Bidirectional charging and discharging scheduling method for multi-line electric bus system with isomer charging piles

Abstract

The present application belongs to the technical field of urban traffic management, and particularly relates to a multi-line electric bus system bidirectional charging and discharging scheduling method containing isomerization charging piles. The present application aims to solve the problem of unbalanced charging resource allocation and decreased utilization efficiency in the station caused by the existing scheduling method, which even affects the departure punctuality and service reliability of some lines. The process is as follows: calculating the deviation between the operation cost of the bus enterprise and the regulation demand of the power distribution network; constructing a multi-line electric bus bidirectional charging and discharging scheduling model; linearizing the non-linear expression in the scheduling model to obtain a linearized multi-line electric bus bidirectional charging and discharging scheduling model; using a branch and bound algorithm to solve the linearized multi-line electric bus bidirectional charging and discharging scheduling model to obtain a scheduling scheme, a bus-pile matching scheme, a charging plan and a discharging plan; and the bus-pile matching scheme is a matching scheme of the electric bus and the charging pile.

Description

Technical Field

[0001] This invention belongs to the field of urban traffic management technology, specifically relating to a bidirectional charging and discharging scheduling method for multi-line electric bus systems. Background Technology

[0002] With the continuous advancement of electrification in urban public transportation, large centralized bus depots have become key energy hubs supporting the operation of multiple electric bus routes. Charging facilities within these depots typically exhibit a heterogeneous configuration, simultaneously deploying conventional charging piles that only support unidirectional charging and bidirectional charging piles with vehicle-to-grid (V2G) capabilities. After completing their designated route operations, electric buses can perform orderly charging or reverse discharging operations based on the availability of charging facilities within the depot and dispatch instructions. In this context, comprehensively considering the constraints on the number of unidirectional and bidirectional charging piles within the depot, and collaboratively optimizing the driving plans, vehicle-charging pile matching schemes, charging plans, and discharging plans for the multi-route electric bus fleet, not only can the efficient utilization of limited charging resources be achieved, but also, while ensuring the normal operation of electric buses, the potential of electric buses as adjustable loads can be leveraged to provide peak shaving and valley filling services to the power distribution network, thereby increasing the revenue of bus companies.

[0003] Currently, a few studies have explored bidirectional charging and discharging scheduling methods for electric buses under the V2G model. However, these studies mostly assume that the charging facilities within the depot are of a single type, failing to fully characterize the differences in electrical characteristics, operating costs, and functions of different types of charging piles. This makes it difficult to achieve precise matching of charging tasks between vehicles and charging piles, i.e., it is impossible to determine when a particular electric bus should choose which type and which charging pile for charging or discharging. At the same time, existing studies mostly focus on single routes, implicitly assuming an ideal number of charging piles. They ignore the queuing phenomenon caused by the overlapping spatiotemporal distribution of charging and discharging demands when multiple electric buses share the same depot, as well as the resource competition relationship under the condition of a limited number of heterogeneous charging piles. This leads to an imbalance in the allocation of charging resources within the depot and a decrease in utilization efficiency, and may even affect the on-time departure and service reliability of some routes. Summary of the Invention

[0004] The purpose of this invention is to address the problems of existing scheduling methods that generally assume a single type and sufficient quantity of charging facilities, and ignore the concurrent access of multiple bus routes to the depot, leading to an imbalance in the allocation of charging resources within the depot and a decrease in utilization efficiency, which may even affect the departure punctuality and service reliability of some routes. Therefore, this invention proposes a bidirectional charging and discharging scheduling method for multi-line electric bus systems with heterogeneous charging piles.

[0005] The specific process of the bidirectional charging and discharging scheduling method for multi-line electric bus systems with heterogeneous charging piles is as follows:

[0006] Step 1: Calculate the operating costs of the public transport company and the deviation between the power distribution network regulation demand;

[0007] Step 2: Construct a bidirectional charging and discharging scheduling model for multi-route electric buses;

[0008] Step 3: Linearize the nonlinear expression in the multi-line electric bus bidirectional charging and discharging scheduling model constructed in Step 2 to obtain the linearized multi-line electric bus bidirectional charging and discharging scheduling model.

[0009] Step 4: Solve the bidirectional charging and discharging scheduling model of multi-line electric buses after linearization in Step 3 using the branch and bound algorithm to obtain the scheduling scheme, vehicle-charging station matching scheme, charging plan and discharging plan;

[0010] The vehicle-charging station matching scheme is a matching scheme between electric buses and charging stations.

