Field weakening method of servo control system, electronic device and storage medium

Abstract

The application discloses a field weakening method of a servo control system, an electronic device and a storage medium. The field weakening method comprises the following steps: acquiring a bus voltage of the servo control system and determining a limit voltage based on the bus voltage; acquiring a current loop direct-axis voltage and a current loop quadrature-axis voltage output by a current loop module; and acquiring a speed loop quadrature-axis current output by a speed loop module. The direct-axis current reference is determined based on the limit voltage, the current loop direct-axis voltage and the current loop quadrature-axis voltage. The quadrature-axis current reference is determined based on the limit voltage, the current loop direct-axis voltage, the current loop quadrature-axis voltage, the speed loop quadrature-axis current and the direct-axis current reference. The current loop direct-axis current and the current loop quadrature-axis current of the current loop module are adjusted based on the direct-axis current reference and the quadrature-axis current reference. Based on the above method, the reliability of the servo control system can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of control, in particular to a field weakening method of a servo control system, an electronic device and a storage medium. BACKGROUND

[0002] For a servo control system, such as a machine tool spindle drive, the motor should have a wide enough speed range to meet the demand of the motor running at a higher speed. However, in the servo control system, the voltage that the inverter can provide to the motor is limited by the inverter itself and the bus voltage, and cannot be increased all the time. During the process of increasing the motor speed, the back electromotive force of the motor will reach the maximum voltage limit value, so that the speed cannot continue to rise, and the torque output cannot meet the requirements. At this time, field weakening needs to be performed in the servo control system to continue to improve the speed range of the motor.

[0003] The existing field weakening method applied to the servo control system is prone to cause the loss of control of the direct-axis current and the quadrature-axis current when the motor is accelerated or decelerated at a high speed, thereby reducing the reliability of the servo control system. SUMMARY

[0004] The technical problem solved by the present application is how to improve the reliability of the servo control system.

[0005] To solve the above technical problem, the first technical solution adopted by the present application is: a field weakening method of a servo control system, applied to the servo control system, the servo control system comprising a speed loop module and a current loop module; the field weakening method comprising: obtaining a bus voltage of the servo control system and determining a limit voltage based on the bus voltage, obtaining a current loop direct-axis voltage and a current loop quadrature-axis voltage output by the current loop module, and obtaining a speed loop quadrature-axis current output by the speed loop module; determining a direct-axis current reference based on the limit voltage, the current loop direct-axis voltage and the current loop quadrature-axis voltage; determining a quadrature-axis current reference based on the limit voltage, the current loop direct-axis voltage, the current loop quadrature-axis voltage, the speed loop quadrature-axis current and the direct-axis current reference; and adjusting the current loop direct-axis current and the current loop quadrature-axis current of the current loop module based on the direct-axis current reference and the quadrature-axis current reference.

[0006] To solve the above technical problem, the second technical solution adopted by the present application is: an electronic device, comprising: a memory and a processor; the memory is used to store program instructions, and the processor is used to execute the program instructions to implement the above method.

[0007] To solve the above technical problem, the third technical solution adopted by the present application is: a computer readable storage medium, the computer readable storage medium stores program instructions, and the program instructions are executed by the processor to implement the above method.

[0008] The application has the beneficial effect that, different from the prior art, the technical scheme of the application calculates the direct-axis current reference quantity and the quadrature-axis current reference quantity respectively based on the current loop direct-axis voltage, the current loop quadrature-axis voltage and the speed loop quadrature-axis current, and compensates and adjusts the current loop direct-axis current and the current loop quadrature-axis current respectively according to the direct-axis current reference quantity and the quadrature-axis current reference quantity, so as to realize field weakening. Based on the above manner, the current loop direct-axis current is adjusted to the size of the direct-axis current reference quantity and the current loop quadrature-axis current is adjusted to the size of the quadrature-axis current reference quantity at the same time, so as to realize indirect adjustment of the current loop direct-axis voltage and the current loop quadrature-axis voltage, to ensure that the motor in the servo control system has good performance while running at high speed, avoid the occurrence of current out of control and other faults, and improve the reliability of the servo control system. BRIEF DESCRIPTION OF DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0010] Figure 1 is a flowchart of an embodiment of the field weakening method of the servo control system of the application;

[0011] Figure 2 is a structural schematic diagram of an embodiment of the servo control system of the application;

[0012] Figure 3 is a flowchart of a second embodiment of the field weakening method of the servo control system of the application;

[0013] Figure 4 is a calculation process schematic diagram of an embodiment of the field weakening method of the application;

[0014] Figure 5 is a calculation process schematic diagram of another embodiment of the field weakening method of the application;

[0015] Figure 6 is a flowchart of a third embodiment of the field weakening method of the servo control system of the application;

[0016] Figure 7 is a structural schematic diagram of an embodiment of the electronic device of the application;

[0017] Figure 8 is a structural schematic diagram of an embodiment of the computer readable storage medium of the application. DETAILED DESCRIPTION

[0018] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of the present application.

