A traction control method applicable to multiple unit trains

Abstract

The present invention belongs to the technical field of traction control for EMUs, and relates to a traction control method applicable to EMU trains. In the speed mode, there are two traction characteristic curves for controlling the target speed in the train control system. The traction characteristic curve a applicable to the case of good normal wheel-rail adhesion includes a low-speed section and a constant power section. The traction characteristic curve b applicable to the case of low wheel-rail adhesion coefficient includes a low-speed section, a constant traction force section, and a constant power section, and it is set according to the traction characteristic curve a. When the train is running, the wheel-rail adhesion coefficient is initially determined according to the current train operation environment. If the train operation environment belongs to the case of low wheel-rail adhesion coefficient, the train is controlled according to the traction characteristic curve b. If the train operation environment is normal, the train is controlled according to the traction characteristic curve a. This control method can not only ensure the running time of the train, but also give full play to the acceleration performance of the train under the condition of good wheel-rail adhesion.

Description

Technical Field

[0001] The present invention belongs to the technical field of traction control of EMUs, and particularly relates to a traction control method applicable to EMU trains. Background Art

[0002] In order to meet the requirements of shortening the departure interval and increasing the departure density, the existing intercity and suburban EMUs in China are characterized by rapid start and rapid stop. The requirement of rapid start results in a greater acceleration when the train runs at the maximum traction force than that of the existing EMUs, and correspondingly, a greater wheel-rail adhesion coefficient is required than that of the existing EMUs. However, the wheel-rail adhesion coefficient is relatively low under the following circumstances.

[0003] (1) Newly built track lines or severely rusted tracks;

[0004] (2) The track line has no vehicle operation for a long time;

[0005] (3) Rain, snow or other weather conditions cause the wheel-rail interface to be slippery;

[0006] (4) Other situations (such as fallen leaves, etc.).

[0007] The existing train operation has a grade mode and a speed mode. The grade mode adjusts the traction force by the traction handle for the purpose of controlling the traction force. The speed mode adjusts the target speed by the traction handle for the purpose of controlling the train speed.

[0008] Since the train signal system aims to control the maximum speed of the train, the speed mode is easier to control the running speed of the train. Therefore, when the EMU runs, the driver is used to operating in the speed mode. In the speed mode, when the current speed is much lower than the target speed, in order to make the train reach the target speed as soon as possible, there will be a situation where the train starts or runs at the maximum traction force. However, when the wheel-rail adhesion coefficient is relatively low, the train is prone to wheel spin. At this time, the train will adopt a wheel spin suppression strategy and automatic sanding to suppress the wheel spin phenomenon. When the driver finds that the train spins frequently, he usually actively reduces the speed to suppress the wheel spin, but this will affect the running time of the train. Summary of the Invention

[0009] Aiming at the above defects of the prior art, the purpose of the present invention is to provide a traction control method applicable to EMU trains. This method has two traction characteristic curves for controlling the target speed in the speed mode. One traction characteristic curve is applicable to the case of good normal wheel-rail adhesion, and the other is applicable to the case of low wheel-rail adhesion coefficient. This control method can effectively solve the technical problem that the train is prone to wheel spin when the wheel-rail adhesion coefficient is relatively low in the existing speed mode. It can not only ensure the running time of the train, but also give full play to the acceleration performance of the train when the wheel-rail adhesion is good.

[0010] To achieve the above object, the present invention adopts the following technical solutions:

[0011] A traction control method applicable to EMU trains, the method comprising the following steps:

[0012] Step S1, in the existing train operation speed mode, there are two traction characteristic curves for controlling the target speed in the train control system. One traction characteristic curve is applicable to the case of good normal wheel-rail adhesion, and the other traction characteristic curve is applicable to the case of low wheel-rail adhesion coefficient; wherein, the traction characteristic curve a applicable to the case of good normal wheel-rail adhesion includes a low-speed section and a constant power section, and the relationship between the train traction force F and the running speed v is as follows:

[0013]

[0014] In the formula, the part where v ≤ v E is the low-speed section of the traction characteristic curve a of the EMU under the speed mode, and v E < v < v max is the constant power section of the traction characteristic curve a under the speed mode; F max is the maximum traction force of the EMU under the traction condition speed mode, k is the slope of the traction characteristic curve a in the low-speed section, v E is the speed corresponding to the demarcation point between the low-speed section and the constant power section on the traction characteristic curve a of the EMU under the speed mode, v max is the maximum running speed of the EMU, P is the constant power in the constant power section, and the traction force when v = v E is F E , and the product of F E and v E is equal to P;

