding to the minimum fluctuation degree under the preset gain.

[0061] Specifically, under low speed conditions, the control of the motor is more obviously affected by nonlinear factors such as the dead zone of the three-phase inverter. At this time, no matter how the observer gain is adjusted, the control effect has almost no change. And through actual measurement statistics, the corresponding observer gain of the motor under low speed conditions is basically the same. Figure 4 As shown, it is a schematic diagram of the actual speed of the towing motor when the reference speed is 300 rpm and the observer gain γ=2000 in one embodiment. Figure 4 The horizontal axis is time, and the vertical axis is speed. △T is the time difference between the two selected time points. MAX is the maximum speed, MIN is the minimum speed, AVG is the average speed, and RMS is the root mean square value. Figure 5 The figure is a schematic diagram of the actual speed of the motor when the reference speed is 500 rpm and the observer gain γ=2000 in one embodiment. γ=2000 is the optimal observer gain corresponding to the speed of 300 rpm (Revolutions Per Minute) and the speed of 500 rpm, and the speed fluctuation is the smallest at this time. Figure 4 and Figure 5It can be seen that when the speed is less than or equal to 500rpm, the same observer gain γ is used, and the control effect on the motor is the same, that is, using the same observer gain, the speed fluctuations of the two are almost the same, and the optimal observer gain of the two is the same. After actual measurement, when the reference speed is less than or equal to 500rpm, the optimal observer gain γ = 2000.

[0062] Then switch the speed from small to large, adjust the observer gain at each speed, and obtain the observer gain when it is adjusted to the minimum fluctuation degree. This observer gain is the optimal observer gain for the speed. In the low speed range, the optimal observer gain of each speed is basically the same and is the observer gain corresponding to the minimum fluctuation degree, which is the preset gain. Then the speed between the change and no change of the observer gain is taken as the maximum speed corresponding to the minimum fluctuation degree under the preset gain.

[0063] Alternatively, a low speed value A can be selected, and the observer gain at the low speed value can be adjusted continuously until the fluctuation degree is minimized, and the corresponding observer gain is obtained, and then the optimal observer gain is obtained, and the optimal observer gain is the preset gain. Then, under the preset gain, if it is still within the low speed range, the fluctuation degree and the low speed A are within an allowable error range; by continuously increasing the speed until the fluctuation degree just exceeds the error range, the maximum speed corresponding to the minimum fluctuation degree under the preset gain is obtained.

[0064] In this embodiment, the observer gain is determined at low speed, and when the reference speed is within this range, the observer gain can be quickly obtained, so that the steady-state output fluctuation of the motor is greatly reduced and the influence on the convergence speed is weak.

[0065] In one embodiment, the preset proportional coefficient and the preset bias coefficient are determined by a plurality of rotational speeds and the optimal observer gain corresponding to each rotational speed; the optimal observer gain is the observer gain that minimizes the fluctuation degree under the rotational speed.

[0066] Specifically, when the reference speed is greater than the preset speed, there is a linear relationship between the reference speed and the observer gain. Then, by obtaining the speed and the corresponding optimal observer gain multiple times and performing fitting or interpolation operations, a linear relationship can be obtained, and then a preset proportional coefficient and a preset bias coefficient can be obtained. It is understandable that for different motors, the preset proportional coefficient and the preset bias coefficient may be different.

