Catenary plane arrangement evaluation method

Abstract

The invention relates to the field of pantograph-catenary relation, and discloses a contact network plane arrangement evaluation method, which comprises the following steps of: 1, respectively calculating a wear factor of each pull-out value interval of a contact network to a sliding block; 2, the wear factors corresponding to the different pull-out value intervals are drawn on a number axis, normalization processing is conducted on the wear factors according to the original height and the maximum allowable wear height of the pantograph, a predicted wear curve of the pantograph slide plate is obtained, and the predicted wear curve corresponds to a predicted wear area S1; 3, defining a standard wear curve, wherein the standard wear curve corresponds to a standard wear area S2; the score x = S1 / S2 is calculated, the score is used for representing the plane layout design economy of the overhead line system, and the higher the score is, the better the economy is. And evaluating the plane arrangement of the overhead line system by investigating the predicted wear area of the pantograph slide block.

Description

Technical Field

[0001] The invention relates to the field of bow-catenary relationship, and in particular to a method for evaluating the plane layout of a contact network. Background Art

[0002] Overhead contact network technology is widely used in urban rail transit to provide traction power for urban rail transit trains. The pantograph slider is a key component of the train. Its main function is to ensure stable power supply to the electric train through good contact with the contact network. It is a consumable part. When the minimum residual height of the slider is worn to the allowable value, the slider needs to be replaced.

[0003] However, the wear rate of the pantograph slider for the same section of contact network varies under different driving speeds, current collection, temperature and other factors, so that the wear shape of the pantograph slider varies in different projects under the same contact network plane layout principle, and the matching of the pantograph and the network varies greatly. In severe cases, an offline arc between the pantograph and the network occurs, resulting in a decrease in the current collection quality, increased mechanical wear of the contact line and the slide plate, resulting in a decrease in the service life of the contact line and the slide plate, and increased use and maintenance costs of the contact line and the slide plate.

[0004] Therefore, a method for evaluating the layout of overhead contact networks is needed to evaluate the economic feasibility of overhead contact networks in different projects. Summary of the invention

[0005] The present invention aims to provide a method for evaluating the plane layout of a contact network, which evaluates the plane layout of the contact network based on the wear of a pantograph slider.

[0006] To achieve the above object, the present invention adopts the following technical solution: a method for evaluating the plane layout of a contact network, comprising the following steps:

[0007] Step 1, respectively calculating the wear factor of the slider for each pull-out value interval of the contact network;

[0008] Step 2: Plot the wear factors corresponding to different pull-out value intervals on the numerical axis, and normalize the wear factors according to the original height of the pantograph and the maximum allowable wear height to obtain the estimated wear curve of the pantograph slide plate. The estimated wear curve corresponds to the estimated wear area S1;

[0009] Step 3: define a standard wear curve, which corresponds to a standard wear area S2; calculate a score x=S1 / S2, which is used to characterize the economic efficiency of the contact network's planar layout design. The higher the score, the better the economy.

[0010] In this scheme, the wear area corresponding to the wear curve is the area between the wear curve and the horizontal axis.

[0011] The beneficial effects of this program are:

[0012] 1. Overhead contact network is divided into flexible overhead contact network and rigid overhead contact network. Generally, overhead flexible contact network is used in the above-ground section, and overhead rigid contact network is used in the underground section. At present, there is no systematic system and scientific method for evaluating the plane layout of the contact network in the industry. Only flexible overhead contact network and rigid overhead contact network are designed independently. According to its characteristics, it is appropriate to examine the safety of current transfer for flexible overhead contact network. However, rigid overhead contact network only examines the safety of current transfer and independently examines the uniformity of its layout. The limitation is too great, so that the same contact network plane layout principle has different wear shapes of pantograph slider in different projects, which will cause pantograph network accidents and affect driving safety. This scheme evaluates the plane layout of the contact network by examining the expected wear area of ​​the pantograph slider. The expected wear area of ​​the pantograph slider needs to comprehensively consider different driving speeds, current collection, temperature and other factors. It is a scientific evaluation method.

