Permanent magnet synchronous motor control parameter self-tuning method and system based on frequency domain analysis

Abstract

The invention discloses a permanent magnet synchronous motor control parameter self-tuning method and system based on frequency domain analysis. The method comprises the steps of current loop control including a PI link, a delay link and a motor model; offline optimization: extracting bandwidth and phase margin indexes of a current loop, and establishing a relationship between control gain and response and stability indexes to reversely solve optimal kp and ki parameters; and online index optimization: in the operation process, the steady-state error of the current is compared with a preset error threshold value, and motor control parameter optimization is carried out according to a comparison result. Based on a current motor vector control architecture, optimization of control parameters can be realized through frequency domain modeling, frequency domain index analysis and the like, so that the control effect of the motor is improved, and meanwhile, the use requirements of the vehicle are met.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a method and system for self-tuning control parameters of a permanent magnet synchronous motor based on frequency domain analysis. Background Art

[0002] Permanent magnet synchronous motors are widely used in the current automotive industry due to their high power density and high efficiency. Highly stable and reliable vehicle application scenarios have increasingly higher requirements for motor control effects.

[0003] The important control parameters of the current motor vector control are the kp and ki parameters of the feedback link. The current common prevention is to traverse and debug kp and ki through engineering methods to obtain a relatively stable control effect. The engineering traversal method has a large workload and may not necessarily obtain the optimal solution; the analysis of dynamic indicators from the time domain perspective often ignores the responsiveness and stability characteristics of the control system itself, and there is no way to quantify these parameters well. In the actual operation of the motor, the mismatch of control parameters caused by the change of motor body parameters due to the heat generated during the operation of the motor cannot be well solved, and the control effect of the motor will degrade. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, the present invention proposes a permanent magnet synchronous motor control parameter self-tuning method based on frequency domain analysis. Based on the current motor vector control architecture, through frequency domain modeling and frequency domain index analysis, the control parameters can be optimized, the control effect of the motor is improved, and the vehicle use requirements are met at the same time.

[0006] Another object of the present invention is to provide a permanent magnet synchronous motor control parameter self-tuning system based on frequency domain analysis.

[0007] A third object of the present invention is to provide a computer device.

[0008] A fourth object of the present invention is to provide a non-transitory computer-readable storage medium.

[0009] To achieve the above object, the present invention proposes a method for self-tuning control parameters of a permanent magnet synchronous motor based on frequency domain analysis, comprising:

[0010] Current loop control: including PI link Delay link -sTΣ , motor model

[0011] Offline optimization: extract the bandwidth and phase margin indicators of the current loop, and establish the relationship between the control gain and the response and stability indicators to reversely solve the optimal kp and ki parameters;

[0012] Online optimization index: During operation, the steady-state error of the current is compared with the preset error threshold to optimize the motor control parameters based on the comparison results.

[0013] The method for self-tuning control parameters of a permanent magnet synchronous motor based on frequency domain analysis in an embodiment of the present invention may also have the following additional technical features:

[0014] In one embodiment of the present invention,

[0015] Determine the open-loop transfer function of the current loop:

[0016]

[0017] Simplify and merge the sampling filter time Tci and the inverter switching period Tpwm, and let Td = Tci + Tpwm to get the following formula:

[0018]

[0019] In one embodiment of the present invention, Kpi*S+Kci and Ld*S+Rs are eliminated, and the proportionality coefficient is Kci; the formula is obtained:

[0020]

[0021] The closed-loop transfer function is as follows:

[0022]

[0023] in,

[0024] K=(Kci*Kpwm) / Rs (6).

[0025] In one embodiment of the present invention, the current loop kp and ki are calculated as:

[0026] According to the conventional second-order system optimization design, The closed-loop transfer function is converted to:

[0027]

[0028] According to the optimal damping ratio of the second-order system ε=0.707, K*Td=0.5, we get

[0029] The input kp and ki parameters are prioritized based on the expected bandwidth.

[0030] In one embodiment of the present invention, the current loop of the motor is analyzed offline, and the control gain of the motor is set to: γ = kp*T / L;

[0031] Extract the motor stability index: Phase margin:

[0032] Extract motor responsiveness metrics: Bandwidth: Where f is the cutoff frequency;

[0033] The desired bandwidth is swept to obtain the relationship between bandwidth and phase margin with respect to control gain, and the kp and ki parameters are inversely solved.

[0034] In one embodiment of the present invention, by judging the current steady-state error, when the error is greater than a preset error threshold, kp and ki are adjusted and fed back online, and when the error is less than the preset error threshold, the loop is exited:

[0035] if|Δiq=iq-iq * |>|iq th |

[0036] Kp=Kp*k*|Δiq|

[0037] Ki=Kp*L / R (9).

