Train speed trajectory optimization method and system using the method

Abstract

The present application discloses a method for optimizing a train speed trajectory and a system for applying the method, the method comprising: obtaining a demand response instruction; determining the current operating condition of the train when obtaining the demand response instruction, the current operating condition including traction condition, cruising condition, coasting condition and braking condition; adjusting the current operating condition of the train according to the demand response instruction, so that the current operating condition of the train is converted to a braking condition, wherein when the current operating condition of the train is a traction condition, the train transitions from the traction condition to the cruising condition or the coasting condition, and then converts to the braking condition; determining the adjusted train speed trajectory, and obtaining the time error and actual energy consumption of the train's operating section according to the adjusted train speed trajectory, wherein the time error and the actual energy consumption are respectively less than the set thresholds corresponding to the two. The above method improves the utilization efficiency of regenerative braking energy while adjusting the load peak on the grid side.

Description

Technical Field

[0001] The present application relates to the technical field of train operation control engineering, and in particular to a method for optimizing a train speed trajectory and a system applying the method. Background Art

[0002] As a traction grid load, high-speed trains not only consume electricity to maintain normal operation, but also feed back energy to the grid through braking operation. They are also a new type of distributed energy system. However, with the increase in electrified railway mileage and transportation volume, the power consumption of traction power supply has also increased, and the problem of railway operation energy consumption has become increasingly serious.

[0003] At present, there are three main research directions for energy management of high-speed train traction systems at home and abroad: The first is low-drag technology. Through aerodynamic drag reduction technology and lightweight technology, the vehicle appearance is designed or the internal component structure is reconstructed. The second is efficient traction system design technology. The development of power electronic devices and high-frequency conversion technology has greatly improved the efficiency of the existing power system of the train, including transformers, converters, motors and other equipment. The third is energy recovery and reuse and comprehensive management. The kinetic energy generated during electric braking is converted into regenerative electrical energy (regenerative braking energy), which is returned to the contact network or supplied to other auxiliary equipment, reducing basic brake wear and achieving energy saving in the power system. Compared with the first two technologies, energy recovery and reuse and comprehensive management is a research direction that is both economical and has practical application value.

[0004] However, most existing research focuses on improving the energy utilization of regenerative braking and reducing total energy consumption from the perspective of the vehicle side. There is an urgent need for a high-speed train distribution network scheduling solution that can consider the dynamic power demand of the power system from the perspective of supply and demand. Summary of the invention

[0005] In order to address the deficiencies of the prior art, the purpose of the present application is to provide a method for optimizing a train speed trajectory and a system using the method, which can improve the efficiency of regenerative braking energy utilization while regulating the load peak on the grid side.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a method for optimizing a train speed trajectory, the method comprising:

[0008] Obtaining demand response instructions, which are generated based on energy consumption on the grid side;

[0009] Determining a current operating condition of the train when obtaining the demand response instruction, wherein the current operating condition includes any one of a traction condition, a cruising condition, an idling condition, and a braking condition;

[0010] Adjusting the current operating condition of the train according to the demand response instruction so that the current operating condition of the train is converted into a braking condition, wherein when the current operating condition of the train is a traction condition, the train transitions from the traction condition to a cruising condition or an idling condition, and then to a braking condition;

[0011] An adjusted train speed trajectory is determined, and a time error and actual energy consumption of a running section of the train are obtained according to the adjusted train speed trajectory, wherein the time error and the actual energy consumption are each less than a set threshold.

[0012] Furthermore, the time error satisfies the following relationship:

[0013] ;

[0014] In the formula, Indicates the time error, represents the actual running time of the adjusted train, Indicates the planned running time of the train;

[0015] The running section includes at least one speed limit section. The train can perform a set of running conditions consisting of traction condition, cruising condition, coasting condition and braking condition in the speed limit section. The actual energy consumption in any speed limit section satisfies the following relationship:

[0016] ;

[0017] In the formula, Indicates the actual energy consumption within the speed limit range. The traction force on the train. The braking force on the train. Indicates the conversion coefficient of mechanical energy into electrical energy in any working condition except braking condition. Represents the regenerative braking energy utilization coefficient.

