A method and system for active fault targeting regulation of a motor-driven mechanical system

Abstract

This invention provides an active fault-targeting control method and system for a motor-driven mechanical system, belonging to the field of motor speed control technology. The invention first periodically measures the three-phase stator current and voltage during motor operation and calculates fault characteristic indicators. Second, it identifies the fault frequency from the fault characteristic indicators and filters to extract a fault-targeting control sequence. Third, it calculates the phase delay generated during the filtering process and applies additional delay processing to the fault-targeting control sequence to achieve phase correction. Finally, it injects the corrected amplitude of the delayed fault-targeting control sequence into the q-axis voltage, generating a control torque with the same amplitude but opposite phase as the fault torque, thereby offsetting the speed fluctuations caused by the fault. This method can identify fault characteristics online from the motor's own electrical signals and actively generate fault-targeting control torque, suppressing fault effects and maintaining stable motor operation without the need for additional actuators.

Description

Technical Field

[0001] This invention relates to the field of motor speed control technology, and in particular to an active fault-targeting control method and system for motor-driven mechanical systems. Background Technology

[0002] Electric motor-driven rotating machinery systems are widely used in electromechanical equipment such as electric vehicles, robots, drones, and underwater propulsion systems. Due to manufacturing or installation errors, as well as degradation and damage caused by prolonged operation, rotating mechanical components are prone to periodic fault torque disturbances. Under the influence of these fault torque disturbances, the speed of the motor and the entire transmission system also exhibits periodic fluctuations. Unstable speeds typically cause additional vibration and noise, affecting the comfort of personnel interaction. Furthermore, speed fluctuations reduce the operational accuracy of the working mechanism, lowering the quality of industrial production. Moreover, the dynamic response caused by speed fluctuations increases the local contact stress of non-faulty components, accelerating the degradation of the overall equipment and reducing its service life. Therefore, identifying the fault characteristics of rotating machinery components and implementing targeted fault-based control to suppress system speed fluctuations caused by faults is of great significance and value.

[0003] Numerous existing methods for motor speed control exist, but most are passive steady-state control. Typical control methods, such as Field-oriented Control (FOC) and Direct-torque Control (DTC), employ a closed-loop speed control mechanism, combined with controllers from various control domains (such as PI control and sliding mode control), to gradually bring the actual speed closer to the given target speed. While these methods have been widely applied, they are essentially passive compensation-based steady-state optimizations. The regulation of each disturbance requires a certain convergence time, and they cannot completely suppress speed fluctuations caused by periodic transient torque disturbances.

[0004] Existing active control methods aim to actively counteract speed fluctuations that need to be suppressed by introducing additional torque excitation to generate a trend with the same amplitude but opposite phase as the fault speed fluctuation. Due to the high cost and installation requirements of introducing additional mechanical / hydraulic / electromagnetic actuators, using the motor itself as the excitation source for targeted fault suppression has significant advantages. However, existing technologies all target the suppression of high-frequency fluctuations in the current itself during motor operation. These current fluctuations are caused by the power supply system and the motor's own structure, and are known or can be pre-calibrated. Fault modes and characteristic frequencies in rotating machinery systems are diverse, typically exhibiting non-sinusoidal periodicity, and the severity of faults gradually increases over time. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides an active fault-targeting control method and system for a motor-driven mechanical system. This invention first calculates fault characteristic indicators and extracts the fault-targeting control sequence to obtain the targeted control torque, thereby offsetting speed fluctuations caused by the fault. Fault characteristic extraction and control are both performed online, eliminating the need for offline analysis during downtime. Secondly, the fault control process relies solely on the motor itself as an actuator, suppressing the impact of the fault and maintaining stable motor operation without the need for any other actuators. To achieve the above objectives, the technical solution is as follows: On one hand, the present invention provides an active fault-targeting control method for a motor-driven mechanical system, the method comprising: S1. Based on the motor-driven mechanical system, fault characteristic indicators are calculated by measuring the three-phase stator current and voltage of the motor. S2. Based on the fault characteristic index, identify the fault frequency and filter and extract it to obtain the fault-targeted control sequence; S3. Based on the fault-targeting control sequence, calculate the phase delay generated by the filtering process and perform additional delay processing on the fault-targeting control sequence to obtain the corrected fault-targeting control sequence. S4. Inject the corrected fault-targeting control sequence into the q-axis voltage to obtain the targeted control torque.

