Permanent magnet synchronous motor speed loop control method and related equipment

Abstract

The invention provides a permanent magnet synchronous motor speed loop control method and related equipment, and the method employs a power reaching law to correct a novel reaching law, enables the system state of a permanent magnet synchronous motor to increase the reaching speed when the system state does not reach a sliding mode surface, and enables the power to be reduced when the system state reaches the sliding mode surface. And the system state can stably reach the sliding mode surface, so that the speed of the system state reaching the sliding mode surface is accelerated. According to the scheme, the buffeting of the motor is reduced through the novel reaching law, the novel reaching law is corrected through the power reaching law, the speed of the system state of the permanent magnet synchronous motor reaching the sliding mode surface is increased, and the permanent magnet synchronous motor can be rapidly stabilized.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly to a speed loop control method for a permanent magnet synchronous motor and related devices. Background Art

[0002] A permanent magnet synchronous motor is a synchronous motor that provides excitation with permanent magnets. It consists of components such as a stator, a rotor, and an end cover. The stator is laminated to reduce iron loss generated during the operation of the motor, and is equipped with a three-phase AC winding, called the armature. Since no excitation current is required and there is no excitation loss, the efficiency and power density of the motor are improved.

[0003] The permanent magnet synchronous motor has the advantages of simple structure, high power density, and convenient maintenance. In the field of modern new energy vehicle drive, the permanent magnet synchronous motor has gradually replaced the DC motor and the asynchronous motor. The applicant has found through research that when the motor drive system of the permanent magnet synchronous motor is used in the speed mode of a passenger car, there are still problems such as poor robustness and large speed fluctuations, which cause motor jitter. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a speed loop control method for a permanent magnet synchronous motor and related devices to solve the problem of large speed fluctuations and motor jitter caused by the permanent magnet motor during operation in the prior art.

[0005] To achieve the above object, embodiments of the present invention provide the following technical solutions:

[0006] A speed loop control method for a permanent magnet synchronous motor, comprising:

[0007] Obtaining the actual value \(i\) of the q-axis current of the stator in the rotating coordinate system q ;

[0008] Using a speed loop controller based on the target approach law to calculate the reference current value of the q-axis The target approach law is obtained by modifying the new approach law with the power approach law;

[0009] Wherein, the new approach law is:

[0010]

[0011] Wherein, \(s\) is the sliding surface; \(sat\) is the saturation function; \(\epsilon\) is the approaching rate; \(q\) is the approaching coefficient; \(\alpha\) is a parameter to be designed and is a positive number; \(\beta\) is a parameter to be designed, and \(\delta\) is the weighted integral gain;

[0012] Based on the actual value \(i\) q and the reference current value perform PI operation, and adjust the actual value \(i\) of the q-axis current based on the operation result q .

[0013] Optionally, in the above permanent magnet synchronous motor speed loop control method, the power approach law is k|s| l sat(s), where,

[0014] The target approach law is:

[0015]

[0016] where ξ1 and ξ2 are power coefficients respectively; k is the power approach coefficient; μ is the minimum value of the power coefficient;

[0017] Optionally, in the above permanent magnet synchronous motor speed loop control method, calculating the reference current value of the q-axis includes:

[0018] Based on the formula and the target approach law, calculating the reference current value of the q-axis

[0019] where c is an adjustment parameter, the ω m is the mechanical angular speed, u = di q / dt, the P n is the number of pole pairs, is the rotor permanent magnet flux linkage.

[0020] Optionally, in the above permanent magnet synchronous motor speed loop control method, obtaining the actual value i q of the q-axis current of the stator in the rotating coordinate system, includes:

[0021] Using the feedback method to obtain the actual value i q of the q-axis current of the stator in the rotating coordinate system.