[0019] The terms "first", "second" in the present application are only for descriptive purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0020] The present application first proposes a field weakening method of a servo control system. The field weakening method is applied to a servo control system, and the servo control system includes a speed loop module and a current loop module.

[0021] As shown in Figure 1 , Figure 1 is a flowchart of an embodiment of the field weakening method of the servo control system of the present application. The field weakening method includes:

[0022] Step S11: obtaining a bus voltage of the servo control system and determining a limit voltage based on the bus voltage, obtaining a current loop direct-axis voltage and a current loop quadrature-axis voltage output by the current loop module, and obtaining a speed loop quadrature-axis current output by the speed loop module.

[0023] Among them, the bus voltage on the bus for supplying power to the servo control system can be obtained, and the limit voltage can be calculated based on the bus voltage. The current loop direct-axis voltage and the current loop quadrature-axis voltage output by the current loop module in the servo control system are obtained, and the speed loop quadrature-axis current output by the speed loop module in the servo control system is obtained.

[0024] Step S12: determining a direct-axis current reference based on the limit voltage, the current loop direct-axis voltage and the current loop quadrature-axis voltage.

[0025] Among them, the limit voltage, the current loop direct-axis voltage and the current loop quadrature-axis voltage can be used to calculate the reference of the current loop direct-axis current, so as to obtain the size of the reference required for subsequent compensation of the current loop direct-axis current.

[0026] Step S13: determining the quadrature-axis current reference quantity based on the limiting voltage, the direct-axis voltage of the current loop, the quadrature-axis voltage of the current loop, the quadrature-axis current of the speed loop and the direct-axis current reference quantity.

[0027] wherein the reference quantity of the quadrature-axis current of the current loop can be calculated based on the limiting voltage, the direct-axis voltage of the current loop and the quadrature-axis voltage of the current loop to obtain the size of the reference quantity which needs to be compensated for the quadrature-axis current of the current loop subsequently.

[0028] Step S14: adjusting the direct-axis current of the current loop and the quadrature-axis current of the current loop of the current loop module based on the direct-axis current reference quantity and the quadrature-axis current reference quantity.

[0029] wherein the direct-axis current of the current loop and the quadrature-axis current of the current loop of the current loop module in the servo control system are compensated respectively according to the direct-axis current reference quantity and the quadrature-axis current reference quantity, so that the direct-axis current of the current loop reaches the direct-axis current reference quantity and the quadrature-axis current of the current loop reaches the quadrature-axis current reference quantity, and then the direct-axis voltage of the current loop and the quadrature-axis voltage of the current loop of the current loop module are reduced, so as to ensure that the current does not lose control and improve the reliability of the system.

[0030] It should be noted that the above step sequence is only an example, and in practice, the sequence between steps can be adjusted according to the logical association between steps, for example, the order between steps S12 and S13 can be arbitrarily exchanged, which is not limited here.

[0031] Unlike the prior art, the technical solution of the present application calculates the direct-axis current reference quantity and the quadrature-axis current reference quantity respectively based on the direct-axis voltage of the current loop, the quadrature-axis voltage of the current loop and the quadrature-axis current of the speed loop, and adjusts the direct-axis current of the current loop and the quadrature-axis current of the current loop respectively according to the direct-axis current reference quantity and the quadrature-axis current reference quantity to realize field weakening. Based on the above method, the direct-axis current of the current loop is adjusted to the size of the direct-axis current reference quantity and the quadrature-axis current of the current loop is adjusted to the size of the quadrature-axis current reference quantity at the same time, so as to indirectly adjust the direct-axis voltage of the current loop and the quadrature-axis voltage of the current loop, so as to ensure that the motor in the servo control system has good performance while running at high speed, avoid the occurrence of current out of control and other faults, and improve the reliability of the servo control system.

