A Method, System and Storage Medium for Active Disturbance Rejection Current Control of a Permanent Magnet Synchronous Motor

Abstract

The present invention discloses an auto-disturbance rejection current control method, system and storage medium for a permanent magnet synchronous motor, belonging to the field of disturbance suppression of permanent magnet motors. Among them, the method includes: carrying out mathematical modeling on the motor according to various periodic and aperiodic disturbances existing in the current loop, and establishing a stator voltage equation of the permanent magnet synchronous motor considering disturbances; designing an extended state observer by using the bandwidth method. Considering the limited bandwidth of the observer, the extended state observer cannot completely observe the total disturbance in the current loop. Therefore, a resonance term is added to the integral sliding surface to form a resonance sliding mode, and a feedback control law is designed by using it to suppress specific harmonics and other disturbances, and improve the anti-interference performance of the system. The present invention improves the tracking performance of the current, further effectively reduces the torque and speed fluctuations in the motor, and enhances the robustness of the control system.

Description

Technical Field

[0001] The present invention relates to the field of disturbance suppression of permanent magnet motors, and particularly to an auto-disturbance rejection current control method, system and storage medium for a permanent magnet synchronous motor. Background Art

[0002] With the increasing maturity of power electronics technology, rare earth permanent magnet materials and motor manufacturing technology, permanent magnet synchronous motors have become the most common AC motors in motor drive systems and are widely used in high-performance direct drive servo applications. However, there are dead zone effects, flux link harmonics, parameter variations and unknown disturbances in the current loop. If traditional proportional integral (PI) control is used, it cannot respond quickly to these disturbances, which will further affect the motor speed and motor control accuracy.

[0003] The auto-disturbance rejection control technology has been widely applied because of its low dependence on the motor mathematical model and its ability to use an extended state observer to observe and compensate for disturbances in real time. Although the larger the bandwidth of the extended state observer, the higher the observation accuracy and response speed, it will be more sensitive to noise; therefore, an auto-disturbance rejection current control method, system and storage medium for a permanent magnet synchronous motor are proposed. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention proposes an auto-disturbance rejection current control method for a permanent magnet synchronous motor. A resonance term is added to the sliding mode surface, and feedback control is designed using it. On the one hand, it can suppress specific harmonics, and on the other hand, it can compensate for the disturbance estimation value, improving the current tracking performance and response speed.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] An auto-disturbance rejection current control method for a permanent magnet synchronous motor, comprising:

[0007] Establish a stator voltage equation of a permanent magnet synchronous motor considering disturbances based on the total error voltage generated by disturbances in the current loop;

[0008] Construct an extended state observer in the auto-disturbance rejection controller based on the stator voltage equation and the bandwidth method, and determine the disturbance estimation value in the current loop through the extended state observer;

[0009] Add a resonance term to the integral sliding mode surface to construct a resonance sliding mode feedback control law, and compensate for the disturbance estimation value through the resonance sliding mode feedback control law and determine the output voltage of the auto-disturbance rejection control.

[0010] Further, the disturbances in the current loop include flux link distortion, dead zone effect, motor parameter variation and unmodeled disturbances, and the equivalent total error voltage of the current loop is expressed as:

[0011]

[0012] where Δu d,flux and Δu q,flux are the error voltages equivalent to the flux linkage distortion in the current loop voltage equation; Δu d,dead and Δu q,dead are the error voltages caused by the dead - zone effect; Δu d,para and Δu q,para are the error voltages caused by parameter variations; Δu d,unkonwn and Δu q,unkonwn are the error voltages generated by unknown disturbances; Δu d and Δu q are the total error voltages of the current loop due to disturbances.

[0013] Furthermore, the stator voltage equation of the permanent magnet synchronous motor considering disturbances is expressed as:

[0014]

[0015] where u d and u q , i d and i q are the d - axis and q - axis components of the stator voltage and current respectively; ψ f is the permanent magnet flux linkage; R is the stator resistance, L d and L q are the d - axis and q - axis inductances respectively, and ω e is the angular frequency of the back electromotive force.

