A method for suppressing electromechanical coupling resonance, a controller and a motor drive system

Abstract

The invention discloses an electromechanical coupling resonance suppression method, a controller and a motor drive system, which relate to the field of electromechanical control technology and solve the problem that electromechanical coupling resonance between an electrical system and a mechanical system of existing complex electromechanical equipment affects system stability and accelerates component failure. The invention comprises the following steps: constructing a dynamic model of a mechanical system; constructing a control algorithm model of a control system: determining that a mathematical model of a control object in the control system includes a mathematical model of a permanent magnet motor and a converter, and designing a motor controller according to the mathematical model; constructing an electromechanical coupling model based on the dynamic model of the mechanical system and the control algorithm model of the control system; and analyzing the resonance characteristics of an electromechanical system based on the electromechanical coupling model to determine a resonance point. The method proposed by the invention combines ADRC, has good control performance when motor parameters change, and is robust to changes in PMSM parameters.

Description

Technical Field

[0001] The present invention relates to the field of electromechanical control technology, and in particular to an electromechanical coupling resonance suppression method, a controller and a motor drive system. Background Art

[0002] Electromechanical equipment is widely used in various fields, and the problem of electromechanical coupling resonance in electromechanical equipment has gradually been discovered. Electromechanical coupling resonance is the resonance caused by the coincidence of the current harmonic frequency generated by the control system in the electromechanical equipment and the natural frequency of the transmission components in the mechanical system. It has a certain impact on the operating stability of the mechanical equipment and the life of the internal components of the equipment.

[0003] In particular, in order to improve the efficiency of rail vehicles, researchers have proposed a permanent magnet direct drive solution, which combines a direct drive system with a permanent magnet synchronous motor. However, the permanent magnet synchronous motor direct drive system is a nonlinear, high-order, and strongly coupled system. This characteristic amplifies the impact of electric torque and control performance on the transmission system. In a permanent magnet direct drive system, the motor directly drives the load to achieve rotational motion, which requires a large torque to be generated at a low speed. Therefore, the frequency of the harmonic torque decreases with the rotor speed, and at certain speeds, it coincides with the modal frequency of the mechanical structure. Harmonic torque can cause electromechanical coupling resonance, endangering system stability and accelerating component failure. Therefore, it is urgent to adopt an effective electromechanical coupling resonance suppression method to ensure safe and comfortable operation of trains.

[0004] In the existing research methods, vibration suppression methods are divided into methods based on rail mechanical transmission systems and methods based on motor control systems. Among them, the methods based on rail mechanical transmission systems mainly focus on the dynamic response and vibration level caused by random vibration. The motor is suspended through a rubber joint, which prevents most of the harmonic torque of the traction motor from being transmitted to the bogie frame or car body, and the electric torque is usually considered to be a constant value, ignoring the influence of harmonic torque, so it is impossible to effectively suppress the electromechanical coupling resonance.

[0005] The motor control system-based method suppresses resonance by suppressing periodic disturbances. Many optimal control algorithms have been proposed, including resonant control, repetitive control, adaptive control, and active disturbance rejection control (ADRC). However, these methods do not specifically analyze the electromechanical coupling resonance problem, and their implementation is relatively complex and the effect is poor. Summary of the invention

[0006] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a method for suppressing electromechanical coupling resonance, a controller and a motor drive system to solve the problem that electromechanical coupling resonance between the electrical system and the mechanical system of existing complex electromechanical equipment affects system stability and accelerates component failure.

[0007] An electromechanical coupling resonance suppression controller includes an extended state observer ESO (QRC-ESO) with a QRC controller added, and the state space equation of the QRC-ESO is:

[0008] ,

[0009] Where z1 is the mechanical angular velocity estimate, z2 is the concentrated disturbance estimate, b 0= 1 / J 0, J 0 is the nominal value of inertia, x 1= ω m , ω m is the mechanical angular velocity, x 2 = d n , d n For concentrated disturbance, u = i s , i s is the stator current, β1 and β2 are the gains of the estimation loop, G QRC It is the representation of QRC, as follows:

[0010] ,

[0011] In the formula, ω c is the cutoff frequency of the QRC controller, ω r is the resonant frequency of the controlled object, K r is the gain coefficient of the QRC controller;

[0012] The error state space equation of QRC-ESO is:

[0013] ,

[0014] Where e1 is the angular velocity estimation error, e1= z1-ω m , e2 is the disturbance estimation error, e2= z2- d n ;

[0015] The transfer function between the angular velocity estimation error e1 of QRC-ESO and the system disturbance x2 is:

[0016] ,

[0017] In the formula, δ(s)=β2(1+G QRC (s));

[0018] The transfer function between the QRC-ESO interference estimate z2 and the system interference x2 is:

[0019] .

[0020] Furthermore, the cut-off frequency of the QRC controller is 10-25 Hz near the resonant frequency, and the gain coefficient of the QRC controller is 0.0001-0.001.

[0021] Further, it includes RS-ADRC, wherein the RS-ADRC uses QRC-ESO as an extended state observer, and the open-loop transfer function of the RS-ADRC is:

[0022] ,

[0023] In the formula, ω c is the cutoff frequency of the QRC controller, ω r is the resonant frequency of the controlled object, K r is the gain coefficient of the QRC controller; ω0 is the bandwidth of the observer, K s is the speed loop gain parameter;

[0024] A method for suppressing electromechanical coupling resonance, comprising:

[0025] Determine the mechanical system structure and control system algorithm of electromechanical equipment, and build the dynamics model of the mechanical system and the control algorithm model of the control system;

[0026] Specifically, the electromechanical equipment includes a permanent magnet direct drive traction system such as a permanent magnet direct drive train, a rotorcraft, a wind turbine of a wind power plant, etc.