[0032] Specifically, as shown in Figure 2 , Figure 2 is a structural schematic diagram of an embodiment of the servo control system of the present application, which usually comprises a field weakening module, a current loop module, a speed loop module, a position loop module, a speed calculation module, a PWM modulation module, a coordinate transformation module, an encoder module, a three-phase inverter module and a motor module.

[0033] The application program corresponding to the above flux-weakening method can be executed by the processor of the flux-weakening module to obtain required corresponding data and calculate corresponding reference quantities based on the data, so as to adjust the current in the current loop to achieve the purpose of flux weakening, thereby avoiding the occurrence of current out-of-control and other faults, ensuring the high-speed operation of the motor in the motor module, and improving the reliability of the servo control system.

[0034] The application further provides a flux-weakening method of a servo control system, which is applied to the servo control system.

[0035] As Figure 3 shown, Figure 3 is a flowchart of a second embodiment of the flux-weakening method of the servo control system, and the flux-weakening method comprises the following steps.

[0036] Step S21: obtaining a bus voltage of the servo control system and determining a limit voltage based on the bus voltage, obtaining a direct-axis current of the current loop output by the current loop module and a quadrature-axis current of the current loop output by the current loop module, and obtaining a quadrature-axis current of the speed loop output by the speed loop module.

[0037] Step S22: determining a direct-axis current reference quantity based on the limit voltage, the direct-axis current of the current loop and the quadrature-axis current of the current loop.

[0038] Step S23: determining a quadrature-axis current reference quantity based on the limit voltage, the direct-axis current of the current loop, the quadrature-axis current of the current loop, the quadrature-axis current of the speed loop and the direct-axis current reference quantity.

[0039] Step S24: adjusting the direct-axis current of the current loop and the quadrature-axis current of the current loop of the current loop module based on the direct-axis current reference quantity and the quadrature-axis current reference quantity.

[0040] Steps S21-S24 in the second embodiment correspond to steps S11-S14 in the first embodiment, and will not be described here.

[0041] Optionally, the determination of the limit voltage based on the bus voltage in step S21 can specifically comprise:

[0042] dividing the bus voltage by a preset constant to obtain a maximum undistorted voltage.

[0043] multiplying the maximum undistorted voltage by a preset coefficient to obtain the limit voltage.

[0044] Specifically, when the PWM modulation module in the servo control system adopts SVPWM modulation technology for modulation, the above preset coefficient can be The limit voltage can be calculated based on the following formula:

[0045]

[0046] U m =ku lim ,k∈(0,1) (2);

[0047] In equations (1) and (2), u lim For the maximum undistorted voltage vector magnitude, u bus U is the bus voltage. m To limit the voltage.

[0048] The limiting voltage can be accurately obtained based on equations (1) and (2). However, the preset coefficient can be 2 or other numbers depending on the actual needs of the servo control system. No specific limit is imposed here.

[0049] Optionally, step S22 may specifically include:

[0050] The first value is obtained by adding the square of the direct-axis voltage of the current loop to the square of the quadrature-axis voltage of the current loop.

[0051] Take the square root of the sum to obtain the second value.

[0052] Subtract the second value from the limiting voltage to obtain the first straight-axis error in the first error quantity.

[0053] Based on the first direct axis error, determine the direct axis current reference value.

[0054] Specifically, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the calculation process of an embodiment of the magnetic weakening method of this application, which can be used to calculate the square of the direct-axis voltage of the current loop. Add the square of the current loop cross-axis voltage To obtain the first value For the sum of squares Take the square root to obtain the second value. Limit voltage U m Subtract the second value To obtain the first straight axis error in the first error quantity

[0055] Furthermore, based on the first direct-axis error, a direct-axis current reference value is determined, which may specifically include:

[0056] The first vertical axis error is processed by PI control to obtain the third value.

[0057] Based on the preset first limiting value, the third value is subjected to limiting processing to obtain the direct-axis current reference value.

[0058] Specifically, such as Figure 4 As shown, the first linear axis error can be obtained from the first error quantity. Then, the error of the first straight axis. PI control processing is performed, and the result of the PI processing is limited based on a preset first limit value to obtain the final direct-axis current reference value i. d_ref It is used to superimpose and compensate the direct-axis current of the current loop.

[0059] It should be noted that the PI processing in this application can also be replaced by a separate I processing, or by using the gradient descent method; no limitation is made here.