[0006] Optionally, in S1, based on the motor-driven mechanical system, fault characteristic indicators are calculated by measuring the three-phase stator current and voltage of the motor, including: S11. Based on the motor drive mechanical system, the three-phase stator current and voltage of the motor are acquired through the analog-to-digital conversion module; S12. Based on the three-phase stator current and voltage of the motor, obtain the stator current and voltage in the orthogonal coordinate system through coordinate transformation; S13. Based on the stator current and voltage in this orthogonal coordinate system, the fault characteristic indicators are obtained through calculation.

[0007] Optionally, the method for calculating the fault characteristic index includes: (1) In the formula, As a fault characteristic indicator, n Represents the discrete-time sequence number. In an orthogonal coordinate system α The current value of the shaft, In an orthogonal coordinate system β The current value of the shaft, In an orthogonal coordinate system α The voltage value of the shaft, In an orthogonal coordinate system β The voltage value of the shaft, RThis is the resistance value of the motor stator winding. i For discrete integral variables, Δ t The time interval for discrete sampling.

[0008] Optionally, in S2, based on the fault characteristic index, the fault frequency is identified and filtered for extraction to obtain a fault-targeted control sequence, including: S21. Based on the fault characteristic index, perform a discrete Fourier transform and identify the frequency component with the largest amplitude to obtain the fault frequency. S22. Using the fault frequency as the center frequency of the bandpass filter, bandpass filter is applied to the fault characteristic index to obtain the fault-targeted control sequence.

[0009] Optionally, in step S3, based on the fault-targeting control sequence, the phase delay generated during the filtering process is calculated, and additional delay processing is applied to the fault-targeting control sequence to obtain a corrected fault-targeting control sequence, including: S31. Based on the fault-targeting control sequence, the delay length of the fault-targeting control sequence is obtained through the phase response of the filter; S32. Based on the delay length of the fault-targeting control sequence, perform additional delay processing and alignment to obtain the corrected fault-targeting control sequence.

[0010] Optionally, the method for calculating the delay length of the fault-targeting modulation sequence includes: (2) In the formula, The delay length of the fault-targeting regulation sequence is given by `round(·)`, which is the integer rounding operation. θ fault This is the phase response of the filter. f fault This represents the fault frequency.

[0011] On the other hand, the present invention provides an active fault-targeting control system for a motor-driven mechanical system. This system is applied to an active fault-targeting control method for a motor-driven mechanical system, and includes: The fault characteristic index calculation module is used to calculate fault characteristic indexes based on the motor drive mechanical system by measuring the three-phase stator current and voltage of the motor. The control sequence acquisition module is used to identify the fault frequency and filter and extract it based on the fault characteristic index to obtain the fault-targeted control sequence; The control sequence correction module is used to calculate the phase delay generated by the filtering process based on the fault-targeted control sequence and perform additional delay processing on the fault-targeted control sequence to obtain the corrected fault-targeted control sequence. The torque control module is used to inject the corrected fault-targeting control sequence into the q-axis voltage to obtain the targeted control torque.

[0012] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects: The above solution, on the one hand, calculates fault characteristic indicators and extracts fault-targeted control sequences to obtain targeted control torque, thereby offsetting speed fluctuations caused by faults. Fault characteristic extraction and control are both performed online, without the need for offline analysis during shutdown. On the other hand, the fault control process relies solely on the motor itself as an actuator, without the need for any other actuators to suppress the impact of faults and maintain stable motor operation. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a flowchart of an embodiment of the active fault-targeting control method for a motor-driven mechanical system of the present invention; Figure 2 This is a flowchart illustrating the calculation of fault characteristic indicators in an embodiment of the active fault-targeting control method for a motor-driven mechanical system of the present invention. Figure 3 This is a flowchart illustrating the fault-targeting control sequence obtained in an embodiment of the active fault-targeting control method for a motor-driven mechanical system of the present invention. Figure 4 This is a flowchart of the modified fault-targeting control sequence obtained in an embodiment of the active fault-targeting control method for a motor-driven mechanical system of the present invention; Figure 5 This is the time-domain waveform of a fault characteristic index of a three-phase permanent magnet synchronous motor in an embodiment of the active fault-targeting control method for a motor-driven mechanical system of the present invention. Figure 6 This is a fault-targeting control voltage waveform diagram in an embodiment of the active fault-targeting control method for a motor-driven mechanical system of the present invention. Figure 7 These are motor speed waveforms in the healthy state, fault state, and after fault-targeting control is enabled in the embodiment of the active fault-targeting control method for the motor-driven mechanical system of the present invention. Figure 8 This is a system block diagram of an embodiment of the active fault-targeting control system for the motor-driven mechanical system of the present invention. Detailed Implementation