[0013] 2. Under the standard wear curve, the slider wears evenly and has a high utilization rate. That is, after the slider is worn, the residual height of the main wear area of ​​the slider is close to the limit value of the minimum residual height (exceeding the limit value will easily affect operational safety).

[0014] 3. This scheme uses a method for evaluating the plane layout of the contact network to evaluate the score of the plane layout of the contact network to examine whether the plane layout of the contact network achieves the expected purpose. In addition to meeting the requirements of safe current collection of the bow and the catenary and considering the characteristics of the contact network itself, the evaluation method should also consider the effects between the bow and the catenary, the interaction effects within the life cycle of the bow and the catenary, and the matching between the bow and the catenary.

[0015] 4. In this scheme, the contact network is divided into multiple pull-out value intervals. For example, the pull-out value range is [100mm, -100mm]. This scheme can divide the pull-out value interval into 20 intervals: [100mm, 90mm], [90mm, 80mm]... [-80mm, -90mm], [-90mm, -100mm], and calculate the wear factor of the contact network at the corresponding position on the slider in each interval (using a computer can divide more intervals, thereby increasing the accuracy of the calculation).

[0016] Since the more accumulated wear factors are, the more wear there is, the estimated wear curve can be obtained according to the wear factors in each interval. The score is determined based on the deviation between the estimated wear curve and the standard wear curve, 0≤x≤1. The closer the score is to 1, the better the solution and the more economical it is.

[0017] Furthermore, the middle section of the standard wear curve has the same height, the end section of the standard wear curve has a gradually decreasing height, and a transition curve is provided between the end section and the middle section of the standard wear curve.

[0018] Furthermore, in step three, a limit wear curve is defined, the middle section of the limit wear curve is the same as the standard wear curve, the height of the end section of the limit wear curve is smaller than the middle section and larger than the end section of the standard wear curve. If the expected wear curve is locally higher than the limit wear curve, the corresponding contact network is locally corrected and the score is re-evaluated.

[0019] Furthermore, the portion of the predicted wear curve that is higher than the standard wear curve is not included in the predicted wear area S1.

[0020] Furthermore, in step 1, the calculation formula of the wear factor ki of the i-th pull-out value interval is:

[0021] ki=∑ 1≤m≤n Km;

[0022] Km=(Kvmm+Kvem)×Q;

[0023] Kvem = γ × Lm;

[0024] Kvmm=β×Lm;

[0025] Km-wear factor within the i-th pull-out value interval;

[0026] Q-correction factor;

[0027] β-Mechanical wear coefficient of the contact network per unit length on the pantograph slider, distinguishing between rigid contact network and flexible contact network. The mechanical wear coefficient of the rigid contact network is β1; the mechanical wear coefficient of the flexible contact network is β2;

[0028] γ-electrical wear coefficient of the contact network per unit length on the pantograph slider;

[0029] Lm-length of the continuous overhead line in the mth section;

[0030] Kvmm-mechanical wear factor of the mth section of continuous overhead contact network on the pantograph slider;

[0031] Kvem - electrical wear factor of the pantograph slider caused by the mth continuous catenary;

[0032] Km-the total wear factor of the pantograph slider on the mth section of continuous overhead contact network;

[0033] n – total number of continuous contact network sections.

[0034] Furthermore, in step 1, basic data is obtained and processed to obtain a mechanical wear coefficient β of the contact network per unit length on the pantograph slider and an electrical wear coefficient γ of the contact network per unit length on the pantograph slider;

[0035] The basic data include the train's designed running speed, traction current value, friction coefficient of specific friction pairs, basic vehicle parameters, and driving organization. The specific friction pair consists of a pantograph slide of certain specifications and a contact line of certain specifications.

[0036] Furthermore, in step one, the basic data also includes the annual temperature of the project location. After processing the basic data, different temperature influence factors T are obtained according to the influence of different temperatures on specific friction pairs. When calculating Km, the correction coefficient Q=T is set.

[0037] Furthermore, in step 2, the wear factor is normalized by drawing the wear factor to form a preliminary wear curve and scaling it proportionally so that the maximum value of the preliminary wear mark curve is equal to the maximum allowable wear height of the slider.

