Train permanent magnet synchronous traction system control method based on fixed time cooperation theory

Abstract

The invention relates to the technical field of rail train control, in particular to a train permanent magnet synchronous traction system control method based on a fixed time cooperation theory, which comprises the following steps: establishing a train permanent magnet synchronous traction system coupling model; defining a dynamic evolution law of a fixed time cooperation theory and a permanent magnet synchronous traction system control law; establishing permanent magnet synchronous traction system speed and current loop error variables; searching an optimal slip speed and calculating a wheel speed reference value; establishing an error macroscopic variable, and predicting the maximum convergence time of the system; by means of the mode, train operation control, wheel rail adhesion control and permanent magnet synchronous traction motor control are considered at the same time in the train permanent magnet synchronous traction system, and the cooperative performance in the power unit is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of rail train control, and in particular to a control method for a train permanent magnet synchronous traction system based on fixed time coordination theory. Background Art

[0002] Rail transit has developed rapidly in recent decades and has become one of the most popular modes of travel. The train traction system is a key part of measuring train performance. In recent years, permanent magnet synchronous traction motors have gradually replaced traditional induction asynchronous motors to improve the power density and efficiency of train traction systems. Therefore, studying the control method of permanent magnet synchronous traction systems is of great significance to the development of rail transit.

[0003] At present, most of the control methods of permanent magnet synchronous traction systems of trains only focus on one aspect of permanent magnet synchronous motor control, train operation control or wheel-rail adhesion control, and ignore the coordinated performance of multiple traction motors and drive wheels in the power unit. Some methods focus on the speed synchronization control of traction motors, but ignore the interaction between motors, wheels, rails and trains. Other methods emphasize the operation control and adhesion dynamics of trains, but omit the implementation of speed and torque commands on the motor side.

[0004] In summary, it is very necessary to propose a control method for a train permanent magnet synchronous traction system that simultaneously considers train operation control, wheel-rail adhesion control and permanent magnet synchronous traction motor control, and ensures the synergy performance within the power unit. Summary of the invention

[0005] The purpose of the present invention is to provide a control method for a train permanent magnet synchronous traction system based on fixed-time coordination theory, aiming to simultaneously consider train operation control, wheel-rail adhesion control and permanent magnet synchronous traction motor control in the train permanent magnet synchronous traction system, and ensure the coordination performance within the power unit.

[0006] To achieve the above object, the present invention adopts a train permanent magnet synchronous traction system control method based on fixed time coordination theory, comprising the following steps:

[0007] Establish the coupling model of permanent magnet synchronous traction system of train;

[0008] Define the dynamic evolution law of fixed-time coordination theory and the control law of permanent magnet synchronous traction system;

[0009] Establish speed and current loop error variables of permanent magnet synchronous traction system;

[0010] Searching for the optimum slip speed and calculating a wheel speed reference value;

[0011] Establish error macro variables and estimate the maximum convergence time of the system.

[0012] Among them, in the steps of establishing the coupling model of the train permanent magnet synchronous traction system:

[0013] The matrix form of the coupling model of the train permanent magnet synchronous traction system is:

[0014]

[0015] Among them, the subscript ".i" represents the parameters and status of the i-th drive axis, x = [v w ,i d ,i q ] T represents the state variable; u=[T m ,u d ,u q ] T Indicates the control amount; d = [-T L / J eq ,0,0] T represents the system disturbance;

[0016]

[0017] v w Indicates the train wheel speed; i d and i q Respectively represent the d and q axis currents of the motor; T m Indicates the electromagnetic torque output by the motor; u d and u q Respectively represent the d and q axis voltages of the motor; T L =RF μ / (η g i g ) represents the equivalent load on the motor side; J eq =J m i g / R+J w / (η g i g R) represents the equivalent moment of inertia of the motor side; B m and J m Respectively represent the viscous damping coefficient and moment of inertia of the motor; ω m Represents the mechanical angular velocity of the motor; R s Indicates the stator resistance of the motor; P n Indicates the number of pole pairs of the motor; L d and L q Respectively represent the d-axis and q-axis inductance of the motor; φ f represents the permanent magnet flux of the motor; R represents the radius of the train wheel; F μ Indicates the train traction; η g and i gRespectively represent the transmission efficiency and transmission ratio of the gearbox; J w Represents the moment of inertia of the train wheels.