[0060] Furthermore, step S23 may specifically include:

[0061] Subtract the second value from the limiting voltage to obtain the first cross-axis error in the first error quantity.

[0062] The first cross-axis error is processed by PI control to obtain a fourth value.

[0063] Based on the preset second limiting value, the fourth value is subjected to limiting processing to obtain the fifth value.

[0064] Add the velocity loop quadrature-axis current to the fifth value to obtain the sixth value.

[0065] The third limiting value is obtained by subtracting the square of the direct-axis current reference value from the square of the preset limiting current.

[0066] Based on the third limiting value, the sixth value is limited to obtain the quadrature axis current reference value.

[0067] Specifically, such as Figure 4 As shown, the error of the first straight axis can be obtained based on the... The first cross-axis error in the first error quantity is obtained using the same calculation method. The first cross-axis error PI control is performed, and the result of the PI control is limited based on a preset second limit value to obtain a fifth value. The fifth value is then added to the velocity loop quadrature-axis current i. q_ASR To obtain the sixth value, finally, the square of the preset limit current is used. Subtract the square of the direct-axis current reference value The third limiting value is used as the basis for limiting the sixth value, which yields the quadrature-axis current reference value i. q_ref It is used to superimpose and compensate for the cross-axis current of the current loop.

[0068] It should be noted that the first linear axis error is included in the first error quantity. Error amount with the first cross axis At that time, another method can be used, such as Figure 5 As shown,Figure 5 is a calculation process schematic diagram of another embodiment of the field weakening method of the present application, the square of the limit voltage can be subtracted from the square of the direct-axis voltage of the current loop The square of the limit voltage can be subtracted from the square of the direct-axis voltage of the current loop And the square root of the corresponding difference is taken to obtain The absolute value |u q_ref | of the direct-axis voltage of the current loop is subtracted To obtain the first direct-axis error quantity The square of the limit voltage can be subtracted from the square of the direct-axis voltage of the current loop The square of the limit voltage can be subtracted from the square of the direct-axis voltage of the current loop And the square root of the corresponding difference is taken to obtain The absolute value |u d_ref | of the direct-axis voltage of the current loop is subtracted To obtain the first direct-axis error quantity Wherein, the calculation of other parts is the same as the calculation process shown in Figure 4 , which will not be described here.

[0069] Unlike the prior art, the technical solution of the present application calculates the direct-axis current reference quantity and the cross-axis current reference quantity based on the direct-axis voltage of the current loop, the cross-axis voltage of the current loop and the cross-axis current of the speed loop, respectively, and compensates and adjusts the direct-axis current of the current loop and the cross-axis current of the current loop according to the direct-axis current reference quantity and the cross-axis current reference quantity, respectively, to realize field weakening. Based on the above-mentioned method, the direct-axis current of the current loop can be adjusted to the size of the direct-axis current reference quantity and the cross-axis current of the current loop can be adjusted to the size of the cross-axis current reference quantity at the same time, to realize indirect adjustment of the direct-axis voltage of the current loop and the cross-axis voltage of the current loop, to ensure that the motor in the servo control system has good performance while running at high speed, to avoid the occurrence of current out of control and other faults, and to improve the reliability of the servo control system.

[0070] The present application also proposes a field weakening method of a servo control system, which is applied to a servo control system, and the servo control system comprises a speed loop module and a current loop module.

[0071] As shown in Figure 6 , the flowchart of the third embodiment of the field weakening method of the servo control system of the present application is shown in Figure 6 , which comprises:

[0072] Step S31: acquiring the bus voltage of the servo control system and determining the limit voltage based on the bus voltage, acquiring the direct-axis voltage and the cross-axis voltage of the current loop module output by the current loop module, and acquiring the cross-axis current of the speed loop module output by the speed loop module.

[0073] Step S32: square the direct-axis voltage of the current loop and square the quadrature-axis voltage of the current loop to obtain a first value, square the sum of the squares to obtain a second value, subtract the second value from the limit voltage to obtain a first error amount.

[0074] The specific method of obtaining the first error amount is the same as that of the foregoing embodiment, which will not be described here.

[0075] Step S33: PWM modulate the bus voltage to obtain the amplitude of the real voltage of the servo control system, and subtract the second value from the amplitude of the real voltage to obtain a second error amount.