[0022] Optionally, in the above permanent magnet synchronous motor speed loop control method, before calculating the reference current value of the q-axis, it further includes:

[0023] Obtaining the configuration parameters of the permanent magnet synchronous motor;

[0024] Based on the preset mapping relationship, obtaining the values of c for q, ε, α, ξ1, ξ2, k, β, and μ that match the configuration parameters.

[0025] Optionally, in the above permanent magnet synchronous motor speed loop control method, when the DC bus voltage of the permanent magnet synchronous motor is 310V;

[0026] The stator resistance is 2.875Ω;

[0027] The stator d-axis inductance is 8.5e-3 mH;

[0028] The stator q-axis inductance is 8.5e-3 mH;

[0029] The permanent magnet flux linkage is 0.175 Wb;

[0030] The number of pole pairs is 4;

[0031] The moment of inertia is 0.003 kg·m 2 ;

[0032] The damping coefficient is 0.008 N·m·s;

[0033] where q = 200, ε = 220, α = 2e4, ξ1 = 1.2, ξ2 = 0.3, k = 20, β = -0.1, μ = 0.1, c = 100.

[0034] A permanent magnet synchronous motor speed loop control device, comprising:

[0035] A current acquisition unit for obtaining the actual value i of the q-axis current of the stator in the rotating coordinate system q ;

[0036] A standard current calculation unit for calculating the reference current value of the q-axis by using a speed loop controller based on the target approaching law The target approaching law is obtained by modifying the new approaching law with the power approaching law;

[0037] Among them, the new approaching law is:

[0038]

[0039] where s is the sliding surface; sat is the saturation function; ε is the approaching rate; q is the approaching coefficient; α is a parameter to be designed and is a positive number; β is a parameter to be designed, and δ is the weighted integral gain;

[0040] A PI operation unit for performing PI operation based on the actual value i q and the reference current value to adjust the actual value i of the q-axis current based on the operation result q .

[0041] A storage medium, on which a computer program is stored, and when the computer program is executed by a processor, each step of the permanent magnet synchronous motor speed loop control method described in any one of the above is implemented.

[0042] A permanent magnet synchronous motor speed loop control device, comprising: a memory and a processor;

[0043] The memory is used to store programs;

[0044] The processor is used to execute the program to implement each step of the data evaluation method described in any one of the above.

[0045] A permanent magnet synchronous motor includes the above permanent magnet synchronous motor speed loop control device.

[0046] Based on the above technical solutions, it can be seen from the solutions provided in the embodiments of the present invention that the present application corrects the new reaching law by using the power reaching law, so that when the system state of the permanent magnet synchronous motor has not reached the sliding mode surface, the reaching speed is increased. When reaching the sliding mode surface, the power will be reduced, so that the system state can reach the sliding mode surface smoothly, thereby accelerating the speed at which the system state reaches the sliding mode surface. It can be seen that the above solution reduces the motor chattering through the new reaching law, and corrects the new reaching law by the power reaching law to improve the speed at which the system state of the permanent magnet synchronous motor reaches the sliding mode surface, so that the permanent magnet synchronous motor can be fast and stable. Description of the Drawings

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0048] Figure 1 It is a schematic flowchart of the permanent magnet synchronous motor speed loop control method disclosed in the embodiments of the present application;

[0049] Figure 2 It is a schematic control flowchart of the permanent magnet synchronous motor vector control system in the existing solution;

[0050] Figure 3 It is a schematic structural diagram of the speed loop controller disclosed in the embodiments of the present application;

[0051] Figure 4 It is a schematic structural diagram of the permanent magnet synchronous motor speed loop control device disclosed in the embodiments of the present application;

[0052] Figure 5 It is a schematic structural diagram of the permanent magnet synchronous motor speed loop control device disclosed in the embodiments of the present application. Detailed Embodiments

[0053] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0054] To solve the problem of motor jitter caused by large rotational speed fluctuations, the applicant's prior application added a weighted integral gain to the traditional exponential reaching law, which can optimize the chattering problem of the motor and increase the robustness of the motor. This application further adds a power reaching law on the basis of the prior application to correct the calculation result of the traditional exponential reaching law. When the system state has not reached the sliding mode surface, the reaching speed is increased. When reaching the sliding mode surface, the power will be reduced, thereby accelerating the speed at which the system state reaches the sliding mode surface. It can be seen that the above solution reduces the motor chattering through weighted integral gain, sacrificing part of the reaching speed (the speed at which the system state reaches the sliding mode surface), and this application makes up for this shortcoming through the power reaching law.

