Heavy haul locomotive asynchronous control method and heavy haul combined train

Abstract

The application provides a heavy haul locomotive asynchronous control method, which considers typical line conditions and cyclic braking conditions, reduces the electric braking force holding time of a slave locomotive, slows down the speed increase of a rear vehicle, reduces the speed difference, reduces the maximum pressure hook force received by a front slave locomotive, and effectively reduces the longitudinal impulse. Compared with the prior art, the heavy haul locomotive asynchronous control method provided by the application obtains a lower train longitudinal impulse. The application also provides a heavy haul combined train.

Description

TECHNICAL FIELD

[0001] The present application relates to a heavy haul locomotive asynchronous control method and a heavy haul combined train, and belongs to the field of longitudinal dynamics of heavy haul combined trains. BACKGROUND

[0002] With the rapid development of China's economy and the adjustment of industrial layout, the transportation of bulk goods has become a necessary part of heavy haul railway transportation, so heavy haul railways in China need to run heavy haul combined trains with large axle loads and long consist to meet this requirement. At present, 20,000-ton heavy haul combined trains have been regularly operated in China, and the next step is to plan to operate 30,000-ton or even higher capacity trains. Compared with 20,000-ton trains, 30,000-ton heavy haul combined trains have longer consist, more locomotives under control, and greater longitudinal impulse during operation, which inevitably requires more stringent driver operation and higher standards for safe and stable train operation.

[0003] In order to ensure the safe and stable operation of 30,000-ton heavy haul combined trains, higher requirements are put forward for the coupler buffer system, air brake system and operation mode of the locomotives under control of long and large consist trains, especially during the cyclic braking and release, the existence of brake release delay effect will inevitably cause a large train longitudinal impulse.

[0004] Regarding the reduction of the longitudinal impulse of long and large heavy haul trains, many scholars have carried out relevant research, mainly in the following aspects:

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

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

[0007] (3) A control strategy of asynchronous matching of air brake 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 influence of the distribution form of heavy haul trains on the longitudinal impulse, it is found that the number of rear cars can be reduced to reduce the longitudinal impulse.

[0009] From the foregoing aspects, it can be seen that the existing research does not consider the influence of brake release delay. Therefore, in order to further avoid the longitudinal impulse of the train, it is necessary to start from the brake release operation mode of the train, and a new heavy haul locomotive asynchronous control technology is proposed to effectively reduce the longitudinal impulse of long and large trains. SUMMARY

[0010] The application aims to provide a heavy haul locomotive asynchronous control method and a heavy haul combined train, which effectively reduces the total longitudinal impulse of the train by reducing the electric braking force maintaining time of the slave locomotive after unloading.

[0011] In order to achieve the above-mentioned purpose, the application adopts the technical scheme of a heavy haul locomotive asynchronous control method, wherein the heavy haul locomotive comprises a master locomotive and a plurality of slave locomotives, and the method comprises:

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

[0013] When the train reaches the release speed, the master locomotive enters the release state and maintains the sustained braking force; after the waiting time is reached, the electric braking force of the slave locomotives is unloaded to F Bi in the unloading time, and after the maintaining time is reached, the electric braking force of the slave locomotives is restored to the sustained braking force;

[0014] According to the front and rear order of the train formation, the electric braking force maintaining time of the slave locomotives is reduced, that is, t m(j+1) =t mj -Δt j , wherein t m(j+1) is the electric braking force maintaining time of the j+1 section slave locomotive, t mj is the electric braking force maintaining time of the j section slave locomotive, Δt j is the electric braking force maintaining time difference value of the j+1 section slave locomotive and the j section slave locomotive, and Δt j > 0; F Bi is the train air braking force of the i section vehicle, i is the vehicle number, 1 ≤ i ≤ N, N is the number of vehicles of the heavy haul combined train, and j is the slave locomotive number.

[0015] By reducing the electric braking force maintaining time of the slave locomotives, the speed increase of the rear vehicles is slowed down, the speed difference is reduced, the maximum pressure hook force received by the front slave locomotive is reduced, and thus the longitudinal impulse of the heavy haul combined train is effectively reduced.

[0016] According to the embodiments of the application, the application can be further optimized, and the technical scheme formed after optimization is as follows:

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

[0018] Based on the longitudinal dynamics model of a 30,000-ton heavy haul combined train, the SS4 locomotive and the tail device are respectively carried at the tail of the heavy haul combined train, and the brake release synchronization of the "1+1+1+SS4" formation and the "1+1+1+controllable tail" formation of the train is compared. The comparison result is as follows:Figure 2 As shown in the figure, the brake release synchronization of the brake train device-equipped train in the 250th and subsequent car positions is poor, and the delay effect is higher than that of the train equipped with the SS4 locomotive at the tail. Therefore, the "1+1+1+SS4" heavy-load combined train can obtain a lower brake release delay effect.