[0018] Among them, in the steps of defining the dynamic evolution law of the fixed-time synergy theory and the control law of the permanent magnet synchronous traction system:

[0019] The dynamic evolution law is:

[0020]

[0021] The control law is:

[0022]

[0023] T = diag[T1, T2, T3] is a positive definite diagonal matrix; ψ = [ψ1, ψ2, ψ3] T are macro variables; α2 and β2 are both positive constants; m2>n2>0 and q2>p2>0 are odd integers; is the partial derivative of the macro variable with respect to the state variable.

[0024] Among them, in the step of establishing the speed and current loop error variables of the permanent magnet synchronous traction system:

[0025] The error variable is e .i =[e v.i ,e d.i ,e q.i ] T :

[0026]

[0027] The subscript ".i" indicates the parameters and status of the i-th drive axis. v 、e d and e q They are wheel speed error, motor d-axis current error and motor q-axis current error respectively; e t and e s Respectively represent wheel speed tracking and synchronization errors; k t and k s denote wheel speed tracking and synchronization coefficients respectively; and Respectively represent the motor d and q axis reference current; N M =4 indicates the number of traction motors in a single motor car; Indicates the reference speed of the train wheels.

[0028] Wherein, in the step of searching for the optimal slip speed and calculating the wheel speed reference value:

[0029] The optimal slip speed search method is to determine dμ / dvs Symbols:

[0030]

[0031] Among them, v s and Represent the slip velocity and slip velocity reference respectively; c s represents the slip velocity search step; μ represents the wheel-rail adhesion coefficient;

[0032] The wheel speed reference value is expressed as:

[0033]

[0034] Among them, v t Indicates the speed of the train body.

[0035] Among them, in the step of establishing error macro variables and estimating the maximum convergence time of the system:

[0036] The macro variables are:

[0037]

[0038] Among them, σ, α1 and β1 are all positive constants; m1>n1>0 and q1>p1>0 are odd integers;

[0039] The maximum convergence time of the permanent magnet synchronous traction system can be expressed as:

[0040]

[0041] in, ρ=(p1+q1) / (2q1), β1′=2 ρ β1 / σ, γ=(m2+n2) / (2n2), λ=(p2+q2) / (2q2), α′ 2j =2 γ α1 / T j , β′ 2j =2 λ β2 / T j , j=1,2,3.

[0042] The present invention discloses a control method for a train permanent magnet synchronous traction system based on the fixed time coordination theory, which establishes a coupling model of the train permanent magnet synchronous traction system; defines the dynamic evolution law of the fixed time coordination theory and the control law of the permanent magnet synchronous traction system; establishes speed and current loop error variables of the permanent magnet synchronous traction system; searches for the optimal slip speed and calculates the wheel speed reference value; establishes error macro variables and estimates the maximum convergence time of the system; and realizes simultaneous consideration of train operation control, wheel-rail adhesion control and permanent magnet synchronous traction motor control in the train permanent magnet synchronous traction system, and ensures the coordination performance within the power unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a flow chart of the steps of the train permanent magnet synchronous traction system control method based on the fixed time coordination theory of the present invention.

[0045] Figure 2 It is a schematic diagram of the principle of the train permanent magnet synchronous traction system control method based on the fixed time coordination theory of the present invention.

[0046] Figure 3 It is a schematic diagram of force analysis of the permanent magnet synchronous motor and the inter-wheel transmission system of the present invention.