[0018] Further, the method comprises:

[0019] The speed limit section where the train is currently located is defined as the first section, and the sections adjacent to the first section before and after are defined as the second section and the third section respectively;

[0020] determining, according to the speed limit values ​​of the first section, the second section, and the third section, an adjustment method of the train when obtaining a demand response instruction;

[0021] Among them, if the speed limit value of the first section is between the speed limit value of the second section and the speed limit value of the third section, and the speed limit value of the second section is less than the speed limit value of the third section, the train does not slow down and is converted from the traction condition to the cruising condition.

[0022] And / or, if the speed limit value of the first interval is between the speed limit value of the second interval and the speed limit value of the third interval, and the speed limit value of the second interval is greater than the speed limit value of the third interval, the train does not accelerate, and is converted from a cruising condition to an inertia condition, and then to a braking condition.

[0023] And / or, if the speed limit value of the first section is lower than the speed limit value of the second section and the speed limit value of the third section, the train maintains the current speed.

[0024] And / or, if the speed limit value in the first section is higher than the speed limit value in the second section and the speed limit value in the third section, the train performs operating condition operations in the order of traction condition, cruising condition, coasting condition and braking condition.

[0025] Furthermore, any speed limit section has a first speed and a second speed, wherein the first speed is the speed of the train when entering the speed limit section, and the second speed is the speed of the train when leaving the speed limit section; the train satisfies at least one of the following conditions during operation:

[0026] The second speed in the first interval is equal to the first speed in the second interval;

[0027] In the same speed limit section, the current speed of the train is less than the speed limit value of the speed limit section.

[0028] Furthermore, the method further comprises:

[0029] Determine whether the train needs to cross at least two speed limit zones to execute the demand response instruction;

[0030] The time when the train speed trajectory adjustment ends in the previous speed limit interval is determined and defined as the first time, the time when the train speed trajectory adjustment is completed in the next speed limit interval is defined as the second time, and the period between the first time and the second time is defined as the adjustment period; if the judgment result is yes, the number of speed limit intervals is determined as the difference between the next speed limit interval and the previous speed limit interval plus the first threshold, and the difference between the second time and the first time is less than the adjustment period, and the number of speed limit intervals satisfies the following relationship:

[0031] ;

[0032] In the formula, Indicates the number of speed limit zones. Indicates the previous speed limit interval. Indicates the next speed limit interval. Indicates the first time, Indicates the second time, Indicates the adjustment period;

[0033] If the judgment result is no, the number of speed limit intervals is determined as the difference between the next speed limit interval and the previous speed limit interval plus the second threshold, and the difference between the second time and the first time is equal to the adjustment period, and the number of speed limit intervals satisfies the following relationship:

[0034] ;

[0035] The first threshold and the second threshold are constants greater than 0, and the first threshold is greater than the second threshold.

[0036] Furthermore, the difference in actual energy consumption of the train speed trajectory before and after receiving the demand response instruction satisfies the following relationship:

[0037] ;

[0038] In the formula, and They represent the actual energy consumption and power before receiving the demand response instruction, and They represent the actual energy consumption and power after receiving the demand response command, Indicates the time when the demand response instruction is received, Indicates the time to complete the demand response instruction, Indicates the distance the train travels when the demand response instruction is completed.

[0039] Furthermore, the method further comprises:

[0040] Get the number of trains in the running section and define all trains as train groups;

[0041] Determine the power climbing trend of the train group. In any interval of the power climbing trend, the power difference between the start and end of the interval satisfies the following relationship:

[0042] ;

[0043] In the formula, The power difference is and Represent the electric power at the start and end time respectively, Indicates the number of trains;

[0044] The power difference also needs to satisfy at least one of the following conditions:

[0045] ;

[0046] ;

[0047] In the formula, and Indicates the climb rate limit of the train group increasing or decreasing within the interval time.

[0048] Further, when determining the power climbing trend of the train group, the power climbing trend is between a first power threshold and a second power threshold, and the first power threshold is less than the second power threshold, wherein the first power threshold and the second power threshold are respectively the minimum and maximum powers that the grid side can accept for feedback from the train group.

[0049] Furthermore, the method further comprises:

[0050] Establish a demand response model for train groups based on power ramp-up trend, time error and actual energy consumption;

[0051] The demand response model is discretized and solved to obtain the train speed trajectories of the train group.