[0011] The beneficial effects of this invention are as follows:

[0012] This invention, through collaborative optimization of the driving schedule, vehicle-charging pile matching scheme, charging schedule, and discharging schedule of multi-route electric bus fleets, can achieve a reasonable allocation of charging and discharging tasks among different types of charging piles, effectively alleviating resource conflicts during peak charging periods and improving the overall utilization rate of charging facilities within the depot. It can effectively reduce waiting time for electric buses, decrease the risk of departure delays and insufficient power caused by charging conflicts, and improve the punctuality and service reliability of bus routes. While ensuring the normal operation of electric buses, it fully explores the potential for bidirectional regulation, participating in auxiliary services such as peak shaving and valley filling in the power distribution network, increasing the revenue of bus companies. Finally, it achieves refined collaborative scheduling of charging pile resources for multi-route electric buses, improving the intelligent operation and management level of the urban public transportation system. Attached Figure Description

[0013] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0014] Specific Implementation Method 1: The specific process of the bidirectional charging and discharging scheduling method for a multi-line electric bus system including heterogeneous charging piles in this implementation method is as follows:

[0015] Step 1: Calculate the operating costs of the public transport company and the deviation between the power distribution network regulation demand;

[0016] Step 2: Construct a bidirectional charging and discharging scheduling model for multi-route electric buses;

[0017] Step 3: Linearize the nonlinear expression in the multi-line electric bus bidirectional charging and discharging scheduling model constructed in Step 2 to obtain the linearized multi-line electric bus bidirectional charging and discharging scheduling model.

[0018] Step 4: Solve the bidirectional charging and discharging scheduling model of multi-line electric buses after linearization in Step 3 using the branch and bound algorithm to obtain the scheduling scheme, vehicle-charging station matching scheme, charging plan and discharging plan;

[0019] The vehicle-charging station matching scheme is a matching scheme between electric buses and charging stations.

[0020] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that step one involves calculating the operating costs of the public transport company and the deviation in distribution network regulation demand; the specific process is as follows:

[0021] Step 11: Calculate the operating costs of the public transport company; the specific process is as follows:

[0022] The scheduling cycle is set to a fixed duration. equally spaced discretization Each time period; the number of one-way charging piles and two-way charging piles within the station are respectively recorded as follows: and Number the one-way charging piles within the station, i.e. Number the bidirectional charging piles within the station. ;

[0023] It is recommended that the scheduling period be set to 24 hours. The value is 15min;

[0024] Calculate the operating costs of public transport companies during the scheduling cycle. ; indicates as:

[0025] (1)

[0026] In the formula, For all electric buses within the station during the designated time period Electricity expenses within the premises; ; For all electric buses within the station during the designated time period Benefits of discharging into the distribution network; ; For service lines electric buses Battery depreciation costs during the scheduling cycle; ; ; The number of electric bus routes sharing the depot. For service lines The number of electric buses;

[0027] Steps one and two: Calculate the distribution network regulation demand deviation; the specific process is as follows:

[0028] Calculate the deviation between the bidirectional charging and discharging volume of electric buses at the depot and the upward and downward adjustment of demand from the power distribution network during the scheduling cycle. ; indicates as:

[0029] (2)

[0030] In the formula, For electric buses Completed the route train schedule Later in the period The amount of charge inside; ; Indicates the line The total number of flights; For electric buses Completed the route train schedule Later in the period The amount of discharge within; Indicates the distribution network during the time period Internally, this leads to a reduction in the energy demand of power stations; Indicates the distribution network during the time period The internal demand for increased energy at the power station.

[0031] The other steps and parameters are the same as in Specific Implementation Method 1.

[0032] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that: all electric buses within the station operate during certain time periods. Electricity expenses The calculation method is as follows:

[0033] All electric buses within the station during the designated time period The total charging amount is greater than or equal to hour, Charging within the limit will be charged according to the consumption incentive price; charging greater than or equal to... The portion charged will be based on the power distribution network charging price;

[0034] All electric buses within the station during the designated time period The total charging amount is less than At that time, all charging volume will be charged according to the consumption incentive price;

[0035] Represented as:

[0036]

[0037] In the formula, variables Indicates time period Is the total charging capacity of all electric buses within the inner station greater than or equal to... ;like but ,otherwise ;

[0038] Indicates time period The typical price for charging electric buses from the power grid; Indicates time period The incentive price for charging electric buses from the power grid. ;

[0039] The electric bus Completed the route train schedule Later in the period Internal charge The expression is:

[0040]

[0041] In the formula, Indicates electric bus Completed the route train schedule The start time of a rechargeable or dischargeable task; Indicates electric bus Completed the route train schedule The end time of a rechargeable or dischargeable task;