[0047] Figure 4 Schematic diagram of the wheel-rail adhesion characteristic curve used in this embodiment of the present invention.

[0048] Figure 5 It is a schematic diagram of train body speed and wheel speed curves of the permanent magnet synchronous traction control system of the present invention.

[0049] Figure 6 It is a schematic diagram of wheel speed tracking error and synchronization error curve of the permanent magnet synchronous traction control system of the present invention.

[0050] Figure 7 It is a schematic diagram of the optimal slip speed of the current line and the slip speed curve of the permanent magnet synchronous traction control system of the present invention.

[0051] Figure 8 It is a schematic diagram of equivalent load torque and output electromagnetic torque curves of the permanent magnet synchronous traction motor of the present invention. DETAILED DESCRIPTION

[0052] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0053] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0054] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0055] See also Figure 1 to Figure 3 The present invention provides a train permanent magnet synchronous traction system control method based on fixed time coordination theory, comprising the following steps:

[0056] S100: Establish a coupling model of the train permanent magnet synchronous traction system.

[0057] Furthermore, in the step of establishing the coupling model of the train permanent magnet synchronous traction system:

[0058] The matrix form of the coupling model of the train permanent magnet synchronous traction system is:

[0059]

[0060] Among them, the subscript ".i" represents the parameters and status of the i-th drive axis, x = [v w ,i d ,i q ] T represents the state variable; u=[T m ,u d ,u q ] T Indicates the control amount; d = [-T L / J eq ,0,0] T represents the system disturbance;

[0061]

[0062] v w Indicates the train wheel speed; i d and i q Respectively represent the d and q axis currents of the motor; T m Indicates the electromagnetic torque output by the motor; u d and u q Respectively represent the d and q axis voltages of the motor; T L =RF μ / (η g i g ) represents the equivalent load on the motor side; J eq =J m i g / R+J w / (η g i g R) represents the equivalent moment of inertia of the motor side; B m and J m Respectively represent the viscous damping coefficient and moment of inertia of the motor; ω m Represents the mechanical angular velocity of the motor; R s Indicates the stator resistance of the motor; P n Indicates the number of pole pairs of the motor; L d and L q Respectively represent the d-axis and q-axis inductance of the motor; φ f represents the permanent magnet flux of the motor; R represents the radius of the train wheel; F μ Indicates the train traction; η g and i g Respectively represent the transmission efficiency and transmission ratio of the gearbox; J w Represents the moment of inertia of the train wheels.

[0063] In this embodiment, the wheel-rail adhesion relationship is:

[0064]

[0065] Among them, v w =Rω w represents the linear speed of the train wheels; R represents the radius of the train wheels; ω w represents the angular velocity of the train wheels; v t represents the train body speed; μ represents the wheel-rail adhesion coefficient; F μ represents the train traction; W represents the axle weight; g represents the acceleration of gravity; a1, a2, a3 and a4 are all Polach model parameters.

[0066] The single-axle dynamic model of the train is:

[0067]

[0068] Where M represents the mass of the carriage; N M =4 indicates the number of motors in the car; J m and J w Respectively represent the rotational inertia of the motor and the drive shaft; T wm It represents the torque applied by the drive shaft to the motor shaft through the gearbox; T mw Represents the torque applied by the motor shaft to the drive shaft through the gearbox; i g =r g2 / r g1 and η g Respectively represent the gear ratio and transmission efficiency; r g1 and r g2 Respectively represent the radius of the driving gear and the driven gear; B m =0 and B w =0 represents the viscous damping coefficient of the motor and the drive shaft respectively; T m Represents the electromagnetic torque output by the motor; ω m and ω w Represent the motor and wheel angular velocity respectively; F f It represents the basic running resistance of the train; b1, b2 and b3 are resistance coefficients.