[0015] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0016] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0017] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0018] like Figure 1 The flowchart shown is an embodiment of the active fault-targeting control method for a motor-driven mechanical system according to the present invention. The present invention provides an active fault-targeting control method for a motor-driven mechanical system, which is implemented by an active fault-targeting control system for a motor-driven mechanical system. The method includes: S1. Based on the motor-driven mechanical system, fault characteristic indicators are calculated by measuring the three-phase stator current and voltage of the motor. Specifically, such as Figure 2 The flowchart shown in the embodiment of the active fault-targeting control method for the motor-driven mechanical system of the present invention calculates the fault characteristic indicators. In step S1, based on the motor-driven mechanical system, the fault characteristic indicators are calculated by measuring the three-phase stator current and voltage of the motor, including: S11. Based on the motor drive mechanical system, the three-phase stator current and voltage of the motor are acquired through the analog-to-digital conversion module; Furthermore, in the motor control board, a microcontroller-based analog-to-digital converter module discretely acquires the three-phase stator current of the motor from the drive circuit. I a [ n ], I b [ n ], I c [ n and voltage U a [ n ], U b [ n ], U c [ n ],in n Represents the discrete time sequence number.

[0019] S12. Based on the three-phase stator current and voltage of the motor, obtain the stator current and voltage in the orthogonal coordinate system through coordinate transformation; Furthermore, based on coordinate transformation, the three-phase stator electronic current and voltage are converted to the α-β orthogonal coordinate system, and the calculation method is as follows: (3) (4) S13. Based on the stator current and voltage in this orthogonal coordinate system, the fault characteristic indicators are obtained through calculation.

[0020] Furthermore, the calculation method for this fault characteristic index includes: (1) In the formula, As a fault characteristic indicator, n Represents the discrete-time sequence number. In an orthogonal coordinate system α The current value of the shaft, In an orthogonal coordinate system β The current value of the shaft, In an orthogonal coordinate system α The voltage value of the shaft, In an orthogonal coordinate system β The voltage value of the shaft, R This is the resistance value of the motor stator winding. i For discrete integral variables, Δ t The time interval for discrete sampling.

[0021] S2. Based on the fault characteristic index, identify the fault frequency and filter and extract it to obtain the fault-targeted control sequence; Specifically, such as Figure 3 The flowchart shown in the embodiment of the active fault-targeting control method for the motor-driven mechanical system of the present invention obtains the fault-targeting control sequence. In step S2, the fault frequency is identified and filtered and extracted based on the fault characteristic index to obtain the fault-targeting control sequence, including: S21. Based on the fault characteristic index, perform a discrete Fourier transform and identify the frequency component with the largest amplitude to obtain the fault frequency. S22. Using the fault frequency as the center frequency of the bandpass filter, bandpass filter is applied to the fault characteristic index to obtain the fault-targeted control sequence.