[0042] Indicates time period At the beginning of ; Indicates time period At the end of the day, ;variable If electric buses Completed the route train schedule Then use a one-way charging station To charge, ,otherwise ;variable If electric buses Completed the route train schedule Use a two-way charging station later To charge, ,otherwise ; This indicates the charging power of a one-way charging station; Indicates the charging power of the bidirectional charging pile;

[0043] The electric bus Completed the route train schedule The start time of a rechargeable or dischargeable task and electric buses Completed the route train schedule End of rechargeable or dischargeable task The expression is:

[0044]

[0045]

[0046] In the formula, This indicates the route based on the departure timetable. The The scheduled departure times for each train service; Indicates the line The Travel time for each trip; Indicates electric bus depots and routes Empty running time between originating stations; Indicates electric bus Completed the route train schedule Waiting time before charging and discharging; Indicates electric bus Completed the route train schedule The duration of subsequent charging or discharging.

[0047] Other steps and parameters are the same as in specific implementation method one or two.

[0048] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: all electric buses within the station operate during certain time periods. Benefits of discharging into the distribution network This means that all electric buses within the depot are operating during the designated time period. The product of the total discharge amount and the discharge price of the distribution network;

[0049] The expression is:

[0050]

[0051] In the formula, Indicates time period The price of electric buses discharging into the power grid;

[0052] The electric bus Completed the route train schedule Later in the period Internal discharge amount The expression is:

[0053]

[0054] In the formula, Indicates the discharge power of the bidirectional charging pile; variable This indicates electric buses. Completed the route train schedule Should a two-way charging station be used afterwards? Discharge occurs, if ,otherwise .

[0055] The other steps and parameters are the same as those in one of the specific implementation methods one to three.

[0056] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the service line... electric buses Battery depreciation costs during the scheduling cycle Equals the depreciation cost per unit of battery energy throughput and service line electric buses The product of the total battery energy throughput during the scheduling cycle;

[0057] The process for obtaining the depreciation cost per unit of battery energy throughput is as follows:

[0058] Calculate the difference A between the battery purchase price and the battery recycling price, calculate B by multiplying 1.6 times the battery rated capacity by the nominal cycle number, and divide A by B to obtain the depreciation cost per unit battery energy throughput.

[0059] The total battery energy throughput is for the service line electric buses The sum of travel energy consumption generated during the execution of each shift's tasks within the scheduling cycle, empty running energy consumption generated between the depot and the line's starting station, charging amount, and discharging amount;

[0060] The expression is:

[0061]

[0062] In the formula, This indicates the purchase price of the batteries for the electric buses; This indicates the recycling price of electric bus batteries; Indicates service lines electric buses The rated capacity of the battery; ; Indicates service lines The number of electric buses; Indicates the nominal number of cycles; ; Indicates service lines The number of electric buses; Indicates the line The Energy consumption per trip; Indicates electric bus depots and routes Energy consumption during empty runs between originating stations; variables If electric buses Completed the route train schedule The following lines will be executed. train schedule ,but ,otherwise ;in ; Indicates the line Total number of train services; variable If electric buses The last trip executed was on the route train schedule ,but ,otherwise ;variable If electric buses Completed the route train schedule Then use a one-way charging station To charge, ,otherwise ;variable If electric buses Completed the route train schedule Use a two-way charging station later To charge, ,otherwise ;variable This indicates electric buses. Completed the route train schedule Should a two-way charging station be used afterwards? Discharge occurs, if ,otherwise .

[0063] The other steps and parameters are the same as in any of the specific implementation methods one to four.

[0064] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One through Five in that: in step two, a multi-line electric bus bidirectional charging and discharging scheduling model is constructed; the specific process is as follows:

[0065] Step 21: Construct the optimization objective of the multi-route electric bus bidirectional charging and discharging scheduling model. The optimization objective of the multi-route electric bus bidirectional charging and discharging scheduling model is to simultaneously minimize... and The optimization objective is shown in the following formula:

[0066] (3)

[0067] In the formula, and Let the weights be the two optimization objectives. The suggested values ​​are 0.6 and 0.4 respectively.