[0038] To achieve the above object, the present invention further provides a permanent magnet synchronous motor control parameter self-tuning system based on frequency domain analysis, comprising:

[0039] Current loop control module: including PI link Delay link -sTΣ , motor model

[0040] Offline optimization module: extracts the bandwidth and phase margin indicators of the current loop, and establishes the relationship between the control gain and the response and stability indicators to reversely solve the optimal kp and ki parameters;

[0041] Online optimization index module: During operation, the steady-state error of the current is compared with the preset error threshold to optimize the motor control parameters based on the comparison results.

[0042] The method and system for self-tuning control parameters of a permanent magnet synchronous motor based on frequency domain analysis in the embodiments of the present invention effectively optimize the control parameters, improve the control effect of the motor, simplify the control process, and meet the use requirements of the vehicle.

[0043] To achieve the above-mentioned purpose, the third aspect embodiment of the present application proposes a computer device, comprising: a processor and a memory; wherein the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the method described in the first aspect embodiment.

[0044] To achieve the above-mentioned purpose, the fourth aspect embodiment of the present application proposes a non-temporary computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the method described in the first aspect embodiment is implemented.

[0045] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0047] Figure 1 is a flow chart of a method for self-tuning control parameters of a permanent magnet synchronous motor based on frequency domain analysis according to an embodiment of the present invention;

[0048] Figure 2 is a block diagram of a current loop control according to an embodiment of the present invention;

[0049] Figure 3 is a basic current loop control diagram according to an embodiment of the present invention;

[0050] Figure 4 is a structural diagram of a permanent magnet synchronous motor control parameter self-tuning system based on frequency domain analysis according to an embodiment of the present invention;

[0051] Figure 5 It is a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0053] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0054] The following describes a method, system, device and storage medium for self-tuning control parameters of a permanent magnet synchronous motor based on frequency domain analysis according to an embodiment of the present invention with reference to the accompanying drawings.

[0055] Figure 1 is a flow chart of a method for self-tuning control parameters of a permanent magnet synchronous motor based on frequency domain analysis according to an embodiment of the present invention. Figure 1 As shown, including:

[0056] S1, current loop control: including PI link Delay link -sTΣ , motor model

[0057] S2, offline optimization: extract the bandwidth and phase margin indicators of the current loop, and establish the relationship between the control gain and the response and stability indicators to reversely solve the optimal kp and ki parameters;

[0058] S3, online optimization index: During operation, the steady-state error of the current is compared with the preset error threshold to optimize the motor control parameters according to the comparison result.

[0059] Specifically, Figure 2 As shown: This is the current loop control block diagram. In the entire control system, it is mainly divided into three parts:

[0060] A basic current loop control, including PI link: Delay link -sTΣ , motor model:

[0061] An offline optimization link: extract the bandwidth and phase margin indicators of the current loop, establish the relationship between the control gain and the response and stability indicators, and then reversely solve the optimal kp and ki parameters.

[0062] An online optimization indicator that determines the imbalance of motor parameters by judging the steady-state error of the current during operation, thereby performing real-time optimization.

[0063] Furthermore, the basic current loop control is as follows Figure 3 As shown:

[0064] Current loop transfer function:

[0065] The open-loop transfer function of the current loop can be obtained:

[0066]

[0067] Simplify and merge the sampling filter time Tci and the inverter switching period Tpwm, and let Td = Tci + Tpwm, and we can get the following formula:

[0068]

[0069] The current loop is the inner loop of the entire control system. The quality of the current loop control performance directly affects the stability of the entire control system. In order to improve the dynamic performance of the current loop and reduce the steady-state error of the entire control system, it is necessary to eliminate the large inertia link of the current loop and use zero-pole cancellation to remove the large inertia link of the control loop. That is to eliminate (Kpi*S+Kci) and (Ld*S+Rs), and the proportional coefficient is Kci. The following formula is obtained:

[0070]

[0071] The closed-loop transfer function is as follows:

[0072]

[0073] in,

[0074] K=(Kci*Kpwm) / Rs (6)

[0075] Current loop kp and ki calculation:

[0076] According to the conventional second-order system optimization design, The closed-loop transfer function is converted into

[0077]

[0078] According to the optimal damping ratio of the second-order system ε=0.707, K*Td=0.5, and we get:

[0079]

[0080] Based on this, the input kp and ki parameters can be obtained preferentially according to the expected bandwidth.

[0081] Furthermore, the frequency domain analysis is optimized offline, including:

[0082] Perform offline analysis on the motor current loop and set the motor control gain to: γ = kp*T / L;

[0083] Extract the motor stability index: Phase margin:

[0084] Extract motor responsiveness metrics: Bandwidth: Where f is the cutoff frequency.

[0085] Therefore, the desired bandwidth can be swept to obtain the relationship between bandwidth and phase margin with respect to control gain, thereby inversely solving the kp and ki parameters.

[0086] To this end, the range of phase margin is set as the constraint of the system to divide the range of gain, and the optimal goal is set to maximize the bandwidth, so that the optimal kp value can be obtained to achieve parameter optimization.

[0087] Constraint: r>40°

[0088] Optimal: max{f}

[0089] Solution: kp, ki.