[0076] The SVPWM modulation can be performed on the bus voltage based on a PWM modulation module in the servo control system to obtain a real voltage output to the three-phase inverter module, the amplitude of the real voltage is obtained based on the real voltage, and the second error amount is obtained by subtracting the difference between the amplitude of the real voltage and the second value.

[0077] Step S34: determine a third error amount based on the first error amount and the second error amount.

[0078] Step S35: determine the direct-axis current reference amount and the quadrature-axis current reference amount based on the third error amount.

[0079] Step S36: adjust the direct-axis current of the current loop and the quadrature-axis current of the current loop of the current loop module based on the direct-axis current reference amount and the quadrature-axis current reference amount.

[0080] The steps S31 and S36 in the third embodiment correspond to the steps S11 and S14 in the first embodiment, which will not be described here. The above step sequence is only an example, and adaptive adjustment can be made according to the logical sequence between the steps, for example, the steps S32 and S33 can be in any order.

[0081] Optionally, the PWM modulation on the bus voltage in step S33 to obtain the amplitude of the real voltage of the servo control system can specifically include:

[0082] The PWM modulation on the bus voltage to obtain the direct-axis real voltage and the quadrature-axis real voltage.

[0083] Square the sum of the direct-axis real voltage and the quadrature-axis real voltage to obtain the amplitude of the real voltage.

[0084] Specifically, the real voltage can include a first real voltage, a second real voltage, and a third real voltage, and the inverse PARK transformation on the first real voltage, the second real voltage, and the third real voltage can obtain the direct-axis real voltage and the quadrature-axis real voltage

[0085] The amplitude of the real voltage can be obtained based on the following formula:

[0086]

[0087] In formula (3), is the amplitude of the real voltage, is the direct-axis real voltage, is the quadrature-axis real voltage.

[0088] Based on the above method, the amplitude of the real voltage can be obtained more accurately.

[0089] Optionally, the step S34 can specifically include:

[0090] Based on the preset weighting coefficient, a weighted average sum of the first error quantity and the second error quantity is calculated to obtain a third error quantity.

[0091] Specifically, the third error quantity can be calculated based on the following formula:

[0092]

[0093] In formula (4), λ is a preset weighting coefficient, is a first direct-axis error quantity in the first error quantity, is a second direct-axis error quantity in the second error quantity, is a third direct-axis error quantity in the third error quantity, is a first quadrature-axis error quantity in the first error quantity, is a second quadrature-axis error quantity in the second error quantity, is a third quadrature-axis error quantity in the third error quantity.

[0094] Based on the above weighting method, different preset weighting coefficients can be set according to different situations to improve the reliability of the servo control system.

[0095] Optionally, the step S35 can specifically include:

[0096] The third direct-axis error quantity and the third quadrature-axis error quantity in the third error quantity are respectively subjected to PI control processing to obtain a seventh value and an eighth value.

[0097] The seventh value is subjected to amplitude limiting processing based on a preset first amplitude limiting value to obtain a direct-axis current reference quantity.

[0098] The eighth value is subjected to amplitude limiting processing based on a preset second amplitude limiting value to obtain a ninth value.

[0099] The ninth value is added to a speed loop quadrature-axis current to obtain a tenth value.

[0100] A square of a preset limit current is subtracted from a square of the direct-axis current reference quantity to obtain a fourth amplitude limiting value.

[0101] The tenth value is limited based on the fourth limiting value to obtain the quadrature-axis current reference quantity.

[0102] Specifically, based on the above manner, it can be understood as equivalent to multiplying the third error quantity by the third limiting value to obtain the fourth error quantity. replacing the Figure 4 in the in the

[0103] Based on the above manner, two error quantities are obtained by two manners and the third error quantity is obtained based on the weighted average and, which is used to calculate the direct-axis current reference quantity and the quadrature-axis current reference quantity for subsequent compensation of the current loop direct-axis current and the current loop quadrature-axis current, which can improve the accuracy of error calculation and further improve the reliability of the servo control system.

[0104] Unlike the prior art, the technical solution of the application calculates the direct-axis current reference quantity and the quadrature-axis current reference quantity based on the current loop direct-axis voltage, the current loop quadrature-axis voltage and the speed loop quadrature-axis current, respectively, and adjusts the current loop direct-axis current and the current loop quadrature-axis current based on the direct-axis current reference quantity and the quadrature-axis current reference quantity, respectively, to realize field weakening. Based on the above manner, the current loop direct-axis current can be adjusted to the size of the direct-axis current reference quantity and the current loop quadrature-axis current can be adjusted to the size of the quadrature-axis current reference quantity at the same time, to realize indirect adjustment of the current loop direct-axis voltage and the current loop quadrature-axis voltage, to ensure that the motor in the servo control system has good performance while running at high speed, to avoid the occurrence of current out of control and other faults, and to improve the reliability of the servo control system.