[0055] When modeling, analyzing, and designing a permanent magnet synchronous motor (PMSM for short), the PMSM needs to meet the following conditions:

[0056] 1) The stator winding current and the rotor permanent magnet magnetic field are sinusoidally distributed in the air gap space;

[0057] 2) The three-phase stator windings are symmetrical and completely identical;

[0058] 3) Eddy current and hysteresis losses in the iron core are not considered, there is no damping winding on the rotor, and the mutual leakage inductance between windings is ignored.

[0059] On the above basis, in the prior art, the permanent magnet synchronous motor model can usually be expressed as follows in the d-q rotating coordinate system:

[0060]

[0061] Among them, u d and u q represent the voltages on the d-axis and q-axis respectively; i d and i q represent the currents on the d-axis and q-axis respectively; Pn is the number of pole pairs; is the magnetic flux of the rotor permanent magnet; ω is the electrical angular velocity of the rotor; Ld, Lq are the inductance components on the d-q axis; r is the stator resistance; T e is the electromagnetic torque; T L is the load torque; J is the moment of inertia.

[0062] The traditional exponential reaching law is as follows:

[0063]

[0064] where S is the sliding mode surface; sgn(s) is the sign function; ε is the reaching rate; q is the reaching coefficient.

[0065] Define the state variables of the PMSM system:

[0066]

[0067] In the formula: ω m is the mechanical angular velocity, and ω ref is the given rotational speed.

[0068] From Equation (1) and Equation (3), we get:

[0069]

[0070] Define u = di q / dt, Equation (4) can be simplified to:

[0071]

[0072] Define the sliding mode surface function as:

[0073] S = cx1 + x2, c > 0 (6)

[0074] From (5) and (6), we can obtain

[0075]

[0076] Substitute the traditional reaching law to get:

[0077]

[0078] That is:

[0079]

[0080] In Equation (9), is the q-axis reference current value output by the controller.

[0081] Design the speed loop controller using the derived Equation (9) to achieve the speed control of the traditional permanent magnet synchronous motor.

[0082] Among them, the above formulas (1)-(9) are all existing formulas.

[0083] Based on the above various formulas, this embodiment discloses a speed loop control method for a permanent magnet synchronous motor. See Figure 1, the method may include:

[0084] Step S101: Obtain the actual value \(i_{qs}\) of the q-axis current of the stator in the rotating coordinate system q .

[0085] The rotating coordinate system in a permanent magnet synchronous motor, also known as the dq coordinate system, is a coordinate system used to describe the magnetic field and current of the motor. In this coordinate system, the d-axis represents the direct axis direction, and the q-axis represents the quadrature axis direction. The d-axis coincides with the axis of the rotor magnetic pole, and the q-axis is perpendicular to the d-axis, and the two are perpendicular to each other. The entire coordinate system rotates together with the rotor at the same angular velocity.

[0086] In the rotating coordinate system, the voltage and current of the motor are decomposed into d-axis and q-axis components. By controlling the values of these components, the magnetic field and torque of the motor can be controlled, thus achieving precise control of the motor. The advantage of this coordinate system is that it can simplify the mathematical model of the motor, making the analysis and control of the motor more convenient.