[0027] The electromechanical coupling model is constructed based on the dynamics model of the mechanical system and the control algorithm model of the control system: the dynamics model interacts with the motor control model. The control algorithm model uses the speed and load signal of the motor rotor in the dynamics model as input signals, processes the output motor control signal through the controller, drives the converter to adjust the motor speed and output drive torque, and the dynamics model calculates the dynamic response characteristics of the dynamics model based on the motor drive torque and its own load torque.

[0028] Based on the electromechanical coupling model, the resonance characteristics of the electromechanical system are analyzed to determine the resonance point: the modal analysis is performed on the dynamic model of the mechanical system to obtain the natural modal frequency information of the transmission components, the stator current and output torque harmonic characteristics in the control algorithm are analyzed to obtain the harmonic current and harmonic torque frequency distribution characteristics, the mechanical modal frequency characteristics are compared and analyzed with the harmonic torque characteristics, the distribution range of the electromechanical system coupling vibration frequency is determined, and then the resonance point is obtained.

[0029] Furthermore, the process of constructing the dynamic model of the mechanical system includes: determining the components of the mechanical system, modeling the transmission components involved in the transmission as flexible bodies to reflect their inherent mechanical modal characteristics and characteristic frequencies, treating the remaining components as rigid bodies to establish a finite element model of the mechanical system, discretizing the finite element model, and then using a substructure modal reduction method to reduce the degrees of freedom of the finite element model to make it a flexible body, so as to ensure that each component can transmit high-frequency vibrations;

[0030] The control algorithm model construction process of the control system includes: determining the mathematical model of the control object in the control system including the mathematical model of the permanent magnet motor and the converter, designing a motor controller according to the mathematical model, and the motor controller includes an ADRC speed loop controller, a dq axis current controller and a PWM modulation algorithm.

[0031] Furthermore, it also includes: designing a coupled vibration suppression algorithm for the resonance point. The resonance source of the electromechanical system is the harmonic torque of the motor. Therefore, it is necessary to design an electromechanical system coupled vibration state observer to observe the harmonic torque and speed fluctuations within a specific frequency range, and output a suppression signal to reduce the amplitude of the harmonic torque near the resonance frequency, thereby reducing the impact of the specific harmonic torque on the vibration of the mechanical system.

[0032] Furthermore, when the electromechanical equipment is a permanent magnet direct-drive train, the construction of the dynamic model of the mechanical system includes first constructing a whole vehicle dynamics model, and then constructing a direct-drive bogie dynamics model; the construction of the control algorithm model of the control system includes constructing a permanent magnet direct-drive motor full-speed domain control algorithm model; the construction of the electromechanical coupling model includes taking the electromagnetic torque and the rotor speed as the key parameters of the electromechanical coupling of the permanent magnet direct-drive system, and building an electromechanical coupling dynamics numerical simulation platform based on the joint simulation of the dynamic model and the control algorithm model; on this basis, the modal analysis of the whole vehicle electromechanical system is carried out, and the electromechanical coupling resonance characteristics and the corresponding coupling vibration suppression algorithm are studied.

[0033] Furthermore, the mechanical system includes: a car body, a bogie frame, a permanent magnet direct drive traction system, an internal axle box and a wheelset. Except for the permanent magnet direct drive traction system, the remaining components can be regarded as rigid bodies. Each wheelset is driven by a permanent magnet direct drive traction system, and each permanent magnet direct drive traction system is composed of a permanent magnet direct drive traction motor, a flexible plate hollow shaft coupling and a motor hanger.

[0034] Among them, the construction of the whole vehicle dynamics model includes: the load of the frame is transmitted to the wheelset through the primary suspension, the car body and the frame are connected through the secondary suspension, and the primary suspension and the secondary suspension are regarded as spring-damper units; the stator of the permanent magnet direct drive motor is fixed on the motor hanger, and the motor hanger is connected to the frame through a hanger and a cantilever, wherein the hanger suspension point mainly provides vertical force at both ends of the motor, and the cantilever can be regarded as a longitudinal and vertical spring-damper unit; the axle box tie rod between the wheelset and the frame, and the traction rod between the bogie and the car body are equivalent to shock absorbers, and the bogie traction force can be transmitted to the car body through the traction rod.

[0035] The wheel-rail contact adopts the creep force model, and the normal direction is selected as Hertzian nonlinear contact.

[0036] The direct drive bogie dynamic model modeling includes: the force transmission flange at one end of the hollow shaft coupling is connected to the motor rotor output end through a flexible plate, the flexible plate is regarded as a spring-damper unit in the longitudinal, vertical and torsional directions, the other end of the hollow shaft coupling is connected to the force transmission disc through a flexible plate, the force transmission disc and the axle are assembled by interference fit, the flexible plate between the hollow shaft and the force transmission disc is equivalent to a spring-damper unit in the longitudinal, vertical and torsional directions, the force transmission disc in the coupling is fixedly connected to the axle, and the two rotate synchronously around the Y axis of the coordinate system. Among them, the axle box body is fixed to the axle through a bearing, and only the degree of freedom of rotation around the Y axis is released between the axle box and the axle, and the motor rotor is fixed to the stator housing through bearings at both ends, and only the degree of freedom of rotation around the Y axis is released between the rotor and the stator.