[0068] Step 22: Construct the constraints for the bidirectional charging and discharging scheduling model of multi-route electric buses; the specific process is as follows:

[0069] Step 221: Ensure that each trip is served by an electric bus, and only by one electric bus, as shown in the following formula:

[0070] (4)

[0071] Step 222: Ensure that the shift connections performed by each electric bus within the scheduling cycle satisfy the flow conservation condition, and that each electric bus forms at most one chain, as shown in the following formula:

[0072] (5)

[0073] In the formula, variables If electric buses The first trip executed was on the route. train schedule ,but ,otherwise ;variable If electric buses Completed the route train schedule The following lines will be executed. train schedule ,but ,otherwise ;in ; Indicates the line The total number of flights;

[0074] Steps 2-3: Ensure that each electric bus starts its daily operation from the depot and returns to the depot after completing its daily operation, as shown in the following formula:

[0075] (6)

[0076] (7)

[0077] In the formula, variables If electric buses The first trip executed was on the route. train schedule ,but ,otherwise ;

[0078] Step 224: Introduce order variables Characterization of execution circuit train schedule electric buses The position in the train number chain;

[0079] The loop link is eliminated as shown in the following formula:

[0080] (8)

[0081] (9)

[0082] In the formula, Indicates the execution line train schedule electric buses The position in the train number chain; This represents a very large constant. ;

[0083] Step 225: Constraints only electric buses Execution line train schedule Only then will it be on the train schedule After the task is completed, a charging or discharging task will be scheduled. During each task, only one of the following three modes can be selected: charging with a unidirectional charging station, charging with a bidirectional charging station, or discharging with a bidirectional charging station, as shown in the following formula:

[0084] (10)

[0085] Step 226: Ensure that there is time feasibility between the electric bus service shifts within the scheduling cycle, with the following constraints:

[0086] (11)

[0087] In the formula, This indicates the route based on the departure timetable. The The scheduled departure times for each train service; ; Indicates the line The total number of flights; This indicates the route based on the departure timetable. The The scheduled departure times for each train service; ; Indicates the line The Travel time for each trip; Indicates electric bus Completed the route train schedule Waiting time before charging and discharging; Indicates electric bus Completed the route train schedule The duration of subsequent charging or discharging; Indicates electric bus depots and routes Empty running time between originating stations;

[0088] Step 227: During the constraint scheduling period, the battery state of charge of each electric bus is maintained within a safe range, as shown in formulas (12) to (16):

[0089] (12)

[0090] (13)

[0091] (14)

[0092] (15)

[0093] (16)

[0094] In the formula, and For electric buses Execution line train schedule and shift The state of charge of the battery at the moment of departure; Indicates electric bus Completed the route train schedule The state of battery charge upon returning to the depot;

[0095] Indicates service lines electric buses The lower limit of the battery's state of charge during the charging and discharging process; Indicates service lines electric buses The upper limit of the battery's state of charge during the charging and discharging process; This indicates the charging power of a one-way charging station; Indicates the charging power of the bidirectional charging pile; This indicates the discharge power of the bidirectional charging pile;

[0096] Step 228: Electric buses Complete the route train schedule The subsequent charging or discharging process is considered as a charging or discharging task, denoted as ;

[0097] Electric buses Complete the route train schedule The subsequent charging or discharging process is considered as a charging or discharging task, denoted as ;

[0098] For any two charge / discharge tasks and Sort them in ascending order of the start time of the charging or discharging task;

[0099] The constraint is that there is no time overlap between adjacent charging and discharging tasks using the same unidirectional and bidirectional charging piles, as shown in formulas (17) to (19):

[0100] (17)

[0101] (18)

[0102] (19)

[0103] In the formula, Indicates electric bus Completed the route train schedule Should a two-way charging station be used afterwards? ,if , if not ; Indicates electric bus Completed the route train schedule Should a two-way charging station be used afterwards? ,if , if not ;variable If electric buses Completed the route train schedule Then use a one-way charging station To charge, ,otherwise ; ; Indicates the line The total number of flights; ; Indicates service lines The number of electric buses; ; The number of electric bus routes sharing the depot; Indicates electric bus Completed the route train schedule The start time of a rechargeable or dischargeable task; Indicates electric bus Completed the route train schedule The end time of a rechargeable or dischargeable task; Indicates electric bus Completed the route train schedule The start time of a rechargeable or dischargeable task; Indicates electric bus Completed the route train schedule The end time of a rechargeable or dischargeable task; Indicates task exist Execute before;

[0104] Step 229: The duration of each charging and discharging cycle must not be less than the minimum charging or discharging time stipulated by the bus company for electric buses on service route 1. As shown in the following formula:

[0105] (20)

[0106] In the formula, Indicates service lines The shortest charging or discharging time for electric buses.

[0107] The other steps and parameters are the same as those in any of the specific implementation methods one to five.