[0087] Specifically, for the q-axis and d-axis of the stator of a permanent magnet synchronous motor:

[0088] d-axis (direct axis): In a permanent magnet synchronous motor, the direction of the center line of the rotor magnetic pole is called the direct axis direction. In the stator of a permanent magnet synchronous motor, the axis corresponding to the center line of the rotor magnetic pole is defined as the d-axis.

[0089] q-axis (quadrature axis): On the perpendicular bisector between two adjacent rotor magnetic poles, it is called the quadrature axis direction, and the corresponding stator axis is called the q-axis.

[0090] When analyzing a permanent magnet synchronous motor, decomposing the current into q-axis and d-axis components can better understand and control the operating state of the permanent magnet synchronous motor. For example, in a permanent magnet synchronous motor, the q-axis current controls the magnetic field of the motor, while the d-axis current controls the torque of the motor. By precisely controlling the magnitude and direction of the q-axis and d-axis currents, precise control of the motor speed, torque, and efficiency can be achieved. Therefore, measuring the q-axis current and d-axis current is crucial during the motor control process.

[0091] This step can obtain the actual value \(i_{qs}\) of the q-axis current of the stator in the rotating coordinate system through a feedback method q , specifically, the Figure 2 is a schematic diagram of the control flow of the vector control system of a permanent magnet synchronous motor in the existing scheme. Refer to Figure 2 , the three-phase alternating current signals \(I_{a}\), a \(I_{b}\), b \(I_{c}\) in the abc three-phase stationary coordinate system of the permanent magnet synchronous motor can be collected c , and through the Clarke-Park transformation, the actual value \(i_{ds}\) of the d-axis current of the stator of the current in the rotating coordinate system can be obtainedd and the actual value i of the q-axis current q .

[0092] Step S102: Using a speed loop controller based on the target reaching law, calculate the reference current value of the q-axis The target reaching law is obtained by modifying the new reaching law with the power reaching law, and the value of the power of the power reaching law decreases as the distance between the system state and the sliding surface decreases;

[0093] In a permanent magnet synchronous motor, the function of the speed loop controller is to ensure that the speed of the motor is consistent with the set speed command value and eliminate the influence of factors such as load torque disturbance on the motor speed. The speed loop controller generates a control signal to adjust the input voltage or current of the motor by comparing the difference between the actual speed and the set speed, so as to change the speed of the motor.

[0094] The role of the reaching law in the speed loop controller is to adjust the dynamic performance and stability of the system. Reaching law control is a commonly used control strategy for adjusting the response speed and stability of the system. By setting appropriate reaching law parameters, the speed and manner of the system state approaching the set value can be controlled.

[0095] In the speed loop controller, the reaching law can be used to adjust the output of the speed regulator to achieve a smooth speed regulation process. By setting appropriate reaching law parameters, the rate of change of the output of the speed regulator can be controlled, thereby adjusting the input voltage or current of the motor to achieve smooth acceleration or deceleration of the motor.

[0096] Among them, the new reaching law is:

[0097] This new reaching law is obtained by modifying the traditional exponential reaching law in formula 2 with the weighted integral gain α|δ|sat(s) to get;

[0098] Among them, s is the sliding surface; sat is the saturation function; ε is the reaching rate; q is the reaching coefficient; α is a parameter to be designed and is a positive number; β is a parameter to be designed, and δ is the weighted integral gain.

[0099] The power reaching law is a reaching law for controlling a system, and its characteristic is that the reaching speed of the system state when approaching the sliding surface is related to the distance from the sliding surface. Specifically, the system state approaches the sliding surface at a larger speed when it is far from the sliding surface, and approaches the sliding surface at a smaller speed when the system state approaches the sliding surface. The characteristic of this reaching law is to adjust the power exponent to adjust the speed of the system state approaching the sliding surface, so as to reduce chattering and improve the tracking performance of the control.

[0100] The speed loop controller obtains the actual value iq Afterwards, based on the actual value i q and the target approaching law, the corresponding reference current value can be calculated

[0101] Step S103: Based on the actual value i q and the reference current value perform PI operation, and adjust the actual value i of the q-axis current based on the operation result q .