[0105] The application also proposes an electronic device, as shown in Figure 7 Figure 7 is a structural schematic diagram of an embodiment of the electronic device of the application, and the electronic device 70 comprises a processor 71, a memory 72 and a bus 73.

[0106] The processor 71 and the memory 72 are connected to the bus 73 respectively, the memory 72 stores program instructions, and the processor 71 is used to execute the program instructions to realize the field weakening method in the above embodiments.

[0107] ​In this embodiment, the processor 71 can also be referred to as a CPU (Central Processing Unit). The processor 71 can be an integrated circuit chip having a processing capability of signals. The processor 71 can also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor 71 can also be any conventional processor or the like.

[0108] Compared with the prior art, the technical scheme of the application calculates the direct-axis current reference and the quadrature-axis current reference based on the current loop direct-axis voltage, the current loop quadrature-axis voltage and the speed loop quadrature-axis current, respectively, and compensates and adjusts the current loop direct-axis current and the current loop quadrature-axis current according to the direct-axis current reference and the quadrature-axis current reference, respectively, to realize field weakening. Based on the above manner, the current loop direct-axis current is adjusted to the size of the direct-axis current reference and the current loop quadrature-axis current is adjusted to the size of the quadrature-axis current reference, so that the current loop direct-axis voltage and the current loop quadrature-axis voltage are indirectly adjusted, to ensure that the motor in the servo control system has good performance while running at high speed, avoid the occurrence of current out of control and other faults, and improve the reliability of the servo control system.

[0109] The application also provides a computer readable storage medium, such as Figure 8 As shown in the figure, Figure 8 is a structural schematic diagram of an embodiment of the computer readable storage medium of the application. The computer readable storage medium 80 stores program instructions 81 thereon. The program instructions 81 are executed by a processor (not shown in the figure) to realize the field weakening method in the above embodiment.

[0110] The computer readable storage medium 80 of the embodiment can be, but is not limited to, a storage unit in a U disk, an SD card, a PD optical drive, a mobile hard disk, a large-capacity floppy disk drive, a flash memory, a multimedia memory card, a server, an FPGA or an ASIC.

[0111] Distinguished from the prior art, the technical scheme of the application calculates the direct-axis current reference quantity and the quadrature-axis current reference quantity respectively based on the current loop direct-axis voltage, the current loop quadrature-axis voltage and the speed loop quadrature-axis current, and compensates and adjusts the current loop direct-axis current and the current loop quadrature-axis current respectively according to the direct-axis current reference quantity and the quadrature-axis current reference quantity, so as to realize the field weakening. Based on the above-mentioned mode, the current loop direct-axis voltage and the current loop quadrature-axis voltage can be indirectly adjusted by simultaneously adjusting the current loop direct-axis current to the size of the direct-axis current reference quantity and adjusting the current loop quadrature-axis current to the size of the quadrature-axis current reference quantity, so as to ensure that the motor in the servo control system has good performance while running at high speed, avoid the occurrence of current out of control and other faults, and improve the reliability of the servo control system.