[0038] This solution also has the following effects:

[0039] 1. This evaluation method considers that the plane layout of the contact network should not only meet the requirements of safe current collection of the catenary and the characteristics of the contact network itself, but also comprehensively considers the wear characteristics of factors such as driving speed, train current collection, ambient temperature, and different characteristics of rigid and flexible contact networks under specific friction pairs. The mechanical wear factor and electrical wear factor under various influencing factors are calculated respectively, and the wear curve L1 of the pantograph slide under the effect of the contact network plane layout to be evaluated is obtained, and compared with the standard curve L_2 that defines a pantograph slide wear factor, the score value of the contact network plane layout is obtained.

[0040] 2. This plan takes into account that in rail transit, overhead flexible contact networks are used in ground sections and overhead rigid contact networks are used in underground sections. The ambient temperature of the underground section is relatively constant, while the ambient temperature of the above-ground section varies greatly. A comprehensive temperature influence factor T is considered, which is mainly used to take the constant temperature of the underground section as a benchmark and consider the uneven wear of the above-ground section caused by changes in ambient temperature. This is mainly reflected in the particularity of the flexible contact network in the above-ground section. Since the probability of using a rigid overhead contact network on the ground is low, generally, when considering the temperature influence factor, no distinction is made between rigid and flexible. However, when the proportion of rigid overhead contact networks in the above-ground section is large, the temperature influence factors T of rigid and flexible should be considered separately.

[0041] 3. This scheme analyzes the influencing factors of the overhead contact network at different mileages and different pull-out value ranges on the wear of the pantograph slide, and obtains the pre-evaluated pantograph slide wear marks under different overhead contact network plane arrangements in a specific project.

[0042] For each specific section of contact network with a length of m, the influence of mechanical contact on the wear of the pantograph slider and the influence of electrical contact on the wear mark of the pantograph slider are discussed separately, and then the wear factor of the pantograph slider for each specific section of contact network with a length of m under the corresponding design speed and design passenger flow conditions is obtained.

[0043] 4. This scheme introduces the concept of wear factor, that is, the mechanical wear coefficient and electrical wear coefficient obtained through experiments and practice to calculate the total wear factor. The mechanical wear coefficient is the mechanical wear of the contact network on the pantograph slider per unit length (1m), and the electrical wear coefficient is the electrical wear of the contact network on the pantograph slider per unit length (1m). The wear factor represents the relative wear speed evaluation factor of the contact network on the slider, not the specific wear depth.

[0044] 5. When the standard wear area S2 remains unchanged, the larger the wear area S1 is expected to be, the higher the utilization rate of the slider is, and therefore the higher the score is.

[0045] 6. Since the contact network can be regarded as moving back and forth laterally on the slider when the train is in operation, there should be a transition curve between the end section and the middle section of the standard wear curve to achieve smooth movement of the contact network on the slider; if the smooth movement of the contact network is not considered, it is an extreme wear curve. Under the extreme wear curve, although the smoothness of the movement of the contact network on the slider is reduced and the current collection quality of the train is reduced to varying degrees, it still meets the relevant technical specifications. Therefore, after weighing the pros and cons, the part of the expected wear curve that is higher than the standard wear curve and lower than the extreme wear curve is not included in the expected wear area, that is, the part higher than the standard wear curve and lower than the extreme wear curve will not increase or decrease the score.

[0046] 7. When the predicted wear curve is locally higher than the limit wear curve, the lateral reciprocating motion of the contact network on the slider is hindered, and local eccentric wear of the contact line is likely to occur, which is not worth the cost. The corresponding contact network layout is unreasonable and needs to be locally corrected and re-evaluated. Therefore, the score is directly taken as 0. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Schematic diagram of wear factor calculation elements of Example 1;

[0048] Figure 2 The standard wear curve and the limit wear curve of Example 1 are shown;

[0049] Figure 3 for Figure 2 Added expected wear curve graph;

[0050] Figure 4 Schematic diagram of the pull-out value interval of Example 1;

[0051] Figure 5 This is a flow chart of the preliminary design of the contact network layout of Example 2;

[0052] Figure 6 It is the V-shaped equal slope model of Example 2;

[0053] Figure 7 is the straight line equal slope model of Example 2;

[0054] Figure 8 is the V-shaped unequal slope model of Example 2;

[0055] Fig. 9 This is the straight line unequal slope model of Example 2. DETAILED DESCRIPTION

[0056] The following is further described in detail through specific implementation methods:

[0057] The reference numerals in the drawings of the specification include: expected wear curve L1, standard wear curve L2, limit wear curve L3, overhead line 1, pantograph center line 2, unscored area 3.