[0052] In a second aspect, the present application also provides a train speed trajectory optimization system to implement any of the train speed trajectory optimization methods in the first aspect.

[0053] The train speed trajectory optimization method proposed in the present invention generates a demand response instruction according to the energy consumption on the power grid side to control the current operating condition of the train, wherein when the train is in the traction condition, the train transitions to the cruising condition and the inertia condition according to the demand response instruction, and then converts to the braking condition, so that the time error and actual energy consumption of the train in the adjusted train speed trajectory are each less than a set threshold value. Thus, the utilization efficiency of regenerative braking energy is improved while regulating the load peak on the power grid side. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a flow chart of a method for optimizing a train speed trajectory in an embodiment of the present application;

[0055] Figure 2 This is a schematic diagram of a train executing a demand response instruction in different speed limit intervals in an embodiment of the present application;

[0056] Figure 3 This is a schematic diagram of a train executing a demand response instruction under different operating conditions in a speed limit section in an embodiment of the present application;

[0057] Figure 4 It is a schematic diagram of the power change of the train during the period of executing the demand response instruction in the embodiment of the present application;

[0058] Figure 5 This is a flow chart of a train executing a demand response instruction across a speed limit section in an embodiment of the present application;

[0059] Figure 6 This is a schematic diagram of the power ramp-up of a train group in an embodiment of the present application;

[0060] Figure 7 Schematic diagram of a system for optimizing train speed trajectory in an embodiment of the present application. DETAILED DESCRIPTION

[0061] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation manner of the present application will be clearly and completely described below in conjunction with the drawings in the implementation manner of the present application.

[0062] The present application provides a train speed trajectory optimization system and a train speed trajectory optimization method, wherein the train speed trajectory optimization system is used to implement the train speed trajectory optimization method. The train speed trajectory optimization system includes at least one train and a train control center, and the train control center is used to control the train travel. The train speed trajectory optimization method is used to optimize the speed trajectory of the train, thereby reducing the energy consumption of the train. Specifically, the train speed trajectory optimization method includes the following steps:

[0063] Step S100: Obtain a demand response instruction, where the demand response instruction is generated according to the energy consumption on the grid side.

[0064] In some embodiments, the demand response instruction is issued from the train control center, and the train control center generates corresponding demand response instructions based on the current energy consumption on the grid side, and / or the current running speed of the train, and / or the time error of the train operation.

[0065] Exemplarily, if the energy consumption on the grid side increases, the train control center sends a demand response instruction to the train, and the train stores part of the energy in energy storage media such as capacitors, batteries and / or flywheels of the train according to the demand response instruction, so that energy can be obtained through the above-mentioned energy storage media when the train speeds up.

[0066] Optionally, if the current running speed of the train is greater than the speed limit of the section on which the train is running, the train will store part of the energy in energy storage media such as capacitors, batteries and / or flywheels of the train according to demand response instructions, so that energy can be obtained through the above-mentioned energy storage media when the train speeds up.

[0067] Optionally, if the train arrives at the next station earlier than the time specified in the train schedule, the train will store part of the energy in the train's capacitors, batteries and / or flywheels and other energy storage media according to the demand response instruction, so that energy can be obtained through the above energy storage media when the train speeds up.

[0068] The above are only a few preferred implementation methods of controlling the train operation status based on the demand response instructions sent by the train control center, which are intended to illustrate the situation where the train control center generates demand response instructions, rather than limiting the optimization method of the train speed trajectory of the embodiment of the present application.

[0069] Step S200: determining the current operating condition of the train when obtaining the demand response instruction, wherein the current operating condition includes any one of a traction condition (TR), a cruising condition (CR), a coasting condition (CO) and a braking condition (BR).

[0070] It should be noted that under constant speed limit conditions, the train will generally go through the traction condition, cruising condition, coasting condition and braking condition in sequence (see Figure 2 As shown in (a)). Among them, v i,e represents the speed when entering the speed limit zone i, and the TR running time and distance are t i,TR and i,TR ; The speed during coasting is v i,c , CO running time and distance are t i,CO and i,CO ; The speed when braking starts is v i,b , BR running time and distance are t i,BR and i,BR ;v i,q represents the speed when leaving the speed limit zone i, and the CR running time and distance are t i,CR and i,CR .