[0108] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One through Six in that: in step three, the nonlinear expression in the multi-line electric bus bidirectional charging and discharging scheduling model constructed in step two is linearized to obtain a linearized multi-line electric bus bidirectional charging and discharging scheduling model; the specific process is as follows:

[0109] Step 31: Define integer variables This indicates the charging or discharging time of the electric bus k during time period f after completing its shift i on route l;

[0110] Introducing auxiliary variables Indicates charging and discharging tasks The end time of the interval overlapping with time period f;

[0111] Introducing auxiliary binary variables ,if ,make =1, otherwise =0;

[0112] Introducing auxiliary variables Indicates charging and discharging tasks The start time of the interval overlapping with time period f;

[0113] Introducing auxiliary binary variables ,if ,make =1, otherwise =0;

[0114] electric buses Completed the route train schedule Later in the period Internal charge The preliminary equivalent is:

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126] Introducing auxiliary variables and ;

[0127] Indicates electric bus Completed the route train schedule Later in the period One-way charging piles are used inside. Charging time;

[0128] Indicates electric bus Completed the route train schedule Later in the period Uses bidirectional charging piles Charging time;

[0129] The electric bus of formula (2) Completed the route train schedule Later in the period Internal charge Equivalent representation as time period The sum of the product of each unidirectional charging pile and its corresponding charging power, and the sum of the product of each bidirectional charging pile's charging time and its corresponding charging power; expressed as follows:

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137] Step 32: Set the parameter Indicates the current segment Total charging capacity of all electric buses in the area With the reduction of energy demand in the distribution network The minimum value;

[0138] All electric buses within the station will be subject to [specific time periods]. Electricity expenses The equivalent expression is the product of the difference C and the general price of charging on the distribution network, plus... The product of the consumption incentive price;

[0139] The difference C represents the time period. The total charging capacity of all electric buses in the area and The difference;

[0140] It is expressed as follows:

[0141]

[0142]

[0143]

[0144]

[0145]

[0146] Step 33: Introduce auxiliary variables Indicates electric bus Completed the route train schedule Later in the period Uses bidirectional charging piles The discharge duration; all electric buses in the station will be subject to the specified discharge time. Benefits of discharging into the distribution network The expression is linearized to be in the time period The product of the total charging time of each bidirectional charging pile used within the area and the discharge power and the discharge price of the power distribution network;

[0147] It is expressed as follows:

[0148]

[0149]

[0150]

[0151]

[0152]

[0153] Steps three and four: Use , , Alternative Linearize formula (16); as follows:

[0154]

[0155]

[0156] Step 35: Introduce sorting variables When the task With the task They were all assigned to one-way charging stations. If the task exist If executed previously, then ,otherwise ;

[0157] Introducing sorting variables When the task With the task They were all assigned to bidirectional charging stations. If the task exist If executed previously, then ,otherwise ;

[0158] Linearize equations (17) and (18) as follows:

[0159]

[0160]

[0161]

[0162]

[0163]

[0164]

[0165] .

[0166] The other steps and parameters are the same as those in one of the specific implementation methods one to six.

[0167] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One through Seven in that: in step four, the branch and bound algorithm is used to solve the multi-line electric bus bidirectional charging and discharging scheduling model after the linearization process in step three, to obtain the scheduling scheme, vehicle-charging station matching scheme, charging plan, and discharging plan; the specific process is as follows:

[0168] Step 41: Generate an initial feasible solution, including a scheduling scheme, a vehicle-to-pile matching scheme, a charging plan, and a discharging plan; use formula (3) to calculate the objective function value corresponding to the initial feasible solution, which is used as the current optimal objective value;

[0169] The linear relaxation problem of the multi-line electric bus bidirectional charging and discharging scheduling model after linearization in step three is used as the root node and added to the set of nodes to be processed.

[0170] Step 42: Determine if the set of nodes to be processed is empty;

[0171] If empty, proceed to step four or six;

[0172] If not empty, select a node from the set of nodes to be processed according to the depth-first search rule, and proceed to step four and three.

[0173] Step 43: Solve the linear relaxation problem corresponding to the selected node;

[0174] If the linear relaxation problem corresponding to the selected node is not feasible, then prune the selected node and return to step 42;

[0175] If the linear relaxation problem corresponding to the selected node is feasible, obtain the relaxed solution and the objective function value of the relaxed solution, and proceed to step four.

[0176] Step 44: Determine whether the objective function value of the relaxed solution is better than the optimal objective value;

[0177] If the objective function value of the relaxed solution is worse than (greater than or equal to) the optimal objective value, then prune the node corresponding to the relaxed solution and return to step 42.

[0178] If the objective function value of the relaxed solution is better than (less than) the optimal objective value, then proceed to steps four and five.

[0179] Steps four and five: Determine whether the relaxed solution contains variables that do not satisfy the integer constraints;

[0180] If the relaxed solution contains variables that do not satisfy the integer constraints, select one of the variables to branch, generate two child nodes, add the two generated child nodes to the set of nodes to be processed, and return to step four two;

[0181] If the relaxed solution does not contain any variables that do not satisfy the integer constraint, update the current optimal objective function value, prune the nodes corresponding to the relaxed solution, and return to step 42.

