Motor constant speed control method of electric traction machine

Abstract

The invention discloses a motor constant speed control method for an electric tractor, and relates to the technical field of line construction, and the method comprises the steps: a tension detection module which collects a tension signal of a wire in the paying-off operation of a high-voltage transmission line in real time; the frequency identification module is electrically connected with the tension detection module and is used for performing frequency domain analysis on the tension signal and identifying a periodic disturbance frequency corresponding to tension fluctuation; the self-adaptive control module comprises a sliding mode controller, and the sliding mode surface design of the sliding mode controller is combined with the periodic disturbance frequency, and a sliding mode control signal is generated based on a traction machine motor rotating speed feedback signal and a rotating speed instruction signal. The sliding mode controller is combined with disturbance frequency design, the anti-interference capacity is high, even if external disturbance exists, constant-speed operation of a traction machine motor can be maintained, paying-off speed fluctuation is reduced, the straightness and tension consistency of wire laying are guaranteed, the operation risk is reduced, the overall efficiency is improved, and stable constant-speed and tension control is achieved; and the manual intervention and fault shutdown times are reduced.

Description

Technical Field

[0001] This invention relates to the field of railway construction technology, specifically to a method for constant speed control of an electric traction machine motor. Background Technology

[0002] In high-voltage transmission line construction projects, wire laying is one of the core construction processes. As a key piece of equipment in wire laying, the constant speed performance of the electric traction machine directly determines the tension stability, laying accuracy, and construction safety of the conductor. With the increase in transmission line voltage levels, spans, and the increasing number of construction scenarios involving complex terrain (such as mountains, hills, and river crossings), the conductor is susceptible to factors such as terrain undulations, wind speed changes, and pulley friction fluctuations during the laying process, resulting in non-steady tension fluctuations. Existing electric traction machine motor constant speed control technologies mostly employ conventional PID control, ordinary sliding mode control, or open-loop control. The core idea of ​​this strategy is to adjust the speed based on the deviation between the motor speed feedback and the command signal to achieve speed stability. However, in actual wire laying operations, conductor tension fluctuations often exhibit significant periodic characteristics. These periodic disturbances are transmitted to the motor through the mechanical transmission link, causing periodic changes in the motor load. The control parameters or sliding surface design of traditional control algorithms do not take into account the disturbance frequency characteristics, resulting in insufficient adaptive adjustment capabilities. When faced with periodic load fluctuations, they are prone to response lag and large overshoot, making it difficult to maintain constant motor speed accuracy. To address this, we propose a constant speed control method for electric traction machines. Summary of the Invention

[0003] To solve the above-mentioned technical problems, a constant speed control method for an electric traction machine is provided, and this technical solution solves the problems mentioned above.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a constant speed control method for an electric traction machine motor, the control steps of which include:

[0005] S1. During high-voltage transmission line laying operations, the tension signal of the conductor is collected in real time through the tension detection module;

[0006] S2. The tension signal is analyzed in the frequency domain by the frequency identification module to identify the periodic disturbance frequency corresponding to the tension fluctuation.

[0007] S3. The adaptive control module dynamically adjusts the sliding surface based on the motor speed command signal and speed feedback signal, combined with the periodic disturbance frequency, to generate a sliding mode control signal.

[0008] S4. The compensation drive module generates a resonance suppression feedforward compensation signal based on the periodic disturbance frequency to compensate for the periodic disturbance when the pulley block passes through.

[0009] S5, the traction machine execution module combines the sliding mode control signal with the feedforward compensation signal and outputs a drive signal to control the operation of the traction motor.

[0010] Preferably, the tension detection module acquires tension signals through a sensor deployed on the pulley block and fixed using a clamp-type mechanism. The acquired signals undergo low-pass filtering and shielded transmission preprocessing, are synchronously acquired at a frequency of 1-2kHz, and the processed signals are transmitted to the frequency identification module.