[0022] Furthermore, such as Figure 5The active fault-targeting control method for the motor-driven mechanical system of the present invention, as shown in the embodiment, obtains the time-domain waveform of the fault characteristic index of a three-phase permanent magnet synchronous motor. All index values ​​within a certain period (typically values ​​from 1 to 10 seconds) are stored to obtain a discrete index sequence. Each value in the sequence is subtracted from its mean, and then a discrete Fourier transform is performed to identify the frequency component with the largest amplitude, which is recorded as the fault frequency. f fault ; Fault characteristic indicators I fault [ n Perform bandpass filtering, with the filter's center frequency set to the fault frequency. f fault The passband width of the filter is set to (1 / 10). f fault The fault-targeted regulation sequence was obtained. C fault [ n ]; S3. Based on the fault-targeting control sequence, calculate the phase delay generated by the filtering process and perform additional delay processing on the fault-targeting control sequence to obtain the corrected fault-targeting control sequence. Specifically, such as Figure 4 The flowchart shown in the embodiment of the active fault-targeting control method for the motor-driven mechanical system of the present invention illustrates the process of obtaining the corrected fault-targeting control sequence. In step S3, based on the fault-targeting control sequence, the phase delay generated by the filtering process is calculated, and additional delay processing is applied to the fault-targeting control sequence to obtain the corrected fault-targeting control sequence, including: S31. Based on the fault-targeting control sequence, the delay length of the fault-targeting control sequence is obtained through the phase response of the filter; Furthermore, the method for calculating the delay length of the fault-targeting modulation sequence includes: (2) In the formula, The delay length of the fault-targeting regulation sequence is given by `round(·)`, which is the integer rounding operation. θ fault This is the phase response of the filter. f fault This represents the fault frequency.

[0023] S32. Based on the delay length of the fault-targeting control sequence, perform additional delay processing and alignment to obtain the corrected fault-targeting control sequence.

[0024] Furthermore, such as Figure 6The diagram shown is an example of the active fault-targeting control method for a motor-driven mechanical system according to the present invention. It illustrates the fault-targeting control voltage waveform, where the fault-targeting control sequence is of length [missing information]. L The delay, multiplied by the amplitude coefficient k Subsequently, the fault-targeting regulation sequence was obtained. kC fault [ nL This is added to the q-axis voltage in the motor control algorithm to generate a regulating torque with the same amplitude but opposite phase as the fault torque, thus targeting and suppressing speed fluctuations caused by the fault. The amplitude coefficient... k The following optimization algorithm can be used to gradually update the results: (5) In the formula, ω r Represents the motor speed. n 1 represents the amplitude coefficient k The corresponding time sequence number during the update.

[0025] S4. Inject the corrected fault-targeting control sequence into the q-axis voltage to obtain the targeted control torque.

[0026] Specifically, such as Figure 7 The motor speed waveforms in the healthy state, fault state, and after enabling fault-targeted control in the embodiment of the active fault-targeted control method for the motor-driven mechanical system of the present invention are shown.

[0027] like Figure 8 The diagram shown is a system block diagram of an embodiment of the active fault-targeting control system for a motor-driven mechanical system according to the present invention. The present invention provides an active fault-targeting control system for a motor-driven mechanical system, which is applied to an active fault-targeting control method for a motor-driven mechanical system. The system includes: a fault characteristic index calculation module, a control sequence acquisition module, a control sequence correction module, and a torque control module. Specifically, The fault characteristic index calculation module is used to calculate fault characteristic indexes based on the motor drive mechanical system by measuring the three-phase stator current and voltage of the motor. The control sequence acquisition module is used to identify the fault frequency and filter and extract it based on the fault characteristic index to obtain the fault-targeted control sequence; The control sequence correction module is used to calculate the phase delay generated by the filtering process based on the fault-targeted control sequence and perform additional delay processing on the fault-targeted control sequence to obtain the corrected fault-targeted control sequence. The torque control module is used to inject the corrected fault-targeting control sequence into the q-axis voltage to obtain the targeted control torque. This invention provides an active fault-targeting control method and system for a motor-driven mechanical system. First, during motor operation, the three-phase stator current and voltage are periodically measured, and fault characteristic indicators are calculated. Second, the fault frequency is identified from the fault characteristic indicators, and a fault-targeting control sequence is extracted through filtering. Third, the phase delay generated during the filtering process is calculated, and the fault-targeting control sequence is subjected to additional delay processing to achieve phase correction. Finally, the amplitude of the delayed fault-targeting control sequence is corrected and injected into the q-axis voltage to generate a control torque with the same amplitude but opposite phase as the fault torque, thereby offsetting the speed fluctuations caused by the fault. This method can identify fault characteristics online from the motor's own electrical signals and actively generate fault-targeting control torque, suppressing the impact of faults and maintaining stable motor operation without the need for additional actuators.