[0182] Step 46: Output the current optimal objective function value and the corresponding relaxed solution as the final optimization result of the multi-line electric bus bidirectional charging and discharging scheduling model after the linearization process in Step 3. The optimization result includes the scheduling scheme, vehicle-charging station matching scheme, charging plan and discharging plan.

[0183] The other steps and parameters are the same as those in any of the specific implementation methods one to seven.

[0184] This invention may have other embodiments. Without departing from the spirit and essence of this invention, those skilled in the art can make various corresponding changes and modifications according to this invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A bidirectional charging and discharging scheduling method for a multi-line electric bus system with heterogeneous charging piles, characterized in that: The specific process of the method is as follows: Step 1: Calculate the operating costs of the public transport company and the deviation between the power distribution network regulation demand; Step 2: Construct a bidirectional charging and discharging scheduling model for multi-route electric buses; Step 3: Linearize the nonlinear expression in the multi-line electric bus bidirectional charging and discharging scheduling model constructed in Step 2 to obtain the linearized multi-line electric bus bidirectional charging and discharging scheduling model. Step 4: Solve the bidirectional charging and discharging scheduling model of multi-line electric buses after linearization in Step 3 using the branch and bound algorithm to obtain the scheduling scheme, vehicle-charging station matching scheme, charging plan and discharging plan; The vehicle-charging station matching scheme is a matching scheme between electric buses and charging stations; Step one involves calculating the operating costs of the public transport company and the deviation between the power grid regulation demand; the specific process is as follows: Step 11: Calculate the operating costs of the public transport company; the specific process is as follows: The scheduling cycle is set to a fixed duration. equally spaced discretization Each time period; the number of one-way charging piles and two-way charging piles within the station are respectively recorded as follows: and ; The one-way charging piles within the station are numbered, i.e. Number the bidirectional charging piles within the station. ; Calculate the operating costs of public transport companies during the scheduling cycle. ; indicates as: (1) In the formula, For all electric buses within the station during the designated time period Electricity expenses within the premises; ; For all electric buses within the station during the designated time period Benefits of discharging into the distribution network; ; For service lines electric buses Battery depreciation costs during the scheduling cycle; ; ; The number of electric bus routes sharing the depot. For service lines The number of electric buses; Steps one and two: Calculate the distribution network regulation demand deviation; the specific process is as follows: Calculate the deviation between the bidirectional charging and discharging volume of electric buses at the depot and the upward and downward adjustment of demand from the power distribution network during the scheduling cycle. ; indicates as: (2) In the formula, For electric buses Completed the route train schedule Later in the period The amount of charge inside; ; Indicates the line The total number of flights; For electric buses Completed the route train schedule Later in the period The amount of discharge within; Indicates the distribution network during the time period Internally, this leads to a reduction in the energy demand of power stations; Indicates the distribution network during the time period Internally, the energy demand of the power station is increased; Step two involves constructing a bidirectional charging and discharging scheduling model for multi-route electric buses; the specific process is as follows: Step 21: Construct the optimization objective of the multi-route electric bus bidirectional charging and discharging scheduling model. The optimization objective of the multi-route electric bus bidirectional charging and discharging scheduling model is to simultaneously minimize... and The optimization objective is shown in the following formula: (3) In the formula, and Let the weights be the two optimization objectives. ; Step 22: Construct the constraints for the bidirectional charging and discharging scheduling model of multi-route electric buses; the specific process is as follows: Step 221: Ensure that each trip is served by an electric bus, and only by one electric bus, as shown in the following formula: (4) In the formula, variables If electric buses Completed the route train schedule The following lines will be executed. train schedule ,but ,otherwise ;in ; Indicates the line Total number of train services; variable If electric buses The last trip executed was on the route For train number i, then ,otherwise ; Step 222: Ensure that the shift connections performed by each electric bus within the scheduling cycle satisfy the flow conservation condition, and that each electric bus forms at most one chain, as shown in the following formula: (5) In the formula, variables If electric buses The first trip executed was on the route. train schedule ,but ,otherwise ;variable If electric buses Completed the route train schedule The following lines will be executed. train schedule ,but ,otherwise ;in ; Indicates the line The total number of flights; Steps 2-3: Ensure that each electric bus starts its daily operation from the depot and returns to the depot after completing its daily operation, as shown in the following formula: (6) (7) In the formula, variables If electric buses The first trip executed was on the route. train schedule ,but ,otherwise ; Step 224: Introduce order variables Characterization of execution circuit train schedule electric buses The position in the train number chain; The loop link is eliminated as shown in the following formula: (8) (9) In the formula, Indicates the execution line train schedule electric buses The position in the train number chain; Represents a constant; Step 225: Constraints only electric buses Execution line train schedule Only then will it be on the train schedule After the task is completed, a charging or discharging task will be scheduled. During each task, only one of the following three modes can be selected: charging with a unidirectional charging station, charging with a bidirectional charging station, or discharging with a bidirectional charging station, as shown in the following formula: (10) In the formula, variables If electric buses Completed the route train schedule Then use a one-way charging station To charge, ,otherwise ;variable If electric buses Completed the route train schedule Use a two-way charging station later To charge, ,otherwise ;variable This indicates electric buses. Completed the route train schedule Should a two-way charging station be used afterwards? Discharge occurs, if ,otherwise ; Step 226: Ensure that there is time feasibility between the electric bus service shifts within the scheduling cycle, with the following constraints: (11) In the formula, This indicates the route based on the departure timetable. The The scheduled departure times for each train service; ; Indicates the line The total number of flights; This indicates the route based on the departure timetable. The The scheduled departure times for each train service; ; Indicates the line The Travel time for each trip; Indicates electric bus Completed the route train schedule Waiting time before charging and discharging; Indicates electric bus Completed the route train schedule The duration of subsequent charging or discharging; Indicates electric bus depots and routes Empty running time between originating stations; Step 227: During the constraint scheduling period, the battery state of charge of each electric bus is maintained within a safe range, as shown in formulas (12) to (16): (12) (13) (14) (15) (16) In the formula, and For electric buses Execution line train schedule and shift The state of charge of the battery at the moment of departure; Indicates electric bus Completed the route train schedule The state of battery charge upon returning to the depot; Indicates service lines electric buses The lower limit of the battery's state of charge during the charging and discharging process; Indicates service lines electric buses The upper limit of the battery's state of charge during the charging and discharging process; Indicates service lines electric buses The rated capacity of the battery; ; Indicates service lines The number of electric buses; Indicates the line The Energy consumption per trip; Indicates electric bus depots and routes Energy consumption during empty runs between originating stations; This indicates the charging power of a one-way charging station; Indicates the charging power of the bidirectional charging pile; This indicates the discharge power of the bidirectional charging pile; Step 228: Electric buses Complete the route train schedule The subsequent charging or discharging process is considered as a charging or discharging task, denoted as Electric buses Complete the route train schedule The subsequent charging or discharging process is considered as a charging or discharging task, denoted as ; For any two charge / discharge tasks and Sort them in ascending order of the start time of the charging or discharging task; The constraint is that there is no time overlap between adjacent charging and discharging tasks using the same unidirectional and bidirectional charging piles, as shown in formulas (17) to (19): (17) (18) (19) In the formula, Indicates electric bus Completed the route train schedule Should a two-way charging station be used afterwards? ,if , if not ; Indicates electric bus Completed the route train schedule Should a two-way charging station be used afterwards? ,if , if not ;variable If electric buses Completed the route train schedule Then use a one-way charging station To charge, ,otherwise ; ; Indicates the line The total number of flights; ; Indicates service lines The number of electric buses; ; The number of electric bus routes sharing the depot; Indicates electric bus Completed the route train schedule The start time of a rechargeable or dischargeable task; Indicates electric bus Completed the route train schedule The end time of a rechargeable or dischargeable task; Indicates electric bus Completed the route train schedule The start time of a rechargeable or dischargeable task; Indicates electric bus Completed the route train schedule The end time of a rechargeable or dischargeable task; Indicates task exist Executed previously; Step 229: The duration of each charging and discharging cycle must not be less than the minimum charging or discharging time stipulated by the bus company for electric buses on service route 1. As shown in the following formula: (20) In the formula, Indicates service lines The shortest charging or discharging time for electric buses.