[0015] Set the traction characteristic curve b applicable to the case of low wheel-rail adhesion coefficient according to the traction characteristic curve of formula (a). The traction characteristic curve b includes a low-speed section, a constant traction force section and a constant power section. The relationship between the EMU traction force F' and the running speed v is as follows:

[0016]

[0017] In the formula, the part where v ≤ v E is the low-speed section of the traction characteristic curve b of the EMU under the speed mode, and v E < v < v' E is the constant traction force section, and v' E < v < v max is the constant power section; K' is controlled between 0.6 - 0.8, and F’ E is the traction force when the speed is v E under the condition of low wheel-rail adhesion coefficient, and v'E For the constant traction force F' of the EMU under the condition of low wheel-rail adhesion coefficient E The speed when the acceleration power reaches P;

[0018] Step S2: When the train is stationary or the controller is returned to zero, the train driver sets the target speed and preliminarily determines the wheel-rail adhesion coefficient according to the current train operation environment. If the train operation environment belongs to the situation of low wheel-rail adhesion coefficient, select the control mode corresponding to the traction characteristic curve b through the HMI traction interface at the main control end, and then send the start of the traction characteristic curve b control mode to the traction control unit through the train control system; if the train operation environment is normal, the HMI at the main control end sends the start of the traction characteristic curve a control mode to the traction control unit through the train control system;

[0019] Step S3: The traction control unit executes the corresponding traction characteristic curve according to the train control system;

[0020] Step S4: The traction motor outputs the traction force according to the requirements of the traction control unit.

[0021] As a preference of the present invention, the operation mode of the EMU train during operation further includes a grade mode. The driver switches between the grade mode and the speed mode through the human-machine interaction device. When the driver executes the traction characteristic curve a or the traction characteristic curve b in the speed mode, after the operation mode is switched from the speed mode to the grade mode and then switched back to the speed mode, the EMU still controls the train according to the original traction characteristic curve.

[0022] As a preference of the present invention, when the train is initially powered on, the train is defaultly controlled to run according to the traction characteristic curve a in the speed mode.

[0023] As a preference of the present invention, K' is 0.75.

[0024] As a preference of the present invention, K is controlled within 0 - 0.3, and the speed in the low-speed section of the traction characteristic curve a is 0 - 64 km / h.

[0025] As a preference of the present invention, after the train driver selects the control mode through the human-machine interaction interface at the main control end, the human-machine interaction interface will prompt the driver in green text about the current mode of the EMU.

[0026] As a preference of the present invention, the situations of low wheel-rail adhesion coefficient include: rainy and snowy weather, track lines with long-term lack of vehicle operation, newly built track lines, rusty tracks, and tracks with fallen leaves.

[0027] The advantages and beneficial effects of the present invention are as follows:

[0028] (1) The control method provided by the present invention has two traction characteristic curves for controlling the target speed in the speed mode. One traction characteristic curve is applicable to the case of good normal wheel-rail adhesion, and the other is applicable to the case of low wheel-rail adhesion coefficient. This control method can effectively solve the technical problem that the train is prone to wheel spin in the case of low wheel-rail adhesion coefficient in the existing speed mode. It can not only ensure the running time of the train, but also give full play to the acceleration performance of the train when the wheel-rail adhesion is good.

[0029] (2) When the situation of poor wheel-rail adhesion (such as rain, snow weather, etc.) occurs, the driver can still use the speed mode for automatic control, avoiding manual speed reduction by the driver, improving the train operation efficiency, and ensuring the running time of the train.

[0030] (3) The parameter settings of the traction characteristic curve b provided by the present invention are designed based on the traction characteristic curve a in the speed mode. It is easy to implement in engineering and can ensure the original maximum operating speed of the train.

[0031] (4) The traction characteristic curve b provided by the present invention is provided with a constant traction force section. The constant traction force section can ensure the smooth operation of the vehicle, and at the same time can ensure that the adhesion traction force is within the control range, ensuring the acceleration performance of the train.