[0102] PI operation refers to proportional-integral operation, which can calculate the control signal by comparing the error between the reference current value q and the actual value i, so as to adjust the output of the permanent magnet synchronous motor, so that the actual value i q gradually approaches the reference current value to enable the permanent magnet synchronous motor to stably output.

[0103] It can be seen from the above solution that in this application, the power approaching law is used to correct the new approaching law, so that when the system state of the permanent magnet synchronous motor has not reached the sliding mode surface, the arrival speed is increased. When reaching the sliding mode surface, the power will be reduced, so that the system state can reach the sliding mode surface smoothly, thereby accelerating the speed of the system state reaching the sliding mode surface. It can be seen that the above solution reduces the motor chattering through the new approaching law, corrects the new approaching law through the power approaching law, improves the speed of the system state of the permanent magnet synchronous motor reaching the sliding mode surface, and enables the permanent magnet synchronous motor to be fast and stable.

[0104] In this embodiment, a specific configuration method of the power approaching law is also disclosed. Specifically, the power approaching law is k|s| λ sat(s), where

[0105] By using the power approaching law to correct the new approaching law, the obtained target approaching law is:[[]]

[0106]

[0107] where ξ1 and ξ2 are respectively the power coefficients; k is the power approaching coefficient; μ is the minimum value of the power coefficient.

[0108] Specifically,[[]] Figure 3 is the structural schematic diagram of the speed loop controller disclosed in the embodiment of this application. Refer to Figure 3, \(x_1\) and \(x_2\) can be calculated based on formula (3), and then \(s\) can be calculated based on \(x_1\) and \(x_2\). Furthermore, the product of \(q\) and \(s\) is used as the parameter term \(qs\) in the target reaching law. Combining \(x_2\) with the adjustment parameter \(c\) can obtain the parameter term \(cx_2\). At the same time, the parameter term \(sat(s)\) in the target reaching law is calculated based on \(s\). Then, by combining the parameter term \(sat(s)\) with \(e\), \(s\), and other parameters, the parameter terms \(esat(s)\), \(a|d|sat(s)\), and \(k|s|\) in the target reaching law can be obtained l \(sat(s)\), and then based on these parameters, the target reaching law can be constructed, and finally, the speed loop controller based on the target reaching law is obtained.

[0109] In this embodiment, the speed loop controller calculates the reference current value of the q-axis The specific process can be as follows:

[0110] Based on formula (7) and the target reaching law, the reference current value of the q-axis is calculated

[0111] Specifically, from formula (7) and the target reaching law, we can obtain:

[0112]

[0113] By transforming the above formula, we get formula Thus, the reference current value of the q-axis can be calculated

[0114] where \(c\) is the adjustment parameter, \(\omega\) m is the mechanical angular speed, \(u = di\) q / dt, \(P\) n is the number of pole pairs, is the rotor permanent magnet flux linkage.

[0115] In this embodiment, to better improve the performance of the permanent magnet synchronous motor, the specific values of the parameters in the target reaching law can be configured based on the configuration parameters of the permanent magnet synchronous motor. Thus, before calculating the reference current value of the q-axis in this solution it further includes: obtaining the configuration parameters of the permanent magnet synchronous motor; obtaining the values of \(q\), \(\varepsilon\), \(\alpha\), \(\xi_1\), \(\xi_2\), \(k\), \(\beta\), and \(\mu\) (i.e., \(c\)) that match the configuration parameters based on a preset mapping relationship. The preset mapping relationship records the mapping relationship between the configuration parameters of the permanent magnet synchronous motor and the parameters in the target reaching law.

[0116] For example, the configuration parameters of the permanent magnet synchronous motor can be as shown in Table 1.