[0058] Example 1

[0059] A method for evaluating the plane layout of a contact network comprises the following steps:

[0060] Step 1: Figure 4 As shown, the figure shows a section of the overhead contact network 1, the dotted lines on the upper and lower sides indicate the position of the maximum pull-out value, and according to the position on the slider corresponding to the range of the pull-out value, it can be divided into multiple pull-out value intervals (using a computer can divide more intervals, thereby increasing the accuracy of the calculation), the area between the two dotted lines indicates all the pull-out value intervals, and the area in the broken line box indicates one of the pull-out value intervals;

[0061] Get basic data and process it as follows Figure 1 The basic data shown in the figure can obtain the mechanical wear coefficient β of the pantograph slider per unit length of the contact network and the electrical wear coefficient γ of the pantograph slider per unit length of the contact network, and the different temperature influence factors T are obtained according to the influence of different temperatures on the specific friction pair; the basic data include the design running speed of the train, the traction current value, the friction coefficient of the specific friction pair, the basic parameters of the vehicle, the driving organization, and the temperature throughout the year at the project site. The specific friction pair is composed of a pantograph slider of a certain specification and a contact wire of a certain specification.

[0062] The wear factor of each pull-out value interval in each section and on the slider is calculated in turn according to the mileage. When all sections within the mileage range are calculated, the calculation is considered completed; the calculation formula for the wear factor ki of the i-th pull-out value interval is:

[0063] ki=∑ 1≤m≤n Km;

[0064] Km=(Kvmm+Kvem)×Q;

[0065] Kvem = γ × Lm;

[0066] Kvmm=β×Lm;

[0067] Km-wear factor within the i-th pull-out value interval;

[0068] Q-correction factor;

[0069] β-Mechanical wear coefficient of the contact network per unit length on the pantograph slider, distinguishing between rigid contact network and flexible contact network. The mechanical wear coefficient of the rigid contact network is β1; the mechanical wear coefficient of the flexible contact network is β2;

[0070] γ-electrical wear coefficient of the contact network per unit length on the pantograph slider;

[0071] Lm-length of the continuous overhead line in the mth section;

[0072] Kvmm-mechanical wear factor of the mth section of continuous overhead contact network on the pantograph slider;

[0073] Kvem - electrical wear factor of the pantograph slider caused by the mth continuous catenary;

[0074] Km-the total wear factor of the pantograph slider on the mth section of continuous overhead contact network;

[0075] n-total number of continuous contact network sections;

[0076] Step 2: Plot the wear factors corresponding to different pull-out value intervals on the numerical axis, and normalize the wear factors according to the original height of the pantograph and the maximum allowable wear height to obtain the estimated wear curve L1 of the pantograph slide plate. The estimated wear curve L1 corresponds to the estimated wear area S1;

[0077] The wear factor is normalized in the following way: the wear factor is plotted to form a preliminary wear scar curve and then scaled proportionally so that the preliminary wear scar curve satisfies: the maximum y value ymax of the preliminary wear scar curve is equal to the effective wear height of the standard wear curve L2, and the minimum y value ymin of the preliminary wear scar curve is equal to 0.