[0016] Furthermore, based on the stator voltage equation and the bandwidth method, an extended state observer in the active disturbance rejection controller is constructed, including the following steps:

[0017] Let We can get

[0018] where b d = 1 / L d and b q = 1 / L q . Based on the form of the Luenberger observer, the constructed extended state observer can be expressed as:

[0019]

[0020]

[0021]

[0022] where z1 is the estimated value of the current i d and i q ; z2 is the disturbance f d and fq Estimated value;

[0023] L1 and L2 are the gain matrix parameters of the observer, satisfying:

[0024] where ω d0 and ω q0 represent the bandwidths of the d-axis and q-axis observers.

[0025] Furthermore, a resonant term is added to the integral sliding surface to construct a resonant sliding mode feedback control law. The output voltage of the active disturbance rejection control is determined by compensating the estimated value of the disturbance through the resonant sliding mode feedback control law, including the following steps:

[0026] Define e d = i dr - i d , e q = i qr - i q as the current error components of the d-axis and q-axis, where i dr , i qr are the current reference values of the d-axis and q-axis. By using vector control i dr = 0, we can obtain:

[0027]

[0028] Adding the resonant term to the integral sliding surface, the resonant sliding mode surface vector and its derivative can be expressed as

[0029] s dq = e + C∫e + KHe

[0030] s·s dq = se + Ce + Hse = se + Ce + KGe

[0031] where s dq = [s d s q T , e = [e d e q T , ∫e = [∫e d ∫e q T , g d = sh d , g q = sh q ;

[0032] To meet the stability condition, we can obtain:

[0033] Wherein, sgn is the sign function, ε d , ε q , η d , η q are all greater than 0;

[0034] Then the output voltage of the active disturbance rejection control is:

[0035] Furthermore, the stability condition of the active disturbance rejection current control method for the permanent magnet synchronous motor is:

[0036] Under the action of the feedback control law, the system reaches the sliding mode surface in a finite time; and on the sliding mode surface, the tracking error approaches 0.

[0037] Furthermore, the q-axis stability judgment includes the following steps:

[0038] Define the Lyapunov function as It can be obtained that:

[0039]

[0040] According to the Lyapunov function theory, when V≥0 and the system is stable;

[0041] When ε q >|z2 - f q |, s q can converge to 0 in a finite time, and the system is stable;

[0042] Combined with the differential equation of the sliding mode surface, it can be obtained that:

[0043]

[0044] a0 = 1, a1 = 2ω c + 2kω c + c,

[0045] According to the Herwitz stability criterion, the sequential determinants of each order of the system characteristic equation are

[0046]

[0047] Because the sequential determinants of each order of the system characteristic equation are all greater than 0, that is, on the sliding mode surface, the tracking error e can approach 0.

[0048] The present invention also discloses an active disturbance rejection current control system for a permanent magnet synchronous motor, including the following modules:

[0049] Error module: Analyze various disturbances existing in the current loop, including flux linkage distortion, dead zone effect, motor parameter variations, and unmodeled disturbances, and obtain the equivalent total error voltage caused by the disturbances.

[0050] Disturbance estimation module: Establish the stator voltage equation of the permanent magnet synchronous motor considering disturbances in the d-q coordinate system, construct the extended state observer in the active disturbance rejection controller based on the stator voltage equation and the bandwidth method, and determine the disturbance estimation value in the current loop through the extended state observer.

[0051] Disturbance compensation module: Add a resonant term to the integral sliding mode surface to construct a resonant sliding mode feedback control law, and compensate the disturbance estimation value through the resonant sliding mode feedback control law.

[0052] Output module: Output the output voltage of the active disturbance rejection control according to the disturbance estimation module and the disturbance compensation module.

[0053] The present invention also discloses a storage medium, in which a computer-executable program is stored. When the computer-executable program is executed by a processor, it is used to implement the active disturbance rejection current control method for the permanent magnet synchronous motor as described in any one of the above.

[0054] The present invention also discloses an electronic device, including:

[0055] At least one memory for storing a program;

[0056] At least one processor for loading the program to execute the active disturbance rejection current control method for the permanent magnet synchronous motor as described in any one of the above.

[0057] Advantages of the present invention:

[0058] By adding a resonant term to the integral sliding mode surface, the present invention can not only improve the robustness of the system but also suppress specific harmonics. Aiming at the problem of limited bandwidth of the extended state observer, the present invention uses resonant sliding mode control in the feedback control law of the active disturbance rejection control to alleviate the influence of disturbances on the tracking performance. The present invention can effectively suppress various periodic and aperiodic disturbances existing in the current loop, improve the three-phase current waveform, and enhance the current tracking performance. Description of the drawings

[0059] The present invention will be further described below with reference to the drawings.