[0071] Step S300: Adjust the current operating condition of the train according to the demand response instruction, so that the current operating condition of the train is converted into a braking condition, wherein, when the current operating condition of the train is a traction condition, the train transitions from the traction condition to a cruising condition or an idling condition, and then converts to a braking condition.

[0072] Step S400: determining the adjusted train speed trajectory, and obtaining the time error and actual energy consumption of the train running section according to the adjusted train speed trajectory, wherein the time error and the actual energy consumption are each less than a set threshold.

[0073] Among them, the time error satisfies the following relationship:

[0074] ;

[0075] In the formula, Indicates the time error, represents the actual running time of the adjusted train, Indicates the planned running time of the train.

[0076] In some embodiments, the running section includes at least one speed limit section, and the train can perform a set of running conditions consisting of traction conditions, cruising conditions, coasting conditions and braking conditions within the speed limit section, and the actual energy consumption within any speed limit section satisfies the following relationship:

[0077] ;

[0078] In the formula, Indicates the actual energy consumption within the speed limit range. The traction force on the train. The braking force on the train. Indicates the conversion coefficient of mechanical energy into electrical energy in any working condition except braking condition. Represents the regenerative braking energy utilization coefficient.

[0079] In the embodiment of the present application, any speed limit interval has a first speed and a second speed, wherein the first speed is the speed of the train when it enters the speed limit interval, and the second speed is the speed of the train when it leaves the speed limit interval. The train meets at least one of the following conditions during the long run:

[0080] The second speed in the second interval is equal to the first speed in the first interval;

[0081] In the same speed limit section, the current speed of the train is less than the speed limit value of the speed limit section.

[0082] For example, the train enters a speed limit value of v i,l The first interval of the first interval, and the first speed of entering the first interval is v i,e , the second speed leaving the first interval is v i,q After the train leaves the first section, the speed limit is v i+1,l The second interval, and the first speed of entering the second interval is v i+1,e , the second speed of leaving the second interval is v i+1,q Among them, v i,q =v i+1,e It should be noted that when the train leaves the first section and enters the second section, if TR is adjacent to BR, BR will be converted to CO.

[0083] Furthermore, at any time in the first section, the running speed of the train is less than v i,l Similarly, at any time in the second section, the train's running speed is less than v i+1,l .

[0084] like Figure 2As shown, in some embodiments, the method for optimizing the train speed trajectory includes: defining the speed limit interval in which the train is currently located as a first interval, and defining the intervals adjacent to the first interval before and after as a second interval and a third interval respectively. Determine the adjustment method of the train when obtaining the demand response instruction according to the speed limit values ​​of the first interval, the second interval, and the third interval. Among them, if the speed limit value of the first interval is between the speed limit value of the second interval and the speed limit value of the second interval, and the speed limit value of the second interval is less than the speed limit value of the third interval, the train does not slow down, and the traction condition is converted to the cruising condition.

[0085] It should be noted that under different speed limit conditions, different operating conditions will be combined into new operating trajectories. According to different speed limit conditions, there are mainly four types of segmentation. It is assumed that all speed limit sections are long enough to allow the train to reach the maximum speed. According to different speed limit conditions, it is assumed that there are n speed limit sections in two adjacent operating stations, and each speed limit section has a complete set of train operating condition operations. Each speed limit section has a corresponding speed limit value. The speed limit value corresponding to each speed limit section is adjusted according to the operating conditions of the train and the energy consumption on the power grid side, so that the train forms the following Figure 2 Conversion strategies for the four operating conditions shown in (b)-(e).

[0086] like Figure 2 As shown in (b), exemplarily, if the speed limit value of the first section is between the speed limit value of the second section and the speed limit value of the third section, and the speed limit value of the second section is less than the speed limit value of the third section, the train does not slow down and is converted from the traction condition to the cruising condition.

[0087] like Figure 2 As shown in (c), optionally, if the speed limit value of the first section is higher than the speed limit value of the second section and the speed limit value of the third section, the train performs the running condition operation in the order of traction condition, cruising condition, coasting condition and braking condition.

[0088] like Figure 2 As shown in (d), optionally, if the speed limit value of the first section is lower than the speed limit value of the second section and the speed limit value of the third section, the train maintains the current speed.