[0069] The permanent magnet synchronous motor equation in the dq synchronous rotating coordinate system is:

[0070]

[0071] Among them, i d and i q Respectively represent the stator current of the motor d and q axes; u d and u q Respectively represent the stator voltage of the motor d and q axes; L d and L q Respectively represent the stator inductance of the motor d and q axes; R s Indicates the motor stator resistance; P n represents the number of pole pairs; φ f Represents the flux linkage of a permanent magnet.

[0072] Define x .i =[v w.i ,i d.i ,i q.i ] T ,u .i =[T m.i ,u d.i ,u q.i ] T .

[0073] The coupling model of the train permanent magnet synchronous traction system is:

[0074]

[0075] The subscript ".i" represents the parameters and status of the i-th drive axis.

[0076]

[0077] T L =RF μ / (η g i g );

[0078] J eq =J m i g / R+J w / (η g i g R).

[0079] S200: Define the dynamic evolution law of fixed-time coordination theory and the control law of permanent magnet synchronous traction system.

[0080] Furthermore, in the step of defining the dynamic evolution law of the fixed-time coordination theory and the control law of the permanent magnet synchronous traction system:

[0081] The dynamic evolution law is:

[0082]

[0083] The control law is:

[0084]

[0085] T = diag[T1, T2, T3] is a positive definite diagonal matrix; ψ = [ψ1, ψ2, ψ3] T are macro variables; α2 and β2 are both positive constants; m2>n2>0 and q2>p2>0 are odd integers; is the partial derivative of the macro variable with respect to the state variable.

[0086] In this embodiment, the macro variable ψ is defined to construct the invariant manifold as follows:

[0087] ψ=ψ(x,t)=0;

[0088] The fixed time theory is introduced to transform the dynamic evolution law of the original cooperative control theory into The improvements are as follows:

[0089]

[0090] Among them, the positive definite diagonal matrix T = diag[T1,T2,T3] is related to the convergence speed; ψ = [ψ1,ψ2,ψ3] T are the macro variables to be designed; α2 and β2 are both normal numbers; m2>n2>0 and q2>p2>0 are odd integers. The selection needs to satisfy the following relationship:

[0091]

[0092] Substituting in:

[0093]

[0094] Arranging the above formula, the control law of the permanent magnet synchronous traction system based on the fixed time theory can be obtained as follows:

[0095]

[0096] in, is the partial derivative of the macro variable with respect to the state variable.

[0097] S300: Establish speed and current loop error variables of the permanent magnet synchronous traction system.

[0098] Further, in the step of establishing the speed and current loop error variables of the permanent magnet synchronous traction system:

[0099] The error variable is e .i =[e v.i ,e d.i ,e q.i ] T :

[0100]

[0101] The subscript ".i" indicates the parameters and status of the i-th drive axis. v 、e d and e q They are wheel speed error, motor d-axis current error and motor q-axis current error respectively; e t and e s Respectively represent wheel speed tracking and synchronization errors; k t and k s denote wheel speed tracking and synchronization coefficients respectively; and Respectively represent the motor d and q axis reference current; N M =4 indicates the number of traction motors in a single motor car; Indicates the reference speed of the train wheels.

[0102] In this embodiment, the speed and current loop errors of the permanent magnet synchronous traction system are defined, the tracking error and synchronization error of each wheel are controlled to be small, and the current of each motor reaches a reference value, so that the corresponding electromagnetic torque can be output. .i =[e v.i ,e d.i ,e q.i ] T for:

[0103]

[0104] S400: Searching for an optimal slip speed and calculating a wheel speed reference value.

[0105] Further, in the step of searching for the optimal slip speed and calculating the wheel speed reference value:

[0106] The optimal slip speed search method is to determine dμ / dv s Symbols:

[0107]

[0108] Among them, v s and Represent the slip velocity and slip velocity reference respectively; c s represents the slip velocity search step; μ represents the wheel-rail adhesion coefficient;

[0109] The wheel speed reference value is expressed as:

[0110]

[0111] Among them, v t Indicates the speed of the train body.