[0032] (5) The present invention conducts simulation tests on two control modes, namely the normal speed mode and the rain and snow mode, under the same line and speed limit conditions. The rain and snow mode can reduce the number of wheel spin and skid by more than 80%. The running time of each station is only 10s - 20s more than that of the normal speed mode. Compared with the scheduled time of the user, there is still a margin of 1 - 3 minutes (different for each interval station); in addition, the present invention has carried out a trial operation with passengers on the main line in rainy days, and the wheel spin phenomenon has been effectively improved, and the running time has been fully guaranteed. Brief Description of the Drawings

[0033] Figure 1 is the flowchart of the traction control method applicable to EMU trains of the present invention;

[0034] Figure 2 is the schematic diagram of the HMI traction interface;

[0035] Figure 3 is the schematic diagram of the HMI rain and snow mode interface;

[0036] Figure 4 is the schematic diagram of the HMI operation interface;

[0037] Figure 5 is the schematic diagram of the traction characteristic curve of the present invention;

[0038] Figure 6Running time comparison between normal mode and rain / snow mode of Train C5811 (short station spacing) Figure 1 ;

[0039] Figure 7 Running time comparison between normal mode and rain / snow mode of Train C5811 (short station spacing) Figure 2 ;

[0040] Figure 8 Running time comparison between normal mode and rain / snow mode of Train C5811 (short station spacing) Figure 3 ;

[0041] Figure 9 Running time comparison between normal mode and rain / snow mode of Train C5811 (short station spacing) Figure 4 ;

[0042] Figure 10 Running time comparison between normal mode and rain / snow mode of Train C5817 (long station spacing) Figure 1 ;

[0043] Figure 11 Running time comparison between normal mode and rain / snow mode of Train C5817 (long station spacing) Figure 2 。 Detailed implementation manners

[0044] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. The present invention will be further described in detail below with reference to the specific implementation manners.

[0045] As Figure 1 shown, a traction control method applicable to EMU trains provided by the present invention includes the following steps:

[0046] Step S1, in the speed mode of the existing train operation, there are two traction characteristic curves for controlling the target speed in the train control system. One traction characteristic curve is applicable to the case of good normal wheel-rail adhesion, and the other traction characteristic curve is applicable to the case of low wheel-rail adhesion coefficient; among them, the traction characteristic curve a applicable to the case of good normal wheel-rail adhesion includes a low-speed section and a constant power section, and the relationship between the train traction force F and the running speed v is as follows:

[0047]

[0048] In the formula, v ≤ v EThe part where E < v < max is the low-speed section of the traction characteristic curve a of the multiple unit in speed mode; F E < v < max The part where max < v < E is the constant power section of the traction characteristic curve a in speed mode; F max is the maximum traction force of the multiple unit in traction mode of speed mode, k is the slope of the traction characteristic curve a in the low-speed section, controlled within 0 - 0.3, v E is the speed corresponding to the demarcation point between the low-speed section and the constant power section on the traction characteristic curve a of the multiple unit in speed mode, v max is the maximum operating speed of the multiple unit, P is the constant power in the constant power section, and the traction force when v = v E is F E F E multiplied by v E equals P;

[0049] Set the traction characteristic curve b applicable to the case of low wheel-rail adhesion coefficient according to the traction characteristic curve of formula (a). The traction characteristic curve b includes a low-speed section, a constant traction force section, and a constant power section. The relationship between the traction force F' of the multiple unit and the operating speed v is as follows:

[0050]

[0051] wherein, when v ≤ v E the part is the low-speed section of the traction characteristic curve b of the multiple unit in speed mode, v E < v < v' E the part is the constant traction force section, v' E < v < v max the part is the constant power section; K' is controlled within 0.6 - 0.8, F' E is the traction force when the speed is v E in the case of low wheel-rail adhesion coefficient, v' E is the speed when the multiple unit reaches the constant traction force F' E in the case of low wheel-rail adhesion coefficient and accelerates to reach the power P;

[0052] Step S2, when the train is stationary or the controller is returned to zero, the train driver sets the target speed, and initially determines the wheel-rail adhesion coefficient according to the current train operation environment. If the train operation environment belongs to the case of low wheel-rail adhesion coefficient, select the control mode corresponding to the traction characteristic curve b through the HMI traction interface at the master control end, and then send the start of the traction characteristic curve b control mode to the traction control unit through the train control system; if the train operation environment is normal, the HMI at the master control end sends the start of the traction characteristic curve a control mode to the traction control unit through the train control system;

[0053] Situations with a relatively low wheel-rail adhesion coefficient include: rainy or snowy weather, track lines without vehicle operation for a long time, newly built track lines, rusty tracks, and tracks with fallen leaves;

[0054] Step S3: The traction control unit executes the corresponding traction characteristic curve according to the train control system;

[0055] Step S4: The traction motor outputs traction force according to the requirements of the traction control unit.