[0089] like Figure 2 As shown in (e), exemplarily, if the speed limit value of the first section is between the speed limit value of the second section and the speed limit value of the third section, and the speed limit value of the second section is greater than the speed limit value of the third section, the train does not accelerate, and is converted from the cruising condition to the inertia condition, and then to the braking condition.

[0090] As a flexible load of the traction grid, high-speed trains participate in the power demand response and can realize the charging and discharging of the grid and exchange power during the conversion between braking deceleration and traction acceleration. The trajectory optimization of trains under demand response can give full play to the train's ability to peak the grid load as a mobile distributed power source.

[0091] The train only generates regenerative braking energy during braking, which can be fed back to the electric traction grid. The traction output in the cruising condition is not 100%, which can reduce power consumption. In addition, since the traction condition and the braking condition cannot be directly converted, the demand response needs to be transitioned when the traction condition occurs, that is, the traction condition is first converted to the coasting condition and then the braking operation is performed. Both the cruising condition and the coasting condition can be directly converted to the braking condition for demand response.

[0092] like Figure 3 As shown, assuming that the demand response starts at time t st The speed limit section is i, t st The corresponding speed and distance are v st , end time t en The speed limit section is j, t en The corresponding speed and distance are v en , the minimum speed v that can be reduced during demand response mq By v i,e 、v i,c 、v i,b and v i,q The corresponding operating time t is derived i,TR ,t i,CO ,t i,BR and t i,CR .

[0093] (1) 0 ≤ t st -t i,e <t i,TR ,like Figure 3 As shown by the middle curve a, t en The operating condition combination in the speed limit interval i before time is TR-CO-BR-CR, s i,CR =0,v i,c =v st , v i,q =v mq .

[0094] (2) t i,TR ≤t st -t i,e <t i,TR +t i,CR ,like Figure 3 As shown in the middle curve b, t en The operating condition combination in the speed limit interval i before time is TR-CR-BR-CR, s i,CO=0,v i,c = v i,b =v st , v i,q =v mq .

[0095] (3) t i,TR +t i,CR ≤t st -t i,e <t i,TR + t i,CR +t i,CO ,like Figure 3 As shown by the middle curve c, t en The operating condition combination in the speed limit interval i before time is TR-CR-CO-BR-CR, v i,b =v st , v i,q =v mq .

[0096] (4) t i,TR +t i,CR +t i,CO ≤t st -t i,e <t i,TR + t i,CR +t i,CO + t i,BR ,like Figure 3 As shown in the middle curve d, when the train actually starts to execute the demand response instruction in the BR condition, it moves to the moment when the braking condition ends (as shown by the arrow). After the speed limit section i ends, the train continues to brake. en The operating condition combination in the speed limit interval i before time is TR-CR-CO-BR-CR, v i,q =v st , v i,q ≠v i+1,e =v mq .

[0097] During the demand response period, the overall running speed of the train is reduced. In order to ensure the punctuality of the train arrival, it is usually necessary to accelerate again. Assume that t en After the time, the train still needs to go through the four operating conditions of TR, CR, CO, and BR in order, and then adjust the operating condition combination according to the type of adjacent speed limit section. In addition, it is also necessary to determine whether the demand response needs to be executed across sections.

[0098] like Figure 4 As shown, in some embodiments, after step S200, the method for optimizing the train speed trajectory further includes:

[0099] Step S301: Determine whether the train needs to cross at least two speed limit sections to execute the demand response instruction.

[0100] Step S302: Determine the time when the last speed limit interval ends the train speed trajectory adjustment, and define it as the first time, the time when the next speed limit interval completes the train speed trajectory adjustment, and define it as the second time, and the period between the first time and the second time is defined as the adjustment period; if the judgment result is yes, the number of speed limit intervals is determined as the difference between the next speed limit interval and the last speed limit interval plus the first threshold, and the difference between the second time and the first time is less than the adjustment period, and the number of speed limit intervals satisfies the following relationship:

[0101] ;

[0102] In the formula, Indicates the number of speed limit zones. Indicates the previous speed limit interval. Indicates the next speed limit interval. Indicates the first time, Indicates the second time, Indicates the adjustment period.