[0090] Furthermore, online parameter optimization includes:

[0091] By judging the current steady-state error, when the error is greater than a certain threshold, kp and ki are adjusted and fed back online. When the error is less than the threshold, the loop is exited.

[0092] if|Δiq=iq-iq * |>|iq th |

[0093] Kp=Kp*k*|Δiq|

[0094] Ki=Kp*L / R (9)

[0095] The method for self-tuning the control parameters of a permanent magnet synchronous motor based on frequency domain analysis in the embodiment of the present invention analyzes from the frequency domain perspective, extracts the phase margin of the motor stability index and the bandwidth of the responsiveness index, and quantifies the motor control effect. The optimization of the target under constraints is achieved, which greatly simplifies the debugging of the motor control parameters and saves the time of engineering testing. During operation, when the motor has parameter mismatch, real-time adjustments can be made to maintain the motor control effect.

[0096] In order to implement the above embodiment, Figure 4 As shown, this embodiment also provides a permanent magnet synchronous motor control parameter self-tuning system 10 based on frequency domain analysis, including:

[0097] Current loop control module 100: including PI link Delay link -sTΣ , motor model

[0098] Offline optimization module 200: extracts the bandwidth and phase margin index of the current loop, and establishes the relationship between the control gain and the response and stability indexes, so as to reversely solve the optimal kp and ki parameters;

[0099] Online optimization index module 300: During operation, the steady-state error of the current is compared with a preset error threshold, so as to optimize the motor control parameters according to the comparison result.

[0100] According to the permanent magnet synchronous motor control parameter self-tuning system based on frequency domain analysis of the embodiment of the present invention, the phase margin of the motor stability index and the bandwidth of the responsiveness index are extracted from the frequency domain perspective to quantify the motor control effect. The target optimization under constraints is realized, which greatly simplifies the debugging of the motor control parameters and saves the time of engineering testing. During operation, when the motor has parameter mismatch, real-time adjustment can be made to maintain the motor control effect.

[0101] In order to implement the method of the above embodiment, the present invention also provides a computer device, such as Figure 5 As shown, the computer device 600 includes a memory 601 and a processor 602; wherein the processor 602 runs a program corresponding to the executable program code by reading the executable program code stored in the memory 601, so as to implement each step of the method described above.

[0102] In order to implement the above embodiments, the present application also proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method described in the above embodiments is implemented.

[0103] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0104] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. A method for self-tuning control parameters of a permanent magnet synchronous motor based on frequency domain analysis, characterized in that: include: Current loop control: including PI link Delay link -sTΣ , motor model Offline optimization: extract the bandwidth and phase margin indicators of the current loop, and establish the relationship between the control gain and the response and stability indicators to reversely solve the optimal kp and ki parameters; Online optimization index: During operation, the steady-state error of the current is compared with the preset error threshold to optimize the motor control parameters based on the comparison results.

2. The method according to claim 1, characterized in that Determine the open-loop transfer function of the current loop: Simplify and merge the sampling filter time Tci and the inverter switching period Tpwm, and let Td = Tci + Tpwm to obtain the following formula:

3. The method according to claim 2, characterized in that Eliminate Kpi*S+Kci and Ld*S+Rs, the proportionality coefficient is Kci; get the formula: The closed-loop transfer function is as follows: in, K=(Kci*Kpwm) / Rs (6).

4. The method according to claim 3, characterized in that Current loop kp and ki calculation: According to the conventional second-order system optimization design, The closed-loop transfer function is converted to: According to the optimal damping ratio of the second-order system ε=0.707, K*Td=0.5, we get The input kp and ki parameters are prioritized based on the expected bandwidth.

5. The method according to claim 4, characterized in that Perform offline analysis on the motor current loop and set the motor control gain to: γ = kp*T / L; Extract the motor stability index: Phase margin: Extract motor responsiveness metrics: Bandwidth: Where f is the cutoff frequency; The desired bandwidth is swept to obtain the relationship between bandwidth and phase margin with respect to control gain, and the kp and ki parameters are inversely solved.

6. The method according to claim 5, characterized in that By judging the current steady-state error, when the error is greater than the preset error threshold, kp and ki are adjusted and fed back online. When the error is less than the preset error threshold, the loop is exited:

7. A permanent magnet synchronous motor control parameter self-tuning system based on frequency domain analysis, characterized in that: include: Current loop control module: including PI link Delay link -sTΣ , motor model Offline optimization module: extracts the bandwidth and phase margin indicators of the current loop, and establishes the relationship between the control gain and the response and stability indicators to reversely solve the optimal kp and ki parameters; Online optimization index module: During operation, the steady-state error of the current is compared with the preset error threshold to optimize the motor control parameters based on the comparison results.

8. A computer device, characterized in that: including a processor and a memory; The processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the permanent magnet synchronous motor control parameter self-tuning method based on frequency domain analysis as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for self-tuning control parameters of a permanent magnet synchronous motor based on frequency domain analysis as described in any one of claims 1 to 6 is implemented.

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