[0011] Preferably, the frequency domain analysis of the tension signal is performed after frequency domain transformation by Fast Fourier Transform. Specifically, the preprocessed signal is processed by Fast Fourier Transform to convert the time domain signal into amplitude spectrum and phase spectrum; amplitude threshold screening, main frequency positioning and interference frequency elimination are performed to extract the core disturbance frequency; sliding iterative analysis with 50% overlap rate is performed, and frequency adaptive tracking is performed in combination with smoothing algorithm.

[0012] Preferably, before performing Fast Fourier Transform (FFT) processing, the sampling frequency and the number of sampling points in the window are verified, and the preprocessed signal is converted into a standard data format suitable for FFT operation; the digital signal processor is called to perform real Fourier operation on the discrete time domain signal with a set number of points, which is mapped into a frequency domain signal characterized by amplitude spectrum and phase spectrum; the amplitude threshold filtering, main frequency positioning and interference frequency suppression process are executed in sequence.

[0013] The core disturbance frequency extraction is achieved by pre-configuring a dedicated interference frequency library for high-voltage power line installation scenarios, including power frequency characteristic frequencies, motor carrier frequencies, and construction vibration characteristic frequencies, and then matching and verifying the candidate main frequencies with the interference frequency library.

[0014] A sliding window iterative mechanism is used to process continuously acquired tension signals. The overlap rate of adjacent windows is set to 50% for iterative calculation. In each iteration, Fourier transform, amplitude threshold screening, main frequency positioning and interference frequency suppression are performed iteratively to solve the core disturbance frequency of the current window and determine the core disturbance frequency for adaptive tracking.

[0015] Preferably, the specific steps within the adaptive control module are as follows:

[0016] The extracted periodic perturbation frequency features are obtained and stored;

[0017] Based on the preset sliding surface design, the rotational speed error signal is calculated, specifically the difference between the command signal and the feedback signal and the error derivative.

[0018] Substituting the difference, error derivative, and disturbance frequency characteristics into the sliding surface equation, we obtain the current sliding surface state value;

[0019] Based on the sliding surface state values ​​and combined with the frequency characteristics of periodic perturbations, an adaptive law is calculated and the adaptive parameters are updated.

[0020] Substitute the sliding surface state value and the updated adaptive parameters into the sliding mode control law, calculate, and output the sliding mode control signal.

[0021] Preferably, the specific calculation formula within the adaptive control module is as follows:

[0022] ;

[0023] in The final output sliding mode control signal, The speed error signal is as follows: ,in For commanded rotational speed, For feedback rotational speed; The derivative of the rotational speed error is obtained by... The derivative is obtained by numerical difference; The frequency of the periodic disturbance; These are the design parameters for the sliding surface, and they are adapted to... ; These are the parameters of the sliding mode control law, where... To approach the gain, This is the chatter suppression coefficient; These are the initial values ​​for the adaptive parameters; For adaptive law gain, To adjust the parameter update speed; The symbolic function is t; t is the time variable. This is for integral operations, used for integral updates of parameters in adaptive laws.

[0024] Preferably, the core functions of the compensation drive module are as follows:

[0025] The system collects the actual operating parameters of the electric traction machine motor and the system-given command signal. Using the system-given command as the control target, it deduces the theoretical target control value of the tension and pulley block based on the real-time operating status of the traction machine motor. The sliding mode control signal generated by the sliding mode control module is mapped to the real-time control parameters of the actual tension and pulley block. A compensation benchmark value is established, the deviation between the actual control parameters and the theoretical target value is quantified, and a nonlinear correction term adapted to the friction characteristics and rotational inertia of the pulley block is incorporated. The compensation gain is dynamically adjusted through an adaptive algorithm. The calculated compensation amount is converted into a drive control signal that can be recognized by the traction machine actuator. After amplitude limiting and rate limiting processing, it is output to the traction machine actuator module to achieve precise compensation control.