[0112] In this embodiment, the optimal slip speed search method is based on dμ / dv s The sign of determines the slip velocity change trend:

[0113]

[0114] in, Indicates the slip speed reference; c s Indicates the sliding speed search step length;

[0115] The train wheel speed reference value is the average value of the sum of the slip speed reference and the train body speed, as follows:

[0116]

[0117] S500: Establish error macro variables and estimate the maximum convergence time of the system.

[0118] Furthermore, in the step of establishing the error macro variables and estimating the maximum convergence time of the system:

[0119] The macro variables are:

[0120]

[0121] Among them, σ, α1 and β1 are all positive constants; m1>n1>0 and q1>p1>0 are odd integers;

[0122] The maximum convergence time of the permanent magnet synchronous traction system can be expressed as:

[0123]

[0124] in, ρ=(p1+q1) / (2q1), β1′=2 ρ β1 / σ, γ=(m2+n2) / (2n2), λ=(p2+q2) / (2q2), α′ 2j =2 γ α1 / T j , β′ 2j =2 λ β2 / T j , j=1,2,3.

[0125] In this implementation, the macro variables based on the fixed time coordination theory are designed as follows:

[0126]

[0127] Among them, σ, α1 and β1 are all normal numbers; m1>n1>0 and q1>p1>0 are odd integers.

[0128] The Lyapunov function used in the Lyapunov theory is:

[0129]

[0130] Calculate the first derivative of the Lyapunov function as:

[0131]

[0132] The above formula can finally be deduced:

[0133]

[0134] in, ρ=(p1+q1) / (2q1), β1′=2 ρβ1 / σ, γ=(m2+n2) / (2n2), λ=(p2+q2) / (2q2), α′ 2j =2 γ α1 / T j , β′ 2j =2 λ β2 / T j , j=1,2,3.

[0135] According to the fixed time theory, we can get the time T that the system converges from any state to the invariant manifold ψ=0 max2 And the time T from the invariant manifold convergence to the error e = 0 max1 :

[0136]

[0137] The maximum convergence time of the permanent magnet synchronous traction system can be expressed as:

[0138]

[0139] Example:

[0140] The parameters of the four motors of the permanent magnet synchronous traction system are as follows: stator resistance R s =0.641Ω; d-axis inductance L d =1.29mH; q-axis inductance L q =2.41mH; permanent magnet flux φ f =0.659Wb; pole pair number P n =4; moment of inertia J m =6kg·m 2 .

[0141] The other parameters of the permanent magnet synchronous traction system are as follows: The radius of the first two wheels R .1 =R .2 =0.41m; radius of the rear two wheels R .3 =R .4 =0.42m; driving shaft moment of inertia J w =80kg·m 2 ; Number of motors in the moving carriage N M =4; carriage mass M = 51.06t; axle mass M = 13.5t; gear ratio i g =2.355; gear transmission efficiency η g =0.95; gravitational acceleration g = 9.8 m / s 2; The basic resistance parameters of train operation are b1=6.796, b2=0.062, b3=0.00143; The adhesion Polach model parameters when the line is dry are a1=0.25, a2=0.089, a3=0.25, a4=0.54; The adhesion Polach model parameters when the line is wet are a1=0.3, a2=0.1, a3=0.3, a4=1.2.

[0142] Based on the above permanent magnet synchronous traction system parameters, a hardware-in-the-loop semi-physical simulation experiment is carried out, and the controller parameters are set as follows: T1 = T2 = T3 = 0.1, k t =10, k s =20, σ=0.5, α1=1, β1=1, α2=2, β2=2, m1=7, n1=5, m2=5, n2=3, p1=3, q1=5, p2=1, q3=3.