[0019] In one preferred embodiment, Δt j = Δt j+1 , wherein Δt j+1 is the electric braking force holding time difference value of the j+2th slave locomotive and the j+1th slave locomotive. Δt j = Δt j+1 , that is, the reduction difference value of the electric braking force holding time selected at the same gradient, can optimize the braking performance, improve the braking efficiency, simplify the braking control, and improve the train safety.

[0020] Based on the same concept, the application also provides a heavy-load combined train, which adopts the heavy-load locomotive asynchronous control method as described above for braking in the air-electric combined cycle braking condition of the downhill line and the air braking cooperating with the electric braking.

[0021] Compared with the prior art, the application has the beneficial effects that: the heavy-load locomotive asynchronous control method for reducing the longitudinal impulse of the long train provided by the application considers the typical line conditions and the cycle braking condition, reduces the electric braking force holding time of the slave locomotive, slows down the speed increase of the rear vehicle, reduces the speed difference, reduces the maximum pressure hook force received by the front slave locomotive, and effectively reduces the longitudinal impulse. Compared with the prior art, the heavy-load locomotive asynchronous control method provided by the application obtains a lower train longitudinal impulse. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the heavy-load locomotive asynchronous control simulation flowchart of one embodiment of the application;

[0023] Figure 2 is a brake release delay comparison chart of different train formations of long trains of one embodiment of the application;

[0024] Figure 3 is a longitudinal car ditch force comparison chart of the "1+1+1+SS4" train formation in the synchronous and asynchronous operation modes of one embodiment of the application;

[0025] Figure 4 is a slave locomotive asynchronous braking curve chart of one embodiment of the application;

[0026] Figure 5 is an electric braking force curve chart of the master-slave locomotive in the asynchronous operation mode of one embodiment of the application, Figure 5(a) is the electric braking force distribution curve of the master-slave locomotive in the asynchronous operation mode, Figure 5 (b) is the electric braking force distribution mode corresponding to different holding times;

[0027] Figure 6 is the train longitudinal impulse statistical graph in the electric braking force distribution mode corresponding to different holding times of an embodiment of the present application. DETAILED DESCRIPTION

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

[0029] Embodiment 1

[0030] Embodiment 1 of the present application considers the coordinated control technology of traction and braking under complex operation conditions according to the existing mature wireless recombination train mode and communication mode in China, simulates the asynchronous control operation of the train, and optimizes the electric braking force adjustment parameters of the asynchronous control slave locomotive to reduce the longitudinal impulse of the long and heavy load combined train as the target. An asynchronous control method is proposed by reducing the holding time of the electric braking force of the slave locomotive after unloading 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, considering the traction and braking characteristics of the locomotive, the air braking process, the characteristics of the coupler and draft gear, the overpassing resistance, the curve resistance and the slope resistance factors, a 30,000-ton heavy load combined train longitudinal dynamics model is established. Among them, each vehicle is a single particle with only longitudinal freedom, and the total degree of freedom of the train is consistent with the number of vehicle nodes N. For a single vehicle, the longitudinal dynamics differential equation is as follows:

[0032]

[0033] Wherein, 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, is the x i derivative of two orders, which is the acceleration of the i-th vehicle, F Ti is the locomotive traction force of the i-th vehicle, when the vehicle is not a locomotive, F Ti =0; F C(i-1) is the rear coupler force of the i-th vehicle, F Ci is the front coupler 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 BiThe train air braking force of the ith section vehicle acting on the locomotive, F Wi The running resistance of the ith section vehicle;

[0034] S2, based on the longitudinal dynamics model established in S1, respectively at the tail of the long train with SS4 locomotive and tail device, compare the brake release synchronization of the train formation of "1+1+1+SS4" and "1+1+1+controllable tail". The comparison results are shown in Figure 2 , at the 250th car and the subsequent car position, the brake release synchronization of the train formation with the tail device is poor, and the delay effect is higher than that of the train formation with the SS4 locomotive at the tail. Therefore, the simulation research based on the "1+1+1+SS4" heavy load combined train formation can obtain lower brake release delay effect.

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

[0036] As shown in Figure 4 , the asynchronous control operation curve. In 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 cycle braking mode, and based on the longitudinal dynamics model established in S1, the electric braking force of the main control locomotive and the slave control locomotive will reach the sustained braking force F D1 , in this embodiment 1, F D1 is 400KN; then the train speed continues to decrease to the release speed, the main control locomotive enters the release position, and waits for t w time, and the electric braking force of the slave control locomotive is unloaded to the train air braking force F Bi of the ith section vehicle within t u , in this embodiment 1, F Bi is 100KN; after t m time, the electric braking force of the slave control locomotive is restored to the sustained braking force F D1 consistent with the main 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 vehicle section i is the calculated friction coefficient of the vehicle in section i, K i is the brake shoe pressure of the i-th vehicle.