[0117]

[0118] Table 1

[0119] Corresponding to Table 1, the parameters in the target reaching law can be:

[0120] q = 200, c = 100, ε = 220, α = 2e4, β = -0.1, ξ1 = 1.2, ξ2 = 0.3, k = 20, β = -0.1, μ = 0.1, and the slope of the saturation function is 5.

[0121] In this embodiment, based on the above permanent magnet synchronous motor speed loop control method, a permanent magnet synchronous motor speed loop control device is disclosed. For the specific working content of each unit in the device, please refer to the content of the above method embodiment.

[0122] The permanent magnet synchronous motor speed loop control device provided by the embodiment of the present invention will be described below. The permanent magnet synchronous motor speed loop control device described below can be correspondingly referred to the permanent magnet synchronous motor speed loop control method described above.

[0123] Specifically, referring to Figure 4 , the permanent magnet synchronous motor speed loop control device disclosed in the embodiment of the present application may include:

[0124] A current acquisition unit 10, which corresponds to step S101 in the above method, and is used to obtain the actual value i of the q-axis current of the stator in the rotating coordinate system q ;

[0125] A standard current calculation unit 20, which corresponds to step S102 in the above method, and is used to calculate the reference current value of the q-axis by using a speed loop controller based on the target reaching law The target reaching law is obtained by modifying the new reaching law with the power reaching law, and the value of the power of the power reaching law decreases as the distance between the system state and the sliding surface decreases;

[0126] Among them, the new reaching law is:

[0127]

[0128] Among them, s is the sliding surface; sat is the saturation function; ε is the reaching rate; q is the reaching coefficient; α is a parameter to be designed and is a positive number; β is a parameter to be designed, and δ is the weighted integral gain;

[0129] A PI operation unit 30, which corresponds to step S103 in the above method, and is used to based on the actual value i qand the reference current value Perform PI operation, and adjust the actual value i of the q-axis current based on the operation result q .

[0130] Corresponding to the above method, the present application also discloses a storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of any one of the above-mentioned permanent magnet synchronous motor speed loop control methods are performed.

[0131] A permanent magnet synchronous motor speed loop control device, see Figure 5 , the device may include: at least one processor 100, at least one communication interface 200, at least one memory 300, and at least one communication bus 400;

[0132] In the embodiments of the present invention, the number of the processor 100, the communication interface 200, the memory 300, and the communication bus 400 is at least one, and the processor 100, the communication interface 200, and the memory 300 complete mutual communication through the communication bus 400; obviously, Figure 5 The communication connection schematic diagram of the processor 100, the communication interface 200, the memory 300, and the communication bus 400 shown is only optional;

[0133] Optionally, the communication interface 200 may be an interface of a communication module, such as an interface of a GSM module;

[0134] The processor 100 may be a central processing unit CPU, or a specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present invention.

[0135] The memory 300 may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory, which stores a preset program corresponding to the above method embodiments.

[0136] A permanent magnet synchronous motor includes the above-mentioned permanent magnet synchronous motor speed loop control device.

[0137] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with the relevant laws, regulations, and standards of relevant countries and regions.

[0138] For the convenience of description, when describing the above system, it is divided into various modules according to functions and described separately. Of course, when implementing the present invention, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0139] Each embodiment in this specification is described in a progressive manner. For the same or similar parts between each embodiment, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments. In particular, for a system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple. For the relevant parts, reference can be made to the partial description of the method embodiment. The system and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative work.

[0140] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in this article can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Skilled professionals can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0141] The steps of the method or algorithm described in combination with the embodiments disclosed in this article can be directly implemented by hardware, a software module executed by a processor, or a combination of the two. The software module can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field.

[0142] It should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0143] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A speed loop control method for a permanent magnet synchronous motor, characterized in that Comprising: Obtain the actual value \(i\) of the stator q-axis current in the rotating coordinate system q ; Adopt a speed loop controller based on the target approach law to calculate the reference current value of the q-axis The target approach law is obtained by correcting the new approach law with the power approach law, and the value of the power of the power approach law decreases as the distance between the system state and the sliding surface decreases; Wherein, the novel reaching law is: Wherein, s is the sliding mode surface; sat is the saturation function; ε is the reaching rate; q is the reaching coefficient; α is a parameter to be designed and is a positive number; β is a parameter to be designed, and δ is the weighted integral gain; Based on the actual value i q and the reference current value perform a PI operation, and adjust the actual value i of the q-axis current based on the operation result q .

2. The speed loop control method of the permanent magnet synchronous motor according to claim 1, wherein The power reaching law is k|s| λ sat(s), where The target reaching law is: Wherein, ξ1 and ξ2 are power coefficients respectively; k is the power reaching coefficient; μ is the minimum value of the power coefficient.

3. The permanent magnet synchronous motor speed loop control method according to claim 1, characterized in that Calculating the reference current value of the q-axis Including: Based on the formula and the calculated reference current value of the q-axis obtained according to the target reaching law where c is an adjustment parameter, the ω m is the mechanical angular speed, u = di q / dt, the P n is the number of pole pairs, is the rotor permanent magnet flux linkage.

4. The permanent magnet synchronous motor speed loop control method according to claim 1, wherein Obtain the actual value \(i\) of the stator q-axis current in the rotating coordinate system q , including: The actual value i of the q-axis current of the stator in the rotating coordinate system is obtained by the feedback method q .

5. The speed loop control method of the permanent magnet synchronous motor according to claim 1, characterized in that Calculate the reference current value of the q-axis Before that, it also includes: Obtain the configuration parameters of the permanent magnet synchronous motor; Based on a preset mapping relationship, obtain the values of q, ε, α, ξ1, ξ2, k, β and μ, i.e., c, that match the configuration parameters.

6. The method for controlling the speed loop of a permanent magnet synchronous motor according to claim 5, wherein When the DC bus voltage of the permanent magnet synchronous motor is 310V; The stator resistance is 2.875Ω; The stator d-axis inductance is 8.5e-3mH; The stator q-axis inductance is 8.5e-3mH; The permanent magnet flux linkage is 0.175Wb; The number of pole pairs is 4; The moment of inertia is 0.003 kg·m 2 ; The damping coefficient is 0.008N·m·s; The q = 200, ε = 220, α = 2e4, ξ1 = 1.2, ξ2 = 0.3, k = 20, β = -0.1, μ = 0.1, c = 100.

7. A speed loop control device for a permanent magnet synchronous motor, characterized in that, Comprising: The current acquisition unit is used to obtain the actual value i of the q-axis current of the stator in the rotating coordinate system q ; A standard current calculation unit, which is used to calculate the reference current value of the q-axis by adopting a speed loop controller based on a target reaching law The target reaching law is obtained by modifying a new reaching law with a power reaching law, and the value of the power of the power reaching law decreases as the distance between the system state and the sliding surface decreases; Wherein, the novel reaching law is: Wherein, s is the sliding mode surface; sat is the saturation function; ε is the reaching rate; q is the reaching coefficient; α is a parameter to be designed and is a positive number; β is a parameter to be designed, and δ is the weighted integral gain; PI operation unit, for performing PI operation based on the actual value i q and the reference current value to adjust the actual value i of the q-axis current based on the operation result q .

8. A storage medium, on which a computer program is stored, characterized in that, When the computer program is executed by a processor, it realizes each step of the method for controlling the speed loop of a permanent magnet synchronous motor according to any one of claims 1-7.

9. A permanent magnet synchronous motor speed loop control device, characterized in that Comprising: A memory and a processor; The memory is used for storing a program; The processor is used for executing the program to realize each step of the data evaluation method according to any one of claims 1-7.

10. A permanent magnet synchronous motor, characterized in that, Comprising the device for controlling the speed loop of a permanent magnet synchronous motor according to claim 9.

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