[0067] For example, when the reference speed is greater than 500 rpm and less than or equal to the motor rated speed n maxWhen the reference speeds are 600rpm, 1000rpm, 1500rpm, 2000rpm, 2500rpm, and 3000rpm, the suitable observer gain γ under different reference speeds is tested. Figure 6 The figure is a schematic diagram of the actual speed of the towing motor when the reference speed is 600 rpm and the observer gain γ=2200 in one embodiment. γ=2200 is the optimal observer gain corresponding to the reference speed of 600 rpm, and the speed fluctuation is minimal at this time. Figure 7 The figure is a schematic diagram of the actual speed of the towing motor when the reference speed is 1000 rpm and the observer gain γ=2800 in one embodiment. γ=2800 is the optimal observer gain corresponding to the reference speed of 1000 rpm, and the speed fluctuation is minimal at this time. Figure 8 The figure is a schematic diagram of the actual speed of the towing motor when the reference speed is 1500 rpm and the observer gain γ=3500 in one embodiment. γ=3500 is the optimal observer gain corresponding to the reference speed of 1500 rpm, and the speed fluctuation is minimal at this time. Fig. 9 The figure is a schematic diagram of the actual speed of the towing motor when the reference speed is 2000 rpm and the observer gain γ=4400 in one embodiment. γ=4400 is the optimal observer gain corresponding to the reference speed of 2000 rpm, at which the speed fluctuation is minimal. Fig.10 The figure is a schematic diagram of the actual speed of the towing motor when the reference speed is 2500 rpm and the observer gain γ=5100 in one embodiment. γ=5100 is the optimal observer gain corresponding to the reference speed of 2500 rpm, at which the speed fluctuation is minimal. Fig.11 The figure is a schematic diagram of the actual speed of the drag motor when the reference speed is 3000rpm and the observer gain γ=6000 in an embodiment. γ=6000 is the optimal observer gain corresponding to the reference speed of 3000rpm, and the speed fluctuation is the smallest at this time. Then, it can be concluded from the above results that when the reference speed is greater than 500rpm, the suitable observer gain γ increases with the increase of the reference speed, showing a linear relationship. The preset proportional coefficient k and the preset bias coefficient b are fitted by the above data, and the above k=1.6 and b=1200. For this motor, when other reference speeds are given, the appropriate observer gain can be calculated according to γ=1.6n+1200. The feasibility of this embodiment has been proved after multiple actual motor operations. It can realize non-reversal starting at any position of the rotor, with a 100% success rate of starting, and a small starting current and smooth starting. The observation angle converges quickly and can converge to the actual angle within one electrical angle cycle; the motor can run stably at different reference speeds, and when the rotor speed is greater than 500rpm, the error between the actual speed and the reference speed is between ±1%. The rotor switches forward and reverse quickly, and the switching process is smooth and without jitter.

[0068] It should be noted that the proportional coefficient and offset are different for motors with different parameters, and need to be actually tested and calculated.

[0069] In this embodiment, the steady-state output fluctuation of the motor can be greatly reduced, and the influence on the convergence speed is weak.

[0070] In one embodiment, the reference speed is less than or equal to the rated speed of the motor, which satisfies the operating conditions of the motor, and the optimal observer gain within the rated speed satisfies the preset gain rule, so that the steady-state output fluctuation of the motor is greatly reduced and the impact on the convergence speed is weak.

[0071] It should be understood that although the above Figure 2 The steps in the flowchart are shown in sequence as indicated by arrows, but these steps are not necessarily executed in the order indicated by arrows or numbers. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 2 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0072] In one embodiment, Fig.12 FIG. 1 is a structural block diagram of an observer gain determination device of a flux observer in one embodiment. Fig.12 A device for determining an observer gain of a flux observer is provided. The device may adopt a software module or a hardware module, or a combination of the two to become a part of a computer device. The device specifically includes: an acquisition module 1202, a current observer gain determination module 1204 and a flux observer determination module 1206, wherein:

[0073] An acquisition module 1202 is used to acquire a reference speed of the motor;

[0074] A current observer gain determination module 1204, configured to determine a current observer gain according to a reference speed and a preset gain determination rule;

[0075] The flux observer determination module 1206 is used to determine the flux observer of the motor according to the current observer gain.

[0076] In one embodiment, the preset gain determination rule includes a linear functional relationship between the reference speed and the current observer gain.