[0037] Furthermore, the electromechanical coupling principle of the electromechanical coupling dynamics numerical simulation platform is as follows: the electromechanical coupling dynamics numerical simulation platform calculates the real-time speed of the motor rotor according to the traction torque and load torque in the dynamic model, and inputs the calculation into the control algorithm model; the control algorithm model adjusts the electromagnetic torque output by the motor according to the difference between the actual speed and the reference speed, so as to realize the operation control of the train; wherein, the linkage parameters in the dynamic model will affect the speed of the motor rotor, and the speed as the input of the traction motor control system will further affect the electromagnetic torque output by the motor, and the electromagnetic torque and the harmonic torque therein will affect the dynamic response of the mechanical structure of the train, thereby realizing the coupling between the mechanical system and the control system, and the linkage parameters include track spectrum, suspension elements, and structural elastic vibration.

[0038] An electromechanical coupling resonance suppression motor drive system adopts an electromechanical coupling resonance suppression controller. The controller is arranged in a control system, and the control system is connected to a mechanical system.

[0039] Furthermore, the control system includes a speed loop controller, a weak magnetic control module, a current loop PI controller, an SVM modulation module and an inverter module. The speed loop controller adopts RS-ADRC. The control principle of the control system is:

[0040] When the motor speed is low, the required reference voltage u s,ref Within the inverter voltage output range, the weak magnetic control module does not work. dq The axis reference current is determined by the MTPA module.

[0041] As the speed gradually increases, the required reference voltage u s,ref Gradually exceeds the inverter voltage output range, at this time the weak magnetic control module is enabled, dq The axis reference current is determined by the field weakening control module, where d The shaft current increases in the reverse direction to weaken the amplitude of the motor's back EMF and broaden the motor's operating speed range.

[0042] The current loop PI controller is based on dq Axis reference current regulation dq Axis reference voltage and input to SVM modulation module,

[0043] The SVM modulation module processes the output inverter switch signal to control the on-off time and sequence of the inverter module.

[0044] Then the three-phase winding current of the permanent magnet direct-drive motor is controlled to achieve the goal of regulating the motor speed and torque.

[0045] The beneficial effects of the present invention include:

[0046] 1. In view of the existing electromechanical coupling resonance problem, the present invention constructs an electromechanical coupling model based on the dynamic model of the mechanical system and the control algorithm model of the control system; based on the electromechanical coupling model, the resonance characteristics of the electromechanical system are analyzed to determine the resonance point, and the resonance point is quickly and accurately understood, so as to design a specific resonance suppression algorithm for the resonance point to solve the problem of electromechanical coupling resonance; based on the processing ideas of the present invention, the electromechanical coupling resonance problem that may occur in various types of electromechanical complex equipment can be solved, which is of great significance to ensuring the system stability of electromechanical complex equipment and delaying component failure.

[0047] 2. The present invention also uses a permanent magnet direct-drive train as an electromechanical device. From the perspective of motor control, the observer is improved to enhance its observation capability of high-frequency signals, and then the current is adjusted in real time according to the disturbance signal. No changes are required in the mechanical structure, and the cost is low.

[0048] 3. The method proposed in the present invention selects a suitable cutoff frequency ω for the observer cand the resonant gain factor K r The cut-off frequency is around 10-25Hz near the resonant frequency. The characteristic components near the resonant frequency should be included as much as possible. The resonant gain coefficient is set between 0.0001 and 0.001. It should be ensured that while amplifying the coupled vibration high-frequency signal, no additional noise signal will be amplified, and the motor performance will not be introduced while additional interference will be introduced.

[0049] 4. The method proposed in the present invention combines ADRC, has good control performance when the motor parameters change, and is robust to changes in PMSM parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 The present invention is a flowchart of an electromechanical coupling resonance suppression control method according to an embodiment of the present invention.

[0051] Figure 2 The figure is a comparison diagram of the effects of suppressing electromechanical coupling vibration between an electromechanical coupling resonance suppression controller involved in an embodiment of the present invention and the prior art.

[0052] Figure 3 It is the current when the electromechanical coupling resonance suppression controller involved in the embodiment of the present invention and the prior art perform control respectively.

[0053] Figure 4 The FFT analysis of the current corresponding to the electromechanical coupling resonance suppression controller involved in the embodiment of the present invention and the prior art when performing control respectively.

[0054] Figure 5 It is the torsional vibration acceleration peak value of the direct drive system when the electromechanical coupling resonance suppression controller involved in the embodiment of the present invention and the prior art are controlled respectively.

[0055] Figure 6 The FFT analysis corresponding to the torsional vibration acceleration peak of the direct drive system when the electromechanical coupling resonance suppression controller involved in the embodiment of the present invention and the prior art are respectively controlled.

[0056] Figure 7 The torque when the electromechanical coupling resonance suppression controller involved in the embodiment of the present invention and the prior art are controlled respectively.

[0057] Figure 8 The FFT analysis of the torque corresponding to the electromechanical coupling resonance suppression controller involved in the embodiment of the present invention and the prior art when performing control respectively.