[0112] The above is only the embodiment of the application, and does not limit the patent scope of the application, and any equivalent structure or equivalent flow transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A method of field weakening for a servo control system, the method comprising: The application is applied to a servo control system, and the servo control system comprises a speed loop module and a current loop module; The field weakening method comprises: The bus voltage of the servo control system is acquired, and a limit voltage is determined based on the bus voltage; the current loop direct-axis voltage and the current loop quadrature-axis voltage output by the current loop module are acquired; and the speed loop quadrature-axis current output by the speed loop module is acquired; The direct-axis current reference quantity is determined based on the limit voltage, the current loop direct-axis voltage and the current loop quadrature-axis voltage; The quadrature-axis current reference quantity is determined based on the limit voltage, the current loop direct-axis voltage, the current loop quadrature-axis voltage, the speed loop quadrature-axis current and the direct-axis current reference quantity; The current loop direct-axis current and the current loop quadrature-axis current of the current loop module are adjusted based on the direct-axis current reference quantity and the quadrature-axis current reference quantity; The direct-axis current reference quantity is determined based on the limit voltage, the current loop direct-axis voltage and the current loop quadrature-axis voltage, and the quadrature-axis current reference quantity is determined based on the limit voltage, the current loop direct-axis voltage, the current loop quadrature-axis voltage, the speed loop quadrature-axis current and the direct-axis current reference quantity, comprising: The square of the current loop direct-axis voltage is added to the square of the current loop quadrature-axis voltage to obtain a first value; the first value is squared to obtain a second value; and the limit voltage is subtracted from the second value to obtain a first error quantity; The bus voltage is PWM modulated to obtain the amplitude of the actual voltage of the servo control system; and the amplitude of the actual voltage is subtracted from the second value to obtain a second error quantity; The weighted average sum of the first error quantity and the second error quantity is calculated based on a preset weighting coefficient to obtain a third error quantity; The direct-axis current reference quantity and the quadrature-axis current reference quantity are determined based on the third error quantity.

2. The field weakening method according to claim 1, characterized in that The limit voltage is determined based on the bus voltage, comprising: The bus voltage is divided by a preset constant to obtain a maximum undistorted voltage; The maximum undistorted voltage is multiplied by a preset coefficient to obtain the limit voltage.

3. The field weakening method of claim 1, wherein, The direct-axis current reference quantity is determined based on the limit voltage, the current loop direct-axis voltage and the current loop quadrature-axis voltage, comprising: The square of the current loop direct-axis voltage is added to the square of the current loop quadrature-axis voltage to obtain a first value; The first value is squared to obtain a second value; The limit voltage is subtracted from the second value to obtain a first direct-axis error quantity in the first error quantity; The direct-axis current reference quantity is determined based on the first direct-axis error quantity.

4. The field weakening method according to claim 3, characterized in that The direct-axis current reference quantity is determined based on the first direct-axis error quantity, comprising: The first direct-axis error quantity is subjected to PI control processing to obtain a third value; The third value is subjected to amplitude limiting processing based on a preset first amplitude limiting value to obtain the direct-axis current reference quantity.

5. The field weakening method according to claim 4, characterized in that, The quadrature-axis current reference quantity is determined based on the limit voltage, the current loop direct-axis voltage, the current loop quadrature-axis voltage, the speed loop quadrature-axis current and the direct-axis current reference quantity, comprising: The limit voltage is subtracted from the second value to obtain a first quadrature-axis error quantity in the first error quantity; The first cross-axis error is processed by PI control to obtain a fourth value; Based on the preset second limiting value, the fourth value is subjected to limiting processing to obtain the fifth value; Add the fifth value to the velocity loop quadrature-axis current to obtain the sixth value; Subtract the square of the direct-axis current reference value from the square of the preset limiting current to obtain the third limiting value; Based on the third limiting value, the sixth value is subjected to limiting processing to obtain the quadrature axis current reference value.

6. The field weakening method of claim 1 wherein, The step of performing PWM modulation on the bus voltage to obtain the amplitude of the actual voltage of the servo control system includes: The bus voltage is PWM modulated to obtain the direct-axis true voltage and the quadrature-axis true voltage; The square root of the sum of the squares of the true voltage along the direct axis and the true voltage along the quadrature axis is taken to obtain the amplitude of the true voltage.

7. The field weakening method of claim 1 wherein, The determination of the direct-axis current reference and the quadrature-axis current reference based on the third error includes: The third direct axis error and the third quadrature axis error in the third error quantity are respectively subjected to PI control processing to obtain the seventh value and the eighth value; Based on a preset first limiting value, the seventh value is subjected to limiting processing to obtain the direct-axis current reference value; Based on the preset second limiting value, the eighth value is subjected to limiting processing to obtain the ninth value; Add the velocity loop quadrature-axis current to the ninth value to obtain the tenth value; Subtract the square of the direct-axis current reference value from the square of the preset limiting current to obtain the fourth limiting value; Based on the fourth limiting value, the tenth value is subjected to limiting processing to obtain the quadrature axis current reference value.

8. An electronic device, comprising: include: Memory and processor; The memory is used to store program instructions, and the processor is used to execute the program instructions to implement the method as described in any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores program instructions that, when executed by a processor, implement the method as described in any one of claims 1 to 7.

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