[0077] In one embodiment, the current observer gain determination module 1204 is configured to use the preset gain as the current observer gain when the reference speed is less than or equal to the preset speed;

[0078] When the reference speed is greater than the preset speed, the current observer gain is determined according to the product of the preset proportional coefficient and the reference speed plus the preset bias coefficient.

[0079] In one embodiment, the preset gain is the observer gain corresponding to the minimum fluctuation degree; the preset rotation speed is the maximum rotation speed corresponding to the minimum fluctuation degree under the preset gain.

[0080] In one embodiment, the preset proportional coefficient and the preset bias coefficient are determined by a plurality of rotational speeds and the optimal observer gain corresponding to each rotational speed; the optimal observer gain is the observer gain that minimizes the fluctuation degree under the rotational speed.

[0081] In one embodiment, the reference speed is less than or equal to the rated speed of the motor.

[0082] The specific definition of the observer gain determination device of the flux observer can be found in the definition of the observer gain determination method of the observer above, which will not be repeated here. Each module in the above-mentioned observer gain determination device of the flux observer can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0083] In one embodiment, a computer device is provided. The computer device may be a terminal device, and its internal structure diagram may be as follows: Fig.13 As shown. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WI FI, an operator network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, an observer gain determination method of an observer is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a key, trackball or touchpad set on the computer device housing, or an external keyboard, touchpad or mouse, etc.

[0084] Those skilled in the art will understand that Fig.13 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0085] In one embodiment, a field programmable gate array is provided, on which a computer program is stored. The field programmable gate array is used to implement the steps of the above-mentioned method embodiments.

[0086] In one embodiment, a motor driver is provided, including a memory, a processor and a three-phase inverter. A computer program is stored in the memory. When the processor executes the computer program, the steps of the above-mentioned method embodiments are implemented. The three-phase inverter is used to drive the motor.

[0087] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps of the above-mentioned method embodiments when executing the computer program.

[0088] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method embodiments are implemented.

[0089] In one embodiment, a computer program product or computer program is provided, the computer program product or computer program includes computer instructions, the computer instructions are stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device performs the steps in the above-mentioned method embodiments.

[0090] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes in the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0091] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for determining an observer gain of a flux observer, characterized in that: The method comprises: Get the reference speed of the motor; Determining a current observer gain according to the reference speed and a preset gain determination rule; A flux observer of the motor is determined according to the current observer gain.

2. The method according to claim 1, characterized in that The preset gain determination rule includes a linear function relationship between the reference rotation speed and the current observer gain.

3. The method according to claim 1, characterized in that The step of determining the current observer gain according to the reference speed and a preset gain determination rule includes: When the reference speed is less than or equal to the preset speed, the preset gain is used as the current observer gain; When the reference speed is greater than the preset speed, the current observer gain is determined according to a product of a preset proportional coefficient and the reference speed plus a preset bias coefficient.

4. The method according to claim 3, characterized in that The preset gain is the observer gain corresponding to the minimum fluctuation degree; the preset speed is the maximum speed corresponding to the minimum fluctuation degree under the preset gain.

5. The method according to claim 3, characterized in that: The preset proportional coefficient and the preset bias coefficient are determined by a plurality of rotational speeds and an optimal observer gain corresponding to each of the rotational speeds; the optimal observer gain is an observer gain that minimizes the fluctuation degree at the rotational speed.

6. The method according to any one of claims 1 to 5, characterized in that: The reference speed is less than or equal to the rated speed of the motor.

7. A device for determining an observer gain of a flux observer, characterized in that: The device comprises: An acquisition module is used to obtain the reference speed of the motor; A current observer gain determination module, used to determine the current observer gain according to the reference speed and a preset gain determination rule; The flux observer determination module is used to determine the flux observer of the motor according to the current observer gain.

8. A field programmable gate array having a computer program stored thereon, characterized in that: The field programmable gate array is used to implement the steps of the method according to any one of claims 1 to 6.

9. A motor driver, comprising a memory, a processor and a three-phase inverter, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented, and the three-phase inverter is used to drive a motor.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

Images