[0058] Fig. 9 The present invention is a schematic structural diagram of an electromechanical coupling resonance suppression motor drive system according to an embodiment of the present invention.

[0059] Fig.10 The present invention is a schematic diagram of the structure of a control system in an electromechanical coupling resonance suppression motor drive system according to an embodiment of the present invention.

[0060] Fig.11 The present invention is a schematic diagram of the structure of RS-ADRC in an electromechanical coupling resonance suppression motor drive system according to an embodiment of the present invention.

[0061] Fig.12 The present invention is a schematic structural diagram of a mechanical system in an electromechanical coupling resonance suppression motor drive system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions 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. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0063] An electromechanical coupling resonance suppression controller includes an extended state observer ESO (QRC-ESO) with a QRC controller added, and the state space equation of the QRC-ESO is:

[0064] ,

[0065] Where z1 is the mechanical angular velocity estimate, z2 is the concentrated disturbance estimate, b 0= 1 / J 0, J 0 is the nominal value of inertia, x 1= ω m , ω m is the mechanical angular velocity, x 2 = d n , d n For concentrated disturbance, u = i s , i s is the stator current, β1 and β2 are the gains of the estimation loop, G QRC It is the representation of QRC, as follows:

[0066] ,

[0067] In the formula, ω c is the cutoff frequency of the QRC controller, ω r is the resonant frequency of the controlled object, K r is the gain coefficient of the QRC controller;

[0068] The error state space equation of QRC-ESO is:

[0069] ,

[0070] Where e1 is the angular velocity estimation error, e1= z1-ω m , e2 is the disturbance estimation error, e2= z2- d n

[0071] The transfer function between the angular velocity estimation error e1 of QRC-ESO and the system disturbance x2 is:

[0072] ,

[0073] In the formula, δ(s)=β2(1+G QRC (s)

[0074] The transfer function between the QRC-ESO interference estimate z2 and the system interference x2 is:

[0075] .

[0076] In another embodiment, a suitable cutoff frequency ω is selected for the QRC-ESO. c and the resonant gain factor K r The cut-off frequency is around 10-25Hz near the resonant frequency. The characteristic components near the resonant frequency should be included as much as possible. The resonant gain coefficient is set between 0.0001 and 0.001. It should be ensured that while amplifying the coupled vibration high-frequency signal, no additional noise signal will be amplified, and the motor performance will not be introduced while additional interference will be introduced.

[0077] In another embodiment, an electromechanical coupling resonance suppression controller includes a RS-ADRC, wherein the RS-ADRC uses a QRC-ESO as an extended state observer, and the open-loop transfer function of the RS-ADRC is:

[0078] ,

[0079] In the formula, ω c is the cutoff frequency of the QRC controller, ω r is the resonant frequency of the controlled object, K r is the gain coefficient of the QRC controller; ω0 is the bandwidth of the observer, Ks is the speed loop gain parameter; .

[0080] The specific implementation structure is as follows Fig.11 As shown (Fig. is the motor reference speed, is the actual speed, is the speed loop gain, In this embodiment, in order to verify the harmonic torque suppression capability of the proposed RS-ADRC control algorithm, a comparative experiment is conducted from 1000 rpm to 1500 rpm, as shown in FIG. Figure 2 As shown. The comparison results show that the PI controller and the anti-disturbance controller have similar 6th harmonic torque amplitudes. The resonant frequency parameter ωr in the QRC-ESO is set to 240 Hz, which corresponds to the 6th harmonic torque frequency at 1200 rpm. As can be seen from the figure, RS-ADRC can significantly suppress the harmonic torque amplitude to a minimum of 5.93% at 1200 rpm. Since QRC-ESO also has an inhibitory effect on torque pulsations near the resonant frequency ωr, the 6th harmonic torque of RS-ADRC is the lowest among the three methods in the speed range of 1000 rpm to 1500 rpm, which can effectively suppress the electromechanical coupling vibration excitation source.

[0081] like Figure 3-8 The control method of the controller proposed by the present invention is compared with the prior art in various aspects, specifically:

[0082] Figure 3 The current waveforms under three methods are: Figure 4 This is the frequency domain analysis diagram of the current. Figure 4 It can be seen that the proposed method has the lowest 5th and 7th current harmonics, so the generated 6th harmonic torque is also the lowest;

[0083] Figure 5 The vibration acceleration time domain waveforms under three methods are: Figure 6 is the frequency domain waveform of vibration acceleration, from Figure 6 It can be seen that the vibration acceleration amplitude of the proposed method is the lowest, and compared with PI, the new method is reduced by 33%;

[0084] Figure 7 The torque waveforms under three methods are: Figure 8 It is the frequency domain diagram of the vibration torque waveform. Figure 8 It can be seen that the 6-fold frequency torque pulsation amplitude of the proposed method is the lowest, and compared with PI, the new method is reduced by 25%.

[0085] In this embodiment, for the permanent magnet direct drive system, the motor torque pulsation within the commonly used speed range will cause coupled vibration of the hollow shaft coupling. In order to ensure the reliability and safety of the system operation, it is necessary to design a coupled vibration suppression algorithm for the permanent magnet direct drive system based on the electromechanical coupling resonance characteristics. The risk of electromechanical coupling vibration can be reduced by suppressing torque pulsation. Specifically, the coupled vibration suppression algorithm for the permanent magnet direct drive system is embodied in an extended state observer QRC-ESO with a quasi-resonant suppression controller added.

