Heavy-load locomotive asynchronous control method and heavy-load combined train

Abstract

The invention provides an asynchronous control method for a heavy-load locomotive, which effectively reduces the longitudinal impulse by reducing the electric braking force retention time of a slave control locomotive, slowing down the acceleration of a rear vehicle, reducing the speed difference and reducing the maximum hook pressing force borne by a front slave control locomotive in consideration of typical line conditions and circulating braking working conditions. Compared with the prior art, the asynchronous control method for the heavy-load locomotive has the advantage that the longitudinal impulse of the train obtained by the asynchronous control method for the heavy-load locomotive is lower. The invention further provides a heavy-load combined train.

Description

Technical Field

[0001] The invention relates to an asynchronous control method for a heavy-load locomotive and a heavy-load combination train, and belongs to the field of longitudinal dynamics of heavy-load combination trains. Background Art

[0002] With the rapid development of my country's economy and the adjustment of industrial layout, the transportation of bulk goods has become an essential part of heavy-duty railway transportation. Therefore, my country's heavy-duty railways need to operate heavy-duty combined trains with large axle weights and long formations to meet this requirement. At present, my country has already operated 20,000-ton heavy-duty combined trains on a regular basis, and plans to operate 30,000-ton or even higher-capacity combined trains in the next step. Compared with 20,000-ton combined trains, 30,000-ton heavy-duty combined trains have longer formations and more controlled locomotives. The longitudinal impulses generated during operation will be greater, which will inevitably require stricter control methods for drivers and put forward higher standards for the safe and stable operation of trains.

[0003] In order to ensure the safe and smooth operation of 30,000-ton heavy-load combination trains, higher requirements are placed on the coupling and buffer systems, air brake systems and the operation methods of the slave locomotives of long and large train sets. Especially during cyclic brake relief, the existence of the brake relief delay effect will inevitably cause a large longitudinal impulse of the train.

[0004] Many scholars have conducted relevant research on reducing the longitudinal impulse of long and heavy-loaded trains, mainly in the following aspects:

[0005] (1) Through the research on coupler buffer wear and air brake system, the longitudinal impulse law of the train is analyzed from multiple aspects;

[0006] (2) By studying the influence of the formation of heavy-load combined trains on longitudinal impulse, it is found that the "1+1+1+SS4" formation can improve the braking relief effect of the vehicle and improve the operation safety of the train;

[0007] (3) A control strategy for asynchronously matching air braking force and locomotive regenerative braking force is proposed, which can effectively reduce the longitudinal coupler force of the combined train;

[0008] (4) By studying the effect of the distribution of freight cars in heavy-load trains on the longitudinal impulse, it was found that the number of freight cars at the rear can be reduced to reduce the longitudinal impulse.

[0009] From the above aspects, it can be seen that the existing research has not considered the impact of brake release delay. Therefore, in order to further avoid the longitudinal impulse of the train, it is urgent to start from the brake release operation mode of the train and propose a new asynchronous control technology for heavy-duty locomotives to effectively reduce the longitudinal impulse of long and large trains. Summary of the invention

[0010] The present invention aims to provide a heavy-load locomotive asynchronous control method and a heavy-load combination train, which can effectively reduce the total longitudinal impulse of the train by reducing the electric braking force holding time of the slave-controlled locomotive after unloading.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is: an asynchronous control method for a heavy-load locomotive, the heavy-load locomotive includes a master control locomotive and a plurality of slave control locomotives, the method comprising:

[0012] When the train reaches the braking speed, the electric braking force of the master locomotive and the slave locomotive is increased to a continuous braking force;

[0013] When the train reaches the relief speed, the master locomotive enters the relief state and maintains the continuous braking force; after the waiting time is reached, the electric braking force of the slave locomotive is unloaded to F within the unloading time. Bi After the holding time is reached, the electric braking force of the slave locomotive is restored to the continuous braking force;

[0014] According to the train formation sequence, the electric braking force holding time of the slave locomotive is reduced, that is, t m(j+1) =t mj -Δt j , where t m(j+1) is the electric braking force holding time of the j+1th slave locomotive, t mj is the electric braking force holding time of the jth slave locomotive, Δt j is the difference in the electric braking force holding time between the j+1th slave locomotive and the jth slave locomotive, Δt j >0; F Bi is the train air braking force of the i-th vehicle, i is the vehicle number, 1≤i≤N, N is the number of vehicles in the heavy-load combination train, and j is the number of the slave locomotive.