[0078] Step 3: Define the standard wear curve L2 and the limit wear curve L3, such as Figure 2As shown, the standard wear curve L2 is represented by a solid line, corresponding to the standard wear area S2, S2 represents the area between the standard wear curve L2 and the horizontal axis, the middle section of the standard wear curve L2 is straight and of equal height, the end section of the standard wear curve L2 is lower than the middle section, and a transition curve is provided between the end section and the middle section of the standard wear curve L2; the limit wear curve L3 is represented by a dotted line, the middle section of the limit wear curve L3 is the same as the standard wear curve L2, the middle section of the limit wear curve L3 is lower than the middle section and higher than the end section of the standard wear curve L2, the middle section and the end section of the limit wear curve L3 are a straight line, the portion between the standard wear curve L2 and the limit wear curve L3 is filled with a slash line, and the filled area is defined as the non-scoring area 3, as shown in FIG. Figure 3 As shown in the figure, if the expected wear area partially falls into the non-scoring area 3, this area cannot be used to calculate the score. The calculated score x = S1 / S2 is used to characterize the economic efficiency of the plane layout design of the contact network 1. The higher the score, the better the economy. If the expected wear curve L1 is partially higher than the limit wear curve L3, the corresponding contact network layout is unreasonable and needs to be re-evaluated after local correction.

[0079] Example 2

[0080] Embodiment 1 is applied to embodiment 2 to design the contact network plane layout;

[0081] A method for designing a contact network plane layout based on an ideal wear mark of a pantograph slider comprises the following steps:

[0082] Step 1: Conduct preliminary design of contact network 1 layout design to obtain the pull-out value of contact network 1; the flow chart is as follows Figure 5 As shown, the specific steps are:

[0083] Step 1.1, input the line, vehicle, and driving related parameters into the database, complete the traction simulation calculation of the train according to the data, obtain the designed traction current value of the train, and import the simulation results into the database;

[0084] Divide the sections of the contact network 1 and design the contact network 1 into flexible contact network and rigid contact network respectively. First, design the plane layout of the flexible contact network according to industry specifications: when designing the straight line segment, try to use the maximum pull-out value, and the pull-out value design of the curved segment must ensure that the contact line and the curve are intersecting when meeting the wind deviation;

[0085] Then the rigid contact network plane layout design is carried out. Since the line shape of the rigid contact network is simpler and less variable than that of the flexible contact network, the corresponding simplified layout model is selected for the rigid contact network in different sections. The layout model includes the following: Figure 6 The V-shaped equal slope model shown in Figure 7 The straight line equal slope model shown in Figure 8 The V-shaped unequal slope model shown and Fig. 9 The straight line unequal slope model shown; Figure 6-Figure 9 In the figure, the dotted line in the middle indicates the position of the pantograph centerline 2 (which is also the centerline of the route), and the bold solid line indicates the overhead contact network 1. The difference between the four layout models lies in the number of key points and the direction of the line segment inclination. k represents the slope of the line segment, and the specific value of the slope is determined according to the pull-out value, route and section length. The straight line equal slope model is used for the layout of the overhead contact network 1 at both ends of the station entrance and exit. The V-shaped unequal slope model and the straight line unequal slope model are used for the layout of the overhead contact network 1 of the turnout and civil air defense door. The layout model of the remaining positions of the rigid overhead contact network selects the V-shaped equal slope model. In principle, the higher the adjustment frequency of the plane layout, the more times the slope changes on the model. The change rate of the pull-out value of the overhead contact network 1 is 2-5mm / m, thereby ensuring the safety and stability of track operation.

[0086] Finally, confirm the mileage and pull-out value of each anchor point, and enter the relevant data of the contact network 1 into the database. The relevant data includes the mileage of each straight-slow point, slow-round point, round-slow point, slow-straight point, curve radius and various design elements of the line in the world coordinate system; it also includes the mileage and pull-out value information of each suspension point of the flexible contact network; it also includes the starting and ending mileage of each section of the rigid contact network, and the pull-out value information at each slope change point; it also includes the data of vehicle amplitude and frequency, and enters the station section information;

[0087] Step 1.2, establish a coordinate system, define the starting point of the route as the origin, the x-coordinate represents the mileage (that is, the center line of the route is regarded as a straight line in an ideal two-dimensional plane, and the straight line is defined as the x-axis of this coordinate system), the y-coordinate represents the pull-out value of the contact network 1 (that is, the straight line passing through the mileage of K0+000.000 and perpendicular to the X-axis is the Y-axis), and use a function to express the contact network 1 of each section;

[0088] Step 1.3, respectively calculating the length of the contact network 1 corresponding to each pull-out value interval of the rigid contact network and the flexible contact network straight section;

[0089] Step 2: using the evaluation method in Example 1, calculate the score of the contact network plan layout;

[0090] Step 3: When the score is less than the passing line, adjust the layout of the contact network 1 and repeat steps 1 to 3; when the score is greater than the passing line, complete the layout of the contact network 1. In this embodiment, the passing line is 0.8 points.