[0026] Preferably, the sliding mode control signal generated by the sliding mode control module is converted into actual tension adjustment threshold and pulley group speed control parameters through a preset control signal and physical quantity mapping model;

[0027] The mean square error method is used to quantify the deviation between the actual control parameters and the theoretical target values ​​when establishing the compensation benchmark value.

[0028] The calculated compensation amount is converted into a recognizable drive control signal and output to the traction machine actuator module according to the interface protocol and calibration parameters of the traction machine actuator.

[0029] Preferably, the traction machine execution module parses the acquired control signals, extracts the core parameters of the tension adjustment command and the pulley group speed control command, and combines them with the preset parameters of the traction machine motor rated power and the pulley group transmission ratio to convert them into drive parameters that the motor driver can recognize; and controls the traction machine motor to release the line at a constant speed.

[0030] Preferably, the control method includes several control modules, specifically:

[0031] The tension detection module collects the tension signal of the conductor during the laying operation of high-voltage transmission lines in real time;

[0032] The frequency identification module is electrically connected to the tension detection module to perform frequency domain analysis on the tension signal and identify the periodic disturbance frequency corresponding to the tension fluctuation.

[0033] The adaptive control module includes a sliding mode controller. The sliding mode controller's sliding surface design incorporates the periodic disturbance frequency and generates a sliding mode control signal based on the traction motor speed feedback signal and speed command signal.

[0034] The compensation drive module and the compensation pulley block perform compensation calculations through periodic disturbances and output the compensated signal to the traction machine execution module.

[0035] The traction machine execution module receives a signal and drives the traction machine to perform the line laying operation.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] This invention first uses a tension detection module to collect conductor tension signals in real time, and then uses a frequency identification module to perform frequency domain analysis to accurately identify the periodic disturbance frequency of tension fluctuations. The sliding mode controller in the adaptive control module designs a sliding surface based on the identified disturbance frequency and generates precise control signals based on motor speed feedback and command signals. The sliding mode controller, designed in conjunction with the disturbance frequency, has strong anti-interference capabilities. Even in the presence of external disturbances, it can maintain the constant speed of the traction motor, reduce the fluctuation of the laying speed, ensure the straightness and tension consistency of the conductor, reduce operational risks, improve overall efficiency, and provide stable constant speed and tension control, reducing manual intervention and the number of downtimes due to malfunctions. Attached Figure Description

[0038] Figure 1 This is a flowchart of the control steps of the present invention. Detailed Implementation

[0039] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0040] Reference Figure 1 As shown, a constant speed control method for an electric traction machine motor includes the following control steps:

[0041] S1. During high-voltage transmission line laying operations, the tension signal of the conductor is collected in real time through the tension detection module;

[0042] S2. The tension signal is analyzed in the frequency domain by the frequency identification module to identify the periodic disturbance frequency corresponding to the tension fluctuation.

[0043] S3. The adaptive control module dynamically adjusts the sliding surface based on the motor speed command signal and speed feedback signal, combined with the periodic disturbance frequency, to generate a sliding mode control signal.

[0044] S4. The compensation drive module generates a resonance suppression feedforward compensation signal based on the periodic disturbance frequency to compensate for the periodic disturbance when the pulley block passes through.

[0045] S5, the traction machine execution module combines the sliding mode control signal with the feedforward compensation signal and outputs a drive signal to control the operation of the traction motor.

[0046] This application's tension detection module captures real-time changes in conductor tension, while the frequency identification module accurately locates the source of periodic disturbances. This prevents conductor breakage or damage due to excessive tension fluctuations, ensuring the quality of wire laying. The sliding mode controller, designed in conjunction with the disturbance frequency, has strong anti-interference capabilities and can quickly compensate for speed deviations, ensuring that the motor speed always matches the command requirements, guaranteeing uniform wire laying speed and reducing subsequent processing workload. The compensation drive module calculates compensation separately for periodic disturbances in the pulley system, directly correcting the execution signal. This reduces laying deviations caused by the mechanical structure itself, improving the straightness and consistency of the line erection.