[0015] By reducing the holding time of the electric braking force of the slave locomotive, the acceleration of the rear vehicle can be slowed down, the speed difference can be reduced, and the maximum hook pressing force on the front slave locomotive can be reduced, thereby effectively reducing the longitudinal impulse of the heavy-load combination train.

[0016] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization:

[0017] In one preferred embodiment, the number of the slave locomotives is 3, and / or the slave locomotive is at the rear of the train.

[0018] Based on the longitudinal dynamics model of a 30,000-ton heavy-load combined train, the SS4 locomotive and the tail device are installed at the rear of the heavy-load combined train to compare the braking and release synchronization of the "1+1+1+SS4" marshaling and the "1+1+1+controllable tail" marshaling. The comparison results are as follows:Figure 2 As shown in the figure, at the 250-car and subsequent car positions, the brake release synchronization of the train set equipped with the tail device is poor, and the delay effect is higher than that of the train set with the SS4 locomotive at the rear. Therefore, the "1+1+1+SS4" heavy-load combination train set can achieve a lower brake release delay effect.

[0019] In one preferred embodiment, Δt j =Δt j+1 , where Δt j+1 Δt is the difference in the electric braking force holding time between the j+2nd slave locomotive and the j+1st slave locomotive. j =Δt j+1 That is, selecting the reduction difference of the electric braking force holding time with equal gradient can optimize the braking performance, improve the braking efficiency, simplify the braking control and enhance the safety of the train.

[0020] Based on the same concept, the present invention also provides a heavy-load combination train, which uses the heavy-load locomotive asynchronous control method as described above to brake on a downhill line under air-electric combined cycle braking conditions of air braking and electric braking.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: the asynchronous control method for heavy-loaded locomotives provided by the present invention reduces the longitudinal impulse of long trains. Considering typical line conditions and cyclic braking conditions, the longitudinal impulse is effectively reduced by reducing the electric braking force holding time of the slave locomotive, slowing down the speed increase of the rear vehicle, reducing the speed difference, and reducing the maximum hook pressing force received by the front slave locomotive. Compared with the prior art, the asynchronous control method for heavy-loaded locomotives provided by the present invention obtains lower longitudinal impulse of the train. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a heavy-load locomotive asynchronous control simulation flow chart of an embodiment of the present invention;

[0023] Figure 2 This is a comparison diagram of the brake release delay of long trains with different marshalings according to an embodiment of the present invention;

[0024] Figure 3 This is a comparison diagram of the longitudinal groove force of a "1+1+1+SS4" marshaling in synchronous and asynchronous operation modes according to an embodiment of the present invention;

[0025] Figure 4 is an asynchronous braking curve diagram of a slave-controlled locomotive according to an embodiment of the present invention;

[0026] Figure 5 is an electric braking force curve diagram of a master-slave control locomotive in an asynchronous operation mode according to an embodiment of the present invention, Figure 5(a) Electric braking force distribution curve of master-slave locomotive in asynchronous operation mode, Figure 5 (b) The electric braking force distribution method corresponding to different holding times;

[0027] Figure 6 It is a statistical diagram of longitudinal impulse of a train under electric braking force distribution modes corresponding to different holding times according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0029] Example 1

[0030] Embodiment 1 of the present invention is based on the existing mature wireless reconnection combined train mode and communication mode in China, takes into account the coordinated control technology of traction and braking under complex operating conditions, simulates the asynchronous control operation of the train, aims to reduce the longitudinal impulse of the long and heavy-loaded combined train, optimizes the electric braking force adjustment parameters of the asynchronous control slave locomotive, and proposes an asynchronous control method by reducing the electric braking force holding time of the slave locomotive after unloading, so as to effectively reduce the total longitudinal impulse of the train. The simulation steps of the method include:

[0031] S1. Based on the longitudinal dynamics theory, the longitudinal dynamics model of a 30,000-ton heavy-duty combined train is established by considering the locomotive's traction braking characteristics, air braking process, coupling and buffer device characteristics, over-phase, curve resistance and slope resistance factors. In this model, each vehicle is assumed to be a single point with only longitudinal freedom, and the total freedom of the train is consistent with the number of vehicle sections N. For a single vehicle, its longitudinal dynamics differential equation is as follows:

[0032]

[0033] Where i is the vehicle number, 1≤i≤N, m i is the mass of the i-th vehicle, x i is the displacement of the i-th vehicle, For x i Find the second derivative, which is the acceleration of the i-th vehicle, F Ti is the locomotive traction of the i-th vehicle. When the vehicle is not a locomotive, F Ti =0; F C(i-1) is the rear hook force of the i-th vehicle, F Ci is the front hook force of the i-th vehicle, and when i=1, F C(i-1) =0, when i=N, F Ci =0, F Di is the regenerative braking force of the i-th vehicle, F Biis the train air braking force of the i-th vehicle, acting on the locomotive, F Wi is the running resistance of the vehicle in section i;

[0034] S2. Based on the longitudinal dynamics model established in S1, the SS4 locomotive and the tail device are installed at the rear of the long train to compare the braking and release synchronization of the "1+1+1+SS4" formation and the "1+1+1+controllable tail" formation. The comparison results are as follows: Figure 2 As shown in the figure, at the 250-car and subsequent car positions, the braking release synchronization of the train with the tail device is poor, and the delay effect is higher than that of the train with the SS4 locomotive at the rear. Therefore, the simulation study based on the "1+1+1+SS4" heavy-load combination train formation can obtain a lower braking release delay effect.

[0035] S3. Based on the "1+1+1+SS4" marshaling mode with lower delay effect selected in S2, this embodiment 1 selects a typical line with a long downhill slope of 10.2‰, and simulates and analyzes the longitudinal impulse changes of the heavy-duty combination train when synchronous braking and asynchronous braking are respectively adopted under the air-electric combined cycle braking condition of air braking with reduced pressure (50kPa) and electric braking. The simulation analysis results are as follows: Figure 3 In the synchronous control mode, the maximum hook pull force is 771.3 kN, and the maximum hook pressure force is 730.5 kN. In the asynchronous control mode, the maximum hook pull force is reduced to 690.4 kN, and the maximum hook pressure force is reduced to 712.3 kN. Therefore, the 30,000-ton heavy-load combination train of this embodiment 1 adopts the asynchronous control mode, which can effectively reduce the maximum coupler force.

[0036] like Figure 4 The asynchronous control operation curve is shown. Under the preferred working condition of this embodiment 1, the asynchronous braking process of the long train is as follows: When the long train reaches the braking speed, the long train enters the cyclic braking mode, and based on the longitudinal dynamic model established in S1, the electric braking force of the master locomotive and the slave locomotive is calculated to reach the continuous braking force F D1 In this embodiment 1, F D1 400KN; then when the train speed continues to decrease to the relief speed, the gate of the master control locomotive enters the relief position and waits for t w After time, the electric braking force of the slave locomotive is u The train air braking force F that is unloaded to the i-th vehicle within the time Bi In this embodiment 1, F Bi is 100KN; keep t m After a certain time, the electric braking force of the slave locomotive is restored to the continuous braking force F D1 , which is consistent with the master control locomotive.

[0037] Wherein, the continuous braking force F D1 The calculation formula is:

[0038]

[0039] Among them, F bm is the maximum continuous braking force, P b is the braking continuous power, v is the running speed of the heavy-load combination train, v b1 is the first braking speed threshold, v b2 is the second braking speed threshold, v b3 is the third braking speed threshold.

[0040] Train air braking force of the i-th vehicle is the calculated friction coefficient of the i-th vehicle, K i is the brake shoe pressure of the i-th vehicle.

[0041] S4, based on the asynchronous control mode of S3, according to the front and rear order of the train formation, by reducing and increasing the electric braking force holding time of the slave locomotive, further simulate and analyze the impact of the two control modes of the electric braking force of the slave locomotive on the longitudinal impulse of the train. Figure 5 (b) shows 6 allocation schemes for the electric braking force holding time of the slave locomotive, which are as follows:

[0042] (1) Reduce the electric braking force holding time of the slave locomotive. Based on the initial electric braking force holding time of the slave locomotive, select the electric braking force holding time of the slave locomotive with a difference of Δt, corresponding to three different values ​​of Δt, which are recorded as slave locomotive electric braking force operation modes 1 to 3, such as Figure 5 As shown in (b), operation mode 1 corresponds to Δt = -1s, operation mode 2 corresponds to Δt = -2s, and operation mode 3 corresponds to Δt = -3s. The influence of different operation modes on the longitudinal impulse level of the train is simulated respectively. For example, when Δt = -3s, the holding time of the electric braking force of the No. 1 slave locomotive is always 20s, and the difference between the holding time of the No. 2 slave locomotive and its holding time is Δt. Then, the holding time of the electric braking force of the No. 2 slave locomotive is 17s, and the holding time of the electric braking force of the rear No. 3 slave locomotive is 14s. The rear locomotive recovers the synchronous control operation mode first compared with the front locomotive.

[0043] (2) Increase the electric braking force holding time of the slave locomotive. Based on the initial electric braking force holding time of the slave locomotive, select the electric braking force holding time of the slave locomotive with a difference of Δt, corresponding to three different values ​​of Δt, which are recorded as slave locomotive electric braking force operation modes 4 to 6, such as Figure 5As shown in (b), operation mode 4 corresponds to Δt=1s, operation mode 5 corresponds to Δt=2s, and operation mode 6 corresponds to Δt=3s. The influence of different operation modes on the longitudinal impulse level of the train is simulated respectively. For example, when Δt=3s, the holding time of the electric braking force of the No. 1 slave locomotive is always 20s, and the difference between the holding time of the No. 2 slave locomotive and its holding time is Δt. Then the holding time of the electric braking force of the No. 2 slave locomotive is 23s, and the holding time of the electric braking force of the rear No. 3 slave locomotive is 26s. The rear locomotive lags behind the leading locomotive in restoring the synchronous control operation mode.

[0044] S5. Based on the six operation modes in S4, the maximum longitudinal coupler force and longitudinal acceleration of the train under different operation modes are simulated and analyzed, such as Figure 6 As shown in the figure, the maximum hook force in the six modes does not change significantly. Among them, in operation mode 3 (reducing the holding time to 3s), the maximum longitudinal hook pressure of the train is 637.8kN, and the maximum longitudinal acceleration is the smallest, which is 5.07m / s 2 , both parameters are kept at a low level, and the comprehensive level of longitudinal impulse is better than other schemes. At this time, the electric braking force of the rear slave locomotive is maintained for a shorter time, and the electric braking force is restored to the same level as the master locomotive more quickly, which slows down the speed increase of the rear vehicle and effectively reduces the longitudinal impulse of the train.

[0045] Based on this, in the long and heavy-load train cyclic braking relief condition, by changing the holding time of the slave locomotive during asynchronous braking, the simulation results show that the longitudinal impulse can be reduced by reducing the holding time of the electric braking force of the slave locomotive.

[0046] Example 2

[0047] Based on the longitudinal dynamics model of the 30,000-ton heavy-load combination train constructed in Example 1, through the analysis of the synchronization of brake relief in different marshaling modes, a "1+1+1+SS4" marshaling mode with lower delay effect is obtained, and through simulation analysis under typical line conditions, it can be seen that the longitudinal impulse of the train is lower when the asynchronous control mode is adopted than in the synchronous control mode. Further analysis shows that the longitudinal impulse of the train can be reduced by reducing the holding time of the electric braking force of the slave locomotive. Therefore, this Example 1 provides a heavy-load locomotive asynchronous control method, which is applied to a heavy-load combination train, wherein the heavy-load locomotive includes a master locomotive and a plurality of slave locomotives, and the method includes:

[0048] When the train reaches the braking speed, the electric braking force of the master locomotive and the slave locomotive increases to the continuous braking force F D1 ;

[0049] When the train reaches the relief speed, the master locomotive enters the relief state and maintains the continuous braking force F D1 ; Wait for t wAfter time, the electric braking force of the slave locomotive is u Unload to F within the time Bi , and keep t m After a certain time, the electric braking force of the slave locomotive is restored to the continuous braking force F D1 ;

[0050] According to the train formation sequence, the electric braking force holding time of the slave locomotive is reduced, that is, t m(j+1) =t mj -Δt j , t m(j+1) is the electric braking force holding time of the j+1th slave locomotive, t mj is the electric braking force holding time of the jth slave locomotive, Δt j is the difference in the electric braking force holding time between the j+1th slave locomotive and the jth slave locomotive, Δt j >0;

[0051] Among them, F Bi is the train air braking force of the i-th vehicle, i is the vehicle number, 1≤i≤N, N is the number of vehicles in the long train, j is the number of the slave locomotive, t w is the waiting time, t u is the unloading time, t m To keep time.