[0086] In another embodiment, a method for suppressing electromechanical coupling resonance is provided, such as Figure 1 As shown, including:

[0087] Determine the mechanical system structure and control system algorithm of electromechanical equipment, and build the dynamics model of the mechanical system and the control algorithm model of the control system;

[0088] Specifically, the electromechanical equipment includes a permanent magnet direct drive traction system such as a permanent magnet direct drive train, a rotorcraft, a wind turbine of a wind power plant, etc.

[0089] Specific modeling methods for different electromechanical equipment include Dynamic modeling of locomotive with direct drive traction system considering electromechanical coupling effect, which involves modeling direct drive trains; Research on electromechanical coupling characteristics and active vibration control of large wind turbine drive chains_Zhang Shijie, which involves modeling wind turbines; Research on electromechanical coupling vibration characteristics of traction drive systems considering inverter harmonic coupling_Ge Xinglai, which involves modeling traditional trains. These are not listed here one by one. Specific references are as follows:

[0090] [1] Zirui Ye, Zaigang Chen et al., Dynamic modeling of locomotive with direct drive traction system considering electromechanical coupling effect[J]. Vehicle System Dynamics International Journal of Vehicle Mechanics andMobility, 2023.

[0091] [2] Zhang Shijie, Research on electromechanical coupling characteristics and active vibration control of transmission chain of large wind turbines[D]. Chongqing: Chongqing University, 2022.

[0092] [3] GE Xinglai, CHANG Yu, et al., Study on electromechanical coupling vibration characteristics of traction drive system considering inverter harmonic coupling[J]. Journal of Electric Machine Control, 2024, 28(6): 110-118.

[0093] The electromechanical coupling model is constructed based on the dynamics model of the mechanical system and the control algorithm model of the control system: the dynamics model interacts with the motor control model. The control algorithm model uses the speed and load signal of the motor rotor in the dynamics model as input signals, processes the output motor control signal through the controller, drives the converter to adjust the motor speed and output drive torque, and the dynamics model calculates the dynamic response characteristics of the dynamics model based on the motor drive torque and its own load torque.

[0094] Based on the electromechanical coupling model, the resonance characteristics of the electromechanical system are analyzed to determine the resonance point: the modal analysis is performed on the dynamic model of the mechanical system to obtain the natural modal frequency information of the transmission components, the stator current and output torque harmonic characteristics in the control algorithm are analyzed to obtain the harmonic current and harmonic torque frequency distribution characteristics, the mechanical modal frequency characteristics are compared and analyzed with the harmonic torque characteristics, the distribution range of the electromechanical system coupling vibration frequency is determined, and then the resonance point is obtained.

[0095] In another embodiment, the process of constructing the dynamic model of the mechanical system includes: determining the components of the mechanical system, modeling the transmission components involved in the transmission as flexible bodies to reflect their inherent mechanical modal characteristics and characteristic frequencies, treating the remaining components as rigid bodies to establish a finite element model of the mechanical system, discretizing the finite element model, and using a substructure modal reduction method to reduce the degrees of freedom of the finite element model to make it a flexible body to ensure that each component can transmit high-frequency vibrations;

[0096] The control algorithm model construction process of the control system includes: determining the mathematical model of the control object in the control system including the mathematical model of the permanent magnet motor and the converter, designing a motor controller according to the mathematical model, and the motor controller includes an ADRC speed loop controller, a dq axis current controller and a PWM modulation algorithm.

[0097] The present invention takes into account the characteristics of both mechanical model and electrical model, and couples the two to model and discovers the problem of electromechanical coupling vibration. Existing modeling is mostly single mechanical modeling or single electrical modeling. In the single mechanical model, the motor torque is equivalent to a constant torque, and the influence of the motor harmonic torque is ignored; in the single electrical modeling, the mechanical model is equivalent to the load mass, and only the influence of mass and inertia is considered, without considering the modal frequency of the mechanical structure itself. Therefore, existing models rarely consider the influence of the coupling characteristics of the two.

[0098] In another embodiment, it also includes: designing a coupled vibration suppression algorithm for the resonance point. The resonance source of the electromechanical system is the harmonic torque of the motor. Therefore, it is necessary to design an electromechanical system coupled vibration state observer to observe the harmonic torque and speed fluctuations within a specific frequency range, and output a suppression signal to reduce the amplitude of the harmonic torque near the resonance frequency, thereby reducing the impact of the specific harmonic torque on the vibration of the mechanical system.

[0099] In another embodiment, when the electromechanical equipment is a permanent magnet direct-drive train, the construction of the dynamic model of the mechanical system includes first constructing a whole vehicle dynamics model, and then constructing a direct-drive bogie dynamics model. The construction of the control algorithm model of the control system includes constructing a permanent magnet direct-drive motor full-speed domain control algorithm model. The construction of the electromechanical coupling model includes taking the electromagnetic torque and rotor speed as the key parameters of the electromechanical coupling of the permanent magnet direct-drive system, and building an electromechanical coupling dynamics numerical simulation platform based on the joint simulation of the dynamic model and the control algorithm model. On this basis, the modal analysis of the whole vehicle electromechanical system is carried out, and the electromechanical coupling resonance characteristics and the corresponding coupling vibration suppression algorithm are studied.