[0143] Figure 4 The adhesion curve of the track used in this embodiment shows that the adhesion coefficient increases first and then decreases as the slip speed increases. The stable area on the left side of the dotted line is less than the maximum adhesion coefficient, and the unstable area on the right side indicates that the wheels are spinning or slipping. In addition, the maximum adhesion coefficient of the wet track is lower than that of the dry track. The carriage was originally running on the dry track, and the front wheels transitioned from the dry track to the wet track at 20 seconds and returned to the dry track at 50 seconds. The rear wheels were delayed by 0.5 seconds compared with the front wheels.

[0144] The control results of the permanent magnet synchronous traction system of the train based on the fixed time coordination theory are as follows: Figure 5 As shown. Figure 5 The linear speed of each wheel and the vehicle body speed are displayed. Obviously, the wheel speed is slightly higher than the train speed, and the difference is the slip speed. The control method of the present invention realizes anti-skid traction control and wheel speed tracking and synchronization control, and has excellent wheel speed error convergence performance. When the adhesion condition changes or high-speed cruising, the method of the present invention can gradually track the reference wheel speed without vibration.

[0145] Figure 6 The tracking error of each wheel and the synchronization error between wheels are shown. Since the reference wheel speed increases gradually rather than in a step-like manner, it is relatively easy to achieve wheel speed tracking during the train startup phase, resulting in smaller tracking and synchronization errors. When the adhesion condition changes between 20s and 50s, the maximum error value does not exceed 0.1m / s, and the maximum error value in the stable state is only 0.025m / s.

[0146] Figure 7 The slip speed of each wheel under different conditions and the reference slip speed are given, reflecting the adhesion utilization and traction efficiency of the system. Figure 4As shown in the figure, the actual adhesion working point change trend is shown by the arrow in the figure. Initially, on the dry track, the adhesion working point gradually moves from the origin to point A. At 20 seconds, the wheel transitions to the wet track, resulting in a sudden change from point A to point B, and then gradually moves from point B to point C. At 50 seconds, when the car returns to the dry track, a sudden change from point C to point D occurs, and then gradually moves from point D back to point A. Figure 7 The slip speed shown is consistent with the above changes, indicating that the multi-permanent magnet synchronous traction system effectively realizes the anti-slip function and ensures the maximum traction efficiency.

[0147]

[0148] The maximum convergence time T of the algorithm used in the present invention max The conservative estimate is 8.0343s. The actual convergence time used in the startup phase, the transition phase from dry rail to wet rail, and the transition phase from wet rail to dry rail is 1.82s, 1.76s, and 1.67s, respectively.

[0149] Figure 8 It is the load torque and output electromagnetic torque on the motor side, which is mainly used to reflect the mechanical output characteristics of the permanent magnet synchronous traction system. During the startup phase, the electromagnetic torque exceeds the load torque, resulting in a rapid increase in the train speed. At 20s, the car enters the low adhesion area, and the electromagnetic torque is controlled to decrease rapidly, thereby preventing the wheels from slipping. At 50s, when the car returns to the high adhesion area, the electromagnetic torque is quickly restored, allowing the traction process to continue until the maximum speed is reached. At about 100s, the electromagnetic torque and the load torque are almost equal, indicating that the train has entered and maintained a high-speed cruising state. The whole process shows that the method used in the present invention can achieve traction control of the train while ensuring the anti-skid performance and efficient traction of the train.

[0150] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the contents disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application.

[0151] It will be appreciated that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A train permanent magnet synchronous traction system control method based on fixed time coordination theory, characterized in that: The steps include: Establish the coupling model of permanent magnet synchronous traction system of train; Define the dynamic evolution law of fixed-time coordination theory and the control law of permanent magnet synchronous traction system; Establish speed and current loop error variables of permanent magnet synchronous traction system; Searching for the optimum slip speed and calculating a wheel speed reference value; Establish error macro variables and estimate the maximum convergence time of the system.