2. The bidirectional charging and discharging scheduling method for a multi-line electric bus system with heterogeneous charging piles according to claim 1, characterized in that: All electric buses within the station during the specified time period Electricity expenses The calculation method is as follows: All electric buses within the station during the designated time period The total charging amount is greater than or equal to hour, Charging within the limit will be charged according to the consumption incentive price; charging greater than or equal to... The portion charged will be based on the power grid charging price; All electric buses within the station during the designated time period The total charging amount is less than At that time, all charging volume will be charged according to the consumption incentive price.

3. The bidirectional charging and discharging scheduling method for a multi-line electric bus system with heterogeneous charging piles according to claim 2, characterized in that: All electric buses within the station during the specified time period Benefits of discharging into the distribution network This means that all electric buses within the depot are operating during the designated time period. The product of the total discharge amount and the discharge price of the distribution network.

4. The bidirectional charging and discharging scheduling method for a multi-line electric bus system with heterogeneous charging piles according to claim 3, characterized in that: The service line electric buses Battery depreciation costs during the scheduling cycle Equals the depreciation cost per unit of battery energy throughput and service line electric buses The product of the total battery energy throughput during the scheduling cycle.

5. The bidirectional charging and discharging scheduling method for a multi-line electric bus system with heterogeneous charging piles according to claim 4, characterized in that: In step three, the nonlinear expression in the multi-line electric bus bidirectional charging and discharging scheduling model constructed in step two is linearized to obtain the linearized multi-line electric bus bidirectional charging and discharging scheduling model; the specific process is as follows: Step 31: Introduce auxiliary variables and ; Indicates electric bus Completed the route train schedule Later in the period One-way charging piles are used inside. Charging time; Indicates electric bus Completed the route train schedule Later in the period Uses bidirectional charging piles The charging time; the electric bus of formula (2) Completed the route train schedule Later in the period Internal charge Equivalent representation as time period The sum of the product of each unidirectional charging pile and its corresponding charging power, and the sum of the product of each bidirectional charging pile and its corresponding charging power; Step 32: Set the parameter Indicates time period The total charging capacity of all electric buses in the area and the reduced energy demand of the power grid. The minimum value; all electric buses within the station during the designated time period Electricity expenses The equivalent expression is the product of the difference C and the general price of charging on the distribution network, plus... The product of the consumption incentive price; The difference C represents the time period. The total charging capacity of all electric buses in the area and The difference; Step 33: Introduce auxiliary variables Indicates electric bus Completed the route train schedule Later in the period Uses bidirectional charging piles Discharge duration; All electric buses within the station will be subject to [specific time periods]. Benefits of discharging into the distribution network The expression is linearized to be in the time period The product of the total charging time of each bidirectional charging pile used within the area and the discharge power and the discharge price of the power distribution network; Steps three and four: Use , , Alternative Linearize formula (16); Step 35: Introduce sorting variables When the task With the task They were all assigned to one-way charging stations. If the task exist If executed previously, then ,otherwise Introducing sorting variables When the task With the task They were all assigned to bidirectional charging stations. If the task exist If executed previously, then ,otherwise Linearize equations (17) and (18).

6. The bidirectional charging and discharging scheduling method for a multi-line electric bus system with heterogeneous charging piles according to claim 5, characterized in that: In step four, the branch and bound algorithm is used to solve the multi-line electric bus bidirectional charging and discharging scheduling model after the linearization process in step three, to obtain the scheduling scheme, vehicle-charging station matching scheme, charging plan, and discharging plan; the specific process is as follows: Step 41: Generate an initial feasible solution, including a scheduling scheme, a vehicle-to-pile matching scheme, a charging plan, and a discharging plan; use formula (3) to calculate the objective function value corresponding to the initial feasible solution, which is used as the current optimal objective value; The linear relaxation problem of the multi-line electric bus bidirectional charging and discharging scheduling model after linearization in step three is used as the root node and added to the set of nodes to be processed. Step 42: Determine if the set of nodes to be processed is empty; If empty, proceed to step four or six; If not empty, select a node from the set of nodes to be processed according to the depth-first search rule, and proceed to step four and three. Step 43: Solve the linear relaxation problem corresponding to the selected node; If the linear relaxation problem corresponding to the selected node is not feasible, then prune the selected node and return to step 42; If the linear relaxation problem corresponding to the selected node is feasible, obtain the relaxed solution and the objective function value of the relaxed solution, and proceed to step four. Step 44: Determine whether the objective function value of the relaxed solution is better than the optimal objective value; If the objective function value of the relaxed solution is worse than the optimal objective value, then prune the node corresponding to the relaxed solution and return to step 42. If the objective function value of the relaxed solution is better than the optimal objective value, then proceed to steps four and five. Steps four and five: Determine whether the relaxed solution contains variables that do not satisfy the integer constraints; If the relaxed solution contains variables that do not satisfy the integer constraints, select one of the variables to branch, generate two child nodes, add the two generated child nodes to the set of nodes to be processed, and return to step four two; If the relaxed solution does not contain any variables that do not satisfy the integer constraint, update the current optimal objective function value, prune the nodes corresponding to the relaxed solution, and return to step 42. Step 46: Output the current optimal objective function value and the corresponding relaxed solution as the final optimization result of the multi-line electric bus bidirectional charging and discharging scheduling model after the linearization process in Step 3. The optimization result includes the scheduling scheme, vehicle-charging station matching scheme, charging plan and discharging plan.

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