[0100] In another embodiment, the mechanical system includes: a car body, a bogie frame, a permanent magnet direct drive traction system, an internal axle box and a wheelset. Except for the permanent magnet direct drive traction system, the remaining components can be regarded as rigid bodies. Each wheelset is driven by a permanent magnet direct drive traction system, and each permanent magnet direct drive traction system is composed of a permanent magnet direct drive traction motor, a flexible plate hollow shaft coupling and a motor hanger.

[0101] In the present invention, the direct-drive train motor is directly connected to the wheel through a hollow shaft, with a transmission ratio of 1:1. The harmonic torque of the motor directly acts on the mechanical system, and the output torque of the direct-drive motor is greater than that of the asynchronous motor in the traditional traction system, and the electromechanical coupling effect is obvious; while in the existing train mechanical system, the motor is connected to the wheel through a gear box, with a transmission ratio of about 3.6:1, and the gear box plays the role of deceleration and torque increase. Therefore, in the existing system, the motor harmonic frequency is higher, far away from the modal frequency of the mechanical system, and the electromechanical coupling effect is not obvious.

[0102] Among them, the construction of the whole vehicle dynamics model includes: the load of the frame is transmitted to the wheelset through the primary suspension, the car body and the frame are connected through the secondary suspension, and the primary suspension and the secondary suspension are regarded as spring-damper units; the stator of the permanent magnet direct drive motor is fixed on the motor hanger, and the motor hanger is connected to the frame through a hanger and a cantilever, wherein the hanger suspension point mainly provides vertical force at both ends of the motor, and the cantilever can be regarded as a longitudinal and vertical spring-damper unit; the axle box tie rod between the wheelset and the frame, and the traction rod between the bogie and the car body are equivalent to shock absorbers, and the bogie traction force can be transmitted to the car body through the traction rod.

[0103] The wheel-rail contact adopts the creep force model, and the normal direction is selected as Hertzian nonlinear contact.

[0104] The direct drive bogie dynamic model modeling includes: the force transmission flange at one end of the hollow shaft coupling is connected to the motor rotor output end through a flexible plate, the flexible plate is regarded as a spring-damper unit in the longitudinal, vertical and torsional directions, the other end of the hollow shaft coupling is connected to the force transmission disc through a flexible plate, the force transmission disc and the axle are assembled by interference fit, the flexible plate between the hollow shaft and the force transmission disc is equivalent to a spring-damper unit in the longitudinal, vertical and torsional directions, the force transmission disc in the coupling is fixedly connected to the axle, and the two rotate synchronously around the Y axis of the coordinate system. Among them, the axle box body is fixed to the axle through a bearing, and only the degree of freedom of rotation around the Y axis is released between the axle box and the axle, and the motor rotor is fixed to the stator housing through bearings at both ends, and only the degree of freedom of rotation around the Y axis is released between the rotor and the stator.

[0105] In addition, full-degree-of-freedom and reduced-degree-of-freedom modal analysis of wheelsets, axle boxes, frames and transmission hollow shafts was carried out. The results showed that the vibration frequency of the flexible body differed by no more than 5% compared with the original model, which has good engineering applicability.

[0106] A full-speed control algorithm model of a permanent magnet direct-drive motor was constructed in Matlab / Simulink.

[0107] In another embodiment, the electromagnetic torque and rotor speed are used as the key parameters of the electromechanical coupling of the permanent magnet direct drive system. On this basis, an electromechanical coupling dynamic numerical simulation platform based on SIMPACK and SIMULINK joint simulation is built. The platform calculates the real-time speed of the motor rotor according to the traction torque and load torque in the dynamic model and inputs it into the traction motor control model. The motor control model adjusts the electromagnetic torque output by the motor according to the difference between the actual speed and the reference speed to achieve the operation control of the train. Among them, the track spectrum, suspension elements, structural elastic vibration, etc. in the dynamic model will affect the speed of the motor rotor. The speed, as the input of the traction motor control system, will affect the electromagnetic torque output by the motor. The electromagnetic torque and the harmonic torque therein will affect the dynamic response of the train mechanical structure, thereby realizing the coupling effect between the mechanical system and the control system.

[0108] Based on the electromechanical coupling modeling, the modal analysis of the electromechanical system of the whole vehicle was carried out, and the resonance frequency characteristics of the electromechanical coupling were studied.

[0109] In this embodiment, within the commonly used speed range (160~200km / h), considering the new wheel (diameter 860mm) and the worn wheel (diameter 790mm), the motor pulsation torque frequency band is concentrated between 790~1182Hz. At the same time, considering the change in coupling stiffness, the hollow shaft torsional rigid body modal frequency is 582~1132Hz, the hollow shaft breathing modal frequency is 785Hz and 833Hz, the hollow shaft first-order vertical bending modal frequency is 1130~1270Hz, and the hollow shaft torsional elastic modal frequency is 1167~1711Hz. Analysis shows that the motor torque pulsation frequency band and the hollow shaft coupling torsional rigid body modal frequency band are highly overlapped, so the motor torque pulsation will cause coupled vibration of the hollow shaft coupling within the commonly used speed range.