[0103] Step S303: If the judgment result is no, the number of speed limit intervals is determined as the difference between the next speed limit interval and the previous speed limit interval plus the second threshold, and the difference between the second time and the first time is equal to the adjustment period, and the number of speed limit intervals satisfies the following relationship:

[0104] ;

[0105] The first threshold and the second threshold are constants greater than 0, and the first threshold is greater than the second threshold.

[0106] When the train speed decreases, the amount of electricity drawn from the power system can be reduced. Compared with the case when there is no grid-side demand plan, the amount of electricity saved by the train during the response period is the demand response potential of the train during this period. The power change of the high-speed train during the demand response period can be expressed as Figure 5 Indicates that the dotted line represents the original operating trajectory without demand response, and the solid line represents the operating trajectory with demand response.

[0107] In the embodiment of the present application, the difference in actual energy consumption of the train speed trajectory before and after receiving the demand response instruction satisfies the following relationship:

[0108] ;

[0109] In the formula, and They represent the actual energy consumption and power before receiving the demand response instruction, and They represent the actual energy consumption and power after receiving the demand response command, Indicates the time when the demand response instruction is received, Indicates the time to complete the demand response instruction, Indicates the distance the train travels when the demand response instruction is completed.

[0110] A single high-speed train has limited demand response capabilities as a load and cannot provide the large amount of electricity required by the power grid in a short period of time. However, for a cluster of high-speed trains, the adjustable capacity of demand response is relatively considerable. The response capacity and duration that can be provided by optimizing train operation scheduling can be greatly improved.

[0111] In some embodiments, the method for optimizing the vehicle speed trajectory further includes:

[0112] Step S500: Obtain the number of trains in the running section, and define all trains as a train group.

[0113] Step S600: Determine the power climbing trend of the train group. In any interval of the power climbing trend, the power difference between the start and end of the interval satisfies the following relationship:

[0114] ;

[0115] In the formula, The power difference is and Represent the electric power at the start and end time respectively, Indicates the number of trains;

[0116] The power difference also needs to satisfy at least one of the following conditions:

[0117] ;

[0118] ;

[0119] In the formula, and Indicates the climb rate limit of the train group increasing or decreasing within the interval time.

[0120] For example, assuming n v The trains are distributed in n r On different railways. At this time, the decision matrix x is expressed as:

[0121] ;

[0122] The decision vector vij of train i running on railway j is expressed as:

[0123] ;

[0124] in The vector is represented as , The elements in are defined as follows:

[0125] ;

[0126] When a single train responds to demand, the power ramp-up speed fed back to the grid through braking operation is constrained by the train acceleration and passenger comfort, and the power ramp-up is relatively stable. Figure 6 Schematic diagrams of multiple trains responding simultaneously are shown in FIG. 1 , where HST1, HST2 and HST3 represent the changing trends of the running speeds of the corresponding trains on different railways. g Indicates the total operating power of multiple trains. When multiple trains respond at the same time, it is necessary not only to ensure the objective response energy capacity, but also to avoid large power fluctuations, and it is necessary to constrain the relevant parameters of power ramp.

[0127] When multiple trains participate in demand response, the power capacity and ramp speed are limited, and HST3 is st At this moment, the brake is not applied immediately, but the coasting mode is adopted to participate in power regulation. en At this moment, HST1 and HST2 continue to mq The train group will continue to run at a certain speed for a certain period of time to ensure the power climbing limit before traction operation. Figure 5 As shown in the solid curve in , the slope of the curve reflects the power climbing speed.

[0128] Based on the above method, the power fluctuation and power target meet the following thresholds when multiple trains participate in demand response:

[0129] For power fluctuations, the unit time interval The power difference at two moments satisfies the climbing condition:

[0130] ;

[0131] ;

[0132] ;

[0133] In the formula and Respectively Moment and The electrical power at the moment, and It represents the increase or decrease in the output value on the demand side of the train per unit time, that is, the upper limit of the climbing rate, which is a fixed constant.

[0134] For the power target, when the train acts as a movable load on the demand side, it meets the power threshold allowed by the grid side:

[0135] ;

[0136] It should be noted that the power climbing trend is between the first power threshold and the second power threshold, and the first power threshold is less than the second power threshold, wherein the first power threshold and the second power threshold They respectively represent the minimum and maximum power that the grid side can accept from the train side, and are also fixed constants.