[0091] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for evaluating the plane layout of a contact network, characterized in that: The following steps are involved: Step 1, respectively calculating the wear factor of the slider for each pull-out value interval of the contact network; Step 2: Plot the wear factors corresponding to different pull-out value intervals on the numerical axis, and normalize the wear factors according to the original height of the pantograph and the maximum allowable wear height to obtain the estimated wear curve of the pantograph slide plate. The estimated wear curve corresponds to the estimated wear area S1; Step 3: define a standard wear curve, which corresponds to a standard wear area S2; calculate a score x=S1 / S2, which is used to characterize the economic efficiency of the contact network's planar layout design. The higher the score, the better the economy.

2. A method for evaluating the plane layout of a contact network according to claim 1, characterized in that: The middle section of the standard wear curve has the same height, the end section of the standard wear curve has a gradually decreasing height, and a transition curve is provided between the end section and the middle section of the standard wear curve.

3. A method for evaluating the plane layout of a contact network according to claim 2, characterized in that: In step three, a limit wear curve is defined. The middle section of the limit wear curve is the same as the standard wear curve. The height of the end section of the limit wear curve is smaller than the middle section and larger than the end section of the standard wear curve. If the expected wear curve is locally higher than the limit wear curve, the corresponding contact network is locally corrected and the score is re-evaluated.

4. A method for evaluating the plane layout of a contact network according to claim 3, characterized in that: The portion of the predicted wear curve that is higher than the standard wear curve is not included in the predicted wear area S1.

5. A method for evaluating the plane layout of a contact network according to claim 1, characterized in that: In step 1, the calculation formula of the wear factor ki of the i-th pull-out value interval is: key:∑ 1≤m≤n Km: Km=(Kvmm+Kvem)×Q; Kvem = γ × Lm; Kvmm=β×Lm; Km-wear factor within the i-th pull-out value interval; Q-correction factor; β-Mechanical wear coefficient of the contact network per unit length on the pantograph slider, distinguishing between rigid contact network and flexible contact network. The mechanical wear coefficient of the rigid contact network is β1; the mechanical wear coefficient of the flexible contact network is β2; γ-electrical wear coefficient of the contact network per unit length on the pantograph slider; Lm-length of the continuous overhead line in the mth section; Kvmm-mechanical wear factor of the mth section of continuous overhead contact network on the pantograph slider; Kvem - electrical wear factor of the pantograph slider caused by the mth continuous catenary; Km-the total wear factor of the pantograph slider on the mth section of continuous overhead contact network; n – total number of continuous contact network sections.

6. A method for evaluating the plane layout of a contact network according to claim 5, characterized in that: In step 1, basic data is obtained and processed to obtain a mechanical wear coefficient β of the contact network per unit length on the pantograph slider and an electrical wear coefficient γ of the contact network per unit length on the pantograph slider; The basic data include the train's designed running speed, traction current value, friction coefficient of specific friction pairs, basic vehicle parameters, and driving organization. The specific friction pair consists of a pantograph slide of certain specifications and a contact line of certain specifications.

7. A method for evaluating the plane layout of a contact network according to claim 6, characterized in that: In step one, the basic data also includes the annual temperature of the project location. After processing the basic data, different temperature influence factors T are obtained according to the influence of different temperatures on specific friction pairs. When calculating Km, the correction coefficient Q=T is set.

8. A method for evaluating the plane layout of a contact network according to claim 1, characterized in that: In step 2, the wear factor is normalized by drawing the wear factor to form a preliminary wear curve and scaling it proportionally so that the maximum value of the preliminary wear mark curve is equal to the maximum allowable wear height of the slider.

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