[0110] Specifically, within the commonly used speed range, the motor torque pulsation will cause coupled vibration of the hollow shaft coupling. In order to ensure the reliability and safety of system operation, it is necessary to design a coupled vibration suppression algorithm for the permanent magnet direct drive system based on the electromechanical coupling resonance characteristics. The risk of electromechanical coupling vibration can be reduced by suppressing torque pulsation. Specifically, the coupled vibration suppression algorithm for the permanent magnet direct drive system is embodied in an extended state observer QRC-ESO with a quasi-resonant suppression controller added.

[0111] Carry out multi-condition simulation of the electromechanical coupling model to collect the torque pulsation and mechanical system vibration signals near the resonance point of the electromechanical system; QRC-ESO observes the electromechanical coupling vibration signal and feeds it back to the speed loop controller to compensate for the torque pulsation by adjusting the current, thereby suppressing the coupling vibration of the electromechanical system.

[0112] In another embodiment, a motor drive system for suppressing electromechanical coupling resonance is provided, such as Fig. 9 As shown, an electromechanical coupling resonance suppression controller is used, and the controller is arranged in a control system, and the control system is connected to the mechanical system.

[0113] In another embodiment, the control system is as follows Fig.10 As shown, it includes a speed loop controller, a weak magnetic control module, a current loop PI controller, an SVM modulation module and an inverter module. The speed loop controller adopts RS-ADRC. The control principle of the control system is:

[0114] When the motor speed is low, the required reference voltage u s,ref Within the inverter voltage output range, the weak magnetic control module does not work. dq The axis reference current is determined by the MTPA module.

[0115] As the speed gradually increases, the required reference voltage u s,ref Gradually exceeds the inverter voltage output range, at this time the weak magnetic control module is enabled, dq The axis reference current is determined by the field weakening control module, where d The shaft current increases in the reverse direction to weaken the amplitude of the motor's back EMF and broaden the motor's operating speed range.

[0116] The current loop PI controller is based on dq Axis reference current regulation dq Axis reference voltage and input to SVM modulation module,

[0117] The SVM modulation module processes the output inverter switch signal to control the on-off time and sequence of the inverter module.

[0118] Then the three-phase winding current of the permanent magnet direct-drive motor is controlled to achieve the goal of regulating the motor speed and torque.

[0119] specific, Fig.10 The symbols mean: is the motor reference speed, is the reference torque, is the d-axis reference current, is the q-axis reference current, is the stator reference voltage, is the actual current of d axis, is the actual current of q axis, is the d-axis reference voltage, is the q-axis reference voltage, Reference voltage electrical angle, is the DC link voltage.

[0120] In another embodiment, the mechanical system is as follows Fig.12 As shown (DOF in the figure stands for "degree of freedom"), it includes: car body, bogie frame, permanent magnet direct drive traction system, built-in axle box and wheelset. Except for the permanent magnet direct drive traction system, the other components can be regarded as rigid bodies. Each wheelset is driven by a permanent magnet direct drive traction system, and each permanent magnet direct drive traction system is composed of a permanent magnet direct drive traction motor, a flexible plate hollow shaft coupling and a motor hanger.

[0121] The above-mentioned embodiments only express the specific implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the protection scope of the present invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An electromechanical coupling resonance suppression controller, characterized in that: The extended state observer ESO (QRC-ESO) with a QRC controller is used to observe the harmonic torque and speed fluctuations within a specific frequency range, and output a suppression signal to reduce the harmonic torque amplitude near the resonance frequency, thereby reducing the influence of the specific harmonic torque on the vibration of the mechanical system. The state space equation of the QRC-ESO is: ， Where z1 is the mechanical angular velocity estimate, z2 is the concentrated disturbance estimate, b 0= 1 / J 0, J 0 is the nominal value of inertia, x 1= ω m , ω m is the mechanical angular velocity, u = i s , i s is the stator current, β1 and β2 are the gains of the estimation loop, G QRC It is the representation of QRC, as follows: ， In the formula, ω c is the cutoff frequency of the QRC controller, ω r is the resonant frequency of the controlled object, K r is the gain coefficient of the QRC controller; The error state space equation of QRC-ESO is: ， Where e1 is the angular velocity estimation error, e1= z1-ω m , e2 is the disturbance estimation error, e2= z2- d n , x 2 = d n , x2 is the system interference, d n For concentrated disturbance; The transfer function between the angular velocity estimation error e1 of QRC-ESO and the system disturbance x2 is: ， In the formula, δ(s)=β2(1+G QRC (s)); The transfer function between the QRC-ESO interference estimate z2 and the system interference x2 is: 。 2. The electromechanical coupling resonance suppression controller according to claim 1, characterized in that: The cutoff frequency of the QRC controller is [ω r -α, ω r +α], α is [10, 25], unit is Hz, and the gain coefficient of the QRC controller is [0.0001, 0.001].

3. The electromechanical coupling resonance suppression controller according to claim 1, characterized in that: The RS-ADRC comprises a RS-ADRC, wherein the RS-ADRC adopts the QRC-ESO according to claim 1 as an extended state observer, and the open-loop transfer function of the RS-ADRC is: ， In the formula, ω c is the cutoff frequency of the QRC controller, ω r is the resonant frequency of the controlled object, K r is the gain coefficient of the QRC controller; ω0 is the bandwidth of the observer, K s is the speed loop gain parameter; .