[0056] To verify the advantages of the control method of the present invention, the following takes C5811 (short station spacing) and C5817 (long station spacing) as examples for simulation experiments. The simulation experiments are to distinguish the situation of good normal wheel-rail adhesion and the situation of relatively low wheel-rail adhesion coefficient. The situation of good normal wheel-rail adhesion is simply referred to as the "normal speed mode", and the situation of relatively low wheel-rail adhesion coefficient is simply referred to as the "rain and snow mode". Table 1 shows the control requirements for the normal speed mode and the rain and snow mode under the speed mode.

[0057] Table 1 Control requirement table for the normal speed mode and the rain and snow mode under the speed mode

[0058]

[0059] The specific control method is as follows:

[0060] 1) When the train is initially powered on, the default is the normal "speed mode" (that is, by default, the train operation is controlled according to the traction characteristic curve a under the speed mode, and the starting traction force is not restricted). In sunny days or when the wheel-rail adhesion is good, the driver can directly operate the controller to start the train without any selection. The train reaches the speed setting target within a short time according to the control requirements of the traction characteristic curve a ( Figure 5 the normal control curve shown). In the low-speed section (0 - 64 km / h), the traction force can reach up to 100% of the maximum capacity (167.5 KN), and the maximum adhesion coefficient required for traction can reach 0.16. When the speed is 64 km / h, the traction force is 153.5 KN;

[0061] 2) Under conditions of relatively low adhesion coefficient such as rainy or snowy weather, on the premise that the train is stationary or the controller is reset to zero, the driver clicks the "rain and snow mode" menu and then clicks "start rain and snow mode" through the traction interface of the left side of the master control end of the HMI to make the train enter the "rain and snow mode" (the starting traction force is restricted under the speed mode), and the driver is prompted in the upper right corner of the "traction interface" and the "operation interface" of the HMI in the form of green text "rain and snow mode" to indicate the current mode of the train (such as Figures 2 to 4 shown);

[0062] 3) When the train control system determines that it enters the rain and snow mode under the speed mode, the train control system selects the traction characteristic curve b ( Figure 5The traction force limit in the low-speed section (0 - 64 km / h) is restricted to 75% (125.6 KN) of the maximum value of the normal control curve (the shown rain and snow mode control curve), and after accelerating to 64 km / h, the traction force (115.1 KN) remains unchanged. After accelerating to 85 km / h and reaching the constant power area, it is controlled according to the constant power area curve, reducing the adhesion coefficient required for traction to 0.12.

[0063] 4) The train control system sends control requirements to the traction control unit through the network communication protocol, and the traction control unit controls the traction motor to execute the corresponding traction force.

[0064] Under the premise that the controller is reset to zero, the driver can click the "Rain and Snow Mode" menu and then click "Stop Rain and Snow Mode" on the traction interface of the main HMI (default left screen) at the master control end to exit the rain and snow mode, and the "Rain and Snow Mode" display on the HMI disappears.

[0065] The results of the simulation experiment are shown in Figures 6 to 11 , and it can be seen from the simulation results that for the two control modes of the normal speed mode and the rain and snow mode, under the same line and speed limit conditions, the rain and snow mode can reduce the number of wheel spin and skid by more than 80%. The running time per station is only 10 s - 20 s more than that of the normal speed mode. Compared with the scheduled time of the user, there is still a margin of 1 - 3 minutes (different for each section station); and the acceleration performance of the train can be fully exerted under the condition of good wheel-rail adhesion in the normal speed mode, and the acceleration performance of the train can also be guaranteed in the rain and snow mode.

[0066] In addition, the present invention also carried out a trial run with passengers on the main line in rainy days. After determining to adopt the control method of the present invention, the wheel spin phenomenon of the train was effectively improved, and the running time was fully guaranteed.

[0067] Since the weather conditions generally last for a period of time, considering that there may be speed / grade mode switching conditions during operation; in order to reduce the driver's operation, the "rain and snow mode" is not automatically exited when switching between the "speed mode" and the "grade mode", the "grade mode" does not limit the exertion of the traction force, and when switching back to the "speed mode", there is no need to re-operate to enter the "rain and snow mode".