[0047] The tension detection module acquires tension signals through sensors deployed on pulley blocks and fixed using clamps. The acquired signals undergo low-pass filtering and shielded transmission preprocessing, and are synchronously acquired at a frequency of 1-2kHz. The processed signals are then transmitted to the frequency identification module.

[0048] The module is deployed on the pulley block via a clamp-type sensor, requiring no modification to the original structure. It is easy to install and highly adaptable. It can capture the real tension changes of the pulley block under force at close range, reducing signal attenuation during transmission. The collected signal is first processed by low-pass filtering to remove high-frequency noise such as mechanical vibration and electromagnetic radiation, and then further isolated from external interference through shielded transmission, effectively avoiding signal distortion and improving signal purity.

[0049] Tension signal frequency domain analysis is performed by converting the signal into the frequency domain using Fast Fourier Transform (FFT). Specifically, the preprocessed signal is processed by FFT to convert the time domain signal into amplitude and phase spectra. Amplitude threshold screening, main frequency localization, and interference frequency elimination are performed to extract the core disturbance frequency. Iterative analysis with a 50% overlap rate is used, combined with a smoothing algorithm for adaptive frequency tracking.

[0050] Before performing a Fast Fourier Transform (FFT), the sampling frequency and the number of sampling points in the window must be verified. The sampling frequency must match the bandwidth characteristics of the tension signal to ensure that the key frequency components in the signal can be fully captured; the number of sampling points in the window should be set according to the frequency resolution requirements to avoid insufficient frequency analysis accuracy due to an inappropriate number of points. At the same time, the preprocessed signal is converted into a standard data format suitable for FFT operations, unifying data types and length specifications to ensure that the digital signal processor can accurately recognize and execute the operation.

[0051] The digital signal processor (DSP) performs real Fourier operations on a set number of discrete time-domain signals. This processor, with its high-efficiency parallel processing capabilities, can quickly complete signal conversion, accurately mapping the time-domain signal into a frequency-domain signal characterized by amplitude and phase spectra. It clearly presents the amplitude and phase relationships of different frequency components. Subsequently, it sequentially executes amplitude threshold filtering, dominant frequency localization, and interference frequency suppression: the amplitude threshold is preset based on the signal characteristics of the high-voltage power line scenario, retaining only effective frequency components with amplitudes exceeding the threshold; dominant frequency localization is achieved by identifying the frequency points with the most concentrated energy in the amplitude spectrum; and interference frequency suppression further purifies the effective signal by weakening the signal strength of non-target frequencies.

[0052] The extraction of core disturbance frequencies relies on a pre-configured interference frequency library specifically for high-voltage power line installation scenarios. The library covers common interference types such as power frequency characteristic frequencies, motor carrier frequencies, and construction vibration characteristic frequencies. It is dynamically updated based on different construction equipment models and environmental conditions to ensure comprehensive interference frequency coverage. During the matching and verification process, the selected candidate frequencies are compared one by one with the interference frequencies in the library. If the similarity between the candidate frequency and the frequency in the library exceeds the preset range, it is determined to be a non-interference frequency and included in the core disturbance frequency candidate set; if there is a high degree of matching, it is determined to be an interference frequency and is removed.

[0053] A sliding window iterative mechanism is employed to process continuously acquired tension signals. The window length is set in conjunction with the sampling frequency and the fluctuation characteristics of the tension signal. This ensures complete capture of a single frequency change cycle without causing frequency tracking lag due to an excessively long window. An overlap rate of 50% is set for adjacent windows during iterative calculations. The overlapping portion ensures the continuity of data between windows and avoids the loss of key frequency information due to window switching. During each iteration, the Fourier transform, amplitude threshold screening, main frequency localization, and interference frequency suppression processes are repeatedly executed to solve for the core disturbance frequency of the current window. The core disturbance frequency results of adjacent windows are compared. If the frequency change is within a reasonable fluctuation range, smoothing is performed to achieve continuous tracking. If a sudden change occurs that exceeds the range, the tracking target is updated in a timely manner, ultimately achieving adaptive tracking of the core disturbance frequency and ensuring real-time capture of the frequency change trend of the tension signal.