2. The train permanent magnet synchronous traction system control method based on fixed time coordination theory as claimed in claim 1 is characterized in that: In the steps of establishing the coupling model of the train permanent magnet synchronous traction system: The matrix form of the coupling model of the train permanent magnet synchronous traction system is: Among them, the subscript ".i" represents the parameters and status of the i-th drive axis, x = [v w ,i d ,i q ] T represents the state variable; u=[T m ,u d ,u q ] T Indicates the control amount; d = [-T L / J eq ,0,0] T represents the system disturbance; v w Indicates the train wheel speed; i d and i q Respectively represent the d and q axis currents of the motor; T m Indicates the electromagnetic torque output by the motor; u d and u q Respectively represent the d and q axis voltages of the motor; T L =RF μ / (η g i g ) represents the equivalent load on the motor side; J eq =J m i g / R+J w / (η g i g R) represents the equivalent moment of inertia of the motor side; B m and J m Respectively represent the viscous damping coefficient and moment of inertia of the motor; ω m Represents the mechanical angular velocity of the motor; R s Indicates the stator resistance of the motor; P n Indicates the number of pole pairs of the motor; L d and L q Respectively represent the d-axis and q-axis inductance of the motor; φ f represents the permanent magnet flux of the motor; R represents the radius of the train wheel; F μ Indicates the train traction; η g and i g Respectively represent the transmission efficiency and transmission ratio of the gearbox; J w Represents the moment of inertia of the train wheels.

3. The train permanent magnet synchronous traction system control method based on fixed time coordination theory as claimed in claim 1 is characterized in that: In the steps of defining the dynamic evolution law of the fixed-time coordination theory and the control law of the permanent magnet synchronous traction system: The dynamic evolution law is: The control law is: T = diag[T1, T2, T3] is a positive definite diagonal matrix; ψ = [ψ1, ψ2, ψ3] T are macro variables; α2 and β2 are both positive constants; m2>n2>0 and q2>p2>0 are odd integers; is the partial derivative of the macro variable with respect to the state variable.

4. The train permanent magnet synchronous traction system control method based on fixed time coordination theory as claimed in claim 1 is characterized in that: In the steps of establishing the speed and current loop error variables of the permanent magnet synchronous traction system: The error variable is e .i =[e v.i ,e d.i ,e q.i ] T : The subscript ".i" indicates the parameters and status of the i-th drive axis. v 、e d and e q They are wheel speed error, motor d-axis current error and motor q-axis current error respectively; e t and e s Respectively represent wheel speed tracking and synchronization errors; k t and k s denote wheel speed tracking and synchronization coefficients respectively; and Respectively represent the motor d and q axis reference current; N M =4 indicates the number of traction motors in a single motor car; Indicates the reference speed of the train wheels.

5. The train permanent magnet synchronous traction system control method based on fixed time coordination theory as claimed in claim 1, characterized in that: In the step of searching for the optimum slip speed and calculating the wheel speed reference value: The optimal slip speed search method is to determine dμ / dv s Symbols: Among them, v s and Respectively represent the slip velocity and slip velocity reference; c s represents the slip velocity search step; μ represents the wheel-rail adhesion coefficient; The wheel speed reference value is expressed as: Among them, v t Indicates the speed of the train body.

6. The train permanent magnet synchronous traction system control method based on fixed time coordination theory as claimed in claim 1 is characterized in that: In the step of establishing the error macro variables and estimating the maximum convergence time of the system: The macro variables are: Among them, σ, α1 and β1 are all positive constants; m1>n1>0 and q1>p1>0 are odd integers; The maximum convergence time of the permanent magnet synchronous traction system can be expressed as: Among them, p=(p1+q1) / (2q1)、 β1′=2 ρ β1 / σ、γ=(m2+n2) / (2n2)、λ=(p2+q2) / (2q2)、α′ 2j =2 γ α1 / T j 、b′ 2j =2 λ β2 / T j ,j=1,2,3.

Images