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, rather than to limit them; although the embodiments of the present invention have been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the embodiments of the present invention.

Claims

1. A traction control method applicable to EMU trains, characterized in that, The method comprises the following steps: Step S1. There are two traction characteristic curves for controlling the target speed in the train control system under the existing train operation speed mode. One traction characteristic curve is applicable to the case of good normal wheel-rail adhesion, and the other traction characteristic curve is applicable to the case of a low wheel-rail adhesion coefficient. Among them, the traction characteristic curve a applicable to the case of good normal wheel-rail adhesion includes a low-speed section and a constant power section. The relationship between the train traction force F and the running speed v is as follows: wherein, v ≤ v E is the low-speed section of the traction characteristic curve a of the EMU in the speed mode, v E < v < v max is the constant power section of the traction characteristic curve a in the speed mode; F max is the maximum traction force of the EMU in the speed mode, k is the slope of the traction characteristic curve a in the low-speed section, v E is the speed corresponding to the demarcation point between the low-speed section and the constant power section of the traction characteristic curve a of the EMU in the speed mode, v max is the maximum operating speed of the EMU, P is the constant power in the constant power section, and the traction force when v = v E is F E , F E multiplied by v E is equal to P; Set the traction characteristic curve b applicable to the case of a low wheel-rail adhesion coefficient according to the traction characteristic curve of formula (a). The traction characteristic curve b includes a low-speed section, a constant traction force section and a constant power section. The relationship between the traction force F' of the motor car and the running speed v is as follows: where \(v\leq v\) E The part of the traction characteristic curve \(b\) of the EMU in the speed mode at low speed, \(v\) E \(<v<v'\) E The part is the constant traction section, \(v'\) E \(<v<v\) max The part is the constant power section; \(K'\) is controlled at \(0.6 - 0.8\), \(F'\) E Is the traction force at a speed of \(v\) when the wheel-rail adhesion coefficient is low E When, \(v'\) E Is the constant traction force \(F'\) of the EMU when the wheel-rail adhesion coefficient is low E The speed when the acceleration power reaches \(P\); Step S2. When the train is stationary or the controller is reset to zero, the train driver sets the target speed, and preliminarily determines the wheel-rail adhesion coefficient according to the current train operation environment. If the train operation environment belongs to the case of a low wheel-rail adhesion coefficient, select the control mode corresponding to the traction characteristic curve b through the HMI traction interface at the master control end, and then send the start traction characteristic curve b control mode to the traction control unit through the train control system; if the train operation environment is normal, the HMI at the master control end sends the start traction characteristic curve a control mode to the traction control unit through the train control system; Step S3. The traction control unit executes the corresponding traction characteristic curve according to the train control system; Step S4. The traction motor outputs the traction force according to the requirements of the traction control unit.

2. The traction control method for EMU trains according to claim 1, characterized in that The operation mode during the operation of the motor car train also includes a gear position mode. The driver switches the gear position mode and the speed mode through the man-machine interaction device. When the driver executes the traction characteristic curve a or the traction characteristic curve b in the speed mode, after the operation mode is switched from the speed mode to the gear position mode and then switched back to the speed mode, the motor car train still controls the train according to the original traction characteristic curve.

3. A traction control method applicable to EMU trains according to claim 1 or 2, characterized in that, When the train is initially powered on, the train is default controlled to run according to the traction characteristic curve a in the speed mode.

4. A traction control method applicable to EMU trains according to claim 1 or 2, characterized in that K' is 0.

75.

5. A traction control method applicable to EMU trains according to claim 1 or 2, characterized in that, K is controlled within 0 - 0.3, and the speed of the low-speed section of the traction characteristic curve a is 0 - 64 km / h.

6. A traction control method applicable to EMU trains according to claim 1 or 2, characterized in that After the train driver selects the control mode through the man-machine interaction interface at the master control end, the man-machine interaction interface will prompt the driver of the current mode of the motor car train in green text.

7. A traction control method applicable to EMU trains according to claim 1 or 2, characterized in that The cases of a low wheel-rail adhesion coefficient include: rainy or snowy weather, track lines with no vehicle operation for a long time, newly built track lines, rusty tracks, and tracks with fallen leaves.

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