[0054] The specific steps within the adaptive control module are as follows:

[0055] The extracted periodic perturbation frequency features are obtained and stored;

[0056] Based on the preset sliding surface design, the rotational speed error signal is calculated, specifically the difference between the command signal and the feedback signal and the error derivative.

[0057] Substituting the difference, error derivative, and disturbance frequency characteristics into the sliding surface equation, we obtain the current sliding surface state value;

[0058] Based on the sliding surface state values ​​and combined with the frequency characteristics of periodic perturbations, an adaptive law is calculated and the adaptive parameters are updated.

[0059] Substitute the sliding surface state value and the updated adaptive parameters into the sliding mode control law, calculate, and output the sliding mode control signal.

[0060] This application module first stores the extracted periodic disturbance frequency characteristics, providing a clear reference for disturbance patterns in subsequent control and avoiding blind control actions. By calculating the difference between the command and feedback signals and the error derivative, it comprehensively captures the static deviation and dynamic change trend of the system, allowing control decisions to accurately match the actual operating state. The error information and disturbance characteristics are substituted into the sliding mode surface equation to solve for the state value. Relying on the inherent characteristics of sliding mode control, the system robustness is enhanced, and the impact of external disturbances is reduced.

[0061] The specific calculation formula within the adaptive control module is as follows:

[0062] ;

[0063] in The final output sliding mode control signal, The speed error signal is as follows: ,in For commanded rotational speed, For feedback rotational speed; The derivative of the rotational speed error is obtained by... The derivative is obtained by numerical difference; The frequency of the periodic disturbance; These are the design parameters for the sliding surface, and they are adapted to... ; These are the parameters of the sliding mode control law, where... To approach the gain, This is the chatter suppression coefficient; These are the initial values ​​for the adaptive parameters; For adaptive law gain, To adjust the parameter update speed; The symbolic function is t; t is the time variable. This is for integral operations, used for integral updates of parameters in adaptive laws.

[0064] The formula in this application incorporates the difference between the command speed and the feedback speed and the error derivative, which not only comprehensively reflects the static deviation of the system, but also accurately captures the dynamic trend of the deviation, providing solid data support for the generation of control signals and avoiding blind adjustment. It incorporates a periodic disturbance frequency related term, which can specifically match the extracted disturbance characteristics and fundamentally offset the impact of periodic interference on tension stability, thereby strengthening the anti-disturbance capability. The formula contains multiple adjustable parameters, which can be flexibly adapted to different high-voltage cable laying conditions. Furthermore, it effectively reduces the inherent chattering phenomenon of sliding mode control through the chattering suppression coefficient, thereby improving the stability of the control process.

[0065] The core functions of the compensation drive module are as follows:

[0066] The system collects the actual operating parameters of the electric traction machine motor and the system-given command signal. Using the system-given command as the control target, it deduces the theoretical target control value of the tension and pulley block based on the real-time operating status of the traction machine motor. The sliding mode control signal generated by the sliding mode control module is mapped to the real-time control parameters of the actual tension and pulley block. A compensation benchmark value is established, the deviation between the actual control parameters and the theoretical target value is quantified, and a nonlinear correction term adapted to the friction characteristics and rotational inertia of the pulley block is incorporated. The compensation gain is dynamically adjusted through an adaptive algorithm. The calculated compensation amount is converted into a drive control signal that can be recognized by the traction machine actuator. After amplitude limiting and rate limiting processing, it is output to the traction machine actuator module to achieve precise compensation control.

[0067] This application module synchronously collects the actual operating parameters of the motor and the given instructions from the system. The derived tension and theoretical target control values ​​of the pulley system are consistent with the real working conditions, providing a clear benchmark for compensation calculation and avoiding compensation deviations caused by target ambiguity. By mapping the sliding mode control signal to actual control parameters, a signal bridge is built between the control module and the actuator, allowing abstract control instructions to be transformed into parameters that the actuator can directly respond to, ensuring that the control logic is effectively implemented.