[0060] Figure 1 It is the schematic diagram of the vector control of the permanent magnet synchronous motor;

[0061] Figure 2 It is the schematic diagram of the active disturbance rejection current control based on resonant sliding mode of the present application;

[0062] Figure 3It is the q - axis current response and spectrogram under the active disturbance rejection control algorithm of this application;

[0063] Figure 4 It is the q - axis current response and spectrogram of this application. Specific embodiments

[0064] 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 embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0065] In the description of this specification, the description referring to terms such as "an embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0066] The following further illustrates the present invention in conjunction with the embodiments, Figure 1 is the vector control schematic diagram of a permanent - magnet synchronous motor, including a double - closed - loop control system of a speed loop and a current loop. The speed loop of the motor adopts PI control, and the current loop adopts the permanent - magnet synchronous motor active - disturbance rejection current control method based on resonant sliding mode provided by the present invention. Its specific block diagram is as Figure 2 shown. The feedback control law designed for the resonant sliding mode is updated in real - time by using an extended state observer, which specifically includes the following steps:

[0067] The disturbances in the current loop generally include flux distortion, dead - zone effect, motor parameter changes, and unmodeled disturbances. Then, the equivalent total error voltage of the current loop can be expressed as

[0068]

[0069] In the formula, Δu d,flux , Δu q,flux are the voltages of the flux distortion equivalent in the current - loop voltage equation; Δu d,dead , Δu q,dead are the voltage components caused by the dead - zone effect; and the flux distortion and dead - zone effect introduce 6 - th harmonic components into the voltage equation in the dq coordinate system. Δu d,para , Δu d,para are the voltage components caused by parameter changes; the error voltage generated by the unknown disturbance is expressed as Δu d,unkonwn , Δu q,unkonwn。Δu d 、Δu q are the total error voltages generated by the current loop due to disturbances. Therefore, the stator voltage equation of the permanent magnet synchronous motor considering disturbances can be obtained:

[0070]

[0071] In the formula, u d 、u q 、i d 、i q are the d-axis and q-axis components of the stator voltage and current respectively; ψ f is the permanent magnet flux linkage; R is the stator resistance, L d and L q are the d-axis and q-axis inductances respectively, and ω e is the angular frequency of the back electromotive force.

[0072] Design the extended state observer using the bandwidth method. Let

[0073]

[0074] We can get

[0075]

[0076] In the formula, b d = 1 / L d 、b q = 1 / L q . With the form of the Luenberger observer, the constructed extended state observer can be expressed as:

[0077]

[0078] In the formula, is the estimated value of the current i d and i q ; is the estimated value of the disturbance f d and f q ;

[0079] L1 and L2 are the gain matrix parameters of the observer and can be designed as:

[0080]

[0081] In the formula, ω d0 and ω q0 represent the bandwidths of the d-axis and q-axis observers. When the bandwidth increases, the response speed and observation accuracy will improve, but the noise suppression ability will decrease. Therefore, a trade-off is needed.

[0082] Design the resonant sliding mode feedback control law. Since the extended state observer cannot fully estimate the disturbance, the traditional proportional feedback control law cannot meet the control requirements. Considering using sliding mode control in the feedback control law to improve the system robustness, but the specific harmonic suppression effect is still not ideal.

[0083] Therefore, a resonant term is added to the integral sliding mode surface to design the sliding mode control:

[0084] Define e d =i dr -i d 、e q =i qr -i q as the current error components on the d and q axes, where i dr 、i qr are the current reference values on the d and q axes. Using vector control i dr =0, we can obtain:

[0085]

[0086] The design of the integral sliding mode surface can eliminate the static error of the system and improve the control accuracy. To suppress specific harmonics, a resonant term is added to the integral sliding mode surface. Then, the resonant sliding mode surface vector and its derivative can be expressed as:

[0087] In the formula, s dq =[s d s q T , e=[e d e q T , ∫e=[∫e d ∫e q T , g d =sh d , g q =sh q ,

[0088] To achieve the control objective and meet the stability condition, we can obtain:

[0089]

[0090] In the formula, sgn is the sign function, and ε d 、ε q 、η d 、η q are all greater than 0.