[0137] Furthermore, in an embodiment of the present application, after obtaining the power climbing trend, time error and actual energy consumption according to the above method, a demand response model of the train group is established based on the power climbing trend, time error and actual energy consumption, and a discretized solution is performed on the demand response model to obtain the train speed trajectory of the train group.

[0138] Exemplarily, an objective function is first obtained, wherein the objective function represents the expectation of optimizing the trajectories of multiple high-speed trains under demand response, which is to minimize the total operating energy consumption and time error while maximizing the reduction in electric energy consumption during the demand response period.

[0139] Maximize the total energy saving of demand response and obtain the following relationship that represents the total energy saving:

[0140] ;

[0141] in is the power when no grid-side demand response is performed, The power for demand response.

[0142] Minimize the average total train operation time error and obtain the following relationship that characterizes the total time error:

[0143] ;

[0144] in For Within the speed limit section, the time a train runs according to the timetable is a constant.

[0145] Minimize the total power consumption of train operation and obtain the following relationship to characterize the total power consumption:

[0146] ;

[0147] Secondly, the objective function is optimized according to the constraints, and a high-speed train group demand response model considering dynamic power ramping is established.

[0148] Specifically, each variable needs to satisfy certain boundary conditions:

[0149] ;

[0150] Train acceleration needs to meet passengers' comfort requirements requirements, among which, .

[0151] In addition, the distance between two adjacent trains on the same track needs to be guaranteed. Always within the safe range, i.e. .

[0152] It can be understood that, considering the above train operation optimization objectives, weights are assigned to the respective objective functions, and finally a high-speed train group demand response model considering dynamic power ramping is established:

[0153] ;

[0154] in, , and All are non-negative weights, corresponding to energy efficiency and time accuracy.

[0155] like Figure 7 As shown, the embodiment of the present application also provides a train speed trajectory optimization system 100, which includes a train control center and at least one train, wherein the train control center includes a fixed terminal and a server or a server cluster composed of multiple servers, the server or the server cluster composed of multiple servers is used to store the train operation schedule, and the fixed terminal generates a corresponding demand response instruction according to the acquired train operation status and in combination with the operation schedule, and sends the demand response instruction to the train. The train and the server are respectively provided with a receiver for receiving the demand response instruction and a transmitter for sending the demand response instruction, so that the signal transmission between the train and the server is carried out in the direction of wireless communication.

[0156] In addition, an embodiment of the present invention further proposes a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method for optimizing the train speed trajectory in the above embodiment is executed.

[0157] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0158] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0159] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as a read-only memory image (ROM) / random access memory (RAM), a disk, or an optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0160] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

[0161] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. A method for optimizing train speed trajectory, characterized in that: include: Obtaining a demand response instruction, wherein the demand response instruction is generated according to energy consumption on the grid side; Determining a current operating condition of the train when the demand response instruction is obtained, wherein the current operating condition includes any one of a traction condition, a cruising condition, an idling condition, and a braking condition; adjusting the current operating condition of the train according to the demand response instruction so that the current operating condition of the train is in the braking condition, wherein when the current operating condition of the train is the traction condition, the train transitions from the traction condition to the cruising condition or the coasting condition, and then to the braking condition; An adjusted train speed trajectory is determined, and a time error and actual energy consumption of an operating section of the train are obtained according to the adjusted train speed trajectory, wherein the operating section includes at least one speed limit interval, and the train can perform a group of operating condition operations consisting of the traction condition, the cruising condition, the coasting condition, and the braking condition within the speed limit interval, and the actual energy consumption within any of the speed limit intervals satisfies the following relationship: ； In the formula, represents the actual energy consumption within the speed limit interval, represents the traction force on the train, represents the braking force on the train, represents the conversion coefficient of mechanical energy into electrical energy in any working condition other than the braking condition, Indicates the regenerative braking energy utilization coefficient; The time error and the actual energy consumption are respectively less than their corresponding set thresholds, and the time error satisfies the following relationship: ； In the formula, represents the time error, represents the actual running time of the train after adjustment, Indicates the planned running time of the train.