[0068] The sliding mode control signal generated by the sliding mode control module is transformed into actual tension adjustment threshold and pulley speed control parameters through a preset control signal and physical quantity mapping model.

[0069] The mean square error method is used to quantify the deviation between the actual control parameters and the theoretical target values ​​when establishing the compensation benchmark value.

[0070] The calculated compensation amount is converted into a recognizable drive control signal and output to the traction machine actuator module according to the interface protocol and calibration parameters of the traction machine actuator.

[0071] This application, through a pre-defined control signal and physical quantity mapping model, can accurately transform abstract sliding mode control signals into actual tension adjustment thresholds and pulley speed control parameters, avoiding mismatch between control signals and physical execution parameters. This allows the control logic to act directly and accurately on actual working conditions, ensuring the rationality of adjustment direction and force. The mean square error method is used to quantify the deviation between actual control parameters and theoretical target values, comprehensively and objectively reflecting the degree of difference between the two, eliminating errors caused by subjective judgment, providing standardized and reliable data support for compensation calculation, making subsequent compensation actions more targeted, and reducing blind adjustments.

[0072] The traction machine execution module analyzes the acquired control signals, extracts the core parameters of the tension adjustment command and the pulley block speed control command, and combines them with the preset parameters of the traction machine motor rated power and the pulley block transmission ratio to convert them into drive parameters that the motor driver can recognize; and controls the traction machine motor to release the line at a constant speed.

[0073] The traction machine execution module of this application first parses the control signal, extracts the core command parameters for tension adjustment and pulley speed control, and then combines them with the rated power of the traction machine motor and the preset parameters of the pulley transmission ratio to convert them into drive parameters that the motor driver can directly recognize. This process avoids execution deviations caused by incompatibility between the control signal and the driver, ensuring that the tension adjustment and speed control commands are accurately implemented without transmission loss. It fully combines the inherent characteristics of the equipment. The rated power parameter of the motor can prevent the motor from burning out due to overload, and the matching of the pulley transmission ratio can keep the speed command consistent with the actual wire laying speed, conforming to the operating rules of the equipment and avoiding mechanical failures or abnormal operation caused by parameter mismatch, thereby improving the reliability of the equipment.

[0074] Specific application examples

[0075] Project Background: In the construction of the ±1100kV Zhundong-Southern Anhui UHV transmission line, the tension laying process is adopted. The tension of a single conductor needs to be precisely controlled at 12-15kN, and the laying speed is required to be 2-3km / h and kept constant to ensure that the eight sub-conductors are laid synchronously and with balanced tension.

[0076] Application solutions:

[0077] S1. A high-precision tension sensor array is installed on the traction board to collect the tension signals of the 8 sub-conductors in real time at a sampling rate of 10kHz, with an accuracy of ±0.5%;

[0078] The sensor converts tension changes into electrical signals, which are then transmitted to the control system via a signal conditioning module.

[0079] S2. The FFT algorithm is used to perform frequency domain analysis on the tension signal to identify the main disturbance frequencies; the system automatically distinguishes between periodic disturbances and random noise and determines the key frequency points that need to be compensated.

[0080] S3. An adaptive sliding mode controller is designed based on a permanent magnet synchronous motor model. The sliding mode surface parameters are dynamically adjusted. The controller integrates the motor speed command and the encoder feedback signal to calculate the sliding mode control quantity. Under parameter perturbation and external disturbance, this algorithm can converge the speed error to within 0.1% within 50ms.

[0081] S4. Generate a same-frequency, opposite-phase compensation signal based on the identified disturbance frequency (3Hz), with an amplitude of 90% of the disturbance amplitude. This feedforward compensation directly acts on the drive link to offset the periodic tension fluctuations generated when the pulley block passes through. After compensation, the tension fluctuation amplitude is reduced from ±1.2kN to ±0.3kN, effectively suppressing the resonance phenomenon.