[0028] It is understood that the present invention has been described through the above embodiments and should not be construed as limiting the implementation and scope of the present invention. Those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A method of active fault-targeted regulation of an electrically driven mechanical system, characterized by, The method includes: S1. Based on the motor-driven mechanical system, fault characteristic indicators are calculated by measuring the three-phase stator current and voltage of the motor. S2. Based on the fault characteristic indicators, identify the fault frequency and filter and extract it to obtain the fault-targeted regulation sequence; S3. Based on the fault-targeting control sequence, calculate the phase delay generated by the filtering process and perform additional delay processing on the fault-targeting control sequence to obtain the corrected fault-targeting control sequence. S4. Inject the corrected fault-targeting control sequence into the q-axis voltage to obtain the targeted control torque.

2. The active fault-targeting regulation method of an electromechanical system according to claim 1, wherein, In step S1, based on the motor-driven mechanical system, fault characteristic indicators are calculated by measuring the three-phase stator current and voltage of the motor, including: S11. Based on the motor drive mechanical system, the three-phase stator current and voltage of the motor are acquired through the analog-to-digital conversion module; S12. Based on the three-phase stator current and voltage of the motor, obtain the stator current and voltage in the orthogonal coordinate system through coordinate transformation; S13. Based on the stator current and voltage in the orthogonal coordinate system, the fault characteristic indicators are obtained through calculation.

3. The active fault-targeting regulation method of an electromechanical system as recited in claim 2, wherein The calculation method for the fault characteristic index includes: （1） In the formula, As a fault characteristic indicator, n Represents the discrete-time sequence number. In an orthogonal coordinate system α The current value of the shaft, In an orthogonal coordinate system β The current value of the shaft, In an orthogonal coordinate system α The voltage value of the shaft, In an orthogonal coordinate system β The voltage value of the shaft, R This is the resistance value of the motor stator winding. i For discrete integral variables, Δ t The time interval for discrete sampling.

4. The active fault-targeting regulation method of an electromechanical system of claim 1, wherein, In step S2, based on the fault characteristic indicators, the fault frequency is identified and filtered for extraction to obtain a fault-targeted regulation sequence, including: S21. Based on the fault characteristic indicators, perform a discrete Fourier transform and identify the frequency component with the largest amplitude to obtain the fault frequency. S22. Using the fault frequency as the center frequency of the bandpass filter, bandpass filter is applied to the fault characteristic index to obtain a fault-targeted control sequence.

5. The active fault-targeting regulation method of an electromechanical system of claim 1, wherein, In step S3, based on the fault-targeting control sequence, the phase delay generated during the filtering process is calculated, and additional delay processing is applied to the fault-targeting control sequence to obtain a corrected fault-targeting control sequence, including: S31. Based on the fault-targeting control sequence, the delay length of the fault-targeting control sequence is obtained through the phase response of the filter; S32. Based on the delay length of the fault-targeting control sequence, perform additional delay processing and alignment to obtain the corrected fault-targeting control sequence.

6. The active fault-targeting regulation method of an electromechanical system of claim 1, wherein, The method for calculating the delay length of the fault-targeting modulation sequence includes: （2） wherein is the delay length of the fault-targeting regulatory sequence, round(·) is the rounding operation, θ fault is the phase response of the filter, f fault is the fault frequency.

7. An active fault-targeting control system for a motor-driven mechanical system, used to implement the active fault-targeting control method for a motor-driven mechanical system as described in any one of claims 1-6, characterized in that, The system includes: The fault characteristic index calculation module is used to calculate fault characteristic indexes based on the motor drive mechanical system by measuring the three-phase stator current and voltage of the motor. The regulation sequence acquisition module is used to identify the fault frequency and filter and extract it based on the fault characteristic indicators to obtain the fault-targeted regulation sequence; The control sequence correction module is used to calculate the phase delay generated by the filtering process based on the fault-targeted control sequence and perform additional delay processing on the fault-targeted control sequence to obtain the corrected fault-targeted control sequence. The torque control module is used to inject the corrected fault-targeting control sequence into the q-axis voltage to obtain the targeted control torque.

Images