4. A method for suppressing electromechanical coupling resonance, characterized in that: include: Determine the mechanical system structure and control system algorithm of electromechanical equipment, and build the dynamics model of the mechanical system and the control algorithm model of the control system; The electromechanical coupling model is constructed based on the dynamics model of the mechanical system and the control algorithm model of the control system: the dynamics model interacts with the motor control model. The control algorithm model uses the speed and load signal of the motor rotor in the dynamics model as input signals, processes the output motor control signal through the controller, drives the converter to adjust the motor speed and output drive torque, and the dynamics model calculates the dynamic response characteristics of the dynamics model based on the motor drive torque and its own load torque. Based on the electromechanical coupling model, the resonance characteristics of the electromechanical system are analyzed to determine the resonance point: the modal analysis is performed on the dynamic model of the mechanical system to obtain the natural modal frequency information of the transmission components, the stator current and output torque harmonic characteristics in the control algorithm are analyzed to obtain the harmonic current and harmonic torque frequency distribution characteristics, the mechanical modal frequency characteristics are compared and analyzed with the harmonic torque characteristics, the distribution range of the electromechanical system coupling vibration frequency is determined, and then the resonance point is obtained; A coupled vibration suppression algorithm is designed for the resonance point. The resonance source of the electromechanical system is the harmonic torque of the motor. For this, a coupled vibration state observer of the electromechanical system is designed to observe the harmonic torque and speed fluctuation within a specific frequency range, and output a suppression signal to reduce the amplitude of the harmonic torque near the resonance frequency, thereby reducing the impact of the specific harmonic torque on the vibration of the mechanical system. The electromechanical system coupled vibration state observer is an extended state observer ESO with a QRC controller added, and the state space equation is: ， Where z1 is the mechanical angular velocity estimate, z2 is the concentrated disturbance estimate, b 0= 1 / J 0, J 0 is the nominal value of inertia, x 1= ω m , ω m is the mechanical angular velocity, u = i s , i s is the stator current, β1 and β2 are the gains of the estimation loop, G QRC It is the representation of QRC, as follows: ， In the formula, ω c is the cutoff frequency of the QRC controller, ω r is the resonant frequency of the controlled object, K r is the gain coefficient of the QRC controller.

5. The electromechanical coupling resonance suppression method according to claim 4, characterized in that: The process of constructing the dynamic model of the mechanical system includes: determining the components of the mechanical system, modeling the transmission components involved in the transmission as flexible bodies to reflect their inherent mechanical modal characteristics and characteristic frequencies, treating the remaining components as rigid bodies to establish a finite element model of the mechanical system, discretizing the finite element model, and then using a substructure modal reduction method to reduce the degrees of freedom of the finite element model to make it a flexible body, so as to ensure that each component can transmit high-frequency vibrations; The control algorithm model construction process of the control system includes: determining the mathematical model of the control object in the control system including the mathematical model of the permanent magnet motor and the converter, designing a motor controller according to the mathematical model, and the motor controller includes an ADRC speed loop controller, a dq axis current PI controller and a PWM modulation algorithm.

6. The electromechanical coupling resonance suppression method according to claim 4, characterized in that: When the electromechanical equipment is a permanent magnet direct-drive train, the construction of the dynamic model of the mechanical system includes first constructing a whole vehicle dynamic model, and then constructing a direct-drive bogie dynamic model. The construction of the control algorithm model of the control system includes constructing a permanent magnet direct-drive motor full-speed domain control algorithm model. The construction of the electromechanical coupling model includes taking the electromagnetic torque and the rotor speed as the key parameters of the electromechanical coupling of the permanent magnet direct-drive system, and building an electromechanical coupling dynamics numerical simulation platform based on the joint simulation of the dynamic model and the control algorithm model. On this basis, the modal analysis of the whole vehicle electromechanical system is carried out, and the electromechanical coupling resonance characteristics and the corresponding coupling vibration suppression algorithm are studied.

7. The electromechanical coupling resonance suppression method according to claim 6, characterized in that: The mechanical system includes: a car body, a bogie frame, a permanent magnet direct drive traction system, an internal axle box and a wheelset. Except for the permanent magnet direct drive traction system, the other components can be regarded as rigid bodies. Each wheelset is driven by a permanent magnet direct drive traction system, and each permanent magnet direct drive traction system is composed of a permanent magnet direct drive traction motor, a flexible plate hollow shaft coupling and a motor hanger.

8. The electromechanical coupling resonance suppression method according to claim 6, characterized in that: The electromechanical coupling principle of the electromechanical coupling dynamic numerical simulation platform is as follows: the electromechanical coupling dynamic numerical simulation platform calculates the real-time speed of the motor rotor according to the traction torque and load torque in the dynamic model, and inputs the calculation into the control algorithm model; the control algorithm model adjusts the electromagnetic torque output by the motor according to the difference between the actual speed and the reference speed, so as to realize the operation control of the train; wherein, the linkage parameters in the dynamic model will affect the speed of the motor rotor, and the speed as the input of the traction motor control system will further affect the electromagnetic torque output by the motor, and the electromagnetic torque and the harmonic torque therein will affect the dynamic response of the mechanical structure of the train, thereby realizing the coupling between the mechanical system and the control system, and the linkage parameters include track spectrum, suspension elements, and structural elastic vibration.

9. An electromechanical coupling resonance suppression motor drive system, characterized in that: An electromechanical coupling resonance suppression controller as described in any one of claims 1 to 3 is used, wherein the controller is arranged in a control system, and the control system is connected to a mechanical system.

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