[0082] S5. The sliding mode control signal and the feedforward compensation signal are superimposed and converted into a PWM signal that can be recognized by the motor driver. The permanent magnet synchronous motor is driven by the vector control algorithm to ensure that the wire feeding speed is stable at 2.5km / h with an error of <±0.5%. The system also monitors parameters such as motor current and temperature to ensure safe operation of the equipment.

[0083] Tension control accuracy has been improved from ±5% of traditional PID to ±1%, reaching an industry-leading level;

[0084] The disturbance suppression effect reduces periodic tension fluctuations by 75%, preventing damage to the conductor due to sudden tension changes;

[0085] Response speed: System settling time < 50ms, achieving millisecond-level control response;

[0086] The efficiency and speed of line laying are increased by 10%, while reducing manual intervention and labor intensity.

[0087] The foregoing has shown and described 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 to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method of controlling the speed of an electric motor of an electric traction machine, characterized in that, The control step comprises: S1, during the laying operation of the high-voltage transmission line, the tension signal of the conductor is collected in real time through a tension detection module; S2, the frequency domain analysis is performed on the tension signal through a frequency identification module, and the periodic disturbance frequency corresponding to the tension fluctuation is identified; S3, the adaptive control module dynamically adjusts the sliding mode surface based on the motor speed instruction signal and the speed feedback signal, and generates a sliding mode control signal in combination with the periodic disturbance frequency; S4, the compensation driving module generates a resonance suppression feedforward compensation signal based on the periodic disturbance frequency, and compensates the periodic disturbance when the pulley set passes; S5, the traction machine execution module combines the sliding mode control signal and the feedforward compensation signal to output a driving signal to control the operation of the traction motor.

2. The method of claim 1, wherein the constant speed control of the electric motor of the electric traction machine is performed by a control unit of the electric traction machine. The tension detection module collects the tension signal through a sensor, the sensor is arranged on the pulley set and is fixed by a hoop; the collected signal is preprocessed by low-pass filtering and shielding transmission, and is collected synchronously at a frequency of 1-2 kHz; and the processed signal is transmitted to the frequency identification module.

3. The method of claim 1, wherein the constant speed control method of the electric motor of the electric traction machine is characterized by the fact that, The frequency domain analysis of the tension signal is analyzed after frequency domain conversion by fast Fourier transform, specifically: the preprocessed signal is processed by fast Fourier transform to convert the time domain signal into amplitude spectrum and phase spectrum; the core disturbance frequency is extracted by amplitude threshold screening, main frequency positioning and interference frequency exclusion; and the frequency is adaptively tracked by sliding iterative analysis with a 50% overlap rate and a smoothing algorithm.

4. The motor constant speed control method of the electric traction machine according to claim 3, characterized in that, before the fast Fourier transform processing, the sampling frequency and the window sampling point number are checked, and the preprocessed signal is converted into a standard data format suitable for fast Fourier transform operation; a digital signal processor is called to execute real Fourier operation on the discrete time domain signal with a set point number, and the frequency domain signal characterized by amplitude spectrum and phase spectrum is mapped; the amplitude threshold screening, main frequency positioning and interference frequency suppression processes are sequentially executed; the core disturbance frequency is extracted by preconfiguring a high-voltage laying scene exclusive interference frequency library including power frequency characteristic frequency, motor carrier frequency and construction vibration characteristic frequency, and matching and checking the candidate main frequency and the interference frequency library; the sliding window iterative mechanism is adopted to process the continuously collected tension signal, and the adjacent window overlap rate is set to 50% for iterative operation; in each iteration process, the Fourier transform, amplitude threshold screening, main frequency positioning and interference frequency suppression processes are iteratively executed to solve the core disturbance frequency of the current window and determine the adaptive tracking of the core disturbance frequency.