2. The method for optimizing train speed trajectory according to claim 1, characterized in that: The method comprises: The speed limit section currently located by the train is defined as a first section, and sections adjacent to and before the first section are defined as a second section and a third section respectively; Determining, according to the speed limit values ​​of the first section, the second section, and the third section, an adjustment mode of the train when obtaining the demand response instruction; If the speed limit value of the first section is between the speed limit value of the second section and the speed limit value of the third section, and the speed limit value of the second section is less than the speed limit value of the third section, the train does not decelerate, and is converted from the traction operating condition to the cruising operating condition; Or, if the speed limit value of the first section is between the speed limit value of the second section and the speed limit value of the third section, and the speed limit value of the second section is greater than the speed limit value of the third section, the train does not accelerate, and is converted from the cruising condition to the inertia condition, and then to the braking condition; or, if the speed limit value of the first section is lower than the speed limit value of the second section and the speed limit value of the third section, the train maintains the current speed; Or, if the speed limit value of the first section is higher than the speed limit value of the second section and the speed limit value of the third section, the train performs operating condition operations in the order of the traction condition, the cruising condition, the coasting condition and the braking condition.

3. The method for optimizing train speed trajectory according to claim 2, characterized in that: Any of the speed limit sections has a first speed and a second speed, wherein the first speed is the speed of the train when it enters the speed limit section, and the second speed is the speed of the train when it leaves the speed limit section; the train satisfies at least one of the following conditions during operation: The second speed in the first interval is equal to the first speed in the second interval; In the same speed limit section, the current speed of the train is less than the speed limit value of the speed limit section.

4. The method for optimizing train speed trajectory according to claim 1, characterized in that: The method further comprises: Determining whether the train needs to cross at least two speed limit sections to execute the demand response instruction; Determine the time when the last speed limit interval ends the train speed trajectory adjustment, and define it as the first time, and the time when the next speed limit interval completes the train speed trajectory adjustment, and define it as the second time, and the period between the first time and the second time is defined as the adjustment period; if the judgment result is yes, the number of the speed limit intervals is determined as the difference between the next speed limit interval and the last speed limit interval plus the first threshold, and the difference between the second time and the first time is less than the adjustment period, and the number of the speed limit intervals satisfies the following relationship: ； In the formula, represents the number of speed limit intervals, Indicates the speed limit range mentioned above. Indicates the next speed limit interval, represents the first time, represents the second time, represents the adjustment period; If the judgment result is no, the number of the speed limit intervals is determined as the difference between the next speed limit interval and the previous speed limit interval plus the second threshold, and the difference between the second time and the first time is equal to the adjustment period, and the number of speed limit intervals satisfies the following relationship: ； The first threshold and the second threshold are constants greater than 0, and the first threshold is greater than the second threshold.

5. The method for optimizing train speed trajectory according to claim 1, characterized in that: The difference in the actual energy consumption of the train speed trajectory before and after receiving the demand response instruction satisfies the following relationship: ； In the formula, and respectively represent the actual energy consumption and power before receiving the demand response instruction, and respectively represent the actual energy consumption and power after receiving the demand response instruction, Indicates the time when the demand response instruction is received, Indicates the time to complete the demand response instruction, Indicates the distance the train has traveled when completing the demand response instruction.

6. The method for optimizing train speed trajectory according to claim 5, characterized in that: The method further comprises: Acquire the number of the trains in the running section, and define all the trains as a train group; The power climbing trend of the train group is determined. In any interval of the power climbing trend, the power difference between the start and end of the interval satisfies the following relationship: ； In the formula, represents the difference in power, and Represent the electric power at the start and end time respectively, represents the number of said train; The power difference also needs to satisfy at least one of the following conditions: ； ； In the formula, and Indicates the climbing rate limit of the train group increased or decreased within the interval time.

7. The method for optimizing train speed trajectory according to claim 6, characterized in that: When determining the power climbing trend of the train group, the power climbing trend is between a first power threshold and a second power threshold, and the first power threshold is less than the second power threshold, wherein the first power threshold and the second power threshold are respectively the minimum and maximum powers that the grid side can accept from the train group.

8. The method for optimizing train speed trajectory according to claim 6, characterized in that: The method further comprises: Establishing a demand response model of the train group based on the power climbing trend, the time error and the actual energy consumption; A discretization solution is performed on the demand response model to obtain the train speed trajectory of the train group.

9. A train speed trajectory optimization system, implementing the train speed trajectory optimization method according to any one of claims 1 to 8.

Images