[0052] Furthermore, the continuous braking force F D1 The calculation formula is:

[0053]

[0054] Among them, F bm is the maximum continuous braking force, P b is the braking continuous power, v is the running speed of the heavy-load combination train, v b1 is the first braking speed threshold, v b2 is the second braking speed threshold, v b3 is the third braking speed threshold.

[0055] Furthermore, the train air braking force F of the i-th vehicle Bi The calculation formula is: in, is the calculated friction coefficient of the i-th vehicle, k i is the brake shoe pressure of the i-th vehicle.

[0056] Furthermore, the number of the slave locomotives is 3.

[0057] Furthermore, the third slave-controlled locomotive is located at the rear of the heavy-load combination train.

[0058] Furthermore, Δt j =Δt j+1 , where Δt j+1 Δt is the difference in the electric braking force holding time between the j+2nd slave locomotive and the j+1st slave locomotive. j =Δt j+1 That is, selecting the reduction difference of the electric braking force holding time with equal gradient has the following advantages:

[0059] 1. Optimize braking performance: Ensure that the braking force changes more evenly during braking, avoid sudden changes in braking force, and reduce the impact and vibration of the train during braking. Evenly changing braking force can improve the braking stability of the train, make the train more stable during braking, and reduce safety hazards caused by uneven braking.

[0060] 2. Improve braking efficiency: It can more effectively utilize braking energy and reduce energy loss during braking. It can not only improve braking efficiency, but also reduce energy consumption to a certain extent.

[0061] 3. Simplify brake control: The design of the brake control system can be simplified. By reducing the variables and complexity in the braking process, the reliability and stability of the brake system can be improved, and the difficulty of maintenance and servicing can be reduced.

[0062] 4. Improve train safety: Isogradient braking can ensure that the train always remains within a safe braking range during the braking process, avoiding safety hazards caused by excessive or insufficient braking force.

[0063] Example 3

[0064] Embodiment 3 of the present invention provides a heavy-load combination train, which uses the heavy-load locomotive asynchronous control method as described in Embodiment 1 to brake on a downhill line under air-electric combined cycle braking conditions of air braking and electric braking.

[0065] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A heavy-load locomotive asynchronous control method, characterized in that: The heavy-load locomotive includes a master locomotive and a slave locomotive, and the method includes: When the train reaches the braking speed, the electric braking force of the master locomotive and the slave locomotive is increased to a continuous braking force; When the train reaches the relief speed, the master locomotive enters the relief state and maintains the continuous braking force; after the waiting time is reached, the electric braking force of the slave locomotive is unloaded to F within the unloading time. Bi After the holding time is reached, the electric braking force of the slave locomotive is restored to the continuous braking force; According to the train marshaling sequence, the electric braking force holding time of the slave locomotive is reduced, that is, t m(j+1) =t mj -Δt j , Among them, t m(j+1) is the electric braking force holding time of the j+1th slave locomotive, t mj is the electric braking force holding time of the jth slave locomotive, Δt j is the difference in the electric braking force holding time between the j+1th slave locomotive and the jth slave locomotive, Δt j >0; F Bi is the train air braking force of the i-th vehicle, i is the vehicle number, 1≤i≤N, N is the number of vehicles in the heavy-load combination train, and j is the number of the slave locomotive.

2. The asynchronous control method for heavy-load locomotive according to claim 1, characterized in that: The number of the slave locomotives is 3, and / or the slave locomotive is at the rear of the train.

3. The asynchronous control method for heavy-load locomotive according to claim 1, characterized in that: Δt j =Δt j+1 , where Δt j+1 It is the time difference between the electric braking force of the j+2th slave-controlled locomotive and the j+1th slave-controlled locomotive.

4. A heavy-load combination train, characterized in that: The heavy-load combination train is braked on a downhill line and under air-electric combined cycle braking conditions of air braking and electric braking, using the heavy-load locomotive asynchronous control method as described in any one of claims 1 to 3.

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