5. The method of claim 1, wherein the motor constant speed control method of an electric traction motor is characterized by, The specific steps in the adaptive control module are: the extracted periodic disturbance frequency characteristics are obtained and stored; based on the preset sliding mode surface design, the speed error signal is calculated, specifically the difference between the instruction signal and the feedback signal and the error derivative; the difference, the error derivative and the disturbance frequency characteristics are substituted into the sliding mode surface equation to obtain the current sliding mode surface state value; based on the sliding mode surface state value and the periodic disturbance frequency characteristics, the adaptive law is calculated and the adaptive parameters are updated; the sliding mode surface state value and the updated adaptive parameters are substituted into the sliding mode control law, and the sliding mode control signal is output after operation.

6. The method for constant speed control of an electric traction machine motor according to claim 5, characterized in that, The specific calculation formula in the adaptive control module is: ; wherein is the final output of the sliding mode control signal, is the speed error signal, specifically: wherein is the command speed, is the feedback speed; is the speed error derivative, obtained by differentiating ; is the periodic disturbance frequency; are the sliding surface design parameters, adapted ; are the sliding mode control law parameters, wherein is the reaching gain, is the chattering suppression coefficient; is the initial value of the adaptive parameter; is the adaptive law gain, is the adjustment parameter update speed; is the sign function; t is the time variable; is the integral operation, used for the integral update of the parameter in the adaptive law.

7. The method of claim 1, wherein the motor constant speed control method of an electric traction motor is characterized by, The core function of the compensation driving module is as follows: The actual operating state parameters of the electric traction motor and the system given instruction signal are collected, and the system given instruction is taken as the control target, and the theoretical target control value of the tension and the pulley set is deduced combined with the real-time operating state of the traction motor; The sliding mode control signal generated by the sliding mode control module is mapped into the real-time control parameters of the actual tension and the pulley set; The compensation reference value is established, the deviation between the actual control parameters and the theoretical target value is quantified, the nonlinear correction term adapting to the friction characteristics and the moment of inertia of the pulley set is fused, and the compensation gain is dynamically adjusted through the adaptive algorithm; the compensation amount obtained by calculation is converted into the driving control signal recognizable by the traction actuator, which is output to the traction actuator after amplitude limiting and rate limiting processing, so as to realize precise compensation control.

8. The method for constant speed control of an electric traction machine according to claim 7, characterized in that, The sliding mode control signal generated by the sliding mode control module is converted into the actual tension adjustment threshold and the pulley set speed control parameter through the preset control signal and physical quantity mapping model; The compensation reference value is established by using the mean square error method to quantify the deviation between the actual control parameters and the theoretical target value; The compensation amount obtained by calculation is converted into the recognizable driving control signal according to the interface protocol and calibration parameters of the traction actuator, and is output to the traction actuator.

9. The method of claim 1, wherein the motor constant speed control method of an electric traction motor is characterized by, The traction actuator module analyzes the obtained control signal, extracts the tension adjustment instruction and the pulley set speed control instruction core parameter, combines the traction motor rated power and the pulley set transmission ratio preset parameter, and converts them into the driving parameters recognizable by the motor driver; the traction motor is controlled to drive the traction motor at constant speed.

10. The method of claim 1, wherein the motor constant speed control method of an electric traction machine is characterized by, The control method includes several control modules, specifically: The tension detection module collects the tension signal of the conductor in the high-voltage transmission line laying operation in real time; The frequency identification module is electrically connected between the tension detection module and the tension signal, and performs frequency domain analysis on the tension signal to identify the periodic disturbance frequency corresponding to the tension fluctuation; The adaptive control module includes a sliding mode controller, the sliding mode surface of the sliding mode controller is designed combined with the periodic disturbance frequency, and the sliding mode control signal is generated based on the traction motor speed feedback signal and the speed instruction signal; The compensation driving module compensates the pulley set through periodic disturbance, performs compensation calculation, and outputs the compensated signal to the traction actuator module; The traction actuator module acquires the signal and drives the traction actuator to perform the laying operation.

Images