[0041] S4, based on the asynchronous control mode of S3, by reducing and increasing the holding time of the electric braking force of the slave locomotive according to the train formation sequence, 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 six distribution schemes for the holding time of the electric braking force of the slave locomotive, 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 the electric braking force operation mode 1 to 3 of the slave locomotive, as follows: Figure 5 As shown in (b), operating mode 1 corresponds to Δt = -1s, operating mode 2 corresponds to Δt = -2s, and operating mode 3 corresponds to Δt = -3s. The effects of different operating modes on the longitudinal impulse level of the train are simulated. For example, when Δt = -3s, the holding time of the electric braking force of the No. 1 slave locomotive is always 20s. The difference between the holding time of the No. 2 slave locomotive and its holding time is Δt. Therefore, 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 resumes the synchronous control operating mode before the leading 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, as shown in Figure 4. Figure 5(b) As shown, operation mode 4 corresponds to At = 1 s, operation mode 5 corresponds to At = 2 s, and operation mode 6 corresponds to At = 3 s. The influence of different operation modes on the train longitudinal impulse level is simulated respectively. For example, when At = 3 s, the holding time of the electric braking force of the No. 1 slave locomotive is always 20 s, the difference between the holding time of the No. 2 slave locomotive and the holding time is At, so the holding time of the electric braking force of the No. 2 slave locomotive is 23 s, and the holding time of the electric braking force of the tail No. 3 slave locomotive is 26 s. The tail locomotive lags behind the front vehicle to recover the synchronous control operation mode.

[0044] S5, based on the six operation modes in S4, the maximum longitudinal train hook force and longitudinal acceleration of the train under different operation modes are simulated and analyzed, as shown in Figure 6 As shown, the maximum pull hook force under the six modes changes slightly. Among them, under operation mode 3 (decrease the holding time by 3 s), the maximum longitudinal pull hook force of the train is 637.8 kN, and the maximum longitudinal acceleration is the smallest, which is 5.07 m / 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 holding time of the electric braking force of the rear slave locomotive is shorter, and the electric braking force is recovered to the same level as the master locomotive faster, which slows down the rear vehicle and effectively reduces the longitudinal impulse of the train.

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

[0046] Embodiment 2

[0047] Based on the 30,000-ton heavy load combined train longitudinal dynamics model built in embodiment 1, through the analysis of the braking and relief synchronization of different marshalling modes, the "1+1+1+SS4" marshalling mode with lower delay effect is obtained, and through the simulation analysis under the typical line conditions, it can be known that the longitudinal impulse of the train under the asynchronous control mode is lower than that under 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, the embodiment 1 provides an asynchronous control method of heavy load locomotive, which is applied to a heavy load combined train, 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 is increased to the sustained braking force F D1 ;

[0049] When the train reaches the relief speed, the master locomotive enters the relief state and keeps the sustained braking force F D1 ; waits for t wAfter time t, 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 Δt is the time difference between the electric braking force of the j+1th slave locomotive and the jth slave locomotive. 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 vehicle sections 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 vehicle in section i, 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] Further, Δt j = Δt j+1 , wherein Δt j+1 is the time difference of the electric braking force of the j+2 section slave locomotive and the j+1 section slave locomotive. Δt j = Δt j+1 , i.e. the reduction difference of the electric braking force holding time selected by the equal gradient, has the following advantages:

[0059] 1. Optimizing braking performance: Ensures that the size of the braking force changes more uniformly during braking, avoiding sudden changes in braking force and reducing the impact and vibration of the train during braking. Uniformly changing braking force can improve the braking stability of the train, making the train more stable during braking and reducing safety hazards caused by uneven braking.

[0060] 2. Improving braking efficiency: Can more effectively utilize braking energy and reduce energy loss during braking. Not only can it improve braking efficiency, but it can also reduce energy consumption to some extent.

[0061] 3. Simplifying brake control: Can simplify the design of the brake control system. By reducing variables and complexity during braking, it can improve the reliability and stability of the braking system and reduce the difficulty of maintenance and maintenance.

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

[0063] Example 3

[0064] Example 3 of the present application provides a heavy load combined train, which adopts the heavy load locomotive asynchronous control method as described in Example 1 for braking under the air-electric combined cycle braking condition of downhill line and air brake cooperating with electric brake.

[0065] The content described in the above examples should be understood as these examples only for more clearly illustrating the present application, and not for limiting the scope of the present application, after reading the present application, the various equivalent forms of the present application. Modification of the skilled in the art falls within the scope of the appended claims of the present application.

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 formation 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 Δt is the time difference between the electric braking force of the j+1th slave locomotive and the jth slave locomotive. 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 vehicle sections 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 The time difference between the electric braking forces 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 under an air-electric combined cycle braking condition in which air braking cooperates with electric braking by adopting the heavy-load locomotive asynchronous control method as described in any one of claims 1 to 3.

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