[0091] ​​​The final output voltage of the active disturbance rejection control is:

[0092] Furthermore, in order to verify the stability of the resonant sliding mode control, two aspects need to be verified. One is that under the action of the feedback control law, the system can reach the sliding mode surface in a finite time, that is, approach 0; the other is that on the sliding mode surface, the tracking error e approaches 0.

[0093] Taking the q-axis stability analysis as an example, the Lyapunov function is defined as It can be obtained that

[0094]

[0095] According to the Lyapunov function theory, when V≥0 and the system is stable. When ε q >|z2 - f q |, s q can converge to 0 in a finite time, and the system is stable. Combining the differential equation of the sliding mode surface, it can be obtained that

[0096]

[0097] a0 = 1, a1 = 2ω c + 2kω c + c,

[0098] According to the Herwitz stability criterion, the sequential determinants of each order of the system characteristic equation can be obtained:

[0099]

[0100] Since the sequential determinants of each order of the system characteristic equation are all greater than 0, that is, on the sliding mode surface, the tracking error e can approach 0.

[0101] Compared with the existing active disturbance rejection current control method for permanent magnet synchronous motors, the present invention is characterized in that the resonant sliding mode control is adopted in the feedback control law. On the one hand, the extended state observer is designed by the bandwidth method to observe the disturbances existing in the current loop in real time; on the other hand, aiming at the problem of limited bandwidth of the observer, the sliding mode control is used to design the feedback control law, and a resonant term is added on the integral sliding mode surface to realize the suppression of specific harmonics and improve the robustness of the control system. Therefore, the present invention can effectively suppress various periodic and aperiodic disturbances existing in the current loop, reduce the steady-state error, and improve the current control accuracy.

[0102] Figure 3 The response result with the q-axis reference current of 0.2 A and the current loop adopting the active disturbance rejection controller is shown. It can be seen from the figure that the q-axis current fluctuates by 0.024 A. Figure 4By adopting the algorithm of the present invention, the q-axis current fluctuation is 0.016 A. According to the q-axis current spectrum diagram, compared with the active disturbance rejection controller algorithm, the 6th harmonic of the current under the algorithm of the present invention is reduced, and the low-order harmonics are also significantly suppressed, indicating that this invention can significantly improve the current tracking performance and disturbance rejection performance.

[0103] An embodiment of the present invention also discloses an electronic device for running a database stored procedure, wherein when running the database stored procedure, it executes a permanent magnet synchronous motor active disturbance rejection current control method as disclosed above and shown in the accompanying drawings of the specification.

[0104] An embodiment of the present invention also discloses a computer storage medium, the storage medium includes a stored database stored procedure, wherein when the database stored procedure runs, it controls the device where the storage medium is located to execute a permanent magnet synchronous motor active disturbance rejection current control method as disclosed above and shown in the accompanying drawings of the specification.

[0105] In the context of the present disclosure, a computer storage medium may be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0106] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the description in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A self-disturbance rejection current control method for a permanent magnet synchronous motor, characterized in that Including: Based on the total error voltage generated by disturbances in the current loop, establish the stator voltage equation of a permanent magnet synchronous motor considering disturbances; Based on the stator voltage equation and the bandwidth method, construct an extended state observer in the active disturbance rejection controller, and determine the disturbance estimation value in the current loop through the extended state observer; Add a resonant term to the integral sliding surface to construct a resonant sliding mode feedback control law, and compensate the disturbance estimation value through the resonant sliding mode feedback control law and determine the output voltage of the active disturbance rejection control; The stator voltage equation of the permanent magnet synchronous motor considering disturbances is expressed as: where, u d , u q , i d , i q are the d - axis and q - axis components of the stator voltage and current respectively; ψ f is the permanent - magnet flux linkage; R is the stator resistance, L d and L q are the d - axis and q - axis inductances respectively, ω e is the angular frequency of the back electromotive force; Based on the stator voltage equation and the bandwidth method, construct an extended state observer in the active disturbance rejection controller, including the following steps: Let It can be obtained that where b d = 1 / L d , b q = 1 / L q , based on the form of the Luenberger observer, the constructed extended state observer can be expressed as: where z1 is the estimated value of current i d and i q ; z2 is the estimated value of disturbance f d and f q ; L1 and L2 are the gain matrix parameters of the observer, satisfying: where ω d0 and ω q0 represent the bandwidths of the d-axis and q-axis observers; Add a resonant term to the integral sliding surface to construct a resonant sliding mode feedback control law, and compensate the disturbance estimation value through the resonant sliding mode feedback control law and determine the output voltage of the active disturbance rejection control, including the following steps: Define e d = i dr - i d 、e q = i qr - i q are the current error components of the d and q axes, where i dr 、i qr are the current reference values of the d and q axes. By using vector control i dr = 0, we can obtain: Adding the resonant term to the integral sliding surface, the resonant sliding mode vector and its derivative can be expressed as s dq = e + C∫e + KHe s·s dq = se + Ce + Hse = se + Ce + KGe where s dq = [s d s q T , e = [e d e q T , ∫e = [∫e d ∫e q T , g d = sh d , g q = sh q ;​​​ To meet the stability condition, it can be obtained that: where sgn is the sign function, ε d , ε q , η d , η q are all greater than 0; Then the output voltage of the active disturbance rejection control is:

2. The auto-disturbance rejection current control method for the permanent magnet synchronous motor according to claim 1, wherein The disturbances in the current loop include flux linkage distortion, dead zone effect, motor parameter variation, and unmodeled disturbances, and the total error voltage of the equivalent current loop is expressed as: where Δu d,flux and Δu q,flux are the error voltages of the equivalent magnetic chain distortion in the current loop voltage equation; Δu d,dead and Δu q,dead are the error voltages caused by the dead - zone effect; Δu d,para and Δu q,para are the error voltages caused by parameter variations; Δu d,unkonwn and Δu q,unkonwn are the error voltages generated by unknown disturbances; Δu d and Δu q are the total error voltages generated by the current loop due to disturbances.

3. The auto-disturbance rejection current control method for a permanent magnet synchronous motor according to claim 1, wherein, The stability condition of the active disturbance rejection current control method for permanent magnet synchronous motors is: Under the action of the feedback control law, the system reaches the sliding surface in finite time; and on the sliding surface, the tracking error approaches 0.

4. The auto-disturbance rejection current control method for the permanent magnet synchronous motor according to claim 1, wherein The q-axis stability judgment includes the following steps: Define the Lyapunov function as It can be obtained that: According to the Lyapunov function theory, when V≥0 and the system is stable; When ε q >|z2 - f q |, s q converges to 0 within a finite time, and the system is stable; Combined with the differential equation of the sliding surface, it can be obtained that: According to the Herwitz stability criterion, the sequential determinants of each order of the system characteristic equation are Because the sequential determinants of each order of the system characteristic equation are all greater than 0, that is, on the sliding surface, the tracking error e can approach 0.

5. A system for implementing the auto-disturbance rejection current control method of the permanent magnet synchronous motor according to any one of claims 1-4, characterized in that, Including the following modules: Error module: Analyze various disturbances existing in the current loop, including flux linkage distortion, dead zone effect, motor parameter variation, and unmodeled disturbances, and obtain the total error voltage equivalent due to disturbances; Disturbance estimation module; Establish the stator voltage equation of a permanent magnet synchronous motor considering disturbances in the d-q coordinate system, construct an extended state observer in the active disturbance rejection controller based on the stator voltage equation and the bandwidth method, and determine the disturbance estimation value in the current loop through the extended state observer; Disturbance compensation module: Add a resonant term to the integral sliding surface to construct a resonant sliding mode feedback control law, and compensate the disturbance estimation value through the resonant sliding mode feedback control law; Output module: Output the output voltage of the active disturbance rejection control according to the disturbance estimation module and the disturbance compensation module.

6. A storage medium, characterized in that, Wherein, a computer-executable program is stored, and when the computer-executable program is executed by a processor, it is used to implement the active disturbance rejection current control method for a permanent magnet synchronous motor as described in any one of claims 1-4.

7. An electronic device, characterized in that , including: At least one memory for storing programs; At least one processor for loading the program to execute the active disturbance rejection current control method for a permanent magnet synchronous motor as